TY - JOUR T1 - Lamins: Nuclear Intermediate Filament Proteins with Fundamental Functions in Nuclear Mechanics and Genome Regulation. JF - Annu Rev Biochem Y1 - 2015 A1 - Gruenbaum, Yosef A1 - Foisner, Roland AB - Lamins are intermediate filament proteins that form a scaffold, termed nuclear lamina, at the nuclear periphery. A small fraction of lamins also localize throughout the nucleoplasm. Lamins bind to a growing number of nuclear protein complexes and are implicated in both nuclear and cytoskeletal organization, mechanical stability, chromatin organization, gene regulation, genome stability, differentiation, and tissue-specific functions. The laminbased complexes and their specific functions also provide insights into possible disease mechanisms for human laminopathies, ranging from muscular dystrophy to accelerated aging, as observed in Hutchinson-Gilford progeria and atypical Werner syndromes. Expected final online publication date for the Annual Review of Biochemistry Volume 84 is June 02, 2015. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates. U1 - http://www.ncbi.nlm.nih.gov/pubmed/25747401?dopt=Abstract ER - TY - JOUR T1 - Lamins: the structure and protein complexes. JF - Curr Opin Cell Biol Y1 - 2015 A1 - Gruenbaum, Yosef A1 - Medalia, Ohad KW - Animals KW - Cell Nucleus KW - Chromatin KW - Humans KW - Lamins KW - Mutation KW - Nuclear Envelope AB - Lamins are nuclear intermediate filament (IF) proteins. They assemble to fibrous structures that are positioned between the inner nuclear membrane and the peripheral chromatin. A small fraction of lamins is also present in the nucleoplasm. Lamins are required to maintain the nuclear structure and, together with their associated proteins, are involved in most nuclear activities. Mutations in lamins cause >14 distinct diseases, called laminopathies, that include heart, muscle, fat and early aging diseases. However, it is not clear how lamins are organized in vivo and how the disease mutations affect lamin organization and functions. Here, we will review structural aspects of lamin assembly, discuss differences between peripheral and nucleoplasmic lamins and describe the protein complexes that lamins form. VL - 32 U1 - http://www.ncbi.nlm.nih.gov/pubmed/25460776?dopt=Abstract ER - TY - JOUR T1 - Nuclear Organization. JF - Annu Rev Biochem Y1 - 2015 A1 - Gruenbaum, Yosef AB - This article discusses three reviews on the theme of nuclear organization. Expected final online publication date for the Annual Review of Biochemistry Volume 84 is June 02, 2015. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates. U1 - http://www.ncbi.nlm.nih.gov/pubmed/25706897?dopt=Abstract ER - TY - JOUR T1 - BAF-1 mobility is regulated by environmental stresses. JF - Mol Biol Cell Y1 - 2014 A1 - Bar, Daniel Z A1 - Davidovich, Maya A1 - Lamm, Ayelet T A1 - Zer, Hagit A1 - Wilson, Katherine L A1 - Gruenbaum, Yosef KW - Amino Acid Sequence KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Carrier Proteins KW - Environment KW - Food Deprivation KW - Green Fluorescent Proteins KW - Heat-Shock Response KW - Intestines KW - Lamins KW - Larva KW - Mass Spectrometry KW - Membrane Proteins KW - Molecular Sequence Data KW - Mutant Proteins KW - Mutation, Missense KW - Nuclear Proteins KW - Phosphorylation KW - Phosphoserine KW - Photobleaching KW - Protein Transport KW - Stress, Physiological AB - Barrier to autointegration factor (BAF) is an essential component of the nuclear lamina that binds lamins, LEM-domain proteins, histones, and DNA. Under normal conditions, BAF protein is highly mobile when assayed by fluorescence recovery after photobleaching and fluorescence loss in photobleaching. We report that Caenorhabditis elegans BAF-1 mobility is regulated by caloric restriction, food deprivation, and heat shock. This was not a general response of chromatin-associated proteins, as food deprivation did not affect the mobility of heterochromatin protein HPL-1 or HPL-2. Heat shock also increased the level of BAF-1 Ser-4 phosphorylation. By using missense mutations that affect BAF-1 binding to different partners we find that, overall, the ability of BAF-1 mutants to be immobilized by heat shock in intestinal cells correlated with normal or increased affinity for emerin in vitro. These results show BAF-1 localization and mobility at the nuclear lamina are regulated by stress and unexpectedly reveal BAF-1 immobilization as a specific response to caloric restriction in C. elegans intestinal cells. VL - 25 IS - 7 U1 - http://www.ncbi.nlm.nih.gov/pubmed/24501420?dopt=Abstract ER - TY - JOUR T1 - Intermediate filaments: a dynamic network that controls cell mechanics. JF - F1000Prime Rep Y1 - 2014 A1 - Gruenbaum, Yosef A1 - Aebi, Ueli AB - In humans the superfamily of intermediate filament (IF) proteins is encoded by more than 70 different genes, which are expressed in a cell- and tissue-specific manner. IFs assemble into approximately 10 nm-wide filaments that account for the principal structural elements at the nuclear periphery, nucleoplasm, and cytoplasm. They are also required for organizing the microtubule and microfilament networks. In this review, we focus on the dynamics of IFs and how modifications regulate it. We also discuss the role of nuclear IF organization in determining nuclear mechanics as well as that of cytoplasmic IFs organization in maintaining cell stiffness, formation of lamellipodia, regulation of cell migration, and permitting cell adhesion. VL - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/25184044?dopt=Abstract ER - TY - JOUR T1 - Measuring the effects of high CO₂ levels in Caenorhabditis elegans. JF - Methods Y1 - 2014 A1 - Zuela, Noam A1 - Friedman, Nurit A1 - Zaslaver, Alon A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Carbon Dioxide KW - Humans KW - Hypercapnia KW - Lung Diseases KW - Models, Animal AB - Carbon dioxide (CO2) is an important molecule in cell metabolism. It is also a byproduct of many physiological processes. In humans, impaired lung function and lung diseases disrupt the body's ability to dispose of CO2 and elevate its levels in the body (hypercapnia). Animal models allow further understanding of how CO2 is sensed in the body and what are the physiological responses to high CO2 levels. This information can provide new strategies in the battle against the detrimental effects of CO2 accumulation in lung diseases. The nematode Caenorhabditis elegans provides us with such a model animal due to its natural ability to sense and navigate through varying concentrations of CO2, as well as the fact that it can be genetically manipulated with ease. Here we describe the different methods used to measure the effects elevated levels of CO2 have on the molecular sensing mechanism and physiology of C. elegans. VL - 68 IS - 3 U1 - http://www.ncbi.nlm.nih.gov/pubmed/24650565?dopt=Abstract ER - TY - JOUR T1 - The response to high CO2 levels requires the neuropeptide secretion component HID-1 to promote pumping inhibition. JF - PLoS Genet Y1 - 2014 A1 - Sharabi, Kfir A1 - Charar, Chayki A1 - Friedman, Nurit A1 - Mizrahi, Inbar A1 - Zaslaver, Alon A1 - Sznajder, Jacob I A1 - Gruenbaum, Yosef AB - Carbon dioxide (CO2) is a key molecule in many biological processes; however, mechanisms by which organisms sense and respond to high CO2 levels remain largely unknown. Here we report that acute CO2 exposure leads to a rapid cessation in the contraction of the pharynx muscles in Caenorhabditis elegans. To uncover the molecular mechanisms underlying this response, we performed a forward genetic screen and found that hid-1, a key component in neuropeptide signaling, regulates this inhibition in muscle contraction. Surprisingly, we found that this hid-1-mediated pathway is independent of any previously known pathways controlling CO2 avoidance and oxygen sensing. In addition, animals with mutations in unc-31 and egl-21 (neuropeptide secretion and maturation components) show impaired inhibition of muscle contraction following acute exposure to high CO2 levels, in further support of our findings. Interestingly, the observed response in the pharynx muscle requires the BAG neurons, which also mediate CO2 avoidance. This novel hid-1-mediated pathway sheds new light on the physiological effects of high CO2 levels on animals at the organism-wide level. VL - 10 IS - 8 U1 - http://www.ncbi.nlm.nih.gov/pubmed/25101962?dopt=Abstract ER - TY - JOUR T1 - Studying lamins in invertebrate models. JF - Adv Exp Med Biol Y1 - 2014 A1 - Lyakhovetsky, Roman A1 - Gruenbaum, Yosef KW - Animals KW - Lamins KW - Models, Biological KW - Molecular Structure KW - Phylogeny AB - Lamins are nuclear intermediate filament proteins that are conserved in all multicellular animals. Proteins that resemble lamins are also found in unicellular organisms and in plants. Lamins form a proteinaceous meshwork that outlines the nucleoplasmic side of the inner nuclear membrane, while a small fraction of lamin molecules is also present in the nucleoplasm. They provide structural support for the nucleus and help regulate many other nuclear activities. Much of our knowledge on the function of nuclear lamins and their associated proteins comes from studies in invertebrate organisms and specifically in the nematode Caenorhabditis elegans and the fruit fly Drosophila melanogaster. The simpler lamin system and the powerful genetic tools offered by these model organisms greatly promote such studies. Here we provide an overview of recent advances in the biology of invertebrate nuclear lamins, with special emphasis on their assembly, cellular functions and as models for studying the molecular basis underlying the pathology of human heritable diseases caused by mutations in lamins A/C. VL - 773 U1 - http://www.ncbi.nlm.nih.gov/pubmed/24563351?dopt=Abstract ER - TY - JOUR T1 - Hutchinson-Gilford progeria syndrome through the lens of transcription. JF - Aging Cell Y1 - 2013 A1 - Prokocimer, Miron A1 - Barkan, Rachel A1 - Gruenbaum, Yosef KW - Adult Stem Cells KW - Cell Nucleus KW - Chromatin Assembly and Disassembly KW - DNA Repair KW - Gene Silencing KW - Humans KW - Lamin Type A KW - Lamin Type B KW - Mechanotransduction, Cellular KW - Nuclear Proteins KW - Phenotype KW - Progeria KW - Protein Precursors KW - Telomere KW - Transcription, Genetic AB - Lamins are nuclear intermediate filaments. In addition to their structural roles, they are implicated in basic nuclear functions such as chromatin organization, DNA replication, transcription, DNA repair, and cell-cycle progression. Mutations in human LMNA gene cause several diseases termed laminopathies. One of the laminopathic diseases is Hutchinson-Gilford progeria syndrome (HGPS), which is caused by a spontaneous mutation and characterized by premature aging. HGPS phenotypes share certain similarities with several apparently comparable medical conditions, such as aging and atherosclerosis, with the conspicuous absence of neuronal degeneration and cancer rarity during the short lifespan of the patients. Cell lines from HGPS patients are characterized by multiple nuclear defects, which include abnormal morphology, altered histone modification patterns, and increased DNA damage. These cell lines provide insight into the molecular pathways including senescence that require lamins A and B1. Here, we review recent data on HGPS phenotypes through the lens of transcriptional deregulation caused by lack of functional lamin A, progerin accumulation, and lamin B1 silencing. VL - 12 IS - 4 U1 - http://www.ncbi.nlm.nih.gov/pubmed/23496208?dopt=Abstract ER - TY - JOUR T1 - Ce-emerin and LEM-2: essential roles in Caenorhabditis elegans development, muscle function, and mitosis. JF - Mol Biol Cell Y1 - 2012 A1 - Barkan, Rachel A1 - Zahand, Adam J A1 - Sharabi, Kfir A1 - Lamm, Ayelet T A1 - Feinstein, Naomi A1 - Haithcock, Erin A1 - Wilson, Katherine L A1 - Liu, Jun A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Cell Proliferation KW - Chromatin KW - Gene Deletion KW - Gene Expression Regulation, Developmental KW - Humans KW - Longevity KW - Membrane Proteins KW - Mesoderm KW - Mitosis KW - Muscle Contraction KW - Muscle, Smooth KW - Muscle, Striated KW - Muscular Dystrophy, Emery-Dreifuss KW - Mutation KW - Nuclear Envelope KW - Nuclear Proteins KW - Sarcomeres KW - Subcutaneous Tissue AB - Emerin and LEM2 are ubiquitous inner nuclear membrane proteins conserved from humans to Caenorhabditis elegans. Loss of human emerin causes Emery-Dreifuss muscular dystrophy (EDMD). To test the roles of emerin and LEM2 in somatic cells, we used null alleles of both genes to generate C. elegans animals that were either hypomorphic (LEM-2-null and heterozygous for Ce-emerin) or null for both proteins. Single-null and hypomorphic animals were viable and fertile. Double-null animals used the maternal pool of Ce-emerin to develop to the larval L2 stage, then arrested. Nondividing somatic cell nuclei appeared normal, whereas dividing cells had abnormal nuclear envelope and chromatin organization and severe defects in postembryonic cell divisions, including the mesodermal lineage. Life span was unaffected by loss of Ce-emerin alone but was significantly reduced in LEM-2-null animals, and double-null animals had an even shorter life span. In addition to striated muscle defects, double-null animals and LEM-2-null animals showed unexpected defects in smooth muscle activity. These findings implicate human LEM2 mutations as a potential cause of EDMD and further suggest human LEM2 mutations might cause distinct disorders of greater severity, since C. elegans lacking only LEM-2 had significantly reduced life span and smooth muscle activity. VL - 23 IS - 4 U1 - http://www.ncbi.nlm.nih.gov/pubmed/22171324?dopt=Abstract ER - TY - JOUR T1 - Evolutionary conserved role of c-Jun-N-terminal kinase in CO2-induced epithelial dysfunction. JF - PLoS One Y1 - 2012 A1 - Vadász, István A1 - Dada, Laura A A1 - Briva, Arturo A1 - Helenius, Iiro Taneli A1 - Sharabi, Kfir A1 - Welch, Lynn C A1 - Kelly, Aileen M A1 - Grzesik, Benno A A1 - Budinger, G R Scott A1 - Liu, Jing A1 - Seeger, Werner A1 - Beitel, Greg J A1 - Gruenbaum, Yosef A1 - Sznajder, Jacob I KW - Animals KW - Burkitt Lymphoma KW - Caenorhabditis elegans KW - Carbon Dioxide KW - Drosophila KW - Enzyme Activation KW - Epithelial Cells KW - Evolution, Molecular KW - Humans KW - JNK Mitogen-Activated Protein Kinases KW - Phosphorylation KW - Protein Kinase C KW - Pulmonary Alveoli KW - Rats KW - Sodium-Potassium-Exchanging ATPase AB - Elevated CO(2) levels (hypercapnia) occur in patients with respiratory diseases and impair alveolar epithelial integrity, in part, by inhibiting Na,K-ATPase function. Here, we examined the role of c-Jun N-terminal kinase (JNK) in CO(2) signaling in mammalian alveolar epithelial cells as well as in diptera, nematodes and rodent lungs. In alveolar epithelial cells, elevated CO(2) levels rapidly induced activation of JNK leading to downregulation of Na,K-ATPase and alveolar epithelial dysfunction. Hypercapnia-induced activation of JNK required AMP-activated protein kinase (AMPK) and protein kinase C-ζ leading to subsequent phosphorylation of JNK at Ser-129. Importantly, elevated CO(2) levels also caused a rapid and prominent activation of JNK in Drosophila S2 cells and in C. elegans. Paralleling the results with mammalian epithelial cells, RNAi against Drosophila JNK fully prevented CO(2)-induced downregulation of Na,K-ATPase in Drosophila S2 cells. The importance and specificity of JNK CO(2) signaling was additionally demonstrated by the ability of mutations in the C. elegans JNK homologs, jnk-1 and kgb-2 to partially rescue the hypercapnia-induced fertility defects but not the pharyngeal pumping defects. Together, these data provide evidence that deleterious effects of hypercapnia are mediated by JNK which plays an evolutionary conserved, specific role in CO(2) signaling in mammals, diptera and nematodes. VL - 7 IS - 10 U1 - http://www.ncbi.nlm.nih.gov/pubmed/23056407?dopt=Abstract ER - TY - JOUR T1 - Filaments assembly of ectopically expressed Caenorhabditis elegans lamin within Xenopus oocytes. JF - J Struct Biol Y1 - 2012 A1 - Grossman, Einat A1 - Dahan, Idit A1 - Stick, Reimer A1 - Goldberg, Martin W A1 - Gruenbaum, Yosef A1 - Medalia, Ohad KW - Animals KW - Caenorhabditis elegans KW - Cytoskeleton KW - Female KW - Gene Expression Regulation KW - Image Processing, Computer-Assisted KW - Lamins KW - Microscopy, Electron, Scanning KW - Nuclear Lamina KW - Oocytes KW - Protein Structure, Tertiary KW - Xenopus laevis AB - Lamins are the major components of the nuclear lamina, a filamentous layer underlying the inner nuclear membrane and attached to the peripheral chromatin. Lamins are required for maintaining nuclear shape and are involved in most nuclear activities. Here, we studied the 3D organization of the nuclear lamina formed upon the expression of Caenorhabditis elegans lamin (Ce-lamin) within the nucleus of a Xenopus laevis oocyte. We show that Ce-lamin forms an intricate 3D meshwork of 5-6 nm lamin protofilaments. The diverse protofilament interactions and organization may shed light upon the unique mechano-elastic properties of the nuclear lamina scaffold supporting the nuclear envelope. The Q159K Hutchinson-Gilford Progeria Syndrome-linked mutation alters interactions between protofilaments within the lamina, leading to the formation of more bundled arrays of less isotropically-oriented protofilaments. Using this system, we show for the first time the organization of lamin proteins that were translated and assembled within the environment of a living cell. VL - 177 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/22085746?dopt=Abstract ER - TY - JOUR T1 - LEM-3 - A LEM domain containing nuclease involved in the DNA damage response in C. elegans. JF - PLoS One Y1 - 2012 A1 - Dittrich, Christina M A1 - Kratz, Katja A1 - Sendoel, Ataman A1 - Gruenbaum, Yosef A1 - Jiricny, Josef A1 - Hengartner, Michael O KW - Alleles KW - Animals KW - Apoptosis KW - Bacterial Proteins KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Cell Cycle KW - Chromatin KW - Cisplatin KW - Cross-Linking Reagents KW - DNA Damage KW - Endodeoxyribonucleases KW - Ethyl Methanesulfonate KW - Genetic Complementation Test KW - Luminescent Proteins KW - Membrane Proteins KW - Models, Genetic KW - Mutation KW - Nuclear Proteins KW - Phenotype KW - Protein Structure, Tertiary KW - Radiation, Ionizing KW - Subcellular Fractions KW - Transgenes KW - Ultraviolet Rays AB - The small nematode Caenorhabditis elegans displays a spectrum of DNA damage responses similar to humans. In order to identify new DNA damage response genes, we isolated in a forward genetic screen 14 new mutations conferring hypersensitivity to ionizing radiation. We present here our characterization of lem-3, one of the genes identified in this screen. LEM-3 contains a LEM domain and a GIY nuclease domain. We confirm that LEM-3 has DNase activity in vitro. lem-3(lf) mutants are hypersensitive to various types of DNA damage, including ionizing radiation, UV-C light and crosslinking agents. Embryos from irradiated lem-3 hermaphrodites displayed severe defects during cell division, including chromosome mis-segregation and anaphase bridges. The mitotic defects observed in irradiated lem-3 mutant embryos are similar to those found in baf-1 (barrier-to-autointegration factor) mutants. The baf-1 gene codes for an essential and highly conserved protein known to interact with the other two C. elegans LEM domain proteins, LEM-2 and EMR-1. We show that baf-1, lem-2, and emr-1 mutants are also hypersensitive to DNA damage and that loss of lem-3 sensitizes baf-1 mutants even in the absence of DNA damage. Our data suggest that BAF-1, together with the LEM domain proteins, plays an important role following DNA damage - possibly by promoting the reorganization of damaged chromatin. VL - 7 IS - 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/22383942?dopt=Abstract ER - TY - JOUR T1 - Structural and physiological phenotypes of disease-linked lamin mutations in C. elegans. JF - J Struct Biol Y1 - 2012 A1 - Bank, Erin M A1 - Ben-Harush, Kfir A1 - Feinstein, Naomi A1 - Medalia, Ohad A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Cell Nucleus KW - Electron Microscope Tomography KW - Fertility KW - Gene Expression Regulation KW - Intermediate Filament Proteins KW - Intermediate Filaments KW - Lamins KW - Mutation, Missense KW - Nuclear Lamina KW - Phenotype AB - The nuclear lamina is a major structural element of the nucleus and is predominately composed of the intermediate filament lamin proteins. Missense mutations in the human lamins A/C cause a family of laminopathic diseases, with no known mechanistic link between the position of the mutation and the resulting disease phenotypes. The Caenorhabditis elegans lamin (Ce-lamin) is structurally and functionally homologous to human lamins, and recent advances have allowed detailed structural analysis of Ce-lamin filaments both in vitro and in vivo. Here, we studied the effect of laminopathic mutations on Ce-lamin filament assembly in vitro and the corresponding physiological phenotypes in animals. We focused on three disease-linked mutations, Q159K, T164P, and L535P, which have previously been shown to affect lamin structure and nuclear localization. Mutations prevented the proper assembly of Ce-lamin into filament and/or paracrystalline arrays. Disease-like phenotypes were observed in strains expressing low levels of these mutant lamins, including decreased fertility and motility coincident with muscle lesions. In addition, the Q159K- and T164P-expressing strains showed a reduced lifespan. Thus, different disease-linked mutations in Ce-lamin exhibit major effects in vivo and in vitro. Using C. elegans as a model system, a comprehensive analysis of the effects of specific lamin mutations from the level of in vitro filament assembly to the physiology of the organism will help uncover the mechanistic differences between these different lamin mutations. VL - 177 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/22079399?dopt=Abstract ER - TY - JOUR T1 - Lamins in development, tissue maintenance and stress. JF - EMBO Rep Y1 - 2012 A1 - Zuela, Noam A1 - Bar, Daniel Z A1 - Gruenbaum, Yosef KW - Cell Differentiation KW - Chromatin KW - DNA Replication KW - Humans KW - Lamin Type A KW - Lamin Type B KW - Nuclear Envelope KW - Stress, Physiological KW - Transcription, Genetic AB - Lamins are nuclear intermediate filament proteins. They provide mechanical stability, organize chromatin and regulate transcription, replication, nuclear assembly and nuclear positioning. Recent studies provide new insights into the role of lamins in development, differentiation and tissue response to mechanical, reactive oxygen species and thermal stresses. These studies also propose the existence of separate filament networks for A- and B-type lamins and identify new roles for the different networks. Furthermore, they show changes in lamin composition in different cell types, propose explanations for the more than 14 distinct human diseases caused by lamin A and lamin C mutations and propose a role for lamin B1 in these diseases. VL - 13 IS - 12 U1 - http://www.ncbi.nlm.nih.gov/pubmed/23146893?dopt=Abstract ER - TY - JOUR T1 - A laminopathic mutation disrupting lamin filament assembly causes disease-like phenotypes in Caenorhabditis elegans. JF - Mol Biol Cell Y1 - 2011 A1 - Bank, Erin M A1 - Ben-Harush, Kfir A1 - Wiesel-Motiuk, Naama A1 - Barkan, Rachel A1 - Feinstein, Naomi A1 - Lotan, Oren A1 - Medalia, Ohad A1 - Gruenbaum, Yosef KW - Amino Acid Sequence KW - Animals KW - Caenorhabditis elegans KW - Cloning, Molecular KW - Cryoelectron Microscopy KW - Cytoskeleton KW - Disease Models, Animal KW - Escherichia coli KW - Genetic Association Studies KW - Green Fluorescent Proteins KW - Humans KW - Lamin Type A KW - Membrane Proteins KW - Molecular Sequence Data KW - Movement KW - Muscles KW - Muscular Dystrophy, Emery-Dreifuss KW - Mutation KW - Nuclear Lamina KW - Nuclear Proteins KW - Phenotype KW - Plasmids KW - Recombinant Proteins KW - Transformation, Bacterial AB - Mutations in the human LMNA gene underlie many laminopathic diseases, including Emery-Dreifuss muscular dystrophy (EDMD); however, a mechanistic link between the effect of mutations on lamin filament assembly and disease phenotypes has not been established. We studied the ΔK46 Caenorhabditis elegans lamin mutant, corresponding to EDMD-linked ΔK32 in human lamins A and C. Cryo-electron tomography of lamin ΔK46 filaments in vitro revealed alterations in the lateral assembly of dimeric head-to-tail polymers, which causes abnormal organization of tetrameric protofilaments. Green fluorescent protein (GFP):ΔK46 lamin expressed in C. elegans was found in nuclear aggregates in postembryonic stages along with LEM-2. GFP:ΔK46 also caused mislocalization of emerin away from the nuclear periphery, consistent with a decreased ability of purified emerin to associate with lamin ΔK46 filaments in vitro. GFP:ΔK46 animals had motility defects and muscle structure abnormalities. These results show that changes in lamin filament structure can translate into disease-like phenotypes via altering the localization of nuclear lamina proteins, and suggest a model for how the ΔK32 lamin mutation may cause EDMD in humans. VL - 22 IS - 15 U1 - http://www.ncbi.nlm.nih.gov/pubmed/21653823?dopt=Abstract ER - TY - JOUR T1 - Caenorhabditis elegans as a model system for studying the nuclear lamina and laminopathic diseases. JF - Nucleus Y1 - 2011 A1 - Bank, Erin M A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Cell Cycle Proteins KW - DNA-Binding Proteins KW - Humans KW - Lamins KW - Membrane Proteins KW - Models, Animal KW - Muscular Dystrophies KW - Mutation KW - Nuclear Lamina KW - Nuclear Proteins AB - The nuclear lamina is a protein-rich network located directly underneath the inner nuclear membrane of metazoan nuclei. The components of the nuclear lamina have been implicated in nearly all nuclear functions; therefore, understanding the structural, mechanical, and signal transducing properties of these proteins is crucial. In addition, mutations in many of these proteins cause a wide range of human diseases, the laminopathies. The structure, function, and interaction of the lamina proteins are conserved among metazoans, emphasizing their fundamental roles in the nucleus. Several of the advances in the field of the nuclear lamina have come from studies performed in Caenorhabditis elegans or on C. elegans proteins expressed in vitro. Here, we discuss the current knowledge about the nuclear lamina, including an overview of the technical tools offered by C. elegans that make it a powerful model organism for the study of the nuclear lamina and laminopathic diseases. VL - 2 IS - 5 U1 - http://www.ncbi.nlm.nih.gov/pubmed/21970988?dopt=Abstract ER - TY - JOUR T1 - Chromatin organization, structure and dynamics. JF - Nucleus Y1 - 2011 A1 - Raška, Ivan A1 - Gruenbaum, Yosef A1 - Hermann, Harald A1 - Neugebauer, Karla KW - Cell Nucleus KW - Chromatin KW - Consensus Development Conferences as Topic KW - Humans VL - 2 IS - 5 U1 - http://www.ncbi.nlm.nih.gov/pubmed/21970985?dopt=Abstract ER - TY - JOUR T1 - An EDMD mutation in C. elegans lamin blocks muscle-specific gene relocation and compromises muscle integrity. JF - Curr Biol Y1 - 2011 A1 - Mattout, Anna A1 - Pike, Brietta L A1 - Towbin, Benjamin D A1 - Bank, Erin M A1 - Gonzalez-Sandoval, Adriana A1 - Stadler, Michael B A1 - Meister, Peter A1 - Gruenbaum, Yosef A1 - Gasser, Susan M KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Disease Models, Animal KW - Heterochromatin KW - Humans KW - Laminin KW - Locomotion KW - Microscopy KW - Muscle Development KW - Muscles KW - Muscular Dystrophy, Emery-Dreifuss KW - Nuclear Envelope KW - Point Mutation KW - Real-Time Polymerase Chain Reaction KW - RNA Interference KW - Trans-Activators AB - BACKGROUND: In worms, as in other organisms, many tissue-specific promoters are sequestered at the nuclear periphery when repressed and shift inward when activated. It has remained unresolved, however, whether the association of facultative heterochromatin with the nuclear periphery, or its release, has functional relevance for cell or tissue integrity. RESULTS: Using ablation of the unique lamin gene in C. elegans, we show that lamin is necessary for the perinuclear positioning of heterochromatin. We then express at low levels in otherwise wild-type worms a lamin carrying a point mutation, Y59C, which in humans is linked to an autosomal-dominant form of Emery-Dreifuss muscular dystrophy. Using embryos and differentiated tissues, we track the subnuclear position of integrated heterochromatic arrays and their expression. In LMN-1 Y59C-expressing worms, we see abnormal retention at the nuclear envelope of a gene array bearing a muscle-specific promoter. This correlates with impaired activation of the array-borne myo-3 promoter and altered expression of a number of muscle-specific genes. However, an equivalent array carrying the intestine-specific pha-4 promoter is expressed normally and shifts inward when activated in gut cells of LMN-1 Y59C worms. Remarkably, adult LMN-1 Y59C animals have selectively perturbed body muscle ultrastructure and reduced muscle function. CONCLUSION: Lamin helps sequester heterochromatin at the nuclear envelope, and wild-type lamin permits promoter release following tissue-specific activation. A disease-linked point mutation in lamin impairs muscle-specific reorganization of a heterochromatic array during tissue-specific promoter activation in a dominant manner. This dominance and the correlated muscle dysfunction in LMN-1 Y59C worms phenocopies Emery-Dreifuss muscular dystrophy. VL - 21 IS - 19 U1 - http://www.ncbi.nlm.nih.gov/pubmed/21962710?dopt=Abstract ER - TY - JOUR T1 - The nuclear lamina and heterochromatin: a complex relationship. JF - Biochem Soc Trans Y1 - 2011 A1 - Bank, Erin M A1 - Gruenbaum, Yosef KW - Animals KW - Genetic Loci KW - Heterochromatin KW - Humans KW - Nuclear Lamina AB - In metazoan cells, the heterochromatin is generally localized at the nuclear periphery, whereas active genes are preferentially found in the nuclear interior. In the present paper, we review current evidence showing that components of the nuclear lamina interact directly with heterochromatin, which implicates the nuclear lamina in a mechanism of specific gene retention at the nuclear periphery and release to the nuclear interior upon gene activation. We also discuss recent data showing that mutations in lamin proteins affect gene positioning and expression, providing a potential mechanism for how these mutations lead to tissue-specific diseases. VL - 39 IS - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/22103511?dopt=Abstract ER - TY - JOUR T1 - Nuclear pore structure: warming up the core. JF - Cell Y1 - 2011 A1 - Harel, Amnon A1 - Gruenbaum, Yosef AB - Structural determination of the nuclear pore complex has been limited by the complexity and size of this cellular megalith. By taking advantage of exceptionally stable nucleoporins from the thermophilic fungus Chaetomium thermophilum, Amlacher et al. (2011) provide new insight into a core element of the nuclear pore scaffold. VL - 146 IS - 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/21784242?dopt=Abstract ER - TY - JOUR T1 - Leptotene/zygotene chromosome movement via the SUN/KASH protein bridge in Caenorhabditis elegans. JF - PLoS Genet Y1 - 2010 A1 - Baudrimont, Antoine A1 - Penkner, Alexandra A1 - Woglar, Alexander A1 - Machacek, Thomas A1 - Wegrostek, Christina A1 - Gloggnitzer, Jiradet A1 - Fridkin, Alexandra A1 - Klein, Franz A1 - Gruenbaum, Yosef A1 - Pasierbek, Pawel A1 - Jantsch, Verena KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Cell Cycle Proteins KW - Cell Nucleus KW - Chromatin KW - Chromosomes KW - Cytoskeleton KW - DNA Breaks, Double-Stranded KW - Genotype KW - Meiotic Prophase I KW - Mitosis KW - Models, Biological KW - Nuclear Proteins KW - Protein Structure, Quaternary KW - Protein Transport KW - Receptors, Cytoplasmic and Nuclear KW - Synaptonemal Complex AB - The Caenorhabditis elegans inner nuclear envelope protein matefin/SUN-1 plays a conserved, pivotal role in the process of genome haploidization. CHK-2-dependent phosphorylation of SUN-1 regulates homologous chromosome pairing and interhomolog recombination in Caenorhabditis elegans. Using time-lapse microscopy, we characterized the movement of matefin/SUN-1::GFP aggregates (the equivalent of chromosomal attachment plaques) and showed that the dynamics of matefin/SUN-1 aggregates remained unchanged throughout leptonene/zygotene, despite the progression of pairing. Movement of SUN-1 aggregates correlated with chromatin polarization. We also analyzed the requirements for the formation of movement-competent matefin/SUN-1 aggregates in the context of chromosome structure and found that chromosome axes were required to produce wild-type numbers of attachment plaques. Abrogation of synapsis led to a deceleration of SUN-1 aggregate movement. Analysis of matefin/SUN-1 in a double-strand break deficient mutant revealed that repair intermediates influenced matefin/SUN-1 aggregate dynamics. Investigation of movement in meiotic regulator mutants substantiated that proper orchestration of the meiotic program and effective repair of DNA double-strand breaks were necessary for the wild-type behavior of matefin/SUN-1 aggregates. VL - 6 IS - 11 U1 - http://www.ncbi.nlm.nih.gov/pubmed/21124819?dopt=Abstract ER - TY - JOUR T1 - The physiological and molecular effects of elevated CO2 levels. JF - Cell Cycle Y1 - 2010 A1 - Azzam, Zaher S A1 - Sharabi, Kfir A1 - Guetta, Julia A1 - Bank, Erin M A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Carbon Dioxide KW - Drosophila melanogaster KW - Humans KW - Hypercapnia KW - Lung AB - Carbon dioxide (CO2) is an end product of cellular respiration, a process by which organisms including all plants, animals, many fungi and some bacteria obtain energy. CO2 has several physiologic roles in respiration, pH buffering, autoregulation of the blood supply and others. Here we review recent findings from studies in mammalian lung cells, Caenorhabditis elegans and Drosophila melanogaster that help shed light on the molecular sensing and response to hypercapnia. VL - 9 IS - 8 U1 - http://www.ncbi.nlm.nih.gov/pubmed/20372066?dopt=Abstract ER - TY - JOUR T1 - Reversal of age-dependent nuclear morphology by inhibition of prenylation does not affect lifespan in Caenorhabditis elegans. JF - Nucleus Y1 - 2010 A1 - Bar, Daniel Z A1 - Gruenbaum, Yosef KW - Aging KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Cell Nucleus KW - Enzyme Inhibitors KW - Farnesyltranstransferase KW - Lamin Type A KW - Longevity KW - Polyenes KW - Polyunsaturated Alkamides KW - Protein Prenylation KW - RNA Interference AB - Fibroblasts derived from Hutchinson-Gilford progeria syndrome (HGPS) patients and dermal cells derived from healthy old humans in culture display age-dependent progressive changes in nuclear architecture due to accumulation of farnesylated lamin A. Treating human HGPS cells or mice expressing farnesylated lamin A with farnesyl transferase inhibitors (FTIs) reverses nuclear phenotypes and extends lifespan. Aging adult Caenorhabditis elegans show changes in nuclear architecture resembling those seen in HGPS fibroblasts, as well as a decline in motility, phenotypes which are also inhibited by the FTI gliotoxin. However, it was not clear whether these effects were due to loss of farnesylation or to side effects of this drug. Here, we used a different FTI, manumycin or downregulated polyprenyl synthetase with RNAi to test the roles of farnesylation in C. elegans aging. Our results show that the age-dependent changes in nuclear morphology depend on farnesylation. We also demonstrate that inhibition of farnesylation does not affect motility or lifespan, suggesting that the effects of blocking protein prenylation on nuclear morphology could be separated from their effects on motility and lifespan. These results provide further understanding of the role of lamin and farnesylation in the normal aging process and in HGPS. VL - 1 IS - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/21327093?dopt=Abstract ER - TY - JOUR T1 - Gliotoxin reverses age-dependent nuclear morphology phenotypes, ameliorates motility, but fails to affect lifespan of adult Caenorhabditis elegans. JF - Cell Motil Cytoskeleton Y1 - 2009 A1 - Bar, Daniel Z A1 - Neufeld, Ester A1 - Feinstein, Naomi A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Cell Aging KW - Cell Movement KW - Cell Nucleus KW - Farnesyltranstransferase KW - Gliotoxin KW - Humans KW - Lamin Type A KW - Longevity KW - Microscopy, Electron, Transmission KW - Movement KW - Nuclear Lamina KW - Phenotype AB - Specific mutations in human LMNA or loss of ZMPSTE26 activity cause abnormal processing of lamin A and early aging diseases, including Hutchinson Gilford progeria syndrome (HGPS). HGPS fibroblasts in culture undergo age-dependent progressive changes in nuclear architecture. Treating these cells with farnesyl transferase inhibitors (FTIs) reverse these nuclear phenotypes and also extend lifespan of mice HGPS models. Dermal cells derived from healthy old humans also accumulate the abnormally processed lamin A. However, the effect of FTIs on normal aging cells was not tested. Aging adult C. elegans cells show changes in nuclear architecture similar to HGPS fibroblasts and down regulating lamin expression in adult C. elegans reduces their lifespan. Here, we show that nuclei of adult C. elegans, in which lamin is down-regulated, have similar phenotypes to normal aging nuclei, but at an earlier age. We further show that treating adult C. elegans with the FTI gliotoxin reverses nuclear phenotypes and improves motility of aging worms. However, the average lifespan of the gliotoxin-treated animals was similar to that of untreated animals. These results suggest that lamins are involved in the process of normal aging in C. elegans. VL - 66 IS - 10 U1 - http://www.ncbi.nlm.nih.gov/pubmed/19235201?dopt=Abstract ER - TY - JOUR T1 - Nuclear lamins: key regulators of nuclear structure and activities. JF - J Cell Mol Med Y1 - 2009 A1 - Prokocimer, Miron A1 - Davidovich, Maya A1 - Nissim-Rafinia, Malka A1 - Wiesel-Motiuk, Naama A1 - Bar, Daniel Z A1 - Barkan, Rachel A1 - Meshorer, Eran A1 - Gruenbaum, Yosef KW - Animals KW - Cell Nucleus KW - Chromatin KW - Humans KW - Lamins KW - Models, Biological KW - Mutation KW - Nuclear Envelope KW - Nuclear Lamina KW - Protein Binding AB - The nuclear lamina is a proteinaceous structure located underneath the inner nuclear membrane (INM), where it associates with the peripheral chromatin. It contains lamins and lamin-associated proteins, including many integral proteins of the INM, chromatin modifying proteins, transcriptional repressors and structural proteins. A fraction of lamins is also present in the nucleoplasm, where it forms stable complexes and is associated with specific nucleoplasmic proteins. The lamins and their associated proteins are required for most nuclear activities, mitosis and for linking the nucleoplasm to all major cytoskeletal networks in the cytoplasm. Mutations in nuclear lamins and their associated proteins cause about 20 different diseases that are collectively called laminopathies'. This review concentrates mainly on lamins, their structure and their roles in DNA replication, chromatin organization, adult stem cell differentiation, aging, tumorogenesis and the lamin mutations leading to laminopathic diseases. VL - 13 IS - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/19210577?dopt=Abstract ER - TY - JOUR T1 - Single-molecule dynamics of nuclear mRNA. JF - F1000 Biol Rep Y1 - 2009 A1 - Shav-Tal, Yaron A1 - Gruenbaum, Yosef AB - In eukaryotes, mRNA molecules are transcribed from nuclear DNA and commute through a labyrinth of nucleoplasmic passageways to the nuclear envelope where they are exported to the cytoplasm. New findings provide tools and insights into the biophysical properties that govern mRNA translocations en route to the cytoplasm and suggest that mRNA molecules move in a discontinuous manner due to transient interactions with the nuclear environment. VL - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/20948657?dopt=Abstract ER - TY - JOUR T1 - SUN-domain and KASH-domain proteins during development, meiosis and disease. JF - Cell Mol Life Sci Y1 - 2009 A1 - Fridkin, A A1 - Penkner, A A1 - Jantsch, V A1 - Gruenbaum, Y KW - Amino Acid Motifs KW - Animals KW - Apoptosis KW - Cell Nucleus KW - Centrosome KW - Cerebellar Ataxia KW - Chromosomes KW - Cytoskeleton KW - Humans KW - Lamins KW - Meiosis KW - Membrane Proteins KW - Models, Biological KW - Muscular Dystrophy, Emery-Dreifuss AB - SUN-domain proteins interact directly with KASH-domain proteins to form protein complexes that connect the nucleus to every major cytoskeleton network. SUN-KASH protein complexes are also required for attaching centrosomes to the nuclear periphery and for alignment of homologous chromosomes, their pairing and recombination in meiosis. Other functions that require SUN-domain proteins include the regulation of apoptosis and maturation and survival of the germline. Laminopathic diseases affect the distribution of the SUN-KASH complexes, and mutations in KASH-domain proteins can cause Emery Dreifuss muscular dystrophy and recessive cerebellar ataxia. This review describes our current knowledge of the role of SUN-KASH domain protein complexes during development, meiosis and disease. VL - 66 IS - 9 U1 - http://www.ncbi.nlm.nih.gov/pubmed/19125221?dopt=Abstract ER - TY - JOUR T1 - The supramolecular organization of the C. elegans nuclear lamin filament. JF - J Mol Biol Y1 - 2009 A1 - Ben-Harush, Kfir A1 - Wiesel, Naama A1 - Frenkiel-Krispin, Daphna A1 - Moeller, Dorothee A1 - Soreq, Eyal A1 - Aebi, Ueli A1 - Harald Herrmann A1 - Gruenbaum, Yosef A1 - Medalia, Ohad KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Lamins KW - Nuclear Lamina AB - Nuclear lamins are involved in most nuclear activities and are essential for retaining the mechano-elastic properties of the nucleus. They are nuclear intermediate filament (IF) proteins forming a distinct meshwork-like layer adhering to the inner nuclear membrane, called the nuclear lamina. Here, we present for the first time, the three-dimensional supramolecular organization of lamin 10 nm filaments and paracrystalline fibres. We show that Caenorhabditis elegans nuclear lamin forms 10 nm IF-like filaments, which are distinct from their cytoplasmic counterparts. The IF-like lamin filaments are composed of three and four tetrameric protofilaments, each of which contains two partially staggered anti-parallel head-to-tail polymers. The beaded appearance of the lamin filaments stems from paired globular tail domains, which are spaced regularly, alternating between 21 nm and 27 nm. A mutation in an evolutionarily conserved residue that causes Hutchison-Gilford progeria syndrome in humans alters the supramolecular structure of the lamin filaments. On the basis of our structural analysis, we propose an assembly pathway that yields the observed 10 nm IF-like lamin filaments and paracrystalline fibres. These results serve also as a platform for understanding the effect of laminopathic mutations on lamin supramolecular organization. VL - 386 IS - 5 U1 - http://www.ncbi.nlm.nih.gov/pubmed/19109977?dopt=Abstract ER - TY - JOUR T1 - The curious case of the ageing cells. JF - Nat Rev Mol Cell Biol Y1 - 2009 A1 - Gruenbaum, Yosef VL - 10 IS - 4 U1 - http://www.ncbi.nlm.nih.gov/pubmed/19309769?dopt=Abstract ER - TY - JOUR T1 - Elevated CO2 levels affect development, motility, and fertility and extend life span in Caenorhabditis elegans. JF - Proc Natl Acad Sci U S A Y1 - 2009 A1 - Sharabi, Kfir A1 - Hurwitz, Anat A1 - Simon, Amos J A1 - Beitel, Greg J A1 - Morimoto, Richard I A1 - Rechavi, Gideon A1 - Sznajder, Jacob I A1 - Gruenbaum, Yosef KW - AIR KW - Animals KW - Aquaporins KW - Caenorhabditis elegans KW - Carbon Dioxide KW - Fertility KW - Gene Expression Regulation KW - Genes, Helminth KW - Hypercapnia KW - Locomotion KW - Longevity KW - Muscle Fibers, Skeletal KW - Oviposition AB - Hypercapnia (high CO(2) levels) occurs in a number of lung diseases and it is associated with worse outcomes in patients with chronic obstructive lung disease (COPD). However, it is largely unknown how hypercapnia is sensed and responds in nonneuronal cells. Here, we used C. elegans to study the response to nonanesthetic CO(2) levels and show that levels exceeding 9% induce aberrant motility that is accompanied by age-dependent deterioration of body muscle organization, slowed development, reduced fertility and increased life span. These effects occur independently of the IGF-R, dietary restriction, egg laying or mitochondrial-induced aging pathways. Transcriptional profiling analysis shows specific and dynamic changes in gene expression after 1, 6, or 72 h of exposure to 19% CO(2) including increased transcription of several 7-transmembrane domain and innate immunity genes and a reduction in transcription of many of the MSP genes. Together, these results suggest specific physiological and molecular responses to hypercapnia, which appear to be independent of early heat shock and HIF mediated pathways. VL - 106 IS - 10 U1 - http://www.ncbi.nlm.nih.gov/pubmed/19237558?dopt=Abstract ER - TY - JOUR T1 - Elevated CO2 suppresses specific Drosophila innate immune responses and resistance to bacterial infection. JF - Proc Natl Acad Sci U S A Y1 - 2009 A1 - Helenius, Iiro Taneli A1 - Krupinski, Thomas A1 - Turnbull, Douglas W A1 - Gruenbaum, Yosef A1 - Silverman, Neal A1 - Johnson, Eric A A1 - Sporn, Peter H S A1 - Sznajder, Jacob I A1 - Beitel, Greg J KW - Acidosis KW - Animals KW - Antimicrobial Cationic Peptides KW - Bacterial Infections KW - Carbon Dioxide KW - Drosophila melanogaster KW - Drosophila Proteins KW - Gene Expression Regulation KW - Hydrogen-Ion Concentration KW - Hypercapnia KW - Immune Tolerance KW - Immunity, Innate KW - Neurons KW - Nitric Oxide KW - Protein Processing, Post-Translational KW - Survival Analysis KW - Transcription Factors AB - Elevated CO(2) levels (hypercapnia) frequently occur in patients with obstructive pulmonary diseases and are associated with increased mortality. However, the effects of hypercapnia on non-neuronal tissues and the mechanisms that mediate these effects are largely unknown. Here, we develop Drosophila as a genetically tractable model for defining non-neuronal CO(2) responses and response pathways. We show that hypercapnia significantly impairs embryonic morphogenesis, egg laying, and egg hatching even in mutants lacking the Gr63a neuronal CO(2) sensor. Consistent with previous reports that hypercapnic acidosis can suppress mammalian NF-kappaB-regulated innate immune genes, we find that in adult flies and the phagocytic immune-responsive S2* cell line, hypercapnia suppresses induction of specific antimicrobial peptides that are regulated by Relish, a conserved Rel/NF-kappaB family member. Correspondingly, modest hypercapnia (7-13%) increases mortality of flies inoculated with E. faecalis, A. tumefaciens, or S. aureus. During E. faecalis and A. tumefaciens infection, increased bacterial loads were observed, indicating that hypercapnia can decrease host resistance. Hypercapnic immune suppression is not mediated by acidosis, the olfactory CO(2) receptor Gr63a, or by nitric oxide signaling. Further, hypercapnia does not induce responses characteristic of hypoxia, oxidative stress, or heat shock. Finally, proteolysis of the Relish IkappaB-like domain is unaffected by hypercapnia, indicating that immunosuppression acts downstream of, or in parallel to, Relish proteolytic activation. Our results suggest that hypercapnic immune suppression is mediated by a conserved response pathway, and illustrate a mechanism by which hypercapnia could contribute to worse outcomes of patients with advanced lung disease, who frequently suffer from both hypercapnia and respiratory infections. VL - 106 IS - 44 U1 - http://www.ncbi.nlm.nih.gov/pubmed/19846771?dopt=Abstract ER - TY - JOUR T1 - Meiotic chromosome homology search involves modifications of the nuclear envelope protein Matefin/SUN-1. JF - Cell Y1 - 2009 A1 - Penkner, Alexandra M A1 - Fridkin, Alexandra A1 - Gloggnitzer, Jiradet A1 - Baudrimont, Antoine A1 - Machacek, Thomas A1 - Woglar, Alexander A1 - Csaszar, Edina A1 - Pasierbek, Pawel A1 - Ammerer, Gustav A1 - Gruenbaum, Yosef A1 - Jantsch, Verena KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Checkpoint Kinase 2 KW - Chromosome Pairing KW - Chromosomes KW - Meiosis KW - Meiotic Prophase I KW - Microtubules KW - Mutation KW - Nuclear Envelope KW - Phosphorylation KW - Protein Kinases KW - Protein Structure, Tertiary KW - Receptors, Cytoplasmic and Nuclear KW - Serine AB - Genome haploidization during meiosis depends on recognition and association of parental homologous chromosomes. The C. elegans SUN/KASH domain proteins Matefin/SUN-1 and ZYG-12 have a conserved role in this process. They bridge the nuclear envelope, connecting the cytoplasm and the nucleoplasm to transmit forces that allow chromosome movement and homolog pairing and prevent nonhomologous synapsis. Here, we show that Matefin/SUN-1 forms rapidly moving aggregates at putative chromosomal attachment sites in the meiotic transition zone (TZ). We analyzed requirements for aggregate formation and identified multiple phosphotarget residues in the nucleoplasmic domain of Matefin/SUN-1. These CHK-2 dependent phosphorylations occur in leptotene/zygotene, diminish during pachytene and are involved in pairing. Mimicking phosphorylation causes an extended TZ and univalents at diakinesis. Our data suggest that the properties of the nuclear envelope are altered during the time window when homologs are sorted and Matefin/SUN-1 aggregates form, thereby controling the movement, homologous pairing and interhomolog recombination of chromosomes. VL - 139 IS - 5 U1 - http://www.ncbi.nlm.nih.gov/pubmed/19913286?dopt=Abstract ER - TY - JOUR T1 - NURD keeps chromatin young. JF - Nat Cell Biol Y1 - 2009 A1 - Meshorer, Eran A1 - Gruenbaum, Yosef KW - Chromatin KW - Chromosomal Proteins, Non-Histone KW - Chromosomes, Bacterial KW - Histone Deacetylases KW - Humans KW - Mi-2 Nucleosome Remodeling and Deacetylase Complex VL - 11 IS - 10 U1 - http://www.ncbi.nlm.nih.gov/pubmed/19794502?dopt=Abstract ER - TY - JOUR T1 - Sensing, physiological effects and molecular response to elevated CO2 levels in eukaryotes. JF - J Cell Mol Med Y1 - 2009 A1 - Sharabi, Kfir A1 - Lecuona, Emilia A1 - Helenius, Iiro Taneli A1 - Beitel, Greg J A1 - Sznajder, Jacob Iasha A1 - Gruenbaum, Yosef KW - Animals KW - Biological Transport KW - Carbon Dioxide KW - Eukaryota KW - Humans KW - Hypercapnia AB - Carbon dioxide (CO(2)) is an important gaseous molecule that maintains biosphere homeostasis and is an important cellular signalling molecule in all organisms. The transport of CO(2) through membranes has fundamental roles in most basic aspects of life in both plants and animals. There is a growing interest in understanding how CO(2) is transported into cells, how it is sensed by neurons and other cell types and in understanding the physiological and molecular consequences of elevated CO(2) levels (hypercapnia) at the cell and organism levels. Human pulmonary diseases and model organisms such as fungi, C. elegans, Drosophila and mice have been proven to be important in understanding of the mechanisms of CO(2) sensing and response. VL - 13 IS - 11-12 U1 - http://www.ncbi.nlm.nih.gov/pubmed/19863692?dopt=Abstract ER - TY - JOUR T1 - Electron microscopy of lamin and the nuclear lamina in Caenorhabditis elegans. JF - Methods Cell Biol Y1 - 2008 A1 - Cohen, Merav A1 - Santarella, Rachel A1 - Wiesel, Naama A1 - Mattaj, Iain A1 - Gruenbaum, Yosef KW - Animals KW - Atmospheric Pressure KW - Caenorhabditis elegans KW - Cryopreservation KW - Cryoultramicrotomy KW - Dimerization KW - Embryo, Nonmammalian KW - Immunohistochemistry KW - Lamins KW - Microscopy, Electron KW - Microwaves KW - Nuclear Lamina KW - Tissue Embedding KW - Tissue Fixation AB - The nuclear lamina is found between the inner nuclear membrane and the peripheral chromatin. Lamins are the main components of the nuclear lamina, where they form protein complexes with integral proteins of the inner nuclear membrane, transcriptional regulators, histones and chromatin modifiers. Lamins are required for mechanical stability, chromatin organization, Pol II transcription, DNA replication, nuclear assembly, and nuclear positioning. Mutations in human lamins cause at least 13 distinct human diseases, collectively termed laminopathies, affecting muscle, adipose, bone, nerve and skin cells, and range from muscular dystrophies to accelerated aging. Caenorhabditis elegans has unique advantages in studying lamins and nuclear lamina genes including low complexity of lamina genes and the unique ability of bacterially expressed C. elegans lamin protein to form stable 10 nm fibers. In addition, transgenic techniques, simple application of RNA interference, sophisticated genetic analyses, and the production of a large collection of mutant lines, all make C. elegans especially attractive for studying the functions of its nuclear lamina genes. In this chapter we will include a short review of our current knowledge of nuclear lamina in C. elegans and will describe electron microscopy techniques used for their analyses. VL - 88 U1 - http://www.ncbi.nlm.nih.gov/pubmed/18617045?dopt=Abstract ER - TY - JOUR T1 - Gone with the Wnt/Notch: stem cells in laminopathies, progeria, and aging. JF - J Cell Biol Y1 - 2008 A1 - Meshorer, Eran A1 - Gruenbaum, Yosef KW - Aging KW - Animals KW - Lamins KW - Membrane Proteins KW - Metalloendopeptidases KW - Mice KW - Progeria KW - Receptors, Notch KW - Signal Transduction KW - Stem Cells KW - Wnt Proteins AB - Specific mutations in the human gene encoding lamin A or in the lamin A-processing enzyme, Zmpste24, cause premature aging. New data on mice and humans suggest that these mutations affect adult stem cells by interfering with the Notch and Wnt signaling pathways. VL - 181 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/18378774?dopt=Abstract ER - TY - JOUR T1 - Laminopathic mutations interfere with the assembly, localization, and dynamics of nuclear lamins. JF - Proc Natl Acad Sci U S A Y1 - 2008 A1 - Wiesel, Naama A1 - Mattout, Anna A1 - Melcer, Shai A1 - Melamed-Book, Naomi A1 - Harald Herrmann A1 - Medalia, Ohad A1 - Aebi, Ueli A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Cell Nucleus KW - Conserved Sequence KW - Crystallization KW - DNA KW - Green Fluorescent Proteins KW - Humans KW - Lamins KW - Microscopy, Electron, Transmission KW - Models, Genetic KW - Mutation KW - Mutation, Missense KW - Nuclear Lamina KW - Peptides KW - Point Mutation KW - Urea AB - Lamins are nuclear intermediate filament proteins and the major building blocks of the nuclear lamina. Besides providing nuclear shape and mechanical stability, lamins are required for chromatin organization, transcription regulation, DNA replication, nuclear assembly, nuclear positioning, and apoptosis. Mutations in human lamins cause many different heritable diseases, affecting various tissues and causing early aging. Although many of these mutations result in nuclear deformation, their effects on lamin filament assembly are unknown. Caenorhabditis elegans has a single evolutionarily conserved lamin protein, which can form stable 10-nm-thick filaments in vitro. To gain insight into the molecular basis of lamin filament assembly and the effects of laminopathic mutations on this process, we investigated mutations in conserved residues of the rod and tail domains that are known to cause various laminopathies in human. We show that 8 of 14 mutant lamins present WT-like assembly into filaments or paracrystals, whereas 6 mutants show assembly defects. Correspondingly, expressing these mutants in transgenic animals shows abnormal distribution of Ce-lamin, abnormal nuclear shape or change in lamin mobility. These findings help in understanding the role of individual residues and domains in laminopathy pathology and, eventually, promote the development of therapeutic interventions. VL - 105 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/18162544?dopt=Abstract ER - TY - JOUR T1 - Rejuvenating premature aging. JF - Nat Med Y1 - 2008 A1 - Meshorer, Eran A1 - Gruenbaum, Yosef KW - Animals KW - Bone Density Conservation Agents KW - Cell Nucleus KW - Diphosphonates KW - Disease Models, Animal KW - Drug Therapy, Combination KW - Farnesyltranstransferase KW - Humans KW - Hydroxymethylglutaryl-CoA Reductase Inhibitors KW - Imidazoles KW - Longevity KW - Mice KW - Mice, Knockout KW - Nuclear Proteins KW - Pravastatin KW - Prenylation KW - Progeria KW - Protein Precursors KW - Tumor Suppressor Protein p53 VL - 14 IS - 7 U1 - http://www.ncbi.nlm.nih.gov/pubmed/18607367?dopt=Abstract ER - TY - JOUR T1 - 141st ENMC International Workshop inaugural meeting of the EURO-Laminopathies project "Nuclear Envelope-linked Rare Human Diseases: From Molecular Pathophysiology towards Clinical Applications", 10-12 March 2006, Naarden, The Netherlands. JF - Neuromuscul Disord Y1 - 2007 A1 - Foisner, Roland A1 - Aebi, Ueli A1 - Bonne, Gisèle A1 - Gruenbaum, Yosef A1 - Novelli, Giuseppe KW - Animals KW - Genetic Predisposition to Disease KW - Humans KW - Laminin KW - Muscular Diseases KW - Nuclear Envelope VL - 17 IS - 8 U1 - http://www.ncbi.nlm.nih.gov/pubmed/17587579?dopt=Abstract ER - TY - JOUR T1 - Barrier to autointegration factor blocks premature cell fusion and maintains adult muscle integrity in C. elegans. JF - J Cell Biol Y1 - 2007 A1 - Margalit, Ayelet A1 - Neufeld, Esther A1 - Feinstein, Naomi A1 - Wilson, Katherine L A1 - Podbilewicz, Benjamin A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Carrier Proteins KW - Cell Movement KW - Epidermis KW - Humans KW - Muscles KW - Muscular Dystrophy, Emery-Dreifuss KW - Nuclear Envelope AB - Barrier to autointegration factor (BAF) binds double-stranded DNA, selected histones, transcription regulators, lamins, and LAP2-emerin-MAN1 (LEM) domain proteins. During early Caenorhabditis elegans embryogenesis, BAF-1 is required to organize chromatin, capture segregated chromosomes within the nascent nuclear envelope, and assemble lamin and LEM domain proteins in reforming nuclei. In this study, we used C. elegans with a homozygous deletion of the baf-1 gene, which survives embryogenesis and larval stages, to report that BAF-1 regulates maturation and survival of the germline, cell migration, vulva formation, and the timing of seam cell fusion. In the seam cells, BAF-1 represses the expression of the EFF-1 fusogen protein, but fusion still occurs in C. elegans lacking both baf-1 and eff-1. This suggests the existence of an eff-1-independent mechanism for cell fusion. BAF-1 is also required to maintain the integrity of specific body wall muscles in adult animals, directly implicating BAF in the mechanism of human muscular dystrophies (laminopathies) caused by mutations in the BAF-binding proteins emerin and lamin A. VL - 178 IS - 4 U1 - http://www.ncbi.nlm.nih.gov/pubmed/17698609?dopt=Abstract ER - TY - JOUR T1 - Barrier-to-autointegration factor--a BAFfling little protein. JF - Trends Cell Biol Y1 - 2007 A1 - Margalit, Ayelet A1 - Brachner, Andreas A1 - Gotzmann, Josef A1 - Foisner, Roland A1 - Gruenbaum, Yosef KW - Amino Acid Sequence KW - Animals KW - DNA-Binding Proteins KW - Gene Expression Regulation KW - Gene Expression Regulation, Developmental KW - Humans KW - Intracellular Signaling Peptides and Proteins KW - Membrane Proteins KW - Molecular Sequence Data KW - Nuclear Envelope KW - Nuclear Proteins KW - Retroviridae KW - Sequence Alignment KW - Virus Integration AB - Barrier-to-autointegration factor (BAF) is an abundant, highly conserved, small and essential protein that binds to dsDNA, chromatin, nuclear lamina proteins, histones and various transcription factors. It was discovered as a cellular component of retrovirus pre-integration complex that inhibits their autointegration in vitro. BAF is also required for many cellular functions, including the higher-order organization of chromatin and the transcription of specific genes. Recent findings suggest further roles for BAF, including nuclear envelope assembly, regulating specific developmental processes and regulating retrovirus infectivity. At least some of these roles are controlled by phosphorylation of the BAF N-terminus by the vaccinia-related kinase. Here, we give an overview of recent advances in the field of BAF with special emphasis on evolution, interacting partners and functions. VL - 17 IS - 4 U1 - http://www.ncbi.nlm.nih.gov/pubmed/17320395?dopt=Abstract ER - TY - JOUR T1 - Invertebrate lamins. JF - Exp Cell Res Y1 - 2007 A1 - Melcer, Shai A1 - Gruenbaum, Yosef A1 - Krohne, Georg KW - Animals KW - Caenorhabditis elegans KW - Drosophila melanogaster KW - Evolution, Molecular KW - Invertebrates KW - Lamins KW - Nuclear Lamina KW - Nuclear Proteins KW - Phylogeny KW - Protein Structure, Tertiary AB - Lamins are the main component of the nuclear lamina and considered to be the ancestors of all intermediate filament proteins. They are localized mainly at the nuclear periphery where they form protein complexes with integral proteins of the nuclear inner membrane, transcriptional regulators, histones and chromatin modifiers. Studying lamins in invertebrate species has unique advantages including the smaller number of lamin genes in the invertebrate genomes and powerful genetic analyses in Caenorhabditis elegans and Drosophila melanogaster. These simpler nuclear lamina systems allow direct analyses of their structure and functions. Here we give an overview of recent advances in the field of invertebrate nuclear lamins with special emphasis on their evolution, assembly and functions. VL - 313 IS - 10 U1 - http://www.ncbi.nlm.nih.gov/pubmed/17451683?dopt=Abstract ER - TY - JOUR T1 - The nuclear envelope protein Matefin/SUN-1 is required for homologous pairing in C. elegans meiosis. JF - Dev Cell Y1 - 2007 A1 - Penkner, Alexandra A1 - Tang, Lois A1 - Novatchkova, Maria A1 - Ladurner, Markus A1 - Fridkin, Alexandra A1 - Gruenbaum, Yosef A1 - Schweizer, Dieter A1 - Loidl, Josef A1 - Jantsch, Verena KW - Animals KW - Animals, Genetically Modified KW - Apoptosis KW - Caenorhabditis elegans Proteins KW - Cell Nucleus KW - Chromosome Pairing KW - DNA Replication KW - Gonads KW - In Situ Hybridization, Fluorescence KW - Meiosis KW - Nuclear Envelope KW - Protein Transport KW - Receptors, Cytoplasmic and Nuclear KW - Recombination, Genetic AB - We identify a highly specific mutation (jf18) in the Caenorhabditis elegans nuclear envelope protein matefin MTF-1/SUN-1 that provides direct evidence for active involvement of the nuclear envelope in homologous chromosome pairing in C. elegans meiosis. The reorganization of chromatin in early meiosis is disrupted in mtf-1/sun-1(jf18) gonads, concomitant with the absence of presynaptic homolog alignment. Synapsis is established precociously and nonhomologously. Wild-type leptotene/zygotene nuclei show patch-like aggregations of the ZYG-12 protein, which fail to develop in mtf-1/sun-1(jf18) mutants. These patches remarkably colocalize with a component of the cis-acting chromosomal pairing center (HIM-8) rather than the centrosome. Our data on this mtf-1/sun-1 allele challenge the previously postulated role of the centrosome/spindle organizing center in chromosome pairing, and clearly support a role for MTF-1/SUN-1 in meiotic chromosome reorganization and in homolog recognition, possibly by mediating local aggregation of the ZYG-12 protein in meiotic nuclei. VL - 12 IS - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/17543861?dopt=Abstract ER - TY - JOUR T1 - Specific and conserved sequences in D. melanogaster and C. elegans lamins and histone H2A mediate the attachment of lamins to chromosomes. JF - J Cell Sci Y1 - 2007 A1 - Mattout, Anna A1 - Goldberg, Michal A1 - Tzur, Yonatan A1 - Margalit, Ayelet A1 - Gruenbaum, Yosef KW - Amino Acid Sequence KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Chromosomes KW - Conserved Sequence KW - Dimerization KW - Drosophila melanogaster KW - Drosophila Proteins KW - Evolution, Molecular KW - Histones KW - Interphase KW - Lamins KW - Molecular Sequence Data KW - Mutagenesis KW - Nuclear Envelope KW - Nuclear Localization Signals KW - Phosphorylation KW - Protein Structure, Tertiary AB - The intimate association between nuclear lamins and chromatin is thought to regulate higher order chromatin organization. Previous studies have mapped a region between the rod domain and the Ig fold in the tail domain of Drosophila melanogaster lamin Dm0, which binds chromatin in vitro via the histone H2A/H2B dimer. This region contains an evolutionarily conserved nuclear localization signal (NLS) KRKR, and a sequence composed of the amino acids TRAT. Here we show that binding of lamin Dm0 to chromatin requires both NLS and TRAT sequences. Substituting either of the threonine residues in the TRAT sequence with negatively charged residues decreases the binding of lamin Dm0 to chromatin, indicating that this binding could be regulated by phosphorylation. Both lamin Dm0 and C. elegans Ce-lamin bind directly to histone H2A in vitro and this binding requires the NLS. The amino and carboxyl tail domains of histone H2A are each essential, but not sufficient, for binding to lamin Dm0; only a polypeptide containing both histone H2A tail domains binds efficiently to lamin Dm0. Taken together, these results suggest that specific residues in lamin Dm0 and histone H2A mediate the attachment of the nuclear lamina to chromosomes in vivo, which could have implications on the understanding of laminopathic diseases. VL - 120 IS - Pt 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/17148572?dopt=Abstract ER - TY - JOUR T1 - High CO2 levels impair alveolar epithelial function independently of pH. JF - PLoS One Y1 - 2007 A1 - Briva, Arturo A1 - Vadász, István A1 - Lecuona, Emilia A1 - Welch, Lynn C A1 - Chen, Jiwang A1 - Dada, Laura A A1 - Trejo, Humberto E A1 - Dumasius, Vidas A1 - Azzam, Zaher S A1 - Myrianthefs, Pavlos M A1 - Batlle, Daniel A1 - Gruenbaum, Yosef A1 - Sznajder, Jacob I KW - Animals KW - Body Fluids KW - Carbon Monoxide KW - Epithelial Cells KW - Hydrogen-Ion Concentration KW - Male KW - Phosphorylation KW - Pulmonary Alveoli KW - Rats KW - Rats, Sprague-Dawley KW - Sodium-Potassium-Exchanging ATPase AB - BACKGROUND: In patients with acute respiratory failure, gas exchange is impaired due to the accumulation of fluid in the lung airspaces. This life-threatening syndrome is treated with mechanical ventilation, which is adjusted to maintain gas exchange, but can be associated with the accumulation of carbon dioxide in the lung. Carbon dioxide (CO2) is a by-product of cellular energy utilization and its elimination is affected via alveolar epithelial cells. Signaling pathways sensitive to changes in CO2 levels were described in plants and neuronal mammalian cells. However, it has not been fully elucidated whether non-neuronal cells sense and respond to CO2. The Na,K-ATPase consumes approximately 40% of the cellular metabolism to maintain cell homeostasis. Our study examines the effects of increased pCO2 on the epithelial Na,K-ATPase a major contributor to alveolar fluid reabsorption which is a marker of alveolar epithelial function. PRINCIPAL FINDINGS: We found that short-term increases in pCO2 impaired alveolar fluid reabsorption in rats. Also, we provide evidence that non-excitable, alveolar epithelial cells sense and respond to high levels of CO2, independently of extracellular and intracellular pH, by inhibiting Na,K-ATPase function, via activation of PKCzeta which phosphorylates the Na,K-ATPase, causing it to endocytose from the plasma membrane into intracellular pools. CONCLUSIONS: Our data suggest that alveolar epithelial cells, through which CO2 is eliminated in mammals, are highly sensitive to hypercapnia. Elevated CO2 levels impair alveolar epithelial function, independently of pH, which is relevant in patients with lung diseases and altered alveolar gas exchange. VL - 2 IS - 11 U1 - http://www.ncbi.nlm.nih.gov/pubmed/18043745?dopt=Abstract ER - TY - JOUR T1 - Live imaging of Caenorhabditis elegans: examples. JF - CSH Protoc Y1 - 2006 A1 - Podbilewicz, Benjamin A1 - Gruenbaum, Yosef VL - 2006 IS - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/22485977?dopt=Abstract ER - TY - JOUR T1 - Live imaging of Caenorhabditis elegans: observation of nematodes and data collection. JF - CSH Protoc Y1 - 2006 A1 - Podbilewicz, Benjamin A1 - Gruenbaum, Yosef VL - 2006 IS - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/22485976?dopt=Abstract ER - TY - JOUR T1 - Live Imaging of Caenorhabditis elegans: preparation of samples. JF - CSH Protoc Y1 - 2006 A1 - Podbilewicz, Benjamin A1 - Gruenbaum, Yosef AB - Caenorhabditis elegans, a small (adults are ~1 mm long), free-living soil nematode that feeds on bacteria, is an ideal organism for applying various live microscopy techniques. The organism is transparent, thus it is possible to microscopically analyze the whole animal throughout its entire life. Its complete cell lineage is known, making it possible to follow developmental and differentiation processes in real time. Furthermore, the development of transgenic techniques, as well as RNA interference (RNAi) methods and sophisticated genetic analyses, and the availability of a large collection of mutant lines all make C. elegans especially attractive for live microscopy. This protocol describes useful techniques for preparing C. elegans for live microscopic analysis. Details of sample preparation depend on the developmental stage of the worm to be studied. VL - 2006 IS - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/22485988?dopt=Abstract ER - TY - JOUR T1 - The nuclear lamina and its proposed roles in tumorigenesis: projection on the hematologic malignancies and future targeted therapy. JF - J Struct Biol Y1 - 2006 A1 - Prokocimer, Miron A1 - Margalit, Ayelet A1 - Gruenbaum, Yosef KW - Animals KW - Cell Nucleus KW - Chromatin KW - Hematologic Neoplasms KW - Humans KW - Lamins KW - Models, Biological KW - Nuclear Lamina AB - The nuclear lamina, a network of lamin filaments and lamin-associated proteins, is located between the inner nuclear membrane and the peripheral chromatin. The nuclear lamina is involved in numerous nuclear functions including maintaining nuclear shape, determining nuclear positioning, organizing chromatin and regulating the cell cycle, DNA replication, transcription, cell differentiation, apoptosis, and aging. Alterations in the composition of nuclear lamins and their associated proteins are currently emerging as an additional event involved in malignant transformation, tumor propagation and progression, thus identifying potential novel targets for future anti-cancer therapy. Here, we review the current knowledge on lamin expression patterns in cells of hematologic malignancies and give an overview on the roles of the nuclear lamina proteins in heterochromatin organization, apoptosis, and aging with special emphasis on the relevance in cancer development. VL - 155 IS - 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/16697219?dopt=Abstract ER - TY - JOUR T1 - Nuclear lamins, diseases and aging. JF - Curr Opin Cell Biol Y1 - 2006 A1 - Mattout, Anna A1 - Dechat, Thomas A1 - Adam, Stephen A A1 - Goldman, Robert D A1 - Gruenbaum, Yosef KW - Aging KW - Amino Acid Sequence KW - Animals KW - Cell Nucleus KW - Genetic Diseases, Inborn KW - Humans KW - Intermediate Filament Proteins KW - Lamin Type A KW - Lamins KW - Models, Biological KW - Models, Molecular KW - Molecular Sequence Data KW - Mutation AB - Nuclear lamins are type V intermediate filament proteins. They are the major building blocks of the peripheral nuclear lamina, a complex meshwork of proteins underlying the inner nuclear membrane. In addition to providing nuclear shape and mechanical stability, they are required for chromatin organization, transcription regulation, DNA replication, nuclear assembly and nuclear positioning. Over the past few years, interest in the lamins has increased because of the identification of at least 12 distinct human diseases associated with mutations in the LMNA gene, which encodes A-type lamins. These diseases, collectively termed laminopathies, affect muscle, adipose, bone, nerve and skin cells and range from muscular dystrophies to accelerated aging. VL - 18 IS - 3 U1 - http://www.ncbi.nlm.nih.gov/pubmed/16632339?dopt=Abstract ER - TY - JOUR T1 - Nuclear morphology: when round kernels do the Charleston. JF - Curr Biol Y1 - 2006 A1 - Melcer, Shai A1 - Gruenbaum, Yosef KW - Animals KW - Cell Nucleus KW - Drosophila KW - Drosophila Proteins KW - Gene Expression Regulation KW - Nuclear Envelope KW - Nuclear Proteins AB - New studies in Drosophila have identified a novel nuclear envelope protein with a farnesyl moiety, termed Kugelkern/Charleston, that helps regulate the size, shape and position of cellular blastoderm nuclei. VL - 16 IS - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/16546068?dopt=Abstract ER - TY - JOUR T1 - The cell nucleus taking centre stage. Workshop on the functional organization of the cell nucleus. JF - EMBO Rep Y1 - 2006 A1 - Gruenbaum, Yosef A1 - Raska, Ivan A1 - Harald Herrmann KW - Animals KW - Cell Line KW - Cell Nucleolus KW - Cell Nucleus KW - Chromatin Assembly and Disassembly KW - Chromosomes KW - Gene Expression Regulation KW - Humans KW - Regulatory Sequences, Nucleic Acid KW - Replication Origin KW - RNA KW - Spliceosomes VL - 7 IS - 12 U1 - http://www.ncbi.nlm.nih.gov/pubmed/17068488?dopt=Abstract ER - TY - JOUR T1 - Matefin/SUN-1 is a nuclear envelope receptor for CED-4 during Caenorhabditis elegans apoptosis. JF - Proc Natl Acad Sci U S A Y1 - 2006 A1 - Tzur, Yonatan B A1 - Margalit, Ayelet A1 - Melamed-Book, Naomi A1 - Gruenbaum, Yosef KW - Animals KW - Apoptosis KW - Apoptosis Regulatory Proteins KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Calcium-Binding Proteins KW - Caspases KW - Down-Regulation KW - Enzyme Activation KW - Helminth Proteins KW - Mitochondria KW - Nuclear Envelope KW - Proto-Oncogene Proteins KW - Proto-Oncogene Proteins c-bcl-2 KW - Receptors, Cytoplasmic and Nuclear KW - Repressor Proteins KW - RNA Interference AB - In Caenorhabditis elegans, the antiapoptotic protein CED-9 is localized at the mitochondria, where it binds the proapoptotic protein CED-4. Induction of apoptosis begins when the proapoptotic protein EGL-1 is expressed and binds CED-9. The binding of EGL-1 to CED-9 releases CED-4 from CED-9 and causes the activation of the caspase CED-3. Upon its release from CED-9, CED-4 rapidly translocates to the nuclear envelope (NE) in a CED-3-independent manner. However, the identity of the NE receptor for CED-4 and its possible role in the execution of apoptosis has remained unknown. Here, we show that the inner nuclear membrane SUN-domain protein matefin/SUN-1 is the NE receptor for CED-4. Our data demonstrate that matefin/SUN-1 binds CED-4 and is specifically required for CED-4 translocation and maintenance at the NE. The role of matefin/SUN-1 in the execution of apoptosis is further suggested by the significant reduction in the number of apoptotic cells in the organism after matefin/SUN-1 down-regulation by RNAi. The finding that matefin/SUN-1 is required for the execution of apoptosis adds an important link between cytoplasmic and nuclear apoptotic events. VL - 103 IS - 36 U1 - http://www.ncbi.nlm.nih.gov/pubmed/16938876?dopt=Abstract ER - TY - JOUR T1 - Solubility properties and specific assembly pathways of the B-type lamin from Caenorhabditis elegans. JF - J Struct Biol Y1 - 2006 A1 - Foeger, Nicole A1 - Wiesel, Naama A1 - Lotsch, Dorothee A1 - Mücke, Norbert A1 - Kreplak, Laurent A1 - Aebi, Ueli A1 - Gruenbaum, Yosef A1 - Harald Herrmann KW - Animals KW - Caenorhabditis elegans Proteins KW - Cell Nucleus KW - Dimerization KW - Intermediate Filament Proteins KW - Lamins KW - Microscopy, Atomic Force KW - Microscopy, Electron, Transmission KW - Solubility AB - Lamins are nucleus-specific intermediate filament (IF) proteins that together with a complex set of membrane proteins form a filamentous meshwork tightly adhering to the inner nuclear membrane and being associated with the nuclear pore complexes. This so-called nuclear lamina provides mechanical stability and, in addition, has been implicated in the spatial organization of the heterochromatin. While increasing knowledge on the biological function of lamins has been obtained in recent years, the assembly mechanism of lamin filaments at the molecular level has remained largely elusive. Therefore, we have now more systematically investigated lamin assembly in vitro. Using Caenorhabditis elegans lamin, which has been reported to assemble into 10-nm filaments under low ionic strength conditions, we investigated the assembly kinetics of this protein into filaments in more detail using both His-tagged and un-tagged recombinant proteins. In particular, we have characterized distinct intermediates in the filament assembly process by analytical ultracentrifugation, electron and atomic force microscopy. In contrast to the general view that lamins assemble only slowly into filaments, we show that in vitro association reactions are extremely fast, and depending on the ionic conditions employed, significant filamentous assemblies form within seconds. VL - 155 IS - 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/16713298?dopt=Abstract ER - TY - JOUR T1 - SUN-domain proteins: 'Velcro' that links the nucleoskeleton to the cytoskeleton. JF - Nat Rev Mol Cell Biol Y1 - 2006 A1 - Tzur, Yonatan B A1 - Wilson, Katherine L A1 - Gruenbaum, Yosef KW - Animals KW - Cytoskeleton KW - Forecasting KW - Models, Biological KW - Nuclear Envelope KW - Nuclear Proteins KW - Phylogeny KW - Protein Structure, Tertiary AB - The novel SUN-domain family of nuclear envelope proteins interacts with various KASH-domain partners to form SUN-domain-dependent 'bridges' across the inner and outer nuclear membranes. These bridges physically connect the nucleus to every major component of the cytoskeleton. SUN-domain proteins have diverse roles in nuclear positioning, centrosome localization, germ-cell development, telomere positioning and apoptosis. By serving both as mechanical adaptors and nuclear envelope receptors, we propose that SUN-domain proteins connect cytoplasmic and nucleoplasmic activities. VL - 7 IS - 10 U1 - http://www.ncbi.nlm.nih.gov/pubmed/16926857?dopt=Abstract ER - TY - JOUR T1 - The nuclear lamina comes of age. JF - Nat Rev Mol Cell Biol Y1 - 2005 A1 - Gruenbaum, Yosef A1 - Margalit, Ayelet A1 - Goldman, Robert D A1 - Shumaker, Dale K A1 - Wilson, Katherine L KW - Actins KW - Aging KW - Animals KW - Centrosome KW - Cytoskeleton KW - Humans KW - Lamins KW - Membrane Proteins KW - Muscular Dystrophies KW - Nuclear Lamina KW - Nuclear Proteins KW - Signal Transduction KW - Thymopoietins AB - Many nuclear proteins form lamin-dependent complexes, including LEM-domain proteins, nesprins and SUN-domain proteins. These complexes have roles in chromatin organization, gene regulation and signal transduction. Some link the nucleoskeleton to cytoskeletal structures, ensuring that the nucleus and centrosome assume appropriate intracellular positions. These complexes provide new insights into cell architecture, as well as a foundation for the understanding of the molecular mechanisms that underlie the human laminopathies - clinical disorders that range from Emery-Dreifuss muscular dystrophy to the accelerated ageing seen in Hutchinson-Gilford progeria syndrome. VL - 6 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/15688064?dopt=Abstract ER - TY - JOUR T1 - Age-related changes of nuclear architecture in Caenorhabditis elegans. JF - Proc Natl Acad Sci U S A Y1 - 2005 A1 - Haithcock, Erin A1 - Dayani, Yaron A1 - Neufeld, Ester A1 - Zahand, Adam J A1 - Feinstein, Naomi A1 - Mattout, Anna A1 - Gruenbaum, Yosef A1 - Liu, Jun KW - Aging KW - Animals KW - Animals, Genetically Modified KW - Blotting, Western KW - Caenorhabditis elegans KW - Insulin KW - Insulin-Like Growth Factor I KW - Microscopy, Electron, Transmission KW - Microscopy, Fluorescence KW - Nuclear Lamina KW - RNA Interference KW - Signal Transduction AB - Mutations in lamins cause premature aging syndromes in humans, including the Hutchinson-Gilford Progeria Syndrome (HGPS) and Atypical Werner Syndrome. It has been shown that HGPS cells in culture undergo age-dependent progressive changes in nuclear architecture. However, it is unknown whether similar changes in nuclear architecture occur during the normal aging process. We have observed that major changes of nuclear architecture accompany Caenorhabditis elegans aging. We found that the nuclear architecture in most nonneuronal cell types undergoes progressive and stochastic age-dependent alterations, such as changes of nuclear shape and loss of peripheral heterochromatin. Furthermore, we show that the rate of these alterations is influenced by the insulin/IGF-1 like signaling pathway and that reducing the level of lamin and lamin-associated LEM domain proteins leads to shortening of lifespan. Our work not only provides evidence for changes of nuclear architecture during the normal aging process of a multicellular organism, but also suggests that HGPS is likely a result of acceleration of the normal aging process. Because the nucleus is vital for many cellular functions, our studies raise the possibility that the nucleus is a prominent focal point for regulating aging. VL - 102 IS - 46 U1 - http://www.ncbi.nlm.nih.gov/pubmed/16269543?dopt=Abstract ER - TY - JOUR T1 - Barrier-to-autointegration factor is required to segregate and enclose chromosomes within the nuclear envelope and assemble the nuclear lamina. JF - Proc Natl Acad Sci U S A Y1 - 2005 A1 - Margalit, Ayelet A1 - Segura-Totten, Miriam A1 - Gruenbaum, Yosef A1 - Wilson, Katherine L KW - Amino Acid Sequence KW - Animals KW - Caenorhabditis elegans KW - Chromosomes KW - Fluorescent Antibody Technique, Indirect KW - Microscopy, Electron, Transmission KW - Molecular Sequence Data KW - RNA Interference KW - Sequence Homology, Amino Acid AB - Barrier-to-autointegration factor (BAF) binds dsDNA, LEM-domain proteins, and lamins. Caenorhabditis elegans BAF requires Ce-lamin and two LEM-domain proteins (Ce-emerin and Ce-MAN1) to localize during nuclear assembly. It was unknown whether Ce-lamin and LEM proteins, in turn, depend on Ce-BAF (mutually dependent structural roles). RNA interference-mediated down-regulation of Ce-BAF caused gross defects in chromosome segregation, chromatin decondensation, and mitotic progression as early as the two-cell stage, and embryos died at the approximately 100-cell stage. Nuclear pores reassembled, whereas Ce-lamin, Ce-emerin, and Ce-MAN1 bound chromatin but remained patchy and disorganized. The nuclear membranes formed but failed to enclose anaphase-bridged chromatin. Time-lapse imaging showed two phenotypes: anaphase-bridged chromatin that eventually resolved, and segregated chromatin that returned to the midzone. Thus, the assembly of BAF, lamins, and LEM-domain proteins is mutually dependent, and is required to capture segregated chromosomes within the nascent nuclear envelope. Embryos that escaped lethality by down-regulation of Ce-BAF grew into sterile adults with misplaced distal tip cells and gonads, further suggesting that mild postembryonic reductions in BAF disrupt tissue-specific functions. VL - 102 IS - 9 U1 - http://www.ncbi.nlm.nih.gov/pubmed/15728376?dopt=Abstract ER - TY - JOUR T1 - Breaking and making of the nuclear envelope. JF - J Cell Biochem Y1 - 2005 A1 - Margalit, Ayelet A1 - Vlcek, Sylvia A1 - Gruenbaum, Yosef A1 - Foisner, Roland KW - Animals KW - Cell Nucleus Division KW - Humans KW - Maturation-Promoting Factor KW - Mitosis KW - Nuclear Lamina KW - Nuclear Pore Complex Proteins AB - During mitosis, a single nucleus gives rise to two nuclei that are identical to the parent nucleus. Mitosis consists of a continuous sequence of events that must be carried out once and only once. Two such important events are the disassembly of the nuclear envelope (NE) during the first stages of mitosis, and its accurate reassembly during the last stages of mitosis. NE breakdown (NEBD) is initiated when maturation-promoting factor (MPF) enters the nucleus and starts phosphorylating nuclear pore complexes (NPCs) and nuclear lamina proteins, followed by NPC and lamina breakdown. Nuclear reassembly starts when nuclear membranes assemble onto the chromatin. This article focuses on the different models of NEBD and reassembly with emphasis on recent data. VL - 95 IS - 3 U1 - http://www.ncbi.nlm.nih.gov/pubmed/15832341?dopt=Abstract ER - TY - JOUR T1 - A lamin-dependent pathway that regulates nuclear organization, cell cycle progression and germ cell development. JF - Novartis Found Symp Y1 - 2005 A1 - Margalit, Ayelet A1 - Liu, Jun A1 - Fridkin, Alexandra A1 - Wilson, Katherine L A1 - Gruenbaum, Yosef KW - Animals KW - Cell Cycle KW - Germ Cells KW - Humans KW - Lamins KW - Muscular Dystrophy, Emery-Dreifuss KW - Nuclear Envelope KW - Nuclear Matrix KW - Nuclear Proteins KW - Signal Transduction AB - The C. elegans genome encodes a single lamin protein (Ce-lamin), three LEM domain proteins (Ce-emerin, Ce-MAN1 and LEM-3) and a single BAF protein (Ce-BAF). Down-regulation of Ce-lamin causes embryonic lethality. Abnormalities include rapid changes in nuclear morphology during interphase, inability of cells to complete mitosis, abnormal condensation of chromatin, clustering of nuclear pore complexes (NPCs), and missing or abnormal germ cells. Ce-emerin and Ce-MAN1 are both embedded in the inner nuclear membrane, and both bind Ce-lamin and Ce-BAF; in addition, both require Ce-lamin for their localization. Mutations in human emerin cause X-linked recessive Emery-Dreifuss muscular dystrophy. In C. elegans, loss of Ce-emerin alone has no detectable phenotype, while loss of 90% Ce-MAN1 causes approximately 15% embryonic lethality. However in worms that lack Ce-emerin, a approximately 90% reduction of Ce-MAN1 is lethal to all embryos by the 100-cell stage, with a phenotype involving chromatin condensation and repeated cycles of anaphase chromosome bridging and cytokinesis. The anaphase-bridged chromatin retained a mitosis-specific phosphohistone H3 epitope, and failed to recruit detectable Ce-lamin or Ce-BAF. Down-regulation of Ce-BAF showed similar phenotypes. These findings suggest that lamin, LEM-domain proteins and BAF are part of a lamina network essential for chromatin organization and cell division, and that Ce-emerin and Ce-MAN1 share at least one and possibly multiple overlapping functions, which may be relevant to Emery-Dreifuss muscular dystrophy. VL - 264 U1 - http://www.ncbi.nlm.nih.gov/pubmed/15773757?dopt=Abstract ER - TY - JOUR T1 - Accumulation of mutant lamin A causes progressive changes in nuclear architecture in Hutchinson-Gilford progeria syndrome. JF - Proc Natl Acad Sci U S A Y1 - 2004 A1 - Goldman, Robert D A1 - Shumaker, Dale K A1 - Erdos, Michael R A1 - Eriksson, Maria A1 - Goldman, Anne E A1 - Gordon, Leslie B A1 - Gruenbaum, Yosef A1 - Khuon, Satya A1 - Mendez, Melissa A1 - Varga, Renée A1 - Collins, Francis S KW - Aged KW - Aged, 80 and over KW - Aging KW - Cell Aging KW - Cell Cycle KW - Cell Nucleus KW - Cell Nucleus Structures KW - Female KW - Fibroblasts KW - Humans KW - Infant KW - Lamin Type A KW - Mitosis KW - Nuclear Envelope KW - Progeria KW - Sequence Deletion AB - Hutchinson-Gilford progeria syndrome (HGPS) is a premature aging disorder, commonly caused by a point mutation in the lamin A gene that results in a protein lacking 50 aa near the C terminus, denoted LADelta50. Here we show by light and electron microscopy that HGPS is associated with significant changes in nuclear shape, including lobulation of the nuclear envelope, thickening of the nuclear lamina, loss of peripheral heterochromatin, and clustering of nuclear pores. These structural defects worsen as HGPS cells age in culture, and their severity correlates with an apparent increase in LADelta50. Introduction of LADelta50 into normal cells by transfection or protein injection induces the same changes. We hypothesize that these alterations in nuclear structure are due to a concentration-dependent dominant-negative effect of LADelta50, leading to the disruption of lamin-related functions ranging from the maintenance of nuclear shape to regulation of gene expression and DNA replication. VL - 101 IS - 24 U1 - http://www.ncbi.nlm.nih.gov/pubmed/15184648?dopt=Abstract ER - TY - JOUR T1 - Intermediate filaments in Caenorhabditis elegans. JF - Methods Cell Biol Y1 - 2004 A1 - Fridkin, Alexandra A1 - Karabinos, Anton A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Cell Nucleus KW - Cytoplasm KW - Fluorescence Recovery After Photobleaching KW - Fluorescent Antibody Technique, Indirect KW - Intermediate Filaments KW - Lamins KW - Microscopy, Electron KW - Microscopy, Immunoelectron KW - Recombinant Proteins VL - 78 U1 - http://www.ncbi.nlm.nih.gov/pubmed/15646636?dopt=Abstract ER - TY - JOUR T1 - Matefin, a Caenorhabditis elegans germ line-specific SUN-domain nuclear membrane protein, is essential for early embryonic and germ cell development. JF - Proc Natl Acad Sci U S A Y1 - 2004 A1 - Fridkin, Alexandra A1 - Mills, Erez A1 - Margalit, Ayelet A1 - Neufeld, Esther A1 - Lee, Kenneth K A1 - Feinstein, Naomi A1 - Cohen, Merav A1 - Wilson, Katherine L A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Germ Cells KW - Lamins KW - Membrane Glycoproteins KW - Nuclear Envelope KW - Nuclear Proteins KW - Protein Structure, Tertiary KW - RNA Interference AB - Caenorhabditis elegans mtf-1 encodes matefin, which has a predicted SUN domain, a coiled-coil region, an anti-erbB-2 IgG domain, and two hydrophobic regions. We show that matefin is a nuclear membrane protein that colocalizes in vivo with Ce-lamin, the single nuclear lamin protein in C. elegans, and binds Ce-lamin in vitro but does not require Ce-lamin for its localization. Matefin is detected in all embryonic cells until midembryogenesis and thereafter only in germ-line cells. Embryonic matefin is maternally deposited, and matefin is the first nuclear membrane protein known to have germ line-restricted expression. Animals homozygous for an mtf-1 deletion allele show that matefin is essential for germ line maturation and survival. However, matefin is also required for embryogenesis because mtf-1 (RNAi) embryos die around the approximately 300-cell stage with defects in nuclear structure, DNA content, and chromatin morphology. Down-regulating matefin in mes-3 animals only slightly enhances embryonic lethality, and elimination of UNC-84, the only other SUN-domain gene in C. elegans, has no affect on mtf-1 (RNAi) animals. Thus, mtf-1 mediates a previously uncharacterized pathway(s) required for embryogenesis as well as germ line proliferation or survival. VL - 101 IS - 18 U1 - http://www.ncbi.nlm.nih.gov/pubmed/15100407?dopt=Abstract ER - TY - JOUR T1 - Dynamic interactions of nuclear lamina proteins with chromatin and transcriptional machinery. JF - Cell Mol Life Sci Y1 - 2003 A1 - Mattout-Drubezki, A A1 - Gruenbaum, Y KW - Animals KW - Chromatin KW - Gene Expression Regulation KW - Heterochromatin KW - Humans KW - Nuclear Lamina KW - Nuclear Proteins KW - RNA Polymerase II KW - Transcription, Genetic AB - The nuclear lamina is a filamentous nuclear structure intimately connected to the inner nuclear membrane. It is composed of lamins, which are also present in the nuclear interior, and lamin-associated proteins. The nuclear lamina is involved directly or indirectly in many nuclear activities, including DNA replication and transcription, nuclear and chromatin organization, cell cycle regulation, cell development and differentiation, nuclear migration and apoptosis. Mutations in nuclear lamina genes cause a wide range of heritable human diseases, the molecular mechanisms for which are not well understood. This review describes our current knowledge of interactions between nuclear lamina proteins and chromatin, chromatin-remodeling factors, specific transcription factors and RNA polymerase II transcription machinery. Recent studies provide new insights into the nature and regulation of these interactions and suggest additional roles for the nuclear lamina. VL - 60 IS - 10 U1 - http://www.ncbi.nlm.nih.gov/pubmed/14618255?dopt=Abstract ER - TY - JOUR T1 - MAN1 and emerin have overlapping function(s) essential for chromosome segregation and cell division in Caenorhabditis elegans. JF - Proc Natl Acad Sci U S A Y1 - 2003 A1 - Liu, Jun A1 - Lee, Kenneth K A1 - Segura-Totten, Miriam A1 - Neufeld, Ester A1 - Wilson, Katherine L A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Cell Division KW - Chromosome Segregation KW - DNA-Binding Proteins KW - Genes, Helminth KW - Humans KW - Membrane Proteins KW - Muscular Dystrophy, Emery-Dreifuss KW - Mutation KW - Nuclear Proteins KW - Phenotype KW - RNA Interference KW - Thymopoietins AB - Emerin and MAN1 are LEM domain-containing integral membrane proteins of the vertebrate nuclear envelope. The function of MAN1 is unknown, whereas emerin is known to interact with nuclear lamins, barrier-to-autointegration factor (BAF), nesprin-1 alpha, and a transcription repressor. Mutations in emerin cause X-linked recessive Emery-Dreifuss muscular dystrophy. Emerin and MAN1 homologs are both conserved in Caenorhabditis elegans, but loss of Ce-emerin has no detectable phenotype. We therefore used C. elegans to test the hypothesis that Ce-MAN1 overlaps functionally with Ce-emerin. Supporting this model, Ce-MAN1 interacted directly with Ce-lamin and Ce-BAF in vitro and required Ce-lamin for its nuclear envelope localization. Interestingly, RNA interference-mediated removal of approximately 90% of Ce-MAN1 was lethal to approximately 15% of embryos. However, in the absence of Ce-emerin, approximately 90% reduction of Ce-MAN1 was lethal to all embryos by the 100-cell stage, with a phenotype involving repeated cycles of anaphase chromosome bridging and cytokinesis ["cell untimely torn" (cut) phenotype]. Immunostaining showed that the anaphase-bridged chromatin specifically retained a mitosis-specific phosphohistone H3 epitope and failed to recruit detectable Ce-lamin or Ce-BAF. These findings show that LEM domain proteins are essential for cell division and that Ce-emerin and Ce-MAN1 share at least one and possibly multiple overlapping functions, which may be relevant to Emery-Dreifuss muscular dystrophy. VL - 100 IS - 8 U1 - http://www.ncbi.nlm.nih.gov/pubmed/12684533?dopt=Abstract ER - TY - JOUR T1 - The nuclear lamina and its functions in the nucleus. JF - Int Rev Cytol Y1 - 2003 A1 - Gruenbaum, Yosef A1 - Goldman, Robert D A1 - Meyuhas, Ronit A1 - Mills, Erez A1 - Margalit, Ayelet A1 - Fridkin, Alexandra A1 - Dayani, Yaron A1 - Prokocimer, Miron A1 - Enosh, Avital KW - Animals KW - Cell Nucleus KW - Genetic Diseases, Inborn KW - Humans KW - Nuclear Lamina KW - Nuclear Proteins AB - The nuclear lamina is a structure near the inner nuclear membrane and the peripheral chromatin. It is composed of lamins, which are also present in the nuclear interior, and lamin-associated proteins. The increasing number of proteins that interact with lamins and the compound interactions between these proteins and chromatin-associated proteins make the nuclear lamina a highly complex but also a very exciting structure. The nuclear lamina is an essential component of metazoan cells. It is involved in most nuclear activities including DNA replication, RNA transcription, nuclear and chromatin organization, cell cycle regulation, cell development and differentiation, nuclear migration, and apoptosis. Specific mutations in nuclear lamina genes cause a wide range of heritable human diseases. These diseases include Emery-Dreifuss muscular dystrophy, limb girdle muscular dystrophy, dilated cardiomyopathy (DCM) with conduction system disease, familial partial lipodystrophy (FPLD), autosomal recessive axonal neuropathy (Charcot-Marie-Tooth disorder type 2, CMT2), mandibuloacral dysplasia (MAD), Hutchison Gilford Progeria syndrome (HGS), Greenberg Skeletal Dysplasia, and Pelger-Huet anomaly (PHA). Genetic analyses in Caenorhabditis elegans, Drosophila, and mice show new insights into the functions of the nuclear lamina, and recent structural analyses have begun to unravel the molecular structure and assembly of lamins and their associated proteins. VL - 226 U1 - http://www.ncbi.nlm.nih.gov/pubmed/12921235?dopt=Abstract ER - TY - JOUR T1 - Nuclear pore protein gp210 is essential for viability in HeLa cells and Caenorhabditis elegans. JF - Mol Biol Cell Y1 - 2003 A1 - Cohen, Merav A1 - Feinstein, Naomi A1 - Wilson, Katherine L A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Cell Survival KW - Embryo, Nonmammalian KW - Fluorescent Antibody Technique, Indirect KW - HeLa Cells KW - Humans KW - Membrane Glycoproteins KW - Microscopy, Electron KW - Nuclear Envelope KW - Nuclear Pore KW - Nuclear Pore Complex Proteins KW - Nuclear Proteins KW - RNA, Small Interfering AB - Gp210 is an evolutionarily conserved membrane protein of the nuclear pore complex (NPC). We studied the phenotypes produced by RNAi-induced downregulation of gp210 in both human (HeLa) cells and Caenorhabditis elegans embryos. HeLa cell viability requires Gp210 activity. The dying cells accumulated clustered NPCs and aberrant membrane structures at the nuclear envelope, suggesting that gp210 is required directly or indirectly for nuclear pore formation and dilation as well as the anchoring or structural integrity of mature NPCs. Essential roles for gp210 were confirmed in C. elegans, where RNAi-induced reduction of gp210 caused embryonic lethality. The nuclear envelopes of embryos with reduced gp210 also had aberrant nuclear membrane structures and clustered NPCs, confirming that gp210 plays critical roles at the nuclear membrane through mechanisms that are conserved from nematodes to humans. VL - 14 IS - 10 U1 - http://www.ncbi.nlm.nih.gov/pubmed/14517331?dopt=Abstract ER - TY - JOUR T1 - Synchronization of interphase events depends neither on mitosis nor on cdk1. JF - Mol Biol Cell Y1 - 2003 A1 - Laronne, Ayelet A1 - Rotkopf, Shay A1 - Hellman, Asaf A1 - Gruenbaum, Yosef A1 - Porter, Andrew C G A1 - Brandeis, Michael KW - CDC2 Protein Kinase KW - Cdc20 Proteins KW - Cdh1 Proteins KW - Cell Cycle Proteins KW - Cells, Cultured KW - Centrosome KW - Chromosomes KW - Cyclin A KW - Cyclin A2 KW - Cyclin B KW - Cyclin B1 KW - Cyclin E KW - Humans KW - Interphase KW - Mitosis KW - Mutation KW - Nuclear Lamina KW - Nuclear Pore KW - Time Factors KW - Ubiquitin-Protein Ligase Complexes AB - Human HT2-19 cells with a conditional cdk1 mutation stop dividing upon cdk1 inactivation and undergo multiple rounds of endoreplication. We show herein that major cell cycle events remain synchronized in these endoreplicating cells. DNA replication alternates with gap phases and cell cycle-specific cyclin E expression is maintained. Centrosomes duplicate in synchrony with chromosome replication, giving rise to polyploid cells with multiple centrosomes. Centrosome migration, a typical prophase event, also takes place in endoreplicating cells. The timing of these events is unaffected by cdk1 inactivation compared with normally dividing cells. Nuclear lamina breakdown, in contrast, previously shown to be dependent on cdk1, does not take place in endoreplicating HT2-19 cells. Moreover, breakdown of all other major components of the nuclear lamina, like the inner nuclear membrane proteins and nuclear pore complexes, seems also to depend on cdk1. Interestingly, the APC/C ubiquitin ligase is activated in these endoreplicating cells by fzr but not by fzy. The oscillations of interphase events are thus independent of cdk1 and of mitosis but may depend on APC/Cfzr activity. VL - 14 IS - 9 U1 - http://www.ncbi.nlm.nih.gov/pubmed/12972560?dopt=Abstract ER - TY - JOUR T1 - The expression, lamin-dependent localization and RNAi depletion phenotype for emerin in C. elegans. JF - J Cell Sci Y1 - 2002 A1 - Gruenbaum, Yosef A1 - Lee, Kenneth K A1 - Liu, Jun A1 - Cohen, Merav A1 - Wilson, Katherine L KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Embryo, Nonmammalian KW - Gene Expression Regulation KW - Laminin KW - Membrane Glycoproteins KW - Membrane Proteins KW - Models, Animal KW - Muscular Dystrophy, Emery-Dreifuss KW - Mutation KW - Nuclear Envelope KW - Nuclear Pore Complex Proteins KW - Nuclear Proteins KW - Phenotype KW - RNA KW - Thymopoietins AB - Emerin belongs to the LEM-domain family of nuclear membrane proteins, which are conserved in metazoans from C. elegans to humans. Loss of emerin in humans causes the X-linked form of Emery-Dreifuss muscular dystrophy (EDMD), but the disease mechanism is not understood. We have begun to address the function of emerin in C. elegans, a genetically tractable nematode. The emerin gene (emr-1) is conserved in C. elegans. We detect Ce-emerin protein in the nuclear envelopes of all cell types except sperm, and find that Ce-emerin co-immunoprecipitates with Ce-lamin from embryo lysates. We show for the first time in any organism that nuclear lamins are essential for the nuclear envelope localization of emerin during early development. We further show that four other types of nuclear envelope proteins, including fellow LEM-domain protein Ce-MAN1, as well as Ce-lamin, UNC-84 and nucleoporins do not depend on Ce-emerin for their localization. This result suggests that emerin is not essential to organize or localize the only lamin (B-type) expressed in C. elegans. We also analyzed the RNAi phenotype resulting from the loss of emerin function in C. elegans under laboratory growth conditions, and found no detectable phenotype throughout development. We propose that C. elegans is an appropriate system in which to study the molecular mechanisms of emerin function in vivo. VL - 115 IS - Pt 5 U1 - http://www.ncbi.nlm.nih.gov/pubmed/11870211?dopt=Abstract ER - TY - JOUR T1 - Fate of the nuclear lamina during Caenorhabditis elegans apoptosis. JF - J Struct Biol Y1 - 2002 A1 - Tzur, Yonatan B A1 - Hersh, Bradley M A1 - Horvitz, H Robert A1 - Gruenbaum, Yosef KW - Animals KW - Apoptosis KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Caspases KW - Cell Nucleus KW - Fluorescent Antibody Technique, Indirect KW - In Situ Nick-End Labeling KW - Lamins KW - Membrane Proteins KW - Nuclear Lamina KW - Nuclear Proteins KW - Plasmids KW - Protein Binding AB - Invertebrates and in Drosophila, lamins and lamin-associated proteins are primary targets for cleavage by caspases. Eliminating mammalian lamins causes apoptosis, whereas expressing mutant lamins that cannot be cleaved by caspase-6 delay apoptosis. Caenorhabditis elegans has a single lamin protein, Ce-lamin, and a caspase, CED-3, that is responsible for most if not all somatic apoptosis. In this study we show that in C. elegans embryos induced to undergo apoptosis Ce-lamin is degraded surprisingly late. In such embryos CED-4 translocated to the nuclear envelope but the cytological localization of Ce-lamin remained similar to that in wild-type embryos. TUNEL labeling indicated that Ce-lamin was degraded only after DNA is fragmented. Ce-lamin, Ce-emerin, or Ce-MAN1 were not cleaved by recombinant CED-3, showing that these lamina proteins are not substrates for CED-3 cleavage. These results suggest that lamin cleavage probably is not essential for apoptosis in C. elegans. VL - 137 IS - 1-2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/12064941?dopt=Abstract ER - TY - JOUR T1 - Ferritin expression modulates cell cycle dynamics and cell responsiveness to H-ras-induced growth via expansion of the labile iron pool. JF - Biochem J Y1 - 2002 A1 - Kakhlon, Or A1 - Gruenbaum, Yosef A1 - Cabantchik, Z Ioav KW - Animals KW - Cell Cycle KW - Cell Division KW - Cyclin A KW - Ferritins KW - Gene Expression Regulation KW - Genes, ras KW - Humans KW - Iron KW - K562 Cells KW - Mice KW - Transfection AB - Repression or overexpression of ferritin accelerated or retarded cell cycling respectively, via changes in the cellular labile iron pool (LIP). A rise in LIP is caused by ferritin repression enhanced growth, induced by H-ras, and reverted growth arrest is induced by dominant negative H-ras. The studies indicate that repression of ferritin expression provides a mechanism by which certain oncogenes lead to cell growth stimulation. VL - 363 IS - Pt 3 U1 - http://www.ncbi.nlm.nih.gov/pubmed/11964143?dopt=Abstract ER - TY - JOUR T1 - Gbx2 interacts with Otx2 and patterns the anterior-posterior axis during gastrulation in Xenopus. JF - Mech Dev Y1 - 2002 A1 - Tour, Ella A1 - Pillemer, Graciela A1 - Gruenbaum, Yosef A1 - Fainsod, Abraham KW - Animals KW - Gastrula KW - Gene Expression Regulation, Developmental KW - Homeodomain Proteins KW - In Situ Hybridization KW - Nerve Tissue Proteins KW - Otx Transcription Factors KW - Protein Binding KW - Protein Structure, Tertiary KW - Time Factors KW - Trans-Activators KW - Transcription, Genetic KW - Xenopus KW - Xenopus laevis KW - Xenopus Proteins AB - Anterior-posterior patterning of the embryo requires the activity of multiple homeobox genes among them Hox, caudal (Cdx, Xcad) and Otx2. During early gastrulation, Otx2 and Xcad2 establish a cross-regulatory network, which is an early event in the anterior-posterior patterning of the embryo. As gastrulation proceeds and the embryo elongates, a new domain forms, which expresses neither, Otx2 nor Xcad2 genes. Early transcription of the Xenopus Gbx2 homologue, Xgbx2a, is spatially restricted between Otx2 and Xcad2. When overexpressed, Otx2 and Xcad2 repress Xgbx2a transcription, suggesting their role in setting the early Xgbx2a expression domain. Homeobox genes have been shown to play crucial roles in the specification of the vertebrate brain. The border between the transcription domains of Otx2 and Gbx2 is the earliest known marker of the region where the midbrain/hindbrain boundary (MHB) organizer will develop. Xgbx2a is a negative regulator of Otx2 and a weak positive regulator of Xcad2. Using obligatory activator and repressor versions of Xgbx2a, we demonstrate that, during early embryogenesis, Xgbx2a acts as a transcriptional repressor. In addition, taking advantage of hormone-inducible versions of Xgbx2a and its antimorph, we show that the ability of Xgbx2a to induce head malformations is restricted to gastrula stages and correlates with its ability to repress Otx2 during the same developmental stages. We therefore suggest that the earliest known step of the MHB formation, the establishment of Otx2/Gbx2 boundary, takes place via mutual inhibitory interactions between these two genes and this process begins as early as at midgastrulation. VL - 112 IS - 1-2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/11850185?dopt=Abstract ER - TY - JOUR T1 - Lamin-dependent localization of UNC-84, a protein required for nuclear migration in Caenorhabditis elegans. JF - Mol Biol Cell Y1 - 2002 A1 - Lee, Kenneth K A1 - Starr, Daniel A1 - Cohen, Merav A1 - Liu, Jun A1 - Han, Min A1 - Wilson, Katherine L A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Centrosome KW - Gene Expression Regulation, Developmental KW - Helminth Proteins KW - Lamins KW - Membrane Glycoproteins KW - Membrane Proteins KW - Mitosis KW - Models, Biological KW - Nuclear Envelope KW - Nuclear Pore Complex Proteins KW - Nuclear Proteins KW - Recombinant Fusion Proteins KW - Thymopoietins AB - Mutations in the Caenorhabditis elegans unc-84 gene cause defects in nuclear migration and anchoring. We show that endogenous UNC-84 protein colocalizes with Ce-lamin at the nuclear envelope and that the envelope localization of UNC-84 requires Ce-lamin. We also show that during mitosis, UNC-84 remains at the nuclear periphery until late anaphase, similar to known inner nuclear membrane proteins. UNC-84 protein is first detected at the 26-cell stage and thereafter is present in most cells during development and in adults. UNC-84 is properly expressed in unc-83 and anc-1 lines, which have phenotypes similar to unc-84, suggesting that neither the expression nor nuclear envelope localization of UNC-84 depends on UNC-83 or ANC-1 proteins. The envelope localization of Ce-lamin, Ce-emerin, Ce-MAN1, and nucleoporins are unaffected by the loss of UNC-84. UNC-84 is not required for centrosome attachment to the nucleus because centrosomes are localized normally in unc-84 hyp7 cells despite a nuclear migration defect. Models for UNC-84 localization are discussed. VL - 13 IS - 3 U1 - http://www.ncbi.nlm.nih.gov/pubmed/11907270?dopt=Abstract ER - TY - JOUR T1 - Nuclear lamins: building blocks of nuclear architecture. JF - Genes Dev Y1 - 2002 A1 - Goldman, Robert D A1 - Gruenbaum, Yosef A1 - Moir, Robert D A1 - Shumaker, Dale K A1 - Spann, Timothy P KW - Cardiomyopathy, Dilated KW - Cell Cycle KW - Cell Nucleus KW - DNA Replication KW - Humans KW - Lamins KW - Lipodystrophy KW - Muscular Dystrophies KW - Nuclear Envelope KW - Nuclear Proteins VL - 16 IS - 5 U1 - http://www.ncbi.nlm.nih.gov/pubmed/11877373?dopt=Abstract ER - TY - JOUR T1 - Otx2 can activate the isthmic organizer genetic network in the Xenopus embryo. JF - Mech Dev Y1 - 2002 A1 - Tour, Ella A1 - Pillemer, Graciela A1 - Gruenbaum, Yosef A1 - Fainsod, Abraham KW - Animals KW - Animals, Genetically Modified KW - Body Patterning KW - Ectoderm KW - Embryonic Induction KW - Gene Dosage KW - Gene Expression Regulation, Developmental KW - Genes, Homeobox KW - Homeodomain Proteins KW - In Situ Hybridization KW - Lac Operon KW - Mesencephalon KW - Nerve Tissue Proteins KW - Organizers, Embryonic KW - Otx Transcription Factors KW - Rhombencephalon KW - Trans-Activators KW - Xenopus laevis KW - Xenopus Proteins AB - Development and differentiation of the vertebrate caudal midbrain and anterior hindbrain are dependent on the isthmic organizer signals at the midbrain/hindbrain boundary (MHB). The future MHB forms at the boundary between the Otx2 and Gbx2 expression domains. Recent studies in mice and chick suggested that the apposition of Otx2- and Gbx2-expressing cells is instrumental for the positioning and early induction of the MHB genetic cascade. We show that Otx2 and Gbx2 perform different roles in this process. We find that ectopically expressed Otx2 on its own can induce a substantial part of the MHB genetic network, namely En2, Wnt1, Pax-2, Fgf8 and Gbx2, in a concentration-dependent manner. This induction does not require protein synthesis and ends during neurulation. In contrast, Gbx2 is a negative regulator of Otx2 and the MHB genes. Based on the temporal patterns of expression of the genes involved, we propose that Otx2 might be the early inducer of the isthmic organizer genetic network while Gbx2 restricts Otx2 expression along the anterior-posterior axis and establishes an Otx2 gradient. VL - 110 IS - 1-2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/11744364?dopt=Abstract ER - TY - JOUR T1 - Repression of ferritin expression modulates cell responsiveness to H-ras-induced growth. JF - Biochem Soc Trans Y1 - 2002 A1 - Kakhlon, O A1 - Gruenbaum, Y A1 - Cabantchik, Z I KW - Cell Division KW - Cell Line KW - Ferritins KW - Gene Expression Regulation KW - Genes, ras KW - Genetic Vectors KW - Humans KW - Iron KW - K562 Cells KW - Protein Subunits KW - ras Proteins KW - Recombinant Proteins KW - Transfection AB - We assessed the role of the cell labile iron pool in mediating oncogene-induced cell proliferation via repression of ferritin expression. When HEK-293 cells, engineered to inducibly express either active (+) or dominant-negative (-) forms of the H-ras oncogene, were treated with antisense nucleotides to ferritin subunits they displayed (a) decreased ferritin levels, (b) increased labile iron pool and either (c) faster growth in cells induced to express H-Ras (+) or (d) recovery from growth retardation in dominant-negative H-Ras-induced cells. Our studies support the view that the role of down-modulation of ferritin expression by some oncogene-evoked proliferation proceeds via expansion of the cellular labile iron pool. VL - 30 IS - 4 U1 - http://www.ncbi.nlm.nih.gov/pubmed/12196194?dopt=Abstract ER - TY - JOUR T1 - Transmission electron microscope studies of the nuclear envelope in Caenorhabditis elegans embryos. JF - J Struct Biol Y1 - 2002 A1 - Cohen, Merav A1 - Tzur, Yonatan B A1 - Neufeld, Esther A1 - Feinstein, Naomi A1 - Delannoy, Michael R A1 - Wilson, Katherine L A1 - Gruenbaum, Yosef KW - Animals KW - Caenorhabditis elegans KW - Cell Death KW - Cell Nucleus KW - Immunohistochemistry KW - Lamins KW - Membrane Proteins KW - Microscopy, Electron KW - Microscopy, Immunoelectron KW - Nuclear Envelope KW - Nuclear Lamina KW - Nuclear Proteins KW - RNA Interference KW - Thymopoietins AB - Nuclear membranes and nuclear pore complexes (NPCs) are conserved in both animals and plants. However, the lamina composition and the dimensions of NPCs vary between plants, yeast, and vertebrates. In this study, we established a protocol that preserves the structure of Caenorhabditis elegans embryonic cells for high-resolution studies with thin-section transmission electron microscopy (TEM). We show that the NPCs are bigger in C. elegans embryos than in yeast, with dimensions similar to those in higher eukaryotes. We also localized the C. elegans nuclear envelope proteins Ce-lamin and Ce-emerin by pre-embedding gold labeling immunoelectron microscopy. Both proteins are present at or near the inner nuclear membrane. A fraction of Ce-lamin, but not Ce-emerin, is present in the nuclear interior. Removing the nuclear membranes leaves both Ce-lamin and Ce-emerin associated with the chromatin. Eliminating the single lamin protein caused cell death as visualized by characteristic changes in nuclear architecture including condensation of chromatin, clustering of NPCs, membrane blebbing, and the presence of vesicles inside the nucleus. Taken together, these results show evolutionarily conserved protein localization, interactions, and functions of the C. elegans nuclear envelope. VL - 140 IS - 1-3 U1 - http://www.ncbi.nlm.nih.gov/pubmed/12490171?dopt=Abstract ER - TY - JOUR T1 - Problems with LAP nomenclature. JF - Nat Cell Biol Y1 - 2001 A1 - Wilson, K L A1 - Benavente, R A1 - Burke, B A1 - Craigie, R A1 - Foisner, R A1 - Furukawa, K A1 - Gerace, L A1 - Goldman, R D A1 - Gruenbaum, Y A1 - Harris, C A1 - Hutchison, C J A1 - Krohne, G A1 - Morris, G E A1 - Otto, H A1 - Simon, A J A1 - Worman, H J KW - Leucine KW - Membrane Proteins KW - Nuclear Proteins KW - Proteins KW - Terminology as Topic VL - 3 IS - 4 U1 - http://www.ncbi.nlm.nih.gov/pubmed/11283624?dopt=Abstract ER - TY - JOUR T1 - Repression of ferritin expression increases the labile iron pool, oxidative stress, and short-term growth of human erythroleukemia cells. JF - Blood Y1 - 2001 A1 - Kakhlon, O A1 - Gruenbaum, Y A1 - Cabantchik, Z I KW - Cell Division KW - Ferritins KW - Humans KW - Iron KW - K562 Cells KW - Leukemia, Erythroblastic, Acute KW - Oxidative Stress AB - The role of ferritin expression on the labile iron pool of cells and its implications for the control of cell proliferation were assessed. Antisense oligodeoxynucleotides were used as tools for modulating the expression of heavy and light ferritin subunits of K562 cells. mRNA and protein levels of each subunit were markedly reduced by 2-day treatment with antisense probes against the respective subunit. Although the combined action of antisense probes against both subunits reduced their protein expression, antisense repression of one subunit led to an increased protein expression of the other. Antisense treatment led to a rise in the steady-state labile iron pool, a rise in the production of reactive oxygen species after pro-oxidative challenges and in protein oxidation, and the down-regulation of transferrin receptors. When compared to the repression of individual subunits, co-repression of each subunit evoked a more than additive increase in the labile iron pool and the extent of protein oxidation. These treatments had no detectable effects on the long-term growth of cells. However, repression of ferritin synthesis facilitated the renewal of growth and the proliferation of cells pre-arrested at the G(1)/S phase. Renewed cell growth was significantly less dependent on external iron supply when ferritin synthesis was repressed and its degradation inhibited by lysosomal antiproteases. This study provides experimental evidence that links the effect of ferritin repression on growth stimulation to the expansion of the labile iron pool. VL - 97 IS - 9 U1 - http://www.ncbi.nlm.nih.gov/pubmed/11313282?dopt=Abstract ER - TY - JOUR T1 - Transcriptional repression, apoptosis, human disease and the functional evolution of the nuclear lamina. JF - Trends Biochem Sci Y1 - 2001 A1 - Cohen, M A1 - Lee, K K A1 - Wilson, K L A1 - Gruenbaum, Y KW - Animals KW - Apoptosis KW - Cell Nucleus Structures KW - Eukaryota KW - Evolution, Molecular KW - Gene Expression Regulation KW - Genetic Diseases, Inborn KW - Heterochromatin KW - Humans KW - Intracellular Membranes KW - Lamins KW - Muscular Dystrophy, Emery-Dreifuss KW - Nuclear Proteins KW - Transcription, Genetic AB - The number and complexity of genes encoding nuclear lamina proteins has increased during metazoan evolution. Emerging evidence reveals that transcriptional repressors such as the retinoblastoma protein, and apoptotic regulators such as CED-4, have functional and dynamic interactions with the lamina. The discovery that mutations in nuclear lamina proteins cause heritable tissue-specific diseases, including Emery-Dreifuss muscular dystrophy, is prompting a fresh look at the nuclear lamina to devise models that can account for its diverse functions and dynamics, and to understand its enigmatic structure. VL - 26 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/11165516?dopt=Abstract ER - TY - JOUR T1 - Repression of the heavy ferritin chain increases the labile iron pool of human K562 cells. JF - Biochem J Y1 - 2001 A1 - Kakhlon, O A1 - Gruenbaum, Y A1 - Cabantchik, Z I KW - Base Sequence KW - DNA Primers KW - DNA, Antisense KW - Ferritins KW - Humans KW - Iron KW - K562 Cells KW - Protein Subunits KW - Reactive Oxygen Species KW - Receptors, Transferrin KW - RNA, Messenger KW - Transfection AB - The role of ferritin in the modulation of the labile iron pool was examined by repressing the heavy subunit of ferritin in K562 cells transfected with an antisense construct. Repression of the heavy ferritin subunit evoked an increase in the chemical levels and pro-oxidant activity of the labile iron pool and, in turn, caused a reduced expression of transferrin receptors and increased expression of the light ferritin subunit. VL - 356 IS - Pt 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/11368756?dopt=Abstract ER - TY - JOUR T1 - The two Xenopus Gbx2 genes exhibit similar, but not identical expression patterns and can affect head formation. JF - FEBS Lett Y1 - 2001 A1 - Tour, E A1 - Pillemer, G A1 - Gruenbaum, Y A1 - Fainsod, A KW - Amino Acid Sequence KW - Animals KW - Cloning, Molecular KW - Gene Expression KW - Gene Expression Profiling KW - Head KW - Homeodomain Proteins KW - Molecular Sequence Data KW - Morphogenesis KW - Protein Isoforms KW - Xenopus laevis KW - Xenopus Proteins AB - Gbx2 homeobox genes are important for formation and function of the midbrain/hindbrain boundary, namely the isthmic organizer. Two Gbx2 genes were identified in Xenopus laevis, differing in 13 amino acids, including a change in the homeodomain. Xgbx2a is activated earlier during gastrulation and reaches higher levels of expression while Xgbx2b is expressed later, at lower levels and has an additional domain in the ventral blood islands. Their overexpression results in microcephalic embryos with shortened axes and defects in brain and notochord formation. Both genes encode functionally homologous proteins, which differ primarily in their temporal and spatial expression patterns. VL - 507 IS - 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/11684099?dopt=Abstract ER - TY - JOUR T1 - C. elegans nuclear envelope proteins emerin, MAN1, lamin, and nucleoporins reveal unique timing of nuclear envelope breakdown during mitosis. JF - Mol Biol Cell Y1 - 2000 A1 - Lee, K K A1 - Gruenbaum, Y A1 - Spann, P A1 - Liu, J A1 - Wilson, K L KW - Amino Acid Sequence KW - Animals KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Cell Cycle KW - Embryo, Nonmammalian KW - Humans KW - Lamins KW - Membrane Proteins KW - Metaphase KW - Mitosis KW - Molecular Sequence Data KW - Nuclear Envelope KW - Nuclear Pore KW - Nuclear Proteins KW - Sequence Alignment KW - Sequence Homology, Amino Acid KW - Thymopoietins AB - Emerin, MAN1, and LAP2 are integral membrane proteins of the vertebrate nuclear envelope. They share a 43-residue N-terminal motif termed the LEM domain. We found three putative LEM domain genes in Caenorhabditis elegans, designated emr-1, lem-2, and lem-3. We analyzed emr-l, which encodes Ce-emerin, and lem-2, which encodes Ce-MAN1. Ce-emerin and Ce-MAN1 migrate on SDS-PAGE as 17- and 52-kDa proteins, respectively. Based on their biochemical extraction properties and immunolocalization, both Ce-emerin and Ce-MAN1 are integral membrane proteins localized at the nuclear envelope. We used antibodies against Ce-MAN1, Ce-emerin, nucleoporins, and Ce-lamin to determine the timing of nuclear envelope breakdown during mitosis in C. elegans. The C. elegans nuclear envelope disassembles very late compared with vertebrates and Drosophila. The nuclear membranes remained intact everywhere except near spindle poles during metaphase and early anaphase, fully disassembling only during mid-late anaphase. Disassembly of pore complexes, and to a lesser extent the lamina, depended on embryo age: pore complexes were absent during metaphase in >30-cell embryos but existed until anaphase in 2- to 24-cell embryos. Intranuclear mRNA splicing factors disassembled after prophase. The timing of nuclear disassembly in C. elegans is novel and may reflect its evolutionary position between unicellular and more complex eukaryotes. VL - 11 IS - 9 U1 - http://www.ncbi.nlm.nih.gov/pubmed/10982402?dopt=Abstract ER - TY - JOUR T1 - Essential roles for Caenorhabditis elegans lamin gene in nuclear organization, cell cycle progression, and spatial organization of nuclear pore complexes. JF - Mol Biol Cell Y1 - 2000 A1 - Liu, J A1 - Rolef Ben-Shahar, T A1 - Riemer, D A1 - Treinin, M A1 - Spann, P A1 - Weber, K A1 - Fire, A A1 - Gruenbaum, Y KW - Animals KW - Animals, Genetically Modified KW - Caenorhabditis elegans KW - Cell Cycle KW - Cell Nucleus Structures KW - Embryo, Nonmammalian KW - Gene Dosage KW - Gene Expression Regulation, Developmental KW - Germ Cells KW - Lamins KW - Male KW - Nuclear Envelope KW - Nuclear Proteins AB - Caenorhabditis elegans has a single lamin gene, designated lmn-1 (previously termed CeLam-1). Antibodies raised against the lmn-1 product (Ce-lamin) detected a 64-kDa nuclear envelope protein. Ce-lamin was detected in the nuclear periphery of all cells except sperm and was found in the nuclear interior in embryonic cells and in a fraction of adult cells. Reductions in the amount of Ce-lamin protein produce embryonic lethality. Although the majority of affected embryos survive to produce several hundred nuclei, defects can be detected as early as the first nuclear divisions. Abnormalities include rapid changes in nuclear morphology during interphase, loss of chromosomes, unequal separation of chromosomes into daughter nuclei, abnormal condensation of chromatin, an increase in DNA content, and abnormal distribution of nuclear pore complexes (NPCs). Under conditions of incomplete RNA interference, a fraction of embryos escaped embryonic arrest and continue to develop through larval life. These animals exhibit additional phenotypes including sterility and defective segregation of chromosomes in germ cells. Our observations show that lmn-1 is an essential gene in C. elegans, and that the nuclear lamins are involved in chromatin organization, cell cycle progression, chromosome segregation, and correct spacing of NPCs. VL - 11 IS - 11 U1 - http://www.ncbi.nlm.nih.gov/pubmed/11071918?dopt=Abstract ER - TY - JOUR T1 - Review: nuclear lamins--structural proteins with fundamental functions. JF - J Struct Biol Y1 - 2000 A1 - Gruenbaum, Y A1 - Wilson, K L A1 - Harel, A A1 - Goldberg, M A1 - Cohen, M KW - Animals KW - Apoptosis KW - Cell Differentiation KW - Cell Nucleus KW - Chromatin KW - DNA Replication KW - Genetic Diseases, Inborn KW - Humans KW - Lamins KW - Mutation KW - Nuclear Envelope KW - Nuclear Proteins AB - The nuclear lamina is located between the inner nuclear membrane and the peripheral chromatin. It is composed of both peripheral and integral membrane proteins, including lamins and lamina-associated proteins. Lamins can interact with one another, with lamina-associated proteins, with nuclear scaffold proteins, and with chromatin. Likewise, most of the lamina-associated proteins are likely to interact directly with chromatin. The nuclear lamina is required for proper cell cycle regulation, chromatin organization, DNA replication, cell differentiation, and apoptosis. Mutations in proteins of the nuclear lamina can disrupt these activities and cause genetic diseases. The structure and assembly of the nuclear lamina proteins and their roles in chromatin organization and cell cycle regulation were recently reviewed. In this review, we discuss the roles of the nuclear lamina in DNA replication and apoptosis and analyze how mutations in nuclear lamina proteins might cause genetic diseases. VL - 129 IS - 2-3 U1 - http://www.ncbi.nlm.nih.gov/pubmed/10806082?dopt=Abstract ER - TY - JOUR T1 - Translocation of C. elegans CED-4 to nuclear membranes during programmed cell death. JF - Science Y1 - 2000 A1 - Chen, F A1 - Hersh, B M A1 - Conradt, B A1 - Zhou, Z A1 - Riemer, D A1 - Gruenbaum, Y A1 - Horvitz, H R KW - Amino Acid Substitution KW - Animals KW - Animals, Genetically Modified KW - Apoptosis KW - Apoptosis Regulatory Proteins KW - Caenorhabditis elegans KW - Caenorhabditis elegans Proteins KW - Calcium-Binding Proteins KW - Caspases KW - Cysteine Endopeptidases KW - Genes, Helminth KW - Helminth Proteins KW - Immunohistochemistry KW - Mitochondria KW - Mutation KW - Nuclear Envelope KW - Phenotype KW - Proto-Oncogene Proteins KW - Proto-Oncogene Proteins c-bcl-2 KW - Repressor Proteins AB - The Caenorhabditis elegans Bcl-2-like protein CED-9 prevents programmed cell death by antagonizing the Apaf-1-like cell-death activator CED-4. Endogenous CED-9 and CED-4 proteins localized to mitochondria in wild-type embryos, in which most cells survive. By contrast, in embryos in which cells had been induced to die, CED-4 assumed a perinuclear localization. CED-4 translocation induced by the cell-death activator EGL-1 was blocked by a gain-of-function mutation in ced-9 but was not dependent on ced-3 function, suggesting that CED-4 translocation precedes caspase activation and the execution phase of programmed cell death. Thus, a change in the subcellular localization of CED-4 may drive programmed cell death. VL - 287 IS - 5457 U1 - http://www.ncbi.nlm.nih.gov/pubmed/10688797?dopt=Abstract ER - TY - JOUR T1 - The tail domain of lamin Dm0 binds histones H2A and H2B. JF - Proc Natl Acad Sci U S A Y1 - 1999 A1 - Goldberg, M A1 - Harel, A A1 - Brandeis, M A1 - Rechsteiner, T A1 - Richmond, T J A1 - Weiss, A M A1 - Gruenbaum, Y KW - Amino Acid Sequence KW - Animals KW - Binding Sites KW - Drosophila KW - Drosophila Proteins KW - Histones KW - Lamins KW - Molecular Sequence Data KW - Nuclear Proteins KW - Protein Binding KW - Sequence Deletion AB - In multicellular organisms, the higher order organization of chromatin during interphase and the reassembly of the nuclear envelope during mitosis are thought to involve an interaction between the nuclear lamina and chromatin. The nuclear distribution of lamins and of peripheral chromatin is highly correlated in vivo, and lamins bind specifically to chromatin in vitro. Deletion mutants of Drosophila lamin Dm0 were expressed to map regions of the protein that are required for its binding to chromosomes. The binding activity requires two regions in the lamin Dm0 tail domain. The apparent Kd of binding of the lamin Dm0 tail domain was found to be approximately 1 microM. Chromatin subfractions were examined to search for possible target molecules for the binding of lamin Dm0. Isolated polynucleosomes, nucleosomes, histone octamer, histone H2A/H2B dimer, and histones H2A or H2B displaced the binding of lamin Dm0 tail to chromosomes. This displacement was specific, because polyamines or proteins such as histones H1, H3, or H4 did not displace the binding of the lamin Dm0 tail to chromosomes. In addition, DNA sequences, including M/SARs, did not interfere with the binding of lamin Dm0 tail domain to chromosomes. Taken together, these results suggest that the interaction between the tail domain of lamin Dm0 and histones H2A and H2B may mediate the attachment of the nuclear lamina to chromosomes in vivo. VL - 96 IS - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/10077600?dopt=Abstract ER - TY - JOUR T1 - Improved protocol for using avian red blood cells as substrates for the polymerase chain reaction. JF - Biotechniques Y1 - 1999 A1 - Bercovich, D A1 - Plotsky, Y A1 - Gruenbaum, Y KW - Alleles KW - Animals KW - Avian Proteins KW - Cell Nucleus KW - Chickens KW - DNA KW - DNA Primers KW - Enzyme Activation KW - Erythrocytes KW - Homeodomain Proteins KW - Polymerase Chain Reaction KW - Substrate Specificity KW - Taq Polymerase VL - 26 IS - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/10376145?dopt=Abstract ER - TY - JOUR T1 - The nuclear lamina: molecular organization and interaction with chromatin. JF - Crit Rev Eukaryot Gene Expr Y1 - 1999 A1 - Goldberg, M A1 - Harel, A A1 - Gruenbaum, Y KW - Animals KW - Cell Nucleus KW - Chromatin KW - Humans KW - Lamin Type B KW - Lamins KW - Nuclear Proteins AB - The nuclear lamina is located between the inner nuclear membrane and the peripheral chromatin. It is composed mainly of nuclear lamins and lamina-associated proteins. The nuclear lamina is involved in nuclear organization, cell cycle regulation, and differentiation. As such, impairment in its architecture and/or function leads to genetic diseases and apoptosis. This article describes the molecular organization of the nuclear lamins, their assembly into filaments, their distribution within the nucleus, and the complex network of interactions between them and other proteins of the inner nuclear membrane. Recent findings unraveled evidence for specific interactions between proteins of the nuclear lamina and the chromatin. These include interactions between nuclear lamins and core histones, Lamina Associated Polypeptide 2 (LAP2), and the Barrier to Autointegration Factor (BAF) and interactions between lamin B receptor (LBR) and the chromodomain protein HP1. Taken together, these studies attribute a role for both the nuclear lamins and the lamina-associated proteins, LAP2 and LBR, in nuclear organization and nuclear assembly. VL - 9 IS - 3-4 U1 - http://www.ncbi.nlm.nih.gov/pubmed/10651245?dopt=Abstract ER - TY - JOUR T1 - Quantitative ratio of primer pairs and annealing temperature affecting PCR products in duplex amplification. JF - Biotechniques Y1 - 1999 A1 - Bercovich, D A1 - Regev, Z A1 - Ratz, T A1 - Luder, A A1 - Plotsky, Y A1 - Gruenbaum, Y KW - Chromosomes, Human, Pair 1 KW - Chromosomes, Human, Pair 11 KW - Chromosomes, Human, Pair 21 KW - DNA KW - DNA Primers KW - Humans KW - Nucleotides KW - Polymerase Chain Reaction KW - Taq Polymerase KW - TEMPERATURE KW - Templates, Genetic KW - Time Factors KW - Y Chromosome AB - The quantity of PCR products that are simultaneously amplified from two different loci in a duplex amplification (DA) are significantly lower for one of the loci, as compared to identical PCR amplification in separate single-band amplifications (SBA). This difference in amplification probably occurs already after the second cycle of amplification. To further analyze this phenomenon, we tested different reaction conditions, including annealing times, a wide range of temperatures, various quantities of the template, several nucleotide concentrations, different amounts of TaqI DNA Polymerase, number of amplification cycles and various amounts of primers and primers ratio. Changing the ratio between the sets of primers in DA had the most significant effect on the relative levels of amplification of the loci with an optimal ratio of 4:1 in favor of the set of primers used to amplify the underrepresented fragment. The optimal annealing temperatures for the tested sets of primers were identical in SBA and different in DA. Possible reasons for this phenomenon are discussed. VL - 27 IS - 4 U1 - http://www.ncbi.nlm.nih.gov/pubmed/10524319?dopt=Abstract ER - TY - JOUR T1 - Interactions among Drosophila nuclear envelope proteins lamin, otefin, and YA. JF - Mol Cell Biol Y1 - 1998 A1 - Goldberg, M A1 - Lu, H A1 - Stuurman, N A1 - Ashery-Padan, R A1 - Weiss, A M A1 - Yu, J A1 - Bhattacharyya, D A1 - Fisher, P A A1 - Gruenbaum, Y A1 - Wolfner, M F KW - Animals KW - Binding Sites KW - Cell Extracts KW - Cell Nucleus KW - Chromosomal Proteins, Non-Histone KW - DNA-Binding Proteins KW - Drosophila melanogaster KW - Drosophila Proteins KW - Fluorescent Antibody Technique, Indirect KW - Insect Proteins KW - Lamins KW - Membrane Proteins KW - Nuclear Proteins KW - Nucleic Acid Hybridization KW - Oocytes KW - Precipitin Tests KW - Salivary Glands KW - Sodium Chloride AB - The nuclear envelope plays many roles, including organizing nuclear structure and regulating nuclear events. Molecular associations of nuclear envelope proteins may contribute to the implementation of these functions. Lamin, otefin, and YA are the three Drosophila nuclear envelope proteins known in early embryos. We used the yeast two-hybrid system to explore the interactions between pairs of these proteins. The ubiquitous major lamina protein, lamin Dm, interacts with both otefin, a peripheral protein of the inner nuclear membrane, and YA, an essential, developmentally regulated protein of the nuclear lamina. In agreement with this interaction, lamin and otefin can be coimmunoprecipitated from the vesicle fraction of Drosophila embryos and colocalize in nuclear envelopes of Drosophila larval salivary gland nuclei. The two-hybrid system was further used to map the domains of interaction among lamin, otefin, and YA. Lamin's rod domain interacts with the complete otefin protein, with otefin's hydrophilic NH2-terminal domain, and with two different fragments derived from this domain. Analogous probing of the interaction between lamin and YA showed that the lamin rod and tail plus part of its head domain are needed for interaction with full-length YA in the two-hybrid system. YA's COOH-terminal region is necessary and sufficient for interaction with lamin. Our results suggest that interactions with lamin might mediate or stabilize the localization of otefin and YA in the nuclear lamina. They also suggest that the need for both otefin and lamin in mediating association of vesicles with chromatin might reflect the function of a protein complex that includes these two proteins. VL - 18 IS - 7 U1 - http://www.ncbi.nlm.nih.gov/pubmed/9632815?dopt=Abstract ER - TY - JOUR T1 - Research notes: Fresh and frozen pools of chicken red blood cells as substrates for direct polymerase chain reaction. JF - Poult Sci Y1 - 1998 A1 - Khatib, H A1 - Sagiv, N A1 - Gruenbaum, Y KW - Animals KW - Blood Preservation KW - Blood Specimen Collection KW - Chickens KW - Chromosome Mapping KW - Cryopreservation KW - DNA KW - Erythrocytes KW - Genotype KW - Microsatellite Repeats KW - Polymerase Chain Reaction KW - Quantitative Trait, Heritable AB - A method is presented for reliable use of pooled chicken blood samples for estimation of microsatellite frequencies by direct polymerase chain reaction (PCR) amplification of DNA. This method overcomes the variability of hematocrit values in individual chickens and eliminates the step of DNA preparation. The estimated frequencies of polymorphic alleles in fresh and frozen pooled blood samples were similar to those obtained by calculating these frequencies from the individual genotyping. When frozen pooled blood samples are used, pools should be prepared prior to their freezing. VL - 77 IS - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/9628542?dopt=Abstract ER - TY - JOUR T1 - Distinct regions specify the targeting of otefin to the nucleoplasmic side of the nuclear envelope. JF - J Biol Chem Y1 - 1997 A1 - Ashery-Padan, R A1 - Weiss, A M A1 - Feinstein, N A1 - Gruenbaum, Y KW - Animals KW - COS Cells KW - Drosophila KW - Lac Operon KW - Membrane Proteins KW - Microscopy, Electron KW - Microscopy, Immunoelectron KW - Molecular Weight KW - Mutagenesis, Site-Directed KW - Nuclear Envelope KW - Nuclear Proteins KW - Protein Conformation KW - Sequence Deletion KW - Solubility KW - Structure-Activity Relationship KW - Transfection AB - Otefin is a 45-kDa nuclear envelope protein with no apparent homology to other known proteins. It includes a large hydrophilic domain, a single carboxyl-terminal hydrophobic sequence of 17 amino acids, and a high content of serine and threonine residues. Cytological labeling located otefin on the nucleoplasmic side of the nuclear envelope. Chemical extraction of nuclei from Drosophila embryos revealed that otefin is a peripheral protein whose association with the nuclear envelope is stronger than that of lamin. Deletion mutants of otefin were expressed in order to identify regions that direct otefin to the nuclear envelope. These experiments revealed that the hydrophobic sequence at the carboxyl terminus is essential for correct targeting to the nuclear envelope, whereas additional regions in the hydrophilic domain of otefin are required for its efficient targeting and stabilization in the nuclear envelope. VL - 272 IS - 4 U1 - http://www.ncbi.nlm.nih.gov/pubmed/8999964?dopt=Abstract ER - TY - JOUR T1 - [Knockout and knockin mice]. JF - Harefuah Y1 - 1997 A1 - Goldberg, M A1 - Gruenbaum, Y KW - Animals KW - Gene Targeting KW - Mice KW - Mice, Knockout KW - Mice, Mutant Strains VL - 132 IS - 4 U1 - http://www.ncbi.nlm.nih.gov/pubmed/9153897?dopt=Abstract ER - TY - JOUR T1 - Localization and posttranslational modifications of otefin, a protein required for vesicle attachment to chromatin, during Drosophila melanogaster development. JF - Mol Cell Biol Y1 - 1997 A1 - Ashery-Padan, R A1 - Ulitzur, N A1 - Arbel, A A1 - Goldberg, M A1 - Weiss, A M A1 - Maus, N A1 - Fisher, P A A1 - Gruenbaum, Y KW - Animals KW - CDC2 Protein Kinase KW - Cell Compartmentation KW - Chromatin KW - Cyclic AMP-Dependent Protein Kinases KW - Drosophila melanogaster KW - Drosophila Proteins KW - Fluorescent Antibody Technique, Indirect KW - Insect Proteins KW - Lamins KW - Membrane Proteins KW - Nuclear Envelope KW - Nuclear Proteins KW - Phosphoproteins KW - Phosphorylation KW - Phosphoserine KW - Protein Processing, Post-Translational AB - Otefin is a peripheral protein of the inner nuclear membrane in Drosophila melanogaster. Here we show that during nuclear assembly in vitro, it is required for the attachment of membrane vesicles to chromatin. With the exception of sperm cells, otefin colocalizes with lamin Dm0 derivatives in situ and presumably in vivo and is present in all somatic cells examined during the different stages of Drosophila development. In the egg chamber, otefin accumulates in the cytoplasm, in the nuclear periphery, and within the nucleoplasm of the oocyte, in a pattern similar to that of lamin Dm0 derivatives. There is a relatively large nonnuclear pool of otefin present from stages 6 to 7 of egg chamber maturation through 6 to 8 h of embryonic development at 25 degrees C. In this pool, otefin is peripherally associated with a fraction containing the membrane vesicles. This association is biochemically different from the association of otefin with the nuclear envelope. Otefin is a phosphoprotein in vivo and is a substrate for in vitro phosphorylation by cdc2 kinase and cyclic AMP-dependent protein kinase. A major site for cdc2 kinase phosphorylation in vitro was mapped to serine 36 of otefin. Together, our data suggest an essential role for otefin in the assembly of the Drosophila nuclear envelope. VL - 17 IS - 7 U1 - http://www.ncbi.nlm.nih.gov/pubmed/9199347?dopt=Abstract ER - TY - JOUR T1 - Nuclear membrane vesicle targeting to chromatin in a Drosophila embryo cell-free system. JF - Mol Biol Cell Y1 - 1997 A1 - Ulitzur, N A1 - Harel, A A1 - Goldberg, M A1 - Feinstein, N A1 - Gruenbaum, Y KW - Animals KW - Cell-Free System KW - Chromatin KW - Drosophila KW - Guanosine 5'-O-(3-Thiotriphosphate) KW - Laminin KW - Membrane Proteins KW - Microscopy, Electron KW - Nuclear Envelope KW - Okadaic Acid AB - A Drosophila cell-free system was used to characterize proteins that are required for targeting vesicles to chromatin and for fusion of vesicles to form nuclear envelopes. Treatment of vesicles with 1 M NaCl abolished their ability to bind to chromatin. Binding of salt-treated vesicles to chromatin could be restored by adding the dialyzed salt extract. Lamin Dm is one of the peripheral proteins whose activity was required, since supplying interphase lamin isoforms Dm1, and Dm2 to the assembly extract restored binding. As opposed to the findings in Xenopus, okadaic acid had no effect on vesicle binding. Trypsin digestion of the salt-stripped vesicles eliminated their association with chromatin even in the presence of the dialyzed salt extract. One vesicles attached to chromatin surface, fusion events took place were found to be sensitive to guanosine 5'-[gamma-thio]triphosphate (GTP gamma S). These chromatin-attached vesicles contained lamin Dm and otefin but not gp210. Thus, these results show that in Drosophila there are two populations of nuclear vesicles. The population that interacts first with chromatin contains lamin and otefin and requires both peripheral and integral membrane proteins, whereas fusion of vesicles requires GTPase activity. VL - 8 IS - 8 U1 - http://www.ncbi.nlm.nih.gov/pubmed/9285817?dopt=Abstract ER - TY - JOUR T1 - Binding of matrix attachment regions to nuclear lamin is mediated by the rod domain and depends on the lamin polymerization state. JF - FEBS Lett Y1 - 1996 A1 - Zhao, K A1 - Harel, A A1 - Stuurman, N A1 - Guedalia, D A1 - Gruenbaum, Y KW - Amino Acid Sequence KW - Animals KW - Crystallization KW - DNA KW - Drosophila melanogaster KW - Drosophila Proteins KW - Fushi Tarazu Transcription Factors KW - Homeodomain Proteins KW - Lamins KW - Molecular Sequence Data KW - Nuclear Matrix KW - Nuclear Proteins KW - Point Mutation KW - Polymers KW - Protein Binding KW - Protein Conformation AB - The nuclear matrix maintains specific interactions with genomic DNA at sites known as matrix attachment regions (M/SARs). M/SARs bind in vitro to lamin polymers. We show that the polymerized alpha-helical rod domain of lamin Dm0 provides by itself the specific binding to the ftz M/SAR. In contrast, unpolymerized rod domain does not bind specifically to this M/SAR. Non-specific binding to DNA is also observed with Dm0 containing a point mutation that impairs its ability to polymerize or with the isolated tail domain. These data suggest that the specific binding of lamins to M/SARs requires the rod domain and depends on the lamin polymerization state. VL - 380 IS - 1-2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/8603728?dopt=Abstract ER - TY - JOUR T1 - Expression of the novel murine homeobox gene Sax-1 in the developing nervous system. JF - Mech Dev Y1 - 1995 A1 - Schubert, F R A1 - Fainsod, A A1 - Gruenbaum, Y A1 - Gruss, P KW - Amino Acid Sequence KW - Animals KW - Base Sequence KW - Cell Differentiation KW - Central Nervous System KW - DNA-Binding Proteins KW - Eye Proteins KW - Fetal Proteins KW - Gastrula KW - Gene Expression Regulation, Developmental KW - Genes, Homeobox KW - Gestational Age KW - Homeodomain Proteins KW - In Situ Hybridization KW - Mesencephalon KW - Mice KW - Mice, Mutant Strains KW - Molecular Sequence Data KW - Nerve Tissue Proteins KW - Nuclear Proteins KW - Paired Box Transcription Factors KW - Prosencephalon KW - Repressor Proteins KW - Rhombencephalon KW - T-Box Domain Proteins KW - Transcription Factors KW - Tumor Cells, Cultured AB - We have isolated the novel murine Sax-1 gene, a member of the NK-1 class of homeobox genes, and report its expression pattern in the developing central nervous system (CNS) in comparison to two other homeobox genes, Evx-1 and Pax-6. Sax-1 was found to be transiently expressed in the developing posterior CNS. First seen in the ectoderm lateral to the primitive streak, the signal later encompassed the neural plate. Posteriorly, the expression domain overlapped with the Evx-1 expression in the streak, while anteriorly it was delimited by the Pax-6 signal in the neural tube. This early phase starting at day 9.5 pc, Sax-1 was expressed in distinct areas of spinal cord, hindbrain and forebrain. Particularly strong signals were detected in rhombomere 1 and in the pretectum. In these areas, subsets of neurons may be marked and specified. In addition to the normal pattern of Sax-1 during development, the expression in different mouse mutants was analysed. In Brachyury curtailed homozygotes, the expression of Sax-1 was found to be reduced during neurulation and even lost at day 9.0 pc. Ventral shift and finally loss of the signal in the ventral spinal cord was observed in Danforth's short tail homozygotes. VL - 51 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/7669696?dopt=Abstract ER - TY - JOUR T1 - Mapping the CdxA gene to a new linkage group in chicken. JF - Anim Genet Y1 - 1995 A1 - Khatib, H A1 - Berkovitz, D A1 - Ratz, T A1 - Plotzki, Y A1 - Fainsod, A A1 - Gruenbaum, Y KW - Animals KW - Avian Proteins KW - Base Sequence KW - Chickens KW - Chromosome Mapping KW - DNA Primers KW - DNA-Binding Proteins KW - Genetic Linkage KW - Homeodomain Proteins KW - Molecular Sequence Data KW - Polymerase Chain Reaction KW - Polymorphism, Genetic VL - 26 IS - 3 U1 - http://www.ncbi.nlm.nih.gov/pubmed/7793703?dopt=Abstract ER - TY - JOUR T1 - How is it that microsatellites and random oligonucleotides uncover DNA fingerprint patterns? JF - Mamm Genome Y1 - 1994 A1 - Kashi, Y A1 - Nave, A A1 - Darvasi, A A1 - Gruenbaum, Y A1 - Soller, M A1 - Beckmann, J S KW - Animals KW - Base Sequence KW - Blotting, Southern KW - Cattle KW - Deoxyribonuclease BamHI KW - Deoxyribonucleases, Type II Site-Specific KW - DNA Fingerprinting KW - DNA Primers KW - DNA, Satellite KW - Genetic Variation KW - Genomic Library KW - Molecular Sequence Data KW - Oligonucleotide Probes KW - Polymerase Chain Reaction KW - Polymorphism, Genetic KW - Random Allocation KW - Repetitive Sequences, Nucleic Acid KW - Restriction Mapping AB - Minisatellites, microsatellites, and short random oligonucleotides all uncover highly polymorphic DNA fingerprint patterns in Southern analysis of genomic DNA that has been digested with a restriction enzyme having a 4-bp specificity. The polymorphic nature of the fragments is attributed to tandem repeat number variation of embedded minisatellite sequences. This explains why DNA fingerprint fragments are uncovered by minisatellite probes, but does not explain how it is that they are also uncovered by microsatellite and random oligonucleotide probes. To clarify this phenomenon, we sequenced a large bovine genomic BamHI restriction fragment hybridizing to the Jeffreys 33.6 minisatellite probe and consisting of small and large Sau3A-resistant subfragments. The large Sau3A subfragment was found to have a complex architecture, consisting of two different minisatellites, flanked and separated by stretches of unique DNA. The three unique sequences were characterized by sequence simplicity, that is, a higher than chance occurrence of tandem or dispersed repetition of simple sequence motifs. This complex repetitive structure explains the absence of Sau3A restriction sites in the large Sau3A subfragment, yet provides this subfragment with the ability to hybridize to a variety of probe sequences. It is proposed that a large class of interspersed tracts sharing this complex yet simplified sequence structure is found in the genome. Each such tract would have a broad ability to hybridize to a variety of probes, yet would exhibit a dearth of restriction sites. For each restriction enzyme having 4-bp specificity, a subclass of such tracts, completely lacking the corresponding restriction sites, will be present. On digestion with the given restriction enzyme, each such tract would form a large fragment.(ABSTRACT TRUNCATED AT 250 WORDS) VL - 5 IS - 9 U1 - http://www.ncbi.nlm.nih.gov/pubmed/8000134?dopt=Abstract ER - TY - JOUR T1 - A role for CdxA in gut closure and intestinal epithelia differentiation. JF - Development Y1 - 1994 A1 - Frumkin, A A1 - Pillemer, G A1 - Haffner, R A1 - Tarcic, N A1 - Gruenbaum, Y A1 - Fainsod, A KW - Animals KW - Cell Differentiation KW - Chick Embryo KW - Endoderm KW - Epithelial Cells KW - Epithelium KW - Genes, Homeobox KW - Immunohistochemistry KW - Intestines KW - Morphogenesis AB - CdxA is a homeobox gene of the caudal type that was previously shown to be expressed in the endoderm-derived gut epithelium during early embryogenesis. Expression of the CDXA protein was studied during intestine morphogenesis from stage 11 (13 somites) to adulthood in the chicken. The CDXA protein can be detected during all stages of gut closure, from stage 11 to 5 days of incubation, and is mainly localized to the intestinal portals, the region where the splanchnopleure is undergoing closure. In this region, which represents the transition between the open and closed gut, the CDXA protein is restricted to the endoderm-derived epithelium. At about day 5 of incubation, the process of formation of the previllous ridges begins, which marks the beginning of the morphogenesis of the villi. From this stage to day 11 expression of CDXA is localized to the epithelial lining of the intestine. In parallel, a gradual increase in CDXA protein expression begins in the mesenchyme that is close in proximity to the CDXA-positive endoderm. Maximal CDXA levels in the mesenchyme are observed at day 9 of incubation. During days 10 and 11 CDXA levels in the mesenchyme remain constant, and by day 12 CDXA becomes undetectable in these cells and the epithelium again becomes the main site of expression. From day 12 of incubation until adulthood the CDXA protein is present in the intestinal epithelium. Until day 18 of incubation expression can be detected along the whole length of the villus with a stronger signal at the tip. With hatching the distribution along the villi changes so that the main site of CDXA protein expression is at the base of the villi and in the crypts. The transient expression of CDXA in the mesenchyme between days 5 and 11 may be related to the interactions taking place between the mesenchyme and the epithelium that ultimately result in the axial specification of the alimentary canal and the differentiation of its various epithelia. The main CDXA spatial distribution during morphogenesis suggests a tight linkage to the formation and differentiation of the intestinal epithelium itself. CDXA appears to play a role in the morphogenetic events leading to closure of the alimentary canal. During previllous ridge formation the CDXA protein is transiently expressed in the mesenchymal cells thought to provide instructive interactions for the regionalization and differentiation of the gut epithelium.(ABSTRACT TRUNCATED AT 400 WORDS) VL - 120 IS - 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/7908627?dopt=Abstract ER - TY - JOUR T1 - The spatial and temporal dynamics of Sax1 (CHox3) homeobox gene expression in the chick's spinal cord. JF - Development Y1 - 1994 A1 - Spann, P A1 - Ginsburg, M A1 - Rangini, Z A1 - Fainsod, A A1 - Eyal-Giladi, H A1 - Gruenbaum, Y KW - Animals KW - Chick Embryo KW - Embryonic Induction KW - Gene Expression KW - Gene Expression Regulation KW - Genes, Homeobox KW - In Situ Hybridization KW - Mesoderm KW - Notochord KW - Restriction Mapping KW - Spinal Cord AB - Sax1 (previously CHox3) is a chicken homeobox gene belonging to the same homeobox gene family as the Drosophila NK1 and the honeybee HHO genes. Sax1 transcripts are present from stage 2 H&H until at least 5 days of embryonic development. However, specific localization of Sax1 transcripts could not be detected by in situ hybridization prior to stage 8-, when Sax1 transcripts are specifically localized in the neural plate, posterior to the hindbrain. From stages 8- to 15 H&H, Sax1 continues to be expressed only in the spinal part of the neural plate. The anterior border of Sax1 expression was found to be always in the transverse plane separating the youngest somite from the yet unsegmented mesodermal plate and to regress with similar dynamics to that of the segregation of the somites from the mesodermal plate. The posterior border of Sax1 expression coincides with the posterior end of the neural plate. In order to study a possible regulation of Sax1 expression by its neighboring tissues, several embryonic manipulation experiments were performed. These manipulations included: removal of somites, mesodermal plate or notochord and transplantation of a young ectopic notochord in the vicinity of the neural plate or transplantation of neural plate sections into the extraembryonic area. The results of these experiments revealed that the induction of the neural plate by the mesoderm has already occurred in full primitive streak embryos, after which Sax1 is autonomously regulated within the spinal part of the neural plate. VL - 120 IS - 7 U1 - http://www.ncbi.nlm.nih.gov/pubmed/7924989?dopt=Abstract ER - TY - JOUR T1 - The chicken CdxA homeobox gene and axial positioning during gastrulation. JF - Development Y1 - 1993 A1 - Frumkin, A A1 - Haffner, R A1 - Shapira, E A1 - Tarcic, N A1 - Gruenbaum, Y A1 - Fainsod, A KW - Animals KW - Avian Proteins KW - Chick Embryo KW - DNA-Binding Proteins KW - Endoderm KW - Gastrula KW - Gene Expression KW - Genes, Homeobox KW - Homeodomain Proteins KW - Immunoenzyme Techniques KW - Immunohistochemistry KW - In Situ Hybridization KW - Morphogenesis AB - The chicken homebox containing gene, CdxA (formerly CHox-cad), was previously shown to be expressed during gastrulation. Localization of CdxA transcripts by in situ hybridization to tissue sections revealed that, during gastrulation, expression of this gene exhibits a posterior localization along the primitive streak. The transcripts are localized to epiblast cells in the vicinity of the primitive streak, to cells of the primitive streak itself and in the definitive endoderm as it replaces the hypoblast. In order to study in greater detail the pattern of expression of the CdxA gene during gastrulation, we expressed the full-length CdxA protein as a fusion protein in E. coli and generated monoclonal antibodies against it. Chicken embryos at different stages of gastrulation were processed for whole-mount immunohistochemical localization of the protein using anti-CdxA antibodies. Once the pattern of expression in the whole embryo was determined, the same embryos were sectioned to determine the identity of the cells expressing the CdxA protein. Detailed analysis of the CdxA protein in embryos, from the onset of primitive streak formation to the beginning of the tail bud stage (stages 2 to 10), has shown different patterns of expression during primitive streak elongation and regression. The CdxA protein is initially detected at the posterior marginal zone and the expression moves rostrally into the primitive streak during mid-streak stages. As the primitive streak elongates, the CdxA stripe of expression moves anteriorly. By definitive streak stages, the CdxA stripe of expression delineates a position along the anterior-posterior axis in the primitive streak. CdxA, like its Drosophila homologue cad, is expressed during gastrulation in a stripe localized to the posterior region of the embryo. These observations suggest that CdxA as a homebox gene may be part of a regulatory network coupled to axial determination during gastrulation in the early chick embryo. VL - 118 IS - 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/7900992?dopt=Abstract ER - TY - JOUR T1 - Isolation and characterization of target sequences of the chicken CdxA homeobox gene. JF - Nucleic Acids Res Y1 - 1993 A1 - Margalit, Y A1 - Yarus, S A1 - Shapira, E A1 - Gruenbaum, Y A1 - Fainsod, A KW - Amino Acid Sequence KW - Animals KW - Avian Proteins KW - Base Sequence KW - Cells, Cultured KW - Chickens KW - DNA KW - DNA-Binding Proteins KW - Genes, Homeobox KW - Homeodomain Proteins KW - Molecular Sequence Data KW - Protein Binding KW - Sequence Homology, Amino Acid KW - Transcription, Genetic AB - The DNA binding specificity of the chicken homeodomain protein CDXA was studied. Using a CDXA-glutathione-S-transferase fusion protein, DNA fragments containing the binding site for this protein were isolated. The sources of DNA were oligonucleotides with random sequence and chicken genomic DNA. The DNA fragments isolated were sequenced and tested in DNA binding assays. Sequencing revealed that most DNA fragments are AT rich which is a common feature of homeodomain binding sites. By electrophoretic mobility shift assays it was shown that the different target sequences isolated bind to the CDXA protein with different affinities. The specific sequences bound by the CDXA protein in the genomic fragments isolated, were determined by DNase I footprinting. From the footprinted sequences, the CDXA consensus binding site was determined. The CDXA protein binds the consensus sequence A, A/T, T, A/T, A, T, A/G. The CAUDAL binding site in the ftz promoter is also included in this consensus sequence. When tested, some of the genomic target sequences were capable of enhancing the transcriptional activity of reporter plasmids when introduced into CDXA expressing cells. This study determined the DNA sequence specificity of the CDXA protein and it also shows that this protein can further activate transcription in cells in culture. VL - 21 IS - 21 U1 - http://www.ncbi.nlm.nih.gov/pubmed/7909943?dopt=Abstract ER - TY - JOUR T1 - Lamin activity is essential for nuclear envelope assembly in a Drosophila embryo cell-free extract. JF - J Cell Biol Y1 - 1992 A1 - Ulitzur, N A1 - Harel, A A1 - Feinstein, N A1 - Gruenbaum, Y KW - Animals KW - Cell Nucleus KW - Cell-Free System KW - Chromatin KW - DNA KW - Drosophila KW - Embryo, Nonmammalian KW - Fluorescent Antibody Technique KW - Lamins KW - Microscopy, Electron KW - Nuclear Envelope KW - Nuclear Proteins AB - The role of the Drosophila lamin protein in nuclear envelope assembly was studied using a Drosophila in vitro assembly system that reconstitutes nuclei from added sperm chromatin or naked DNA. Upon incubation of the embryonic assembly extract with anti-Drosophila lamin antibodies, the attachment of nuclear membrane vesicles to chromatin surface and nuclear envelope formation did not occur. Lamina assembly and nuclear membrane vesicles attachment to the chromatin were inhibited only when the activity of the 75-kD lamin isoform was inhibited in both soluble and membrane-vesicles fractions. Incubation of decondensed sperm chromatin with an extract that was depleted of nuclear membranes revealed the presence of lamin molecules on the chromatin periphery. In addition, high concentrations of bacterially expressed lamin molecules added to the extract, were able to associate with the chromatin periphery, and did not inhibit nuclear envelope assembly. After nuclear reconstitution, a fraction of the lamin pool was converted into the typical 74- and 76-kD isoforms. Together, these data strongly support an essential role of the lamina in nuclear envelope assembly. VL - 119 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/1527167?dopt=Abstract ER - TY - JOUR T1 - A minisatellite from bovine which produces highly polymorphic DNA fingerprint patterns in mammals and chickens. JF - Anim Genet Y1 - 1992 A1 - Kashi, Y A1 - Nave, A A1 - Gruenbaum, Y A1 - Soller, M A1 - Beckmann, J S KW - Animals KW - Base Sequence KW - Cattle KW - Chickens KW - DNA Fingerprinting KW - DNA, Satellite KW - Genetic Markers KW - Mammals VL - 23 IS - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/1492711?dopt=Abstract ER - TY - JOUR T1 - A new minisatellite probe shows highly polymorphic hybridization pattern in human. JF - Nucleic Acids Res Y1 - 1992 A1 - Kashi, Y A1 - Tikochinski, Y A1 - Nave, A A1 - Beckmann, J S A1 - Soller, M A1 - Gruenbaum, Y KW - Animals KW - Blotting, Southern KW - Cattle KW - DNA Probes KW - Female KW - Humans KW - Male KW - Myoglobin KW - Polymorphism, Genetic KW - Repetitive Sequences, Nucleic Acid VL - 20 IS - 4 U1 - http://www.ncbi.nlm.nih.gov/pubmed/1542594?dopt=Abstract ER - TY - JOUR T1 - A chicken caudal homologue, CHox-cad, is expressed in the epiblast with posterior localization and in the early endodermal lineage. JF - Development Y1 - 1991 A1 - Frumkin, A A1 - Rangini, Z A1 - Ben-Yehuda, A A1 - Gruenbaum, Y A1 - Fainsod, A KW - Amino Acid Sequence KW - Animals KW - Base Sequence KW - Chick Embryo KW - Endoderm KW - Gastrula KW - Gene Expression KW - Genes, Homeobox KW - Molecular Sequence Data KW - Sequence Homology, Nucleic Acid AB - CHox-cad is a chicken homeobox gene whose homeodomain is homologous to the Drosophila caudal and the murine Cdx1 genes. Based on sequence analysis of a 2.5 kb CHox-cad cDNA clone, we deduced that the primary translation product consists of 248 amino acids. Comparison between the cDNA and genomic clones revealed the presence of an intron within the CHox-cad homeodomain between amino acids 44 and 45. The onset of CHox-cad transcription correlates temporarily with the beginning of gastrulation. During primitive streak stages CHox-cad exhibits a caudally localized pattern of expression restricted to the epiblast and the primitive streak. At these stages, CHox-cad transcripts can also be detected in the definitive endoderm cells. Later in embryogenesis CHox-cad is expressed in the epithelial lining of the embryonic gut and yolk sac. After four days of chicken development, no CHox-cad transcripts could be detected. The early CHox-cad posterior expression in the germ layer undergoing gastrulation and its continuous expression in the early endodermal lineage raise the possibility of CHox-cad involvement in the establishment of the definitive endoderm. VL - 112 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/1685114?dopt=Abstract ER - TY - JOUR T1 - CHox E, a chicken homeogene of the H2.0 type exhibits dorso-ventral restriction in the proliferating region of the spinal cord. JF - Mech Dev Y1 - 1991 A1 - Rangini, Z A1 - Ben-Yehuda, A A1 - Shapira, E A1 - Gruenbaum, Y A1 - Fainsod, A KW - Amino Acid Sequence KW - Animals KW - Base Sequence KW - Cell Differentiation KW - Cell Division KW - Chick Embryo KW - DNA KW - Embryonic and Fetal Development KW - Gene Expression Regulation KW - Genes, Homeobox KW - Introns KW - Molecular Sequence Data KW - Neurons KW - Spinal Cord KW - Transcription, Genetic AB - CHox E is a novel chicken homeogene that belongs to the H2.0 family of homeodomains. Its homeobox sequence is interrupted by an intron between amino acids 44 and 45. Expression of CHox E during embryogenesis is localized to the central nervous system. The anterior boundary of CHox E expression can initially be localized to rhombomere number 1, later in development this boundary reaches up to the rhombencephalic isthmus. CHox E expression in the spinal cord localizes dorso-ventrally to the dorsal half of the basal plate. CHox E expression is always restricted to the proliferating region, the ventricular zone. As the ventricular zone becomes restricted laterally, so does the CHox E expressing region. Once this region of the ventricular zone ceases to exist, CHox E specific transcripts become undetectable. The site and time of CHox E expression suggest a very early function in the differentiation of the cells derived from that region of the ventricular zone. VL - 35 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/1683253?dopt=Abstract ER - TY - JOUR T1 - Non-immunological precipitation of protein-DNA complexes using glutathione-S-transferase fusion proteins. JF - Nucleic Acids Res Y1 - 1991 A1 - Fainsod, A A1 - Margalit, Y A1 - Haffner, R A1 - Gruenbaum, Y KW - Animals KW - Chemical Precipitation KW - Chickens KW - Cloning, Molecular KW - DNA KW - DNA-Binding Proteins KW - Electrophoresis KW - Escherichia coli KW - Genetic Techniques KW - Glutathione Transferase KW - Polymerase Chain Reaction KW - Recombinant Fusion Proteins VL - 19 IS - 14 U1 - http://www.ncbi.nlm.nih.gov/pubmed/1861996?dopt=Abstract ER - TY - JOUR T1 - Effect of CpG methylation on gene expression in transfected plant protoplasts. JF - Gene Y1 - 1990 A1 - Hershkovitz, M A1 - Gruenbaum, Y A1 - Renbaum, P A1 - Razin, A A1 - Loyter, A KW - Blotting, Southern KW - Gene Expression Regulation, Enzymologic KW - In Vitro Techniques KW - Methylation KW - Plasmids KW - Protoplasts KW - Transfection AB - Activity of the cat gene driven by the cauliflower mosaic virus 35S promoter has been assayed by transfecting petunia protoplasts with the pUC8CaMVCAT plasmid. In vitro methylation of this plasmid with M.HpaII (methylates C in CCGG sites) and M.HhaI (methylates GCGC sites) did not affect bacterial chloramphenicol acetyltransferase (CAT) activity. It should be noted, however, that no HpaII or HhaI sites are present in the promoter sequence. In contrast, in vitro methylation of the plasmid with the spiroplasma methylase M.SssI, which methylates all CpG sites, resulted in complete inhibition of CAT activity. The promoter sequence contains 16 CpG sites and 13 CpNpG sites that are known to be methylation sites in plant DNA. In the light of this fact, and considering the results of the experiments presented here, we conclude that methylation at all CpG sites leaving CpNpG sites unmethylated is sufficient to block gene activity in a plant cell. Methylation of CpNpG sites in plant cells may, therefore, play a role other than gene silencing. VL - 94 IS - 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/2258051?dopt=Abstract ER - TY - JOUR T1 - Fibroblast growth factor during mesoderm induction in the early chick embryo. JF - Development Y1 - 1990 A1 - Mitrani, E A1 - Gruenbaum, Y A1 - Shohat, H A1 - Ziv, T KW - Amino Acid Sequence KW - Animals KW - Base Sequence KW - Cell Differentiation KW - Chick Embryo KW - Embryonic Induction KW - Fibroblast Growth Factors KW - Genomic Library KW - Heparin KW - Mesoderm KW - Molecular Sequence Data KW - Suramin KW - Transcription, Genetic AB - A chick genomic clone that reveals a high degree of homology to the mammalian and Xenopus bFGF gene has been isolated. The pattern of expression of bFGF has been examined during early chick embryogenesis. RNA blot analysis revealed that chick bFGF is already transcribed at pregastrula stages. Immunolabeling analysis indicated that bFGF protein is present at these early developmental stages and is distributed evenly in the epiblast, hypoblast and marginal zone of the chick blastula. Substances that can inhibit FGF action were applied to early chick blastoderms grown in vitro under defined culture conditions (DCM). Both heparin and suramin were capable of blocking the formation of mesodermal structures in a dose-dependent manner. Our results indicate that FGF-like substances may need to be present for axial structures to develop although they may be acting earlier during the induction of non-axial mesoderm. VL - 109 IS - 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/2401202?dopt=Abstract ER - TY - JOUR T1 - Isolation and characterization of the Drosophila nuclear envelope otefin cDNA. JF - J Biol Chem Y1 - 1990 A1 - Padan, R A1 - Nainudel-Epszteyn, S A1 - Goitein, R A1 - Fainsod, A A1 - Gruenbaum, Y KW - Amino Acid Sequence KW - Animals KW - Base Sequence KW - Blotting, Western KW - Cloning, Molecular KW - Cricetinae KW - DNA KW - Drosophila KW - Escherichia coli KW - Fluorescent Antibody Technique KW - Gene Expression KW - Membrane Proteins KW - Mesocricetus KW - Molecular Sequence Data KW - Molecular Weight KW - Nuclear Envelope KW - Nuclear Proteins KW - Nucleic Acid Hybridization KW - Plasmids KW - Protein Biosynthesis KW - Restriction Mapping KW - Transfection AB - We have recently identified and characterized a 53-kDa inner nuclear membrane-associated protein in Drosophila and termed it otefin. Here we report the isolation and characterization of cDNA and genomic clones of the otefin gene. Based on sequence analysis, we deduced that the primary translation product has a calculated mass of 45 kDa, contains many serine and threonine residues, and is mostly hydrophilic. However, in the carboxyl terminus, there is a hydrophobic region which may serve as a membrane anchoring domain. RNA blot analysis indicated that the otefin gene codes for a single poly(A+) transcript of 1.6 kilobases and that relatively large amounts of this transcript are present during developmental stages in which many nuclear divisions occur. Polyclonal antibodies raised against the cDNA translation product react with a 58-kDa mammalian nuclear envelope protein, demonstrating evolutionary conservation. VL - 265 IS - 14 U1 - http://www.ncbi.nlm.nih.gov/pubmed/2186029?dopt=Abstract ER - TY - JOUR T1 - Large restriction fragments containing poly-TG are highly polymorphic in a variety of vertebrates. JF - Nucleic Acids Res Y1 - 1990 A1 - Kashi, Y A1 - Tikochinsky, Y A1 - Genislav, E A1 - Iraqi, F A1 - Nave, A A1 - Beckmann, J S A1 - Gruenbaum, Y A1 - Soller, M KW - Animals KW - Base Sequence KW - Blotting, Southern KW - Cattle KW - Chickens KW - Drosophila KW - Female KW - Horses KW - Humans KW - Male KW - Mice KW - Molecular Sequence Data KW - Nucleotide Mapping KW - Plasmids KW - Polydeoxyribonucleotides KW - Polymorphism, Restriction Fragment Length KW - Sheep AB - Southern blots of genomic DNA from a variety of species digested by restriction endonucleases having a four-bp specificity, were probed with a bovine genomic clone consisting of seven tandem poly-TG stretches separated by a 29bp linker sequence. Highly variable DNA 'fingerprint' patterns were obtained in chicken, sheep, and horse, moderately variable DNA 'fingerprints' in mouse and man, and a monomorphic pattern in Drosophila. In chicken, horse and man a (TG)10 synthetic oligonucleotide probe gave results identical to those given by the bovine probe. Furthermore, in chicken the DNA fingerprint variation showed typical Mendelian inheritance and differed from the fingerprints obtained with Jeffreys 33.6 and M13 minisatellite probes. Thus, for a variety of vertebrate species, poly-TG-containing probes can uncover useful genetic variation. VL - 18 IS - 5 U1 - http://www.ncbi.nlm.nih.gov/pubmed/1969619?dopt=Abstract ER - TY - JOUR T1 - Molecular analysis of the Drosophila nuclear lamin gene. JF - Genomics Y1 - 1990 A1 - Osman, M A1 - Paz, M A1 - Landesman, Y A1 - Fainsod, A A1 - Gruenbaum, Y KW - Amino Acid Sequence KW - Animals KW - Base Sequence KW - Biological Evolution KW - Drosophila melanogaster KW - Gene Expression Regulation KW - Genes KW - Intermediate Filament Proteins KW - Lamins KW - Molecular Sequence Data KW - Multigene Family KW - Nuclear Proteins KW - Regulatory Sequences, Nucleic Acid KW - Sequence Homology, Nucleic Acid AB - A complete nucleotide sequence of a 4.2-kb genomic fragment containing the Drosophila lamin gene and flanking sequences is presented. Primer extension experiments and sequence analysis revealed that transcription starts from a single promoter. The lamin maternal 2.8-kb transcript and the 3.0-kb zygotic transcript are generated from two alternative polyadenylation sites. The gene contains four exons. The first intron is 7 bp upstream of the first AUG site. The two other introns are located within the alpha-helical rod domain of the protein: one in coil 1B in the 42-amino-acid domain that is absent in vertebrate cytoplasmic intermediate filament proteins and the other in coil 2 at a position different from intron positions within the vertebrate intermediate filament genes. Together with the sequence homology analysis, the data suggest either that the lamin gene was the ancestral gene of intermediate filament genes or that the lamin gene diverged from other intermediate filament genes early in evolution. VL - 8 IS - 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/2123469?dopt=Abstract ER - TY - JOUR T1 - Parentage identification in the bovine using "deoxyribonucleic acid fingerprints". JF - J Dairy Sci Y1 - 1990 A1 - Kashi, Y A1 - Lipkin, E A1 - Darvasi, A A1 - Nave, A A1 - Gruenbaum, Y A1 - Beckmann, J S A1 - Soller, M KW - Animals KW - Blotting, Southern KW - Cattle KW - DNA Fingerprinting KW - Female KW - Male KW - Nucleic Acid Hybridization KW - Pedigree KW - Poisson Distribution KW - Probability VL - 73 IS - 11 U1 - http://www.ncbi.nlm.nih.gov/pubmed/2273157?dopt=Abstract ER - TY - JOUR T1 - (TG)n uncovers a sex-specific hybridization pattern in cattle. JF - Genomics Y1 - 1990 A1 - Kashi, Y A1 - Iraqi, F A1 - Tikochinski, Y A1 - Ruzitsky, B A1 - Nave, A A1 - Beckmann, J S A1 - Friedmann, A A1 - Soller, M A1 - Gruenbaum, Y KW - Animals KW - Bacteriophage lambda KW - Base Sequence KW - Blotting, Southern KW - Cattle KW - Cloning, Molecular KW - DNA, Satellite KW - Female KW - Humans KW - Male KW - Molecular Sequence Data KW - Multigene Family KW - Nucleic Acid Hybridization KW - Polymorphism, Restriction Fragment Length KW - Repetitive Sequences, Nucleic Acid KW - Restriction Mapping KW - Sex Characteristics AB - Screening of a bovine genomic library with the human minisatellite 33.6 probe uncovered a family of clones that, when used to probe Southern blots of bovine genomic DNA digested with the restriction enzyme HaeIII or MboI, revealed sexually dimorphic, but otherwise virtually monomorphic, patterns among the larger DNA fragments to which they hybridized. Characterization of one of these clones revealed that it contains different minisatellite sequences. The sexual dimorphism hybridization pattern observed with this clone was found to be due to multiple copies of two tandemly interspersed repeats: the simple sequence (TG)n and a previously undescribed 29-bp sequence. Both repeats appear to share many genomic loci including autosomal loci. In contrast, Southern analysis of AluI- or HinfI-digested bovine DNA with the (TG)n repeat used as a probe yielded substantial polymorphism. These results show that (i) different minisatellites can be found in a cluster, (ii) both simple and more complex repeated sequences other than the simple quaternary (GATA)n repeat can be sexually dimorphic, and (iii) simple repeats can reveal substantial polymorphism. VL - 7 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/1970798?dopt=Abstract ER - TY - JOUR T1 - The chicken homeo box genes CHox1 and CHox3: cloning, sequencing and expression during embryogenesis. JF - Gene Y1 - 1989 A1 - Rangini, Z A1 - Frumkin, A A1 - Shani, G A1 - Guttmann, M A1 - Eyal-Giladi, H A1 - Gruenbaum, Y A1 - Fainsod, A KW - Amino Acid Sequence KW - Animals KW - Base Sequence KW - Chick Embryo KW - Cloning, Molecular KW - DNA KW - Drosophila melanogaster KW - Gene Expression Regulation KW - Genes, Homeobox KW - Humans KW - Mice KW - Molecular Sequence Data KW - Nucleic Acid Hybridization KW - Restriction Mapping KW - Sequence Homology, Nucleic Acid KW - Species Specificity KW - Xenopus laevis AB - Several Drosophila genes involved in the control of segmentation and segment identity share a 183-bp conserved sequence termed homeo box. Homeo box sequences have been detected and cloned from the genomes of insects like Drosophila to vertebrates such as mouse and man. Two chicken homeo box genes CHox1 and CHox3, are described. Cloning of the CHox1 and CHox3 homeo boxes was performed using Drosophila and murine homeo box sequences as probes under low-stringency conditions. Analysis of both chicken homeo box sequences revealed them to be homeo boxes that have diverged from the Antennapedia class with homologies to homeo boxes of other organisms in the range of 75-42% at the nucleotide level and 69-41% at the protein level. Analysis of CHox3 expression during early embryo development showed that the gene codes for five transcripts 1.3, 1.9, 2.6, 5.6 and 7.9 kb in size. Three of the transcripts (1.3, 1.9 and 5.6 kb) are also recognized by a flanking non-homeo box containing probe. The levels of the different transcripts changed during the first five days of development. The most abundant transcripts (1.3 and 1.9 kb) are already present at the time the egg is laid. Their transcription peaks at day 1 of incubation and then decreases. The CHox1 transcripts are present at very low levels between days 2.5 and 4 of development. These two chicken genes represent bona fide Hox genes in a branch of vertebrates that evolved parallel to mammals. VL - 76 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/2568317?dopt=Abstract ER - TY - JOUR T1 - Nuclear envelope assembly around sperm chromatin in cell-free preparations from Drosophila embryos. JF - FEBS Lett Y1 - 1989 A1 - Ulitzur, N A1 - Gruenbaum, Y KW - Adenosine Triphosphate KW - Animals KW - Cell Nucleus KW - Cell-Free System KW - Chickens KW - Chromatin KW - DNA Topoisomerases, Type II KW - Drosophila melanogaster KW - In Vitro Techniques KW - Lamins KW - Male KW - Morphogenesis KW - Novobiocin KW - Nuclear Envelope KW - Nuclear Proteins KW - Spermatozoa AB - Chicken sperm chromatin initiated an assembly of interphase-like nuclei in a cell-free cytoplasmic preparation from 1-6 h old Drosophila melanogaster embryos. The formation of these interphase-like nuclei from the condensed sperm chromatin happened in a series of distinct steps. Anti-Drosophila lamin monoclonal antibody stained the assembled nuclei in a pattern indistinguishable from normal Drosophila nuclei. This assembly process required an ATP regenerating system and could be blocked by the addition of novobiocin into the cell-free extract. VL - 259 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/2557241?dopt=Abstract ER - TY - JOUR T1 - Persistence of major nuclear envelope antigens in an envelope-like structure during mitosis in Drosophila melanogaster embryos. JF - J Cell Sci Y1 - 1989 A1 - Harel, A A1 - Zlotkin, E A1 - Nainudel-Epszteyn, S A1 - Feinstein, N A1 - Fisher, P A A1 - Gruenbaum, Y KW - Animals KW - Antibodies, Monoclonal KW - Antigens KW - Drosophila melanogaster KW - Embryo, Nonmammalian KW - Lamins KW - Membrane Proteins KW - Microscopy, Electron KW - Mitosis KW - Nuclear Envelope KW - Nuclear Proteins AB - Using monoclonal antibodies, we followed the fate of three different nuclear envelope proteins during mitosis in Drosophila early embryos by indirect immunofluorescence microscopy. Two of these proteins, lamin and otefin, a newly characterized nuclear envelope polypeptide with an apparent Mr of 53,000, are apparently present in an envelope-like structure that is present throughout mitosis. Immunoelectron microscopy of interphase nuclei indicates that otefin, like lamin, is not a component of nuclear pore complexes. In contrast with lamin and otefin, gp188, a putative pore complex component, was completely redistributed through the surrounding cytoplasm during prophase in comparable early embryo specimens and was present in an envelope only in interphase. Together with previous morphological studies by other workers, these data suggest that the entire mitotic apparatus including condensed chromosomes and spindle is enclosed by an envelope throughout mitosis during early embryogenesis in Drosophila. This 'spindle envelope', as it has been named by others, contains both lamin and otefin but probably not pore complex proteins. VL - 94 ( Pt 3) U1 - http://www.ncbi.nlm.nih.gov/pubmed/2517292?dopt=Abstract ER - TY - JOUR T1 - Drosophila nuclear lamin precursor Dm0 is translated from either of two developmentally regulated mRNA species apparently encoded by a single gene. JF - J Cell Biol Y1 - 1988 A1 - Gruenbaum, Y A1 - Landesman, Y A1 - Drees, B A1 - Bare, J W A1 - Saumweber, H A1 - Paddy, M R A1 - Sedat, J W A1 - Smith, D E A1 - Benton, B M A1 - Fisher, P A KW - Amino Acid Sequence KW - Animals KW - Base Sequence KW - Cloning, Molecular KW - DNA KW - Drosophila melanogaster KW - Drosophila Proteins KW - Female KW - Genes KW - Immunoassay KW - Lamins KW - Molecular Sequence Data KW - Nuclear Proteins KW - Nucleic Acid Hybridization KW - Protein Biosynthesis KW - Protein Precursors KW - RNA, Messenger KW - Sequence Homology, Nucleic Acid KW - Transcription, Genetic AB - A cDNA clone encoding a portion of Drosophila nuclear lamins Dm1 and Dm2 has been identified by screening a lambda-gt11 cDNA expression library using Drosophila lamin-specific monoclonal antibodies. Two different developmentally regulated mRNA species were identified by Northern blot analysis using the initial cDNA as a probe, and full-length cDNA clones, apparently corresponding to each message, have been isolated. In vitro transcription of both full-length cDNA clones in a pT7 transcription vector followed by in vitro translation in wheat germ lysate suggests that both clones encode lamin Dm0, the polypeptide precursor of lamins Dm1 and Dm2. Nucleotide sequence analyses confirm the impression that both cDNA clones code for the identical polypeptide, which is highly homologous with human lamins A and C as well as with mammalian intermediate filament proteins. The two clones differ in their 3'-untranslated regions. In situ hybridization of lamin cDNA clones to Drosophila polytene chromosomes shows only a single locus of hybridization at or near position 25F on the left arm of chromosome 2. Southern blot analyses of genomic DNA are consistent with the notion that a single or only a few highly similar genes encoding Drosophila nuclear lamin Dm0 exist in the genome. VL - 106 IS - 3 U1 - http://www.ncbi.nlm.nih.gov/pubmed/3126192?dopt=Abstract ER - TY - JOUR T1 - Biosynthesis and interconversion of Drosophila nuclear lamin isoforms during normal growth and in response to heat shock. JF - J Cell Biol Y1 - 1987 A1 - Smith, D E A1 - Gruenbaum, Y A1 - Berrios, M A1 - Fisher, P A KW - Animals KW - Cloning, Molecular KW - Drosophila KW - Drosophila Proteins KW - Embryo, Nonmammalian KW - Heat-Shock Proteins KW - Hot Temperature KW - Lamins KW - Nuclear Envelope KW - Nucleoproteins KW - Protein Biosynthesis KW - Transcription, Genetic AB - Two major immunocross-reactive polypeptides of the Drosophila nuclear envelope, distinguishable in interphase cells on the basis of one-dimensional SDS-PAGE mobility, have been localized to the nuclear lamina by immunoelectron microscopy. These have been designated lamins Dm1 and Dm2. Both lamins are apparently derived posttranslationally from a single, primary translation product, lamin Dm0. A pathway has been established whereby lamin Dm0 is processed almost immediately upon synthesis in the cytoplasm to lamin Dm1. Processing occurs posttranslationally, is apparently proteolytic, and has been reconstituted from cell-free extracts in vitro. Processing in vitro is ATP dependent. Once assembled into the nuclear envelope, a portion of lamin Dm1 is converted into lamin Dm2 by differential phosphorylation. Throughout most stages of development and in Schneider 2 tissue culture cells, both lamin isoforms are present in approximately equal abundance. However, during heat shock, lamin Dm2 is converted nearly quantitatively into lamin Dm1. Implications for understanding the regulation of nuclear lamina plasticity through normal growth and in response to heat shock are discussed. VL - 105 IS - 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/3624309?dopt=Abstract ER - TY - JOUR T1 - Spatial organization of chromosomes in the salivary gland nuclei of Drosophila melanogaster. JF - J Cell Biol Y1 - 1986 A1 - Hochstrasser, M A1 - Mathog, D A1 - Gruenbaum, Y A1 - Saumweber, H A1 - Sedat, J W KW - Animals KW - Cell Nucleus KW - Chromosomes KW - Drosophila melanogaster KW - Nuclear Envelope KW - Salivary Glands AB - Using a computer-based system for model building and analysis, three-dimensional models of 24 Drosophila melanogaster salivary gland nuclei have been constructed from optically or physically sectioned glands, allowing several generalizations about chromosome folding and packaging in these nuclei. First and most surprising, the prominent coiling of the chromosomes is strongly chiral, with right-handed gyres predominating. Second, high frequency appositions between certain loci and the nuclear envelope appear almost exclusively at positions of intercalary heterochromatin; in addition, the chromocenter is always apposed to the envelope. Third, chromosomes are invariably separated into mutually exclusive spatial domains while usually extending across the nucleus in a polarized (Rabl) orientation. Fourth, the arms of each autosome are almost always juxtaposed, but no other relative arm positions are strongly favored. Finally, despite these nonrandom structural features, each chromosome is found to fold into a wide variety of different configurations. In addition, a set of nuclei has been analyzed in which the normally aggregrated centromeric regions of the chromosomes are located far apart from one another. These nuclei have the same architectural motifs seen in normal nuclei. This implies that such characteristics as separate chromosome domains and specific chromosome-nuclear envelope contacts are largely independent of the relative placement of the different chromosomes within the nucleus. VL - 102 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/3079766?dopt=Abstract ER - TY - JOUR T1 - Characteristic folding pattern of polytene chromosomes in Drosophila salivary gland nuclei. JF - Nature Y1 - 1984 A1 - Mathog, D A1 - Hochstrasser, M A1 - Gruenbaum, Y A1 - Saumweber, H A1 - Sedat, J KW - Animals KW - Cell Nucleus KW - Chromosomes KW - DNA KW - Drosophila melanogaster KW - Models, Genetic KW - Models, Molecular KW - Salivary Glands AB - A computer-based system for recording and analysing light microscope images, combined with classical cytogenetic analysis, has revealed the spatial organization of the giant chromosomes of Drosophila salivary gland cells. Each polytene chromosome arm folds up in a characteristic way, contacts the nuclear surface at specific sites and is topologically isolated from all other arms. VL - 308 IS - 5958 U1 - http://www.ncbi.nlm.nih.gov/pubmed/6424026?dopt=Abstract ER - TY - JOUR T1 - Spatial organization of the Drosophila nucleus: a three-dimensional cytogenetic study. JF - J Cell Sci Suppl Y1 - 1984 A1 - Gruenbaum, Y A1 - Hochstrasser, M A1 - Mathog, D A1 - Saumweber, H A1 - Agard, D A A1 - Sedat, J W KW - Animals KW - Cell Nucleus KW - Chromosomes KW - Computers KW - Drosophila melanogaster KW - Microscopy, Fluorescence KW - Models, Genetic KW - Salivary Glands KW - Transcription, Genetic AB - The combination of optical fluorescence microscopy with digital image processing and analysis has been used to examine the three-dimensional organization of chromosomes within intact polytene nuclei. Although the arrangement indicates a high degree of flexibility, there are many conserved features between nuclei at the same developmental state. For example, chromosome arms are loosely coiled with centromeres clustered at the opposite end of the nucleus from the telomeres. Individual chromosome arms are not interwoven but occupy different spatial domains. Chromosomal sites that contact the envelope correlate with intercalary heterochromatin. Connections are observed between actively transcribing regions. VL - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/6442295?dopt=Abstract ER - TY - JOUR T1 - Effect of DNA methylation on gene expression. JF - Cold Spring Harb Symp Quant Biol Y1 - 1983 A1 - Cedar, H A1 - Stein, R A1 - Gruenbaum, Y A1 - Naveh-Many, T A1 - Sciaky-Gallili, N A1 - Razin, A KW - Adenine Phosphoribosyltransferase KW - Adenoviridae KW - Animals KW - Cell Transformation, Neoplastic KW - Cricetinae KW - DNA KW - Genes KW - Globins KW - Humans KW - L Cells (Cell Line) KW - Macromolecular Substances KW - Methylation KW - Teratoma VL - 47 Pt 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/6574866?dopt=Abstract ER - TY - JOUR T1 - Methylation of replicating and post-replicated mouse L-cell DNA. JF - Proc Natl Acad Sci U S A Y1 - 1983 A1 - Gruenbaum, Y A1 - Szyf, M A1 - Cedar, H A1 - Razin, A KW - Animals KW - Deoxyguanine Nucleotides KW - DNA KW - DNA Replication KW - Kinetics KW - L Cells (Cell Line) KW - Methylation KW - Mice KW - Phosphorus Radioisotopes KW - S-Adenosylhomocysteine KW - S-Adenosylmethionine AB - We have introduced [alpha-32P]dGTP into permeabilized cells and measured the degree of methylation at CpG sites by nearest-neighbor analysis. This method reveals a lag of approximately 1 min between DNA synthesis and the modification event. When methylation is inhibited by the addition of S-adenosyl-L-homocysteine in the presence of continued DNA synthesis, the resulting hemimethylated sites are methylated immediately after the release of inhibition. The results suggest that the methylase activity in the cell allows immediate methylation but conditions at the replication fork bring about a short delay in the onset of the modification reaction. VL - 80 IS - 16 U1 - http://www.ncbi.nlm.nih.gov/pubmed/6576364?dopt=Abstract ER - TY - JOUR T1 - Sequence and substrate specificity of isolated DNA methylases from Escherichia coli C. JF - J Bacteriol Y1 - 1983 A1 - Urieli-Shoval, S A1 - Gruenbaum, Y A1 - Razin, A KW - Base Sequence KW - DNA (Cytosine-5-)-Methyltransferase KW - DNA, Bacterial KW - Escherichia coli KW - Methylation KW - Methyltransferases KW - Substrate Specificity AB - Two DNA methylase activities of Escherichia coli C, the mec (designates DNA-cytosine-methylase gene, which is also designated dcm) and dam gene products, were physically separated by DEAE-cellulose column chromatography. The sequence and substrate specificity of the two enzymes were studied in vitro. The experiments revealed that both enzymes show their expected sequence specificity under in vitro conditions, methylating symmetrically on both DNA strands. The mec enzyme methylates exclusively the internal cytosine residue of CCATGG sequences, and the dam enzyme methylates adenine residues at GATC sites. Substrate specificity experiments revealed that both enzymes methylate in vitro unmethylated duplex DNA as efficiently as hemimethylated DNA. The results of these experiments suggest that the methylation at a specific site takes place by two independent events. A methyl group in a site on one strand of the DNA does not facilitate the methylation of the same site on the opposite strand. With the dam methylase it was found that the enzyme is incapable of methylating GATC sites located at the ends of DNA molecules. VL - 153 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/6336735?dopt=Abstract ER - TY - JOUR T1 - The absence of detectable methylated bases in Drosophila melanogaster DNA. JF - FEBS Lett Y1 - 1982 A1 - Urieli-Shoval, S A1 - Gruenbaum, Y A1 - Sedat, J A1 - Razin, A KW - Animals KW - Cytosine KW - DNA KW - Drosophila melanogaster KW - Methylation KW - Salivary Glands VL - 146 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/6814955?dopt=Abstract ER - TY - JOUR T1 - Clonal inheritance of the pattern of DNA methylation in mouse cells. JF - Proc Natl Acad Sci U S A Y1 - 1982 A1 - Stein, R A1 - Gruenbaum, Y A1 - Pollack, Y A1 - Razin, A A1 - Cedar, H KW - 5-Methylcytosine KW - Animals KW - Bacteriophage phi X 174 KW - Cloning, Molecular KW - Cytosine KW - DNA KW - DNA (Cytosine-5-)-Methyltransferase KW - DNA, Viral KW - Haemophilus influenzae KW - L Cells (Cell Line) KW - Methylation KW - Methyltransferases KW - Mice AB - DNA-mediated gene transfer was used to investigate the mode of inheritance of 5-methylcytosine in mouse L cells. Unmethylated phi X174 replicative form DNA remains unmethylated after its introduction and integration into these cells. On the other hand, phi X174 replicative form DNA that was methylated in vitro at its C-C-G-G residues retains these methylations as shown by restriction enzyme analysis with Hpa II and Msp I to detect methylation at this specific site. Although these unselected methylated vectors are prone to lose 30-40% of their methyl moieties upon transfection, this demethylation appears to be random. Once established, the resulting methylation pattern is stable for at least 100 cell generations. In order to examine the specificity of methylation inheritance, fully hemimethylated duplex phi X174 DNA was synthesized in vitro from primed single-strand phi X174 DNA by using 5-methyl deoxycytidine 5'-triphosphate. This molecule was inserted into mouse L cells by cotransformation and subsequently was analyzed by a series of restriction enzymes. Only methylations located at C-G residues were conserved after many generations of cell growth. The results suggest that the inheritance of the cellular DNA methylation pattern is based on a C-G-specific methylase that operates on newly replicated hemimethylated DNA. VL - 79 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/6459581?dopt=Abstract ER - TY - JOUR T1 - Substrate and sequence specificity of a eukaryotic DNA methylase. JF - Nature Y1 - 1982 A1 - Gruenbaum, Y A1 - Cedar, H A1 - Razin, A KW - Animals KW - Base Sequence KW - DNA (Cytosine-5-)-Methyltransferase KW - Kinetics KW - L Cells (Cell Line) KW - Methyltransferases KW - Mice KW - Neoplasms, Experimental KW - Protein Biosynthesis KW - Substrate Specificity VL - 295 IS - 5850 U1 - http://www.ncbi.nlm.nih.gov/pubmed/7057921?dopt=Abstract ER - TY - JOUR T1 - Studies on the biological role of DNA methylation: V. The pattern of E.coli DNA methylation. JF - Nucleic Acids Res Y1 - 1982 A1 - Szyf, M A1 - Gruenbaum, Y A1 - Urieli-Shoval, S A1 - Razin, A KW - Base Composition KW - Base Sequence KW - DNA KW - DNA Replication KW - DNA Restriction Enzymes KW - DNA, Bacterial KW - DNA, Ribosomal KW - Escherichia coli KW - Genes KW - Methylation KW - Nucleic Acid Hybridization KW - RNA, Ribosomal AB - The distribution of the methylatable sites GATC and CCATGG was studied by analyzing the molecular average size of restriction fragments of E. coli DNA. Both sites were found to be randomly distributed, reflecting a random pattern of methylation. The methylation pattern of specific sequences such as the origin of replication and rRNA genes has been studied in wild type E. coli and a methylation deficient (dam- dcm-) mutant. These sequences were found to be methylated in wild type cells and unmethylated in the mutant indicating that there is no effect of the state of methylation of these sequences on their expression. Analysis of the state of methylation of GATC sites in newly replicating DNA using the restriction enzyme Dpn I (cleaves only when both strands are methylated) revealed no detectable hemimethylated DNA suggesting that methylation occurs at the replication fork. Taking together the results presented here and previously published data (5), we arrive at the conclusion that the most likely function of E. coli DNA methylations is probably in preventing nuclease activity. VL - 10 IS - 22 U1 - http://www.ncbi.nlm.nih.gov/pubmed/6296768?dopt=Abstract ER - TY - JOUR T1 - Methylation of CpG sequences in eukaryotic DNA. JF - FEBS Lett Y1 - 1981 A1 - Gruenbaum, Y A1 - Stein, R A1 - Cedar, H A1 - Razin, A KW - Animals KW - Base Sequence KW - Carcinoma, Ehrlich Tumor KW - Cytosine KW - DNA KW - DNA (Cytosine-5-)-Methyltransferase KW - Guanine KW - Kinetics KW - Methylation KW - Methyltransferases KW - Mice KW - Species Specificity KW - Substrate Specificity VL - 124 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/7215556?dopt=Abstract ER - TY - JOUR T1 - Restriction enzyme digestion of hemimethylated DNA. JF - Nucleic Acids Res Y1 - 1981 A1 - Gruenbaum, Y A1 - Cedar, H A1 - Razin, A KW - Bacteriophage phi X 174 KW - Base Sequence KW - DNA Polymerase I KW - DNA Repair KW - DNA Restriction Enzymes KW - DNA, Viral KW - Escherichia coli AB - Hemimethylated duplex DNA of the bacteriophage phi X 174 was synthesized using primed repair synthesis is in vitro with E. coli DNA polymerase I followed by ligation to produce the covalently closed circular duplex (RFI). Single-stranded phi X DNA was used as a template, a synthetic oligonucleotide as primer and 5-methyldeoxycytidine-5'-triphosphate (5mdCTP) was used in place of dCTP. The hemimethylated product was used as substrate for cleavage by various restriction enzymes. Out of the 17 enzymes tested, only 5 (BstN I, Taq I, Hinc II, Hinf I and Hpa I) cleaved the hemimethylated DNA. Two enzymes (Msp I and Hae III) were able to produce nicks on the unmethylated strand of the cleavage site. Msp I, which is known to cleave at CCGG when the internal cytosine residue is methylated, does not cleave when both cytosines are methylated. Another enzyme, Apy I, cleaves at the sequence CCTAGG when the internal cytosine is methylated, but is inactive on hemimethylated DNA in which both cytosines are methylated. Hemimethylated molecules should be useful for studying DNA methylation both in vivo and in vitro. VL - 9 IS - 11 U1 - http://www.ncbi.nlm.nih.gov/pubmed/6269052?dopt=Abstract ER - TY - JOUR T1 - Sequence specificity of methylation in higher plant DNA. JF - Nature Y1 - 1981 A1 - Gruenbaum, Y A1 - Naveh-Many, T A1 - Cedar, H A1 - Razin, A KW - 5-Methylcytosine KW - Animals KW - Base Sequence KW - Cytosine KW - DNA KW - DNA Restriction Enzymes KW - Methylation KW - Mice KW - Plants VL - 292 IS - 5826 U1 - http://www.ncbi.nlm.nih.gov/pubmed/6267477?dopt=Abstract ER - TY - JOUR T1 - Studies on the biological role of dna methylation; IV. Mode of methylation of DNA in E. coli cells. JF - Nucleic Acids Res Y1 - 1980 A1 - Razin, A A1 - Urieli, S A1 - Pollack, Y A1 - Gruenbaum, Y A1 - Glaser, G KW - Base Sequence KW - DNA (Cytosine-5-)-Methyltransferase KW - DNA Restriction Enzymes KW - DNA, Bacterial KW - Escherichia coli KW - Methylation KW - Methyltransferases KW - Molecular Weight AB - Two pairs of restriction enzyme isoschizomers were used to study in vivo methylation of E. coli and extrachromosomal DNA. By use of the restriction enzymes MboI (which cleaves only the unmethylated GATC sequence) and its isoschizomer Sau3A (indifferent to methylated adenine at this sequence), we found that all the GATC sites in E. coli and in extrachromosomal DNAs are symmetrically methylated on both strands. The calculated number of GATC sites in E. coli DNA can account for all its m6Ade residues. Foreign DNA, like mouse mtDNA, which is not methylated at GATC sites became fully methylated at these sequences when introduced by transfection into E. coli cells. This experiment provides the first evidence for the operation of a de novo methylation mechanism for E. coli methylases not involved in restriction modification. When the two restriction enzyme isoschizomers, EcoRII and ApyI, were used to analyze the methylation pattern of CCTAGG sequences in E. coli C and phi X174 DNA, it was found that all these sites are methylated. The number of CCTAGG sites in E. coli C DNA does not account for all m5Cyt residues. VL - 8 IS - 8 U1 - http://www.ncbi.nlm.nih.gov/pubmed/6253948?dopt=Abstract ER -