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Kuzelova A, Dupacova N, Antosova B, Sunny SS, Kozmik Z, Paces J, Skoultchi AI, Stopka T, Kozmik Z. Chromatin Remodeling Enzyme Snf2h Is Essential for Retinal Cell Proliferation and Photoreceptor Maintenance. Cells 2023; 12:cells12071035. [PMID: 37048108 PMCID: PMC10093269 DOI: 10.3390/cells12071035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 03/31/2023] Open
Abstract
Chromatin remodeling complexes are required for many distinct nuclear processes such as transcription, DNA replication, and DNA repair. However, the contribution of these complexes to the development of complex tissues within an organism is poorly characterized. Imitation switch (ISWI) proteins are among the most evolutionarily conserved ATP-dependent chromatin remodeling factors and are represented by yeast Isw1/Isw2, and their vertebrate counterparts Snf2h (Smarca5) and Snf2l (Smarca1). In this study, we focused on the role of the Snf2h gene during the development of the mammalian retina. We show that Snf2h is expressed in both retinal progenitors and post-mitotic retinal cells. Using Snf2h conditional knockout mice (Snf2h cKO), we found that when Snf2h is deleted, the laminar structure of the adult retina is not retained, the overall thickness of the retina is significantly reduced compared with controls, and the outer nuclear layer (ONL) is completely missing. The depletion of Snf2h did not influence the ability of retinal progenitors to generate all the differentiated retinal cell types. Instead, the Snf2h function is critical for the proliferation of retinal progenitor cells. Cells lacking Snf2h have a defective S-phase, leading to the entire cell division process impairments. Although all retinal cell types appear to be specified in the absence of the Snf2h function, cell-cycle defects and concomitantly increased apoptosis in Snf2h cKO result in abnormal retina lamination, complete destruction of the photoreceptor layer, and consequently, a physiologically non-functional retina.
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Affiliation(s)
- Andrea Kuzelova
- Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Naoko Dupacova
- Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Barbora Antosova
- Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Sweetu Susan Sunny
- Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Zbynek Kozmik
- Laboratory of Genomics and Bioinformatics, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Jan Paces
- Laboratory of Genomics and Bioinformatics, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Arthur I. Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461, USA
| | - Tomas Stopka
- Biocev, First Faculty of Medicine, Charles University, Prumyslova 595, 252 50 Vestec, Czech Republic
| | - Zbynek Kozmik
- Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
- Research Unit for Rare Diseases, Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
- Correspondence: ; Tel.: +420-241-062-100; Fax: +420-224-310-955
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Kuzelova A, Dupacova N, Antosova B, Sunny SS, Kozmik Z, Paces J, Skoultchi AI, Stopka T, Kozmik Z. Chromatin remodeling enzyme Snf2h is essential for retinal cell proliferation and photoreceptor maintenance. bioRxiv 2023:2023.02.13.528323. [PMID: 36824843 PMCID: PMC9948993 DOI: 10.1101/2023.02.13.528323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Chromatin remodeling complexes are required for many distinct nuclear processes such as transcription, DNA replication and DNA repair. However, how these complexes contribute to the development of complex tissues within an organism is poorly characterized. Imitation switch (ISWI) proteins are among the most evolutionarily conserved ATP-dependent chromatin remodeling factors and are represented by yeast Isw1/Isw2, and their vertebrate counterparts Snf2h (Smarca5) and Snf2l (Smarca1). In this study, we focused on the role of the Snf2h gene during development of the mammalian retina. We show that Snf2h is expressed in both retinal progenitors and post-mitotic retinal cells. Using Snf2h conditional knockout mice ( Snf2h cKO), we found that when Snf2h is deleted the laminar structure of the adult retina is not retained, the overall thickness of the retina is significantly reduced compared with controls, and the outer nuclear layer (ONL) is completely missing. Depletion of Snf2h did not influence the ability of retinal progenitors to generate all of the differentiated retinal cell types. Instead, Snf2h function is critical for proliferation of retinal progenitor cells. Cells lacking Snf2h have a defective S-phase, leading to the entire cell division process impairments. Although, all retinal cell types appear to be specified in the absence of Snf2h function, cell cycle defects and concomitantly increased apoptosis in Snf2h cKO result in abnormal retina lamination, complete destruction of the photoreceptor layer and, consequently, in a physiologically non-functional retina.
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Andreyeva EN, Emelyanov AV, Nevil M, Sun L, Vershilova E, Hill CA, Keogh MC, Duronio RJ, Skoultchi AI, Fyodorov DV. Drosophila SUMM4 complex couples insulator function and DNA replication control. eLife 2022; 11:e81828. [PMID: 36458689 PMCID: PMC9917439 DOI: 10.7554/elife.81828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 11/28/2022] [Indexed: 12/05/2022] Open
Abstract
Asynchronous replication of chromosome domains during S phase is essential for eukaryotic genome function, but the mechanisms establishing which domains replicate early versus late in different cell types remain incompletely understood. Intercalary heterochromatin domains replicate very late in both diploid chromosomes of dividing cells and in endoreplicating polytene chromosomes where they are also underreplicated. Drosophila SNF2-related factor SUUR imparts locus-specific underreplication of polytene chromosomes. SUUR negatively regulates DNA replication fork progression; however, its mechanism of action remains obscure. Here, we developed a novel method termed MS-Enabled Rapid protein Complex Identification (MERCI) to isolate a stable stoichiometric native complex SUMM4 that comprises SUUR and a chromatin boundary protein Mod(Mdg4)-67.2. Mod(Mdg4) stimulates SUUR ATPase activity and is required for a normal spatiotemporal distribution of SUUR in vivo. SUUR and Mod(Mdg4)-67.2 together mediate the activities of gypsy insulator that prevent certain enhancer-promoter interactions and establish euchromatin-heterochromatin barriers in the genome. Furthermore, SuUR or mod(mdg4) mutations reverse underreplication of intercalary heterochromatin. Thus, SUMM4 can impart late replication of intercalary heterochromatin by attenuating the progression of replication forks through euchromatin/heterochromatin boundaries. Our findings implicate a SNF2 family ATP-dependent motor protein SUUR in the insulator function, reveal that DNA replication can be delayed by a chromatin barrier, and uncover a critical role for architectural proteins in replication control. They suggest a mechanism for the establishment of late replication that does not depend on an asynchronous firing of late replication origins.
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Affiliation(s)
- Evgeniya N Andreyeva
- Department of Cell Biology, Albert Einstein College of MedicineBronxUnited States
| | | | - Markus Nevil
- UNC-SPIRE, University of North CarolinaChapel HillUnited States
| | - Lu Sun
- EpiCypherDurhamUnited States
| | - Elena Vershilova
- Department of Cell Biology, Albert Einstein College of MedicineBronxUnited States
| | - Christina A Hill
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel HillChapel HillUnited States
| | | | - Robert J Duronio
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel HillChapel HillUnited States
- Lineberger Comprehensive Cancer Center, University of North CarolinaChapel HillUnited States
- Department of Biology, University of North CarolinaChapel HillUnited States
- Department of Genetics, University of North CarolinaChapel HillUnited States
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of MedicineBronxUnited States
| | - Dmitry V Fyodorov
- Department of Cell Biology, Albert Einstein College of MedicineBronxUnited States
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Daily JP, Skoultchi AI, Tomaselli GF. A tribute to Paul S. Frenette (1965–2021). J Clin Invest 2021. [DOI: 10.1172/jci155100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Willcockson MA, Healton SE, Weiss CN, Bartholdy BA, Botbol Y, Mishra LN, Sidhwani DS, Wilson TJ, Pinto HB, Maron MI, Skalina KA, Toro LN, Zhao J, Lee CH, Hou H, Yusufova N, Meydan C, Osunsade A, David Y, Cesarman E, Melnick AM, Sidoli S, Garcia BA, Edelmann W, Macian F, Skoultchi AI. H1 histones control the epigenetic landscape by local chromatin compaction. Nature 2021; 589:293-298. [PMID: 33299182 PMCID: PMC8110206 DOI: 10.1038/s41586-020-3032-z] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 10/06/2020] [Indexed: 01/29/2023]
Abstract
H1 linker histones are the most abundant chromatin-binding proteins1. In vitro studies indicate that their association with chromatin determines nucleosome spacing and enables arrays of nucleosomes to fold into more compact chromatin structures. However, the in vivo roles of H1 are poorly understood2. Here we show that the local density of H1 controls the balance of repressive and active chromatin domains by promoting genomic compaction. We generated a conditional triple-H1-knockout mouse strain and depleted H1 in haematopoietic cells. H1 depletion in T cells leads to de-repression of T cell activation genes, a process that mimics normal T cell activation. Comparison of chromatin structure in normal and H1-depleted CD8+ T cells reveals that H1-mediated chromatin compaction occurs primarily in regions of the genome containing higher than average levels of H1: the chromosome conformation capture (Hi-C) B compartment and regions of the Hi-C A compartment marked by PRC2. Reduction of H1 stoichiometry leads to decreased H3K27 methylation, increased H3K36 methylation, B-to-A-compartment shifting and an increase in interaction frequency between compartments. In vitro, H1 promotes PRC2-mediated H3K27 methylation and inhibits NSD2-mediated H3K36 methylation. Mechanistically, H1 mediates these opposite effects by promoting physical compaction of the chromatin substrate. Our results establish H1 as a critical regulator of gene silencing through localized control of chromatin compaction, 3D genome organization and the epigenetic landscape.
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Affiliation(s)
| | - Sean E Healton
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Cary N Weiss
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Boris A Bartholdy
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Yair Botbol
- Department of Pathology, Albert Einstein College of Medicine, New York, NY, USA
| | - Laxmi N Mishra
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Dhruv S Sidhwani
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Tommy J Wilson
- Department of Neurology, Columbia University College of Physicians and Surgeons, Columbia University Medical Center, New York Presbyterian Hospital, New York, NY, USA
| | - Hugo B Pinto
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Maxim I Maron
- Department of Biochemistry, Albert Einstein College of Medicine, New York, NY, USA
| | - Karin A Skalina
- Department of Pathology, Albert Einstein College of Medicine, New York, NY, USA
| | - Laura Norwood Toro
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Jie Zhao
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Chul-Hwan Lee
- Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
- Department of Pharmacology, Seoul National University College of Medicine, Seoul, Korea
| | - Harry Hou
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Nevin Yusufova
- Cell & Molecular Biology Graduate Program, Weill Cornell Medicine, New York, NY, USA
- Division of Hematology/Oncology, Department of Medicine, Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Cem Meydan
- Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA
| | - Adewola Osunsade
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Tri-Institutional PhD Program in Chemical Biology, New York, NY, USA
| | - Yael David
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Tri-Institutional PhD Program in Chemical Biology, New York, NY, USA
| | - Ethel Cesarman
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Ari M Melnick
- Division of Hematology/Oncology, Department of Medicine, Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Simone Sidoli
- Department of Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Smilow Center for Translational Research, Philadelphia, PA, USA
- Department of Biochemistry, Albert Einstein College of Medicine, New York, NY, USA
| | - Benjamin A Garcia
- Department of Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Smilow Center for Translational Research, Philadelphia, PA, USA
| | - Winfried Edelmann
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Fernando Macian
- Department of Pathology, Albert Einstein College of Medicine, New York, NY, USA
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA.
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Wheat JC, Sella Y, Willcockson M, Skoultchi AI, Bergman A, Singer RH, Steidl U. Single-molecule imaging of transcription dynamics in somatic stem cells. Nature 2020; 583:431-436. [PMID: 32581360 PMCID: PMC8577313 DOI: 10.1038/s41586-020-2432-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 03/31/2020] [Indexed: 12/17/2022]
Abstract
Molecular noise is a natural phenomenon inherent to all biological systems1,2. How stochastic processes give rise to the robust outcomes supportive of tissue homeostasis is a conundrum. Here, to quantitatively investigate this issue, we use single-molecule mRNA FISH (smFISH) on stem cells derived from hematopoietic tissue to measure the transcription dynamics of three key transcription factor (TF) genes: PU.1, Gata1 and Gata2. Our results indicate that infrequent, stochastic bursts of transcription result in the co-expression of these antagonistic TF in the majority of hematopoietic stem and progenitor cells. Moreover, by pairing smFISH to time-lapse microscopy and the analysis of pedigrees, we find that while individual stem cell clones produce offspring that are in transcriptionally related states, akin to a transcriptional priming phenomenon, the underlying transition dynamics between states are nevertheless best captured by stochastic and reversible models. As such, the outcome of a stochastic process can produce cellular behaviors that may be incorrectly inferred to have arisen from deterministic dynamics. In light of our findings, we propose a model whereby the intrinsic stochasticity of gene expression facilitates, rather than impedes, concomitant maintenance of transcriptional plasticity and stem cell robustness.
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Affiliation(s)
- Justin C Wheat
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA.,Ruth L. and David S. Gottesman Institute for Stem Cell Research and Regenerative Medicine, Albert Einstein College of Medicine, New York, NY, USA
| | - Yehonatan Sella
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Michael Willcockson
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Aviv Bergman
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, New York, NY, USA.,Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, USA.,Department of Pathology, Albert Einstein College of Medicine, New York, NY, USA.,Santa Fe Institute, Santa Fe, NM, USA
| | - Robert H Singer
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA.,Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, USA.,Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, New York, NY, USA.,Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, New York, NY, USA.,Janelia Research Campus of the HHMI, Ashburn, VA, USA
| | - Ulrich Steidl
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA. .,Ruth L. and David S. Gottesman Institute for Stem Cell Research and Regenerative Medicine, Albert Einstein College of Medicine, New York, NY, USA. .,Department of Medicine (Oncology), Albert Einstein College of Medicine-Montefiore Medical Center, New York, NY, USA. .,Albert Einstein Cancer Center, Albert Einstein College of Medicine, New York, NY, USA.
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Sollberger G, Streeck R, Apel F, Caffrey BE, Skoultchi AI, Zychlinsky A. Linker histone H1.2 and H1.4 affect the neutrophil lineage determination. eLife 2020; 9:52563. [PMID: 32391789 PMCID: PMC7250579 DOI: 10.7554/elife.52563] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 05/08/2020] [Indexed: 12/23/2022] Open
Abstract
Neutrophils are important innate immune cells that tackle invading pathogens with different effector mechanisms. They acquire this antimicrobial potential during their maturation in the bone marrow, where they differentiate from hematopoietic stem cells in a process called granulopoiesis. Mature neutrophils are terminally differentiated and short-lived with a high turnover rate. Here, we show a critical role for linker histone H1 on the differentiation and function of neutrophils using a genome-wide CRISPR/Cas9 screen in the human cell line PLB-985. We systematically disrupted expression of somatic H1 subtypes to show that individual H1 subtypes affect PLB-985 maturation in opposite ways. Loss of H1.2 and H1.4 induced an eosinophil-like transcriptional program, thereby negatively regulating the differentiation into the neutrophil lineage. Importantly, H1 subtypes also affect neutrophil differentiation and the eosinophil-directed bias of murine bone marrow stem cells, demonstrating an unexpected subtype-specific role for H1 in granulopoiesis.
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Affiliation(s)
- Gabriel Sollberger
- Max Planck Institute for Infection Biology, Department of Cellular Microbiology, Berlin, Germany.,University of Dundee, School of Life Sciences, Division of Cell Signalling and Immunology, Dundee, United Kingdom
| | - Robert Streeck
- Max Planck Institute for Infection Biology, Department of Cellular Microbiology, Berlin, Germany.,Institut für Biologie, Humboldt Universität zu Berlin, Berlin, Germany
| | - Falko Apel
- Max Planck Institute for Infection Biology, Department of Cellular Microbiology, Berlin, Germany.,Institut für Biologie, Humboldt Universität zu Berlin, Berlin, Germany
| | | | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, United States
| | - Arturo Zychlinsky
- Max Planck Institute for Infection Biology, Department of Cellular Microbiology, Berlin, Germany
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Zhang C, Chen Z, Yin Q, Fu X, Li Y, Stopka T, Skoultchi AI, Zhang Y. The chromatin remodeler Snf2h is essential for oocyte meiotic cell cycle progression. Genes Dev 2020; 34:166-178. [PMID: 31919188 PMCID: PMC7000916 DOI: 10.1101/gad.331157.119] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 12/16/2019] [Indexed: 12/13/2022]
Abstract
In this study, Zhang et al. set out to describe the molecular mechanisms underlying meiotic chromatin remodeling and meiotic resumption during oocyte development. Using a combination of in vivo and genomic approaches, the authors demonstrate that Snf2h, the catalytic subunit of ISWI family complexes, is critical in driving meiotic progression and acts by regulating the expression of genes important for maturation-promoting factor (MPF) activation. Oocytes are indispensable for mammalian life. Thus, it is important to understand how mature oocytes are generated. As a critical stage of oocytes development, meiosis has been extensively studied, yet how chromatin remodeling contributes to this process is largely unknown. Here, we demonstrate that the ATP-dependent chromatin remodeling factor Snf2h (also known as Smarca5) plays a critical role in regulating meiotic cell cycle progression. Females with oocyte-specific depletion of Snf2h are infertile and oocytes lacking Snf2h fail to undergo meiotic resumption. Mechanistically, depletion of Snf2h results in dysregulation of meiosis-related genes, which causes failure of maturation-promoting factor (MPF) activation. ATAC-seq analysis in oocytes revealed that Snf2h regulates transcription of key meiotic genes, such as Prkar2b, by increasing its promoter chromatin accessibility. Thus, our studies not only demonstrate the importance of Snf2h in oocyte meiotic resumption, but also reveal the mechanism underlying how a chromatin remodeling factor can regulate oocyte meiosis.
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Affiliation(s)
- Chunxia Zhang
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Division of Hematology/Oncology, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Zhiyuan Chen
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Division of Hematology/Oncology, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Qiangzong Yin
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Division of Hematology/Oncology, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Xudong Fu
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Division of Hematology/Oncology, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Yisi Li
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Division of Hematology/Oncology, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Department of Automation, Tsinghua University, Beijing 100084, China
| | - Tomas Stopka
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Yi Zhang
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Division of Hematology/Oncology, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.,Harvard Stem Cell Institute, Boston, Massachusetts 02115, USA
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Limi S, Zhao Y, Guo P, Lopez-Jones M, Zheng D, Singer RH, Skoultchi AI, Cvekl A. Bidirectional Analysis of Cryba4-Crybb1 Nascent Transcription and Nuclear Accumulation of Crybb3 mRNAs in Lens Fibers. Invest Ophthalmol Vis Sci 2019; 60:234-244. [PMID: 30646012 PMCID: PMC6336207 DOI: 10.1167/iovs.18-25921] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Purpose Crystallin gene expression during lens fiber cell differentiation is tightly spatially and temporally regulated. A significant fraction of mammalian genes is transcribed from adjacent promoters in opposite directions ("bidirectional" promoters). It is not known whether two proximal genes located on the same allele are simultaneously transcribed. Methods Mouse lens transcriptome was analyzed for paired genes whose transcriptional start sites are separated by less than 5 kbp to identify coexpressed bidirectional promoter gene pairs. To probe these transcriptional mechanisms, nascent transcription of Cryba4, Crybb1, and Crybb3 genes from gene-rich part of chromosome 5 was visualized by RNA fluorescent in situ hybridizations (RNA FISH) in individual lens fiber cell nuclei. Results Genome-wide lens transcriptome analysis by RNA-seq revealed that the Cryba4-Crybb1 pair has the highest Pearson correlation coefficient between their steady-state mRNA levels. Analysis of Cryba4 and Crybb1 nascent transcription revealed frequent simultaneous expression of both genes from the same allele. Nascent Crybb3 transcript visualization in "early" but not "late" differentiating lens fibers show nuclear accumulation of the spliced Crybb3 transcripts that was not affected in abnormal lens fiber cell nuclei depleted of chromatin remodeling enzyme Snf2h (Smarca5). Conclusions The current study shows for the first time that two highly expressed lens crystallin genes, Cryba4 and Crybb1, can be simultaneously transcribed from adjacent bidirectional promoters and do not show nuclear accumulation. In contrast, spliced Crybb3 mRNAs transiently accumulate in early lens fiber cell nuclei. The gene pairs coexpressed during lens development showed significant enrichment in human "cataract" phenotype.
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Affiliation(s)
- Saima Limi
- Departments of Genetics, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Yilin Zhao
- Departments of Genetics, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Peng Guo
- Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Melissa Lopez-Jones
- Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Deyou Zheng
- Departments of Genetics, Albert Einstein College of Medicine, Bronx, New York, United States.,Neurology, Albert Einstein College of Medicine, Bronx, New York, United States.,Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Robert H Singer
- Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Arthur I Skoultchi
- Cell Biology, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Ales Cvekl
- Departments of Genetics, Albert Einstein College of Medicine, Bronx, New York, United States.,Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, New York, United States
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10
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Zikmund T, Kokavec J, Turkova T, Savvulidi F, Paszekova H, Vodenkova S, Sedlacek R, Skoultchi AI, Stopka T. ISWI ATPase Smarca5 Regulates Differentiation of Thymocytes Undergoing β-Selection. J Immunol 2019; 202:3434-3446. [PMID: 31068388 DOI: 10.4049/jimmunol.1801684] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 04/15/2019] [Indexed: 01/13/2023]
Abstract
Development of lymphoid progenitors requires a coordinated regulation of gene expression, DNA replication, and gene rearrangement. Chromatin-remodeling activities directed by SWI/SNF2 superfamily complexes play important roles in these processes. In this study, we used a conditional knockout mouse model to investigate the role of Smarca5, a member of the ISWI subfamily of such complexes, in early lymphocyte development. Smarca5 deficiency results in a developmental block at the DN3 stage of αβ thymocytes and pro-B stage of early B cells at which the rearrangement of Ag receptor loci occurs. It also disturbs the development of committed (CD73+) γδ thymocytes. The αβ thymocyte block is accompanied by massive apoptotic depletion of β-selected double-negative DN3 cells and premitotic arrest of CD4/CD8 double-positive cells. Although Smarca5-deficient αβ T cell precursors that survived apoptosis were able to undergo a successful TCRβ rearrangement, they exhibited a highly abnormal mRNA profile, including the persistent expression of CD44 and CD25 markers characteristic of immature cells. We also observed that the p53 pathway became activated in these cells and that a deficiency of p53 partially rescued the defect in thymus cellularity (in contrast to early B cells) of Smarca5-deficient mice. However, the activation of p53 was not primarily responsible for the thymocyte developmental defects observed in the Smarca5 mutants. Our results indicate that Smarca5 plays a key role in the development of thymocytes undergoing β-selection, γδ thymocytes, and also B cell progenitors by regulating the transcription of early differentiation programs.
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Affiliation(s)
- Tomas Zikmund
- BIOCEV, First Faculty of Medicine, Charles University, Vestec 25250, Czech Republic
| | - Juraj Kokavec
- BIOCEV, First Faculty of Medicine, Charles University, Vestec 25250, Czech Republic
| | - Tereza Turkova
- BIOCEV, First Faculty of Medicine, Charles University, Vestec 25250, Czech Republic
| | - Filipp Savvulidi
- Institute of Pathological Physiology, First Faculty of Medicine, Charles University, Prague 12853, Czech Republic
| | - Helena Paszekova
- BIOCEV, First Faculty of Medicine, Charles University, Vestec 25250, Czech Republic
| | - Sona Vodenkova
- Institute of Experimental Medicine, Czech Academy of Sciences, Prague 14220, Czech Republic.,Third Faculty of Medicine, Charles University, Prague 10000, Czech Republic
| | - Radislav Sedlacek
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, Vestec 25250, Czech Republic; and
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx 10461, NY
| | - Tomas Stopka
- BIOCEV, First Faculty of Medicine, Charles University, Vestec 25250, Czech Republic;
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11
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Limi S, Senecal A, Coleman R, Lopez-Jones M, Guo P, Polumbo C, Singer RH, Skoultchi AI, Cvekl A. Transcriptional burst fraction and size dynamics during lens fiber cell differentiation and detailed insights into the denucleation process. J Biol Chem 2018; 293:13176-13190. [PMID: 29959226 DOI: 10.1074/jbc.ra118.001927] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 06/11/2018] [Indexed: 01/05/2023] Open
Abstract
Genes are transcribed in irregular pulses of activity termed transcriptional bursts. Cellular differentiation requires coordinated gene expression; however, it is unknown whether the burst fraction (i.e. the number of active phases of transcription) or size/intensity (the number of RNA molecules produced within a burst) changes during cell differentiation. In the ocular lens, the positions of lens fiber cells correlate precisely with their differentiation status, and the most advanced cells degrade their nuclei. Here, we examined the transcriptional parameters of the β-actin and lens differentiation-specific α-, β-, and γ-crystallin genes by RNA fluorescent in situ hybridization (FISH) in the lenses of embryonic day (E) E12.5, E14.5, and E16.5 mouse embryos and newborns. We found that cellular differentiation dramatically alters the burst fraction in synchronized waves across the lens fiber cell compartment with less dramatic changes in burst intensity. Surprisingly, we observed nascent transcription of multiple genes in nuclei just before nuclear destruction. Nuclear condensation was accompanied by transfer of nuclear proteins, including histone and nonhistone proteins, to the cytoplasm. Although lens-specific deletion of the chromatin remodeler SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A member 5 (Smarca5/Snf2h) interfered with denucleation, persisting nuclei remained transcriptionally competent and exhibited changes in both burst intensity and fraction depending on the gene examined. Our results uncover the mechanisms of nascent transcriptional control during differentiation and chromatin remodeling, confirm the burst fraction as the major factor adjusting gene expression levels, and reveal transcriptional competence of fiber cell nuclei even as they approach disintegration.
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Affiliation(s)
| | | | | | | | | | | | - Robert H Singer
- Anatomy and Structural Biology.,Cell Biology.,Neuroscience, and
| | | | - Ales Cvekl
- From the Departments of Genetics, .,Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, New York 10461
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12
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Andreyeva EN, Bernardo TJ, Kolesnikova TD, Lu X, Yarinich LA, Bartholdy BA, Guo X, Posukh OV, Healton S, Willcockson MA, Pindyurin AV, Zhimulev IF, Skoultchi AI, Fyodorov DV. Regulatory functions and chromatin loading dynamics of linker histone H1 during endoreplication in Drosophila. Genes Dev 2017; 31:603-616. [PMID: 28404631 PMCID: PMC5393055 DOI: 10.1101/gad.295717.116] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Accepted: 03/03/2017] [Indexed: 12/22/2022]
Abstract
Here, Andreyeva et al. show that linker histone H1 is required for the underreplicated phenomenon in Drosophila salivary glands, in which tissues undergo endoreplication without cell division, and the latest replicating regions occasionally fail to complete endoreplication, resulting in underreplicated domains of polytene chromosomes. They demonstrate that H1 directly interacts with the suppressor of underreplication (SUUR) protein and is required for SUUR binding to chromatin in vivo and that the localization of H1 in chromatin changes profoundly during the endocycle. Eukaryotic DNA replicates asynchronously, with discrete genomic loci replicating during different stages of S phase. Drosophila larval tissues undergo endoreplication without cell division, and the latest replicating regions occasionally fail to complete endoreplication, resulting in underreplicated domains of polytene chromosomes. Here we show that linker histone H1 is required for the underreplication (UR) phenomenon in Drosophila salivary glands. H1 directly interacts with the Suppressor of UR (SUUR) protein and is required for SUUR binding to chromatin in vivo. These observations implicate H1 as a critical factor in the formation of underreplicated regions and an upstream effector of SUUR. We also demonstrate that the localization of H1 in chromatin changes profoundly during the endocycle. At the onset of endocycle S (endo-S) phase, H1 is heavily and specifically loaded into late replicating genomic regions and is then redistributed during the course of endoreplication. Our data suggest that cell cycle-dependent chromosome occupancy of H1 is governed by several independent processes. In addition to the ubiquitous replication-related disassembly and reassembly of chromatin, H1 is deposited into chromatin through a novel pathway that is replication-independent, rapid, and locus-specific. This cell cycle-directed dynamic localization of H1 in chromatin may play an important role in the regulation of DNA replication timing.
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Affiliation(s)
- Evgeniya N Andreyeva
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russian Federation
| | - Travis J Bernardo
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Tatyana D Kolesnikova
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russian Federation.,Novosibirsk State University, Novosibirsk 630090, Russian Federation
| | - Xingwu Lu
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Lyubov A Yarinich
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russian Federation.,Novosibirsk State University, Novosibirsk 630090, Russian Federation
| | - Boris A Bartholdy
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Xiaohan Guo
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Olga V Posukh
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russian Federation
| | - Sean Healton
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Michael A Willcockson
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Alexey V Pindyurin
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russian Federation
| | - Igor F Zhimulev
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russian Federation.,Novosibirsk State University, Novosibirsk 630090, Russian Federation
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Dmitry V Fyodorov
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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13
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Kokavec J, Zikmund T, Savvulidi F, Kulvait V, Edelmann W, Skoultchi AI, Stopka T. The ISWI ATPase Smarca5 (Snf2h) Is Required for Proliferation and Differentiation of Hematopoietic Stem and Progenitor Cells. Stem Cells 2017; 35:1614-1623. [PMID: 28276606 DOI: 10.1002/stem.2604] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 12/14/2016] [Accepted: 01/09/2017] [Indexed: 12/17/2022]
Abstract
The imitation switch nuclear ATPase Smarca5 (Snf2h) is one of the most conserved chromatin remodeling factors. It exists in a variety of oligosubunit complexes that move DNA with respect to the histone octamer to generate regularly spaced nucleosomal arrays. Smarca5 interacts with different accessory proteins and represents a molecular motor for DNA replication, repair, and transcription. We deleted Smarca5 at the onset of definitive hematopoiesis (Vav1-iCre) and observed that animals die during late fetal development due to anemia. Hematopoietic stem and progenitor cells accumulated but their maturation toward erythroid and myeloid lineages was inhibited. Proerythroblasts were dysplastic while basophilic erythroblasts were blocked in G2/M and depleted. Smarca5 deficiency led to increased p53 levels, its activation at two residues, one associated with DNA damage (S15Ph °s ) second with CBP/p300 (K376Ac ), and finally activation of the p53 targets. We also deleted Smarca5 in committed erythroid cells (Epor-iCre) and observed that animals were anemic postnatally. Furthermore, 4-hydroxytamoxifen-mediated deletion of Smarca5 in the ex vivo cultures confirmed its requirement for erythroid cell proliferation. Thus, Smarca5 plays indispensable roles during early hematopoiesis and erythropoiesis. Stem Cells 2017;35:1614-1623.
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Affiliation(s)
- Juraj Kokavec
- BIOCEV, First Faculty of Medicine, Charles University, Czech Republic.,Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Tomas Zikmund
- BIOCEV, First Faculty of Medicine, Charles University, Czech Republic
| | - Filipp Savvulidi
- BIOCEV, First Faculty of Medicine, Charles University, Czech Republic
| | - Vojtech Kulvait
- BIOCEV, First Faculty of Medicine, Charles University, Czech Republic
| | - Winfried Edelmann
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Tomas Stopka
- BIOCEV, First Faculty of Medicine, Charles University, Czech Republic
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14
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Xu N, Lu X, Kavi H, Emelyanov AV, Bernardo TJ, Vershilova E, Skoultchi AI, Fyodorov DV. BEN domain protein Elba2 can functionally substitute for linker histone H1 in Drosophila in vivo. Sci Rep 2016; 6:34354. [PMID: 27687115 PMCID: PMC5043383 DOI: 10.1038/srep34354] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 09/09/2016] [Indexed: 01/20/2023] Open
Abstract
Metazoan linker histones are essential for development and play crucial roles in organization of chromatin, modification of epigenetic states and regulation of genetic activity. Vertebrates express multiple linker histone H1 isoforms, which may function redundantly. In contrast, H1 isoforms are not present in Dipterans, including D. melanogaster, except for an embryo-specific, distantly related dBigH1. Here we show that Drosophila BEN domain protein Elba2, which is expressed in early embryos and was hypothesized to have insulator-specific functions, can compensate for the loss of H1 in vivo. Although the Elba2 gene is not essential, its mutation causes a disruption of normal internucleosomal spacing of chromatin and reduced nuclear compaction in syncytial embryos. Elba2 protein is distributed ubiquitously in polytene chromosomes and strongly colocalizes with H1. In H1-depleted animals, ectopic expression of Elba2 rescues the increased lethality and ameliorates abnormalities of chromosome architecture and heterochromatin functions. We also demonstrate that ectopic expression of BigH1 similarly complements the deficiency of H1 protein. Thus, in organisms that do not express redundant H1 isoforms, the structural and biological functions performed by canonical linker histones in later development, may be shared in early embryos by weakly homologous proteins, such as BigH1, or even unrelated, non-homologous proteins, such as Elba2.
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Affiliation(s)
- Na Xu
- Albert Einstein College of Medicine, Department of Cell Biology, Bronx, NY 10461, USA
| | - Xingwu Lu
- Albert Einstein College of Medicine, Department of Cell Biology, Bronx, NY 10461, USA
| | - Harsh Kavi
- Albert Einstein College of Medicine, Department of Cell Biology, Bronx, NY 10461, USA
| | | | - Travis J. Bernardo
- Albert Einstein College of Medicine, Department of Cell Biology, Bronx, NY 10461, USA
| | - Elena Vershilova
- Albert Einstein College of Medicine, Department of Cell Biology, Bronx, NY 10461, USA
| | - Arthur I. Skoultchi
- Albert Einstein College of Medicine, Department of Cell Biology, Bronx, NY 10461, USA
| | - Dmitry V. Fyodorov
- Albert Einstein College of Medicine, Department of Cell Biology, Bronx, NY 10461, USA
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15
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He S, Limi S, McGreal RS, Xie Q, Brennan LA, Kantorow WL, Kokavec J, Majumdar R, Hou H, Edelmann W, Liu W, Ashery-Padan R, Zavadil J, Kantorow M, Skoultchi AI, Stopka T, Cvekl A. Chromatin remodeling enzyme Snf2h regulates embryonic lens differentiation and denucleation. Development 2016; 143:1937-47. [PMID: 27246713 PMCID: PMC4920164 DOI: 10.1242/dev.135285] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/21/2016] [Indexed: 12/30/2022]
Abstract
Ocular lens morphogenesis is a model for investigating mechanisms of cellular differentiation, spatial and temporal gene expression control, and chromatin regulation. Brg1 (Smarca4) and Snf2h (Smarca5) are catalytic subunits of distinct ATP-dependent chromatin remodeling complexes implicated in transcriptional regulation. Previous studies have shown that Brg1 regulates both lens fiber cell differentiation and organized degradation of their nuclei (denucleation). Here, we employed a conditional Snf2h(flox) mouse model to probe the cellular and molecular mechanisms of lens formation. Depletion of Snf2h induces premature and expanded differentiation of lens precursor cells forming the lens vesicle, implicating Snf2h as a key regulator of lens vesicle polarity through spatial control of Prox1, Jag1, p27(Kip1) (Cdkn1b) and p57(Kip2) (Cdkn1c) gene expression. The abnormal Snf2h(-/-) fiber cells also retain their nuclei. RNA profiling of Snf2h(-/) (-) and Brg1(-/-) eyes revealed differences in multiple transcripts, including prominent downregulation of those encoding Hsf4 and DNase IIβ, which are implicated in the denucleation process. In summary, our data suggest that Snf2h is essential for the establishment of lens vesicle polarity, partitioning of prospective lens epithelial and fiber cell compartments, lens fiber cell differentiation, and lens fiber cell nuclear degradation.
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Grants
- R01 EY012200 NEI NIH HHS
- R01 CA079057 NCI NIH HHS
- R01 DK096266 NIDDK NIH HHS
- R01 GM116143 NIGMS NIH HHS
- R01 EY013022 NEI NIH HHS
- R01 CA076329 NCI NIH HHS
- T32 GM007491 NIGMS NIH HHS
- R56 CA079057 NCI NIH HHS
- R01 EY014237 NEI NIH HHS
- 001 World Health Organization
- R01 EY022645 NEI NIH HHS
- Grant support: R01 EY012200 (AC), EY014237 (AC), EY014237-7S1 (AC), EY013022 (MK), CA079057 (AIS), EY022645 (WL), T32 GM007491 (SL), GACR: P305/12/1033 (TS, JK), UNCE: 204021 (TS, JK), and an unrestricted grant from Research to Prevent Blindness to the Department of Ophthalmology and Visual Sciences. TS is member of the BIOCEV ? Biotechnology and Biomedicine Centre of the Academy of Sciences and Charles University (CZ.1.05/1.1.00/02.0109) supported by the European Regional Development Fund. The Israel Science Foundation 610/10, the Israel Ministry of Science 36494, the Ziegler Foundation and the Binational Science Foundation (2013016) to RAP.
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Affiliation(s)
- Shuying He
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Saima Limi
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Rebecca S McGreal
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Qing Xie
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Lisa A Brennan
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Wanda Lee Kantorow
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Juraj Kokavec
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA First Faculty of Medicine, Charles University, 121 08 Prague, Czech Republic
| | - Romit Majumdar
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Harry Hou
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Winfried Edelmann
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Wei Liu
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine Tel-Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Jiri Zavadil
- Department of Pathology and NYU Center for Health Informatics and Bioinformatics, New York University Langone Medical Center, New York, NY 10016, USA Mechanisms of Carcinogenesis Section, International Agency for Research on Cancer, Lyon Cedex 08 69372, France
| | - Marc Kantorow
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Tomas Stopka
- First Faculty of Medicine, Charles University, 121 08 Prague, Czech Republic
| | - Ales Cvekl
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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16
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Kavi H, Emelyanov AV, Fyodorov DV, Skoultchi AI. Independent Biological and Biochemical Functions for Individual Structural Domains of Drosophila Linker Histone H1. J Biol Chem 2016; 291:15143-55. [PMID: 27226620 DOI: 10.1074/jbc.m116.730705] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Indexed: 12/20/2022] Open
Abstract
Linker histone H1 is among the most abundant components of chromatin. H1 has profound effects on chromosome architecture. H1 also helps to tether DNA- and histone-modifying enzymes to chromatin. Metazoan linker histones have a conserved tripartite structure comprising N-terminal, globular, and long, unstructured C-terminal domains. Here we utilize truncated Drosophila H1 polypeptides in vitro and H1 mutant transgenes in vivo to interrogate the roles of these domains in multiple biochemical and biological activities of H1. We demonstrate that the globular domain and the proximal part of the C-terminal domain are essential for H1 deposition into chromosomes and for the stability of H1-chromatin binding. The two domains are also essential for fly viability and the establishment of a normal polytene chromosome structure. Additionally, through interaction with the heterochromatin-specific histone H3 Lys-9 methyltransferase Su(var)3-9, the H1 C-terminal domain makes important contributions to formation and H3K9 methylation of heterochromatin as well as silencing of transposons in heterochromatin. Surprisingly, the N-terminal domain does not appear to be required for any of these functions. However, it is involved in the formation of a single chromocenter in polytene chromosomes. In summary, we have discovered that linker histone H1, similar to core histones, exerts its multiple biological functions through independent, biochemically separable activities of its individual structural domains.
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Affiliation(s)
- Harsh Kavi
- From the Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Alexander V Emelyanov
- From the Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Dmitry V Fyodorov
- From the Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Arthur I Skoultchi
- From the Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461
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17
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Geeven G, Zhu Y, Kim BJ, Bartholdy BA, Yang SM, Macfarlan TS, Gifford WD, Pfaff SL, Verstegen MJAM, Pinto H, Vermunt MW, Creyghton MP, Wijchers PJ, Stamatoyannopoulos JA, Skoultchi AI, de Laat W. Local compartment changes and regulatory landscape alterations in histone H1-depleted cells. Genome Biol 2015; 16:289. [PMID: 26700097 PMCID: PMC4699363 DOI: 10.1186/s13059-015-0857-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 12/09/2015] [Indexed: 12/27/2022] Open
Abstract
Background Linker histone H1 is a core chromatin component that binds to nucleosome core particles and the linker DNA between nucleosomes. It has been implicated in chromatin compaction and gene regulation and is anticipated to play a role in higher-order genome structure. Here we have used a combination of genome-wide approaches including DNA methylation, histone modification and DNase I hypersensitivity profiling as well as Hi-C to investigate the impact of reduced cellular levels of histone H1 in embryonic stem cells on chromatin folding and function. Results We find that depletion of histone H1 changes the epigenetic signature of thousands of potential regulatory sites across the genome. Many of them show cooperative loss or gain of multiple chromatin marks. Epigenetic alterations cluster to gene-dense topologically associating domains (TADs) that already showed a high density of corresponding chromatin features. Genome organization at the three-dimensional level is largely intact, but we find changes in the structural segmentation of chromosomes specifically for the epigenetically most modified TADs. Conclusions Our data show that cells require normal histone H1 levels to expose their proper regulatory landscape. Reducing the levels of histone H1 results in massive epigenetic changes and altered topological organization particularly at the most active chromosomal domains. Changes in TAD configuration coincide with epigenetic landscape changes but not with transcriptional output changes, supporting the emerging concept that transcriptional control and nuclear positioning of TADs are not causally related but independently controlled by the locally associated trans-acting factors. Electronic supplementary material The online version of this article (doi:10.1186/s13059-015-0857-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Geert Geeven
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.
| | - Yun Zhu
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.
| | - Byung Ju Kim
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA.
| | - Boris A Bartholdy
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA.
| | - Seung-Min Yang
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA.
| | - Todd S Macfarlan
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, 20892, USA.
| | - Wesley D Gifford
- Gene Expression Laboratory and the Howard Hughes Medical Institute, The Salk Institute for Biological Studies, 10010 North Torrey Pines, La Jolla, CA, 92037, USA.
| | - Samuel L Pfaff
- Gene Expression Laboratory and the Howard Hughes Medical Institute, The Salk Institute for Biological Studies, 10010 North Torrey Pines, La Jolla, CA, 92037, USA.
| | - Marjon J A M Verstegen
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.
| | - Hugo Pinto
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA
| | - Marit W Vermunt
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.
| | - Menno P Creyghton
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.
| | - Patrick J Wijchers
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.
| | - John A Stamatoyannopoulos
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA. .,Department of Medicine, Division of Oncology, University of Washington, Seattle, WA, 98195, USA.
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA.
| | - Wouter de Laat
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.
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18
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Xu N, Emelyanov AV, Fyodorov DV, Skoultchi AI. Drosophila linker histone H1 coordinates STAT-dependent organization of heterochromatin and suppresses tumorigenesis caused by hyperactive JAK-STAT signaling. Epigenetics Chromatin 2014; 7:16. [PMID: 25177369 PMCID: PMC4149798 DOI: 10.1186/1756-8935-7-16] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 07/08/2014] [Indexed: 02/06/2023] Open
Abstract
Background Within the nucleus of eukaryotic cells, chromatin is organized into compact, silent regions called heterochromatin and more loosely packaged regions of euchromatin where transcription is more active. Although the existence of heterochromatin has been known for many years, the cellular factors responsible for its formation have only recently been identified. Two key factors involved in heterochromatin formation in Drosophila are the H3 lysine 9 methyltransferase Su(var)3-9 and heterochromatin protein 1 (HP1). The linker histone H1 also plays a major role in heterochromatin formation in Drosophila by interacting with Su(var)3-9 and helping to recruit it to heterochromatin. Drosophila STAT (Signal transducer and activator of transcription) (STAT92E) has also been shown to be involved in the maintenance of heterochromatin, but its relationship to the H1-Su(var)3-9 heterochromatin pathway is unknown. STAT92E is also involved in tumor formation in flies. Hyperactive Janus kinase (JAK)-STAT signaling due to a mutation in Drosophila JAK (Hopscotch) causes hematopoietic tumors Results We show here that STAT92E is a second partner of H1 in the regulation of heterochromatin structure. H1 physically interacts with STAT92E and regulates its ectopic localization in the chromatin. Mis-localization of STAT92E due to its hyperphosphorylation or H1 depletion disrupts heterochromatin integrity. The contribution of the H1-STAT pathway to heterochromatin formation is mechanistically distinct from that of H1 and Su(var)3-9. The recruitment of STAT92E to chromatin by H1 also plays an important regulatory role in JAK-STAT induced tumors in flies. Depleting the linker histone H1 in flies carrying the oncogenic hopscotchTum-l allele enhances tumorigenesis, and H1 overexpression suppresses tumorigenesis. Conclusions Our results suggest the existence of two independent pathways for heterochromatin formation in Drosophila, one involving Su(var)3-9 and HP1 and the other involving STAT92E and HP1. The H1 linker histone directs both pathways through physical interactions with Su(var)3-9 and STAT92E, as well with HP1. The physical interaction of H1 and STAT92E confers a regulatory role on H1 in JAK-STAT signaling. H1 serves as a molecular reservoir for STAT92E in chromatin, enabling H1 to act as a tumor suppressor and oppose an oncogenic mutation in the JAK-STAT signaling pathway.
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Affiliation(s)
- Na Xu
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Alexander V Emelyanov
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Dmitry V Fyodorov
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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Alvarez-Saavedra M, De Repentigny Y, Lagali PS, Raghu Ram EVS, Yan K, Hashem E, Ivanochko D, Huh MS, Yang D, Mears AJ, Todd MAM, Corcoran CP, Bassett EA, Tokarew NJA, Kokavec J, Majumder R, Ioshikhes I, Wallace VA, Kothary R, Meshorer E, Stopka T, Skoultchi AI, Picketts DJ. Snf2h-mediated chromatin organization and histone H1 dynamics govern cerebellar morphogenesis and neural maturation. Nat Commun 2014; 5:4181. [PMID: 24946904 PMCID: PMC4083431 DOI: 10.1038/ncomms5181] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 05/15/2014] [Indexed: 12/28/2022] Open
Abstract
Chromatin compaction mediates progenitor to post-mitotic cell transitions and modulates gene expression programs, yet the mechanisms are poorly defined. Snf2h and Snf2l are ATP-dependent chromatin remodelling proteins that assemble, reposition and space nucleosomes, and are robustly expressed in the brain. Here we show that mice conditionally inactivated for Snf2h in neural progenitors have reduced levels of histone H1 and H2A variants that compromise chromatin fluidity and transcriptional programs within the developing cerebellum. Disorganized chromatin limits Purkinje and granule neuron progenitor expansion, resulting in abnormal post-natal foliation, while deregulated transcriptional programs contribute to altered neural maturation, motor dysfunction and death. However, mice survive to young adulthood, in part from Snf2l compensation that restores Engrailed-1 expression. Similarly, Purkinje-specific Snf2h ablation affects chromatin ultrastructure and dendritic arborization, but alters cognitive skills rather than motor control. Our studies reveal that Snf2h controls chromatin organization and histone H1 dynamics for the establishment of gene expression programs underlying cerebellar morphogenesis and neural maturation.
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Affiliation(s)
- Matías Alvarez-Saavedra
- 1] Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6 [2] Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
| | - Yves De Repentigny
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6
| | - Pamela S Lagali
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6
| | - Edupuganti V S Raghu Ram
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Keqin Yan
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6
| | - Emile Hashem
- 1] Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6 [2] Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
| | - Danton Ivanochko
- 1] Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6 [2] Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
| | - Michael S Huh
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6
| | - Doo Yang
- 1] Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5 [2] Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
| | - Alan J Mears
- Vision Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6
| | - Matthew A M Todd
- 1] Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6 [2] Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
| | - Chelsea P Corcoran
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6
| | - Erin A Bassett
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
| | - Nicholas J A Tokarew
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
| | - Juraj Kokavec
- Institute of Pathologic Physiology, First Faculty of Medicine, Charles University in Prague, Prague 12853, Czech Republic
| | - Romit Majumder
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Ilya Ioshikhes
- 1] Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5 [2] Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
| | - Valerie A Wallace
- 1] Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5 [2] Vision Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6
| | - Rashmi Kothary
- 1] Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6 [2] Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
| | - Eran Meshorer
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Tomas Stopka
- Institute of Pathologic Physiology, First Faculty of Medicine, Charles University in Prague, Prague 12853, Czech Republic
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - David J Picketts
- 1] Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6 [2] Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5 [3] Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
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20
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Popova EY, Grigoryev SA, Fan Y, Skoultchi AI, Zhang SS, Barnstable CJ. Developmentally regulated linker histone H1c promotes heterochromatin condensation and mediates structural integrity of rod photoreceptors in mouse retina. J Biol Chem 2013; 288:17895-907. [PMID: 23645681 DOI: 10.1074/jbc.m113.452144] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mature rod photoreceptor cells contain very small nuclei with tightly condensed heterochromatin. We observed that during mouse rod maturation, the nucleosomal repeat length increases from 190 bp at postnatal day 1 to 206 bp in the adult retina. At the same time, the total level of linker histone H1 increased reaching the ratio of 1.3 molecules of total H1 per nucleosome, mostly via a dramatic increase in H1c. Genetic elimination of the histone H1c gene is functionally compensated by other histone variants. However, retinas in H1c/H1e/H1(0) triple knock-outs have photoreceptors with bigger nuclei, decreased heterochromatin area, and notable morphological changes suggesting that the process of chromatin condensation and rod cell structural integrity are partly impaired. In triple knock-outs, nuclear chromatin exposed several epigenetic histone modification marks masked in the wild type chromatin. Dramatic changes in exposure of a repressive chromatin mark, H3K9me2, indicate that during development linker histone plays a role in establishing the facultative heterochromatin territory and architecture in the nucleus. During retina development, the H1c gene and its promoter acquired epigenetic patterns typical of rod-specific genes. Our data suggest that histone H1c gene expression is developmentally up-regulated to promote facultative heterochromatin in mature rod photoreceptors.
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Affiliation(s)
- Evgenya Y Popova
- Department of Neural and Behavioral Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
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21
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Lu X, Wontakal SN, Kavi H, Kim BJ, Guzzardo PM, Emelyanov AV, Xu N, Hannon GJ, Zavadil J, Fyodorov DV, Skoultchi AI. Drosophila H1 regulates the genetic activity of heterochromatin by recruitment of Su(var)3-9. Science 2013; 340:78-81. [PMID: 23559249 DOI: 10.1126/science.1234654] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Eukaryotic genomes harbor transposable elements and other repetitive sequences that must be silenced. Small RNA interference pathways play a major role in their repression. Here, we reveal another mechanism for silencing these sequences in Drosophila. Depleting the linker histone H1 in vivo leads to strong activation of these elements. H1-mediated silencing occurs in combination with the heterochromatin-specific histone H3 lysine 9 methyltransferase Su(var)3-9. H1 physically interacts with Su(var)3-9 and recruits it to chromatin in vitro, which promotes H3 methylation. We propose that H1 plays a key role in silencing by tethering Su(var)3-9 to heterochromatin. The tethering function of H1 adds to its established role as a regulator of chromatin compaction and accessibility.
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Affiliation(s)
- Xingwu Lu
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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22
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Alvarez-Saavedra M, Lagali P, Yan K, Hashem E, Mears A, De Repentigny Y, Wallace VA, Kothary R, Stopka T, Skoultchi AI, Picketts DJ. Coordinated epigenetic regulation of Engrailed-1 by the chromatin remodelers Smarca1 and Smarca5 mediates cerebellar morphogenesis. Epigenetics Chromatin 2013. [PMCID: PMC3620705 DOI: 10.1186/1756-8935-6-s1-p105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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23
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Yang SM, Kim BJ, Norwood Toro L, Skoultchi AI. H1 linker histone promotes epigenetic silencing by regulating both DNA methylation and histone H3 methylation. Proc Natl Acad Sci U S A 2013; 110:1708-13. [PMID: 23302691 PMCID: PMC3562819 DOI: 10.1073/pnas.1213266110] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Epigenetic silencing in mammals involves DNA methylation and posttranslational modifications of core histones. Here we show that the H1 linker histone plays a key role in regulating both DNA methylation and histone H3 methylation at the H19 and Gtl2 loci in mouse ES cells. Some, but not all, murine H1 subtypes interact with DNA methyltransferases DNMT1 and DNMT3B. The interactions are direct and require a portion of the H1 C-terminal domain. Expression of an H1 subtype that interacts with DNMT1 and DNMT3B in ES cells leads to their recruitment and DNA methylation of the H19 and Gtl2 imprinting control regions. H1 also interferes with binding of the SET7/9 histone methyltransferase to the imprinting control regions, inhibiting production of an activating methylation mark on histone H3 lysine 4. H1-dependent recruitment of DNMT1 and DNMT3B and interference with the binding of SET7/9 also were observed with chromatin reconstituted in vitro. The data support a model in which H1 plays an active role in helping direct two processes that lead to the formation of epigenetic silencing marks. The data also provide evidence for functional differences among the H1 subtypes expressed in somatic mammalian cells.
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Affiliation(s)
| | | | - Laura Norwood Toro
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Arthur I. Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461
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24
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Wontakal SN, Guo X, Will B, Shi M, Raha D, Mahajan MC, Weissman S, Snyder M, Steidl U, Zheng D, Skoultchi AI. A large gene network in immature erythroid cells is controlled by the myeloid and B cell transcriptional regulator PU.1. PLoS Genet 2011; 7:e1001392. [PMID: 21695229 PMCID: PMC3111485 DOI: 10.1371/journal.pgen.1001392] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 05/10/2011] [Indexed: 01/17/2023] Open
Abstract
PU.1 is a hematopoietic transcription factor that is required for the development of myeloid and B cells. PU.1 is also expressed in erythroid progenitors, where it blocks erythroid differentiation by binding to and inhibiting the main erythroid promoting factor, GATA-1. However, other mechanisms by which PU.1 affects the fate of erythroid progenitors have not been thoroughly explored. Here, we used ChIP-Seq analysis for PU.1 and gene expression profiling in erythroid cells to show that PU.1 regulates an extensive network of genes that constitute major pathways for controlling growth and survival of immature erythroid cells. By analyzing fetal liver erythroid progenitors from mice with low PU.1 expression, we also show that the earliest erythroid committed cells are dramatically reduced in vivo. Furthermore, we find that PU.1 also regulates many of the same genes and pathways in other blood cells, leading us to propose that PU.1 is a multifaceted factor with overlapping, as well as distinct, functions in several hematopoietic lineages.
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Affiliation(s)
- Sandeep N. Wontakal
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Xingyi Guo
- The Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Britta Will
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Minyi Shi
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
- Department of Genetics, Stanford University, Stanford, California, United States of America
| | - Debasish Raha
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - Milind C. Mahajan
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Sherman Weissman
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Michael Snyder
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
- Department of Genetics, Stanford University, Stanford, California, United States of America
| | - Ulrich Steidl
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Deyou Zheng
- The Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York, United States of America
- Departments of Genetics and Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
- * E-mail: (AI Skoultchi); (D Zheng)
| | - Arthur I. Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
- * E-mail: (AI Skoultchi); (D Zheng)
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25
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Eskeland R, Leeb M, Grimes GR, Kress C, Boyle S, Sproul D, Gilbert N, Fan Y, Skoultchi AI, Wutz A, Bickmore WA. Ring1B compacts chromatin structure and represses gene expression independent of histone ubiquitination. Mol Cell 2010; 38:452-64. [PMID: 20471950 DOI: 10.1016/j.molcel.2010.02.032] [Citation(s) in RCA: 408] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 11/04/2009] [Accepted: 02/15/2010] [Indexed: 10/19/2022]
Abstract
How polycomb group proteins repress gene expression in vivo is not known. While histone-modifying activities of the polycomb repressive complexes (PRCs) have been studied extensively, in vitro data have suggested a direct activity of the PRC1 complex in compacting chromatin. Here, we investigate higher-order chromatin compaction of polycomb targets in vivo. We show that PRCs are required to maintain a compact chromatin state at Hox loci in embryonic stem cells (ESCs). There is specific decompaction in the absence of PRC2 or PRC1. This is due to a PRC1-like complex, since decompaction occurs in Ring1B null cells that still have PRC2-mediated H3K27 methylation. Moreover, we show that the ability of Ring1B to restore a compact chromatin state and to repress Hox gene expression is not dependent on its histone ubiquitination activity. We suggest that Ring1B-mediated chromatin compaction acts to directly limit transcription in vivo.
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Affiliation(s)
- Ragnhild Eskeland
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
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26
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Papetti M, Wontakal SN, Stopka T, Skoultchi AI. GATA-1 directly regulates p21 gene expression during erythroid differentiation. Cell Cycle 2010; 9:1972-80. [PMID: 20495378 DOI: 10.4161/cc.9.10.11602] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Lineage-determination transcription factors coordinate cell differentiation and proliferation by controlling the synthesis of lineage-specific gene products as well as cell cycle regulators. GATA-1 is a master regulator of erythropoiesis. Its role in regulating erythroid-specific genes has been extensively studied, whereas its role in controlling genes that regulate cell proliferation is less understood. Ectopic expression of GATA-1 in erythroleukemia cells releases the block to their differentiation and leads to terminal cell division. An early event in reprogramming the erythroleukemia cells is induction of the cyclin-dependent kinase inhibitor p21. Remarkably, ectopic expression of p21 also induces the erythroleukemia cells to differentiate. We now report that GATA-1 directly regulates transcription of the p21 gene in both erythroleukemia cells and normal erythroid progenitors. Using reporter, electrophoretic mobility shift, and chromatin immunoprecipitation assays, we show that GATA-1 stimulates p21 gene transcription by binding to consensus binding sites in the upstream region of the p21 gene promoter. This activity is also dependent on a binding site for Sp1/KLF-like factors near the transcription start site. Our findings indicate that p21 is a crucial downstream gene target and effector of GATA-1 during red blood cell terminal differentiation.
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Affiliation(s)
- Michael Papetti
- 1Department of Cell Biology, Montefiore Medical Center, Bronx, NY, USA
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27
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Choe KS, Ujhelly O, Wontakal SN, Skoultchi AI. PU.1 directly regulates cdk6 gene expression, linking the cell proliferation and differentiation programs in erythroid cells. J Biol Chem 2009; 285:3044-52. [PMID: 19955566 DOI: 10.1074/jbc.m109.077727] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Cell proliferation and differentiation are highly coordinated processes during normal development. Most leukemia cells are blocked from undergoing terminal differentiation and also exhibit uncontrolled proliferation. Dysregulated expression of transcription factor PU.1 is strongly associated with Friend virus-induced erythroleukemia. PU.1 inhibits erythroid differentiation by binding to and inhibiting GATA-1. PU.1 also may be involved in controlling proliferation of erythroid cells. We reported previously that the G(1) phase-specific cyclin-dependent kinase 6 (CDK6) also blocks erythroid differentiation. We now report that PU.1 directly stimulates transcription of the cdk6 gene in both normal erythroid progenitors and erythroleukemia cells, as well as in macrophages. We propose that PU.1 coordinates proliferation and differentiation in immature erythroid cells by inhibiting the GATA-1-mediated gene expression program and also by regulating expression of genes that control progression through the G(1) phase of the cell cycle, the period during which the decision to differentiate is made.
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Affiliation(s)
- Kevin S Choe
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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28
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Burda P, Curik N, Kokavec J, Basova P, Mikulenkova D, Skoultchi AI, Zavadil J, Stopka T. PU.1 activation relieves GATA-1-mediated repression of Cebpa and Cbfb during leukemia differentiation. Mol Cancer Res 2009; 7:1693-703. [PMID: 19825991 DOI: 10.1158/1541-7786.mcr-09-0031] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Hematopoietic transcription factors GATA-1 and PU.1 bind each other on DNA to block transcriptional programs of undesired lineage during hematopoietic commitment. Murine erythroleukemia (MEL) cells that coexpress GATA-1 and PU.1 are blocked at the blast stage but respond to molecular removal (downregulation) of PU.1 or addition (upregulation) of GATA-1 by inducing terminal erythroid differentiation. To test whether GATA-1 blocks PU.1 in MEL cells, we have conditionally activated a transgenic PU.1 protein fused with the estrogen receptor ligand-binding domain (PUER), resulting in activation of a myeloid transcriptional program. Gene expression arrays identified components of the PU.1-dependent transcriptome negatively regulated by GATA-1 in MEL cells, including CCAAT/enhancer binding protein alpha (Cebpa) and core-binding factor, beta subunit (Cbfb), which encode two key hematopoietic transcription factors. Inhibition of GATA-1 by small interfering RNA resulted in derepression of PU.1 target genes. Chromatin immunoprecipitation and reporter assays identified PU.1 motif sequences near Cebpa and Cbfb that are co-occupied by PU.1 and GATA-1 in the leukemic blasts. Significant derepression of Cebpa and Cbfb is achieved in MEL cells by either activation of PU.1 or knockdown of GATA-1. Furthermore, transcriptional regulation of these loci by manipulating the levels of PU.1 and GATA-1 involves quantitative increases in a transcriptionally active chromatin mark: acetylation of histone H3K9. Collectively, we show that either activation of PU.1 or inhibition of GATA-1 efficiently reverses the transcriptional block imposed by GATA-1 and leads to the activation of a myeloid transcriptional program directed by PU.1.
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Affiliation(s)
- Pavel Burda
- Institute of Pathological Physiology and Center of Experimental Hematology, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
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29
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Abstract
Nucleosome movement is, at least in part, facilitated by ISWI ATPase Smarca5 (Snf2h). Smarca5 gene inactivation in mouse demonstrated its requirement at blastocyst stage; however its role at later stages is not completely understood. We herein determined nuclear distribution of Smarca5 and histone marks associated with actively transcribed and repressed chromatin structure in embryonic and adult murine tissues and in tumor cells. Confocal microscopy images demonstrate that Smarca5 is localized mainly in euchromatin and to lesser extent also in heterochromatin and nucleoli. Smarca5 heterozygous mice for a null allele display decreased levels of histone H3 modifications and defects in heterochromatin foci supporting role of Smarca5 as a key regulator of global chromatin structure.
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Affiliation(s)
- Jarmila Vargova
- Pathological Physiology and Center of Experimental Hematology, First Faculty of Medicine, Charles University, Prague, Czech Republic
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30
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Lu X, Wontakal SN, Emelyanov AV, Morcillo P, Konev AY, Fyodorov DV, Skoultchi AI. Linker histone H1 is essential for Drosophila development, the establishment of pericentric heterochromatin, and a normal polytene chromosome structure. Genes Dev 2009; 23:452-65. [PMID: 19196654 PMCID: PMC2648648 DOI: 10.1101/gad.1749309] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Accepted: 01/05/2009] [Indexed: 01/22/2023]
Abstract
We generated mutant alleles of Drosophila melanogaster in which expression of the linker histone H1 can be down-regulated over a wide range by RNAi. When the H1 protein level is reduced to approximately 20% of the level in wild-type larvae, lethality occurs in the late larval - pupal stages of development. Here we show that H1 has an important function in gene regulation within or near heterochromatin. It is a strong dominant suppressor of position effect variegation (PEV). Similar to other suppressors of PEV, H1 is simultaneously involved in both the repression of euchromatic genes brought to the vicinity of pericentric heterochromatin and the activation of heterochromatic genes that depend on their pericentric localization for maximal transcriptional activity. Studies of H1-depleted salivary gland polytene chromosomes show that H1 participates in several fundamental aspects of chromosome structure and function. First, H1 is required for heterochromatin structural integrity and the deposition or maintenance of major pericentric heterochromatin-associated histone marks, including H3K9Me(2) and H4K20Me(2). Second, H1 also plays an unexpected role in the alignment of endoreplicated sister chromatids. Finally, H1 is essential for organization of pericentric regions of all polytene chromosomes into a single chromocenter. Thus, linker histone H1 is essential in Drosophila and plays a fundamental role in the architecture and activity of chromosomes in vivo.
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Affiliation(s)
- Xingwu Lu
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Sandeep N. Wontakal
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Alexander V. Emelyanov
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Patrick Morcillo
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Alexander Y. Konev
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Dmitry V. Fyodorov
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Arthur I. Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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31
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Abstract
Malignant transformation often leads to both loss of normal proliferation control and inhibition of cell differentiation. Some tumor cells can be stimulated to reenter their differentiation program and to undergo terminal growth arrest. The in vitro differentiation of mouse erythroleukemia (MEL) cells is an important example of tumor cell reprogramming. MEL cells are malignant erythroblasts that are blocked from differentiating into mature RBC due to dysregulated expression of the transcription factor PU.1, which binds to and represses GATA-1, the major transcriptional regulator of erythropoiesis. We used RNA interference to ask whether inhibiting PU.1 synthesis was sufficient to cause MEL cells to lose their malignant properties. We report here that transfection of MEL cells with a PU.1-specific short interfering RNA oligonucleotide causes the cells to resume erythroid differentiation, accumulate hemoglobin, and undergo terminal growth arrest. RNA interference directed at specific, aberrantly expressed transcription factors may hold promise for the development of potent antitumor therapies in other hematologic malignancies.
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Affiliation(s)
- Michael Papetti
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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32
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Murga M, Jaco I, Fan Y, Soria R, Martinez-Pastor B, Cuadrado M, Yang SM, Blasco MA, Skoultchi AI, Fernandez-Capetillo O. Global chromatin compaction limits the strength of the DNA damage response. ACTA ACUST UNITED AC 2007; 178:1101-8. [PMID: 17893239 PMCID: PMC2064646 DOI: 10.1083/jcb.200704140] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In response to DNA damage, chromatin undergoes a global decondensation process that has been proposed to facilitate genome surveillance. However, the impact that chromatin compaction has on the DNA damage response (DDR) has not directly been tested and thus remains speculative. We apply two independent approaches (one based on murine embryonic stem cells with reduced amounts of the linker histone H1 and the second making use of histone deacetylase inhibitors) to show that the strength of the DDR is amplified in the context of “open” chromatin. H1-depleted cells are hyperresistant to DNA damage and present hypersensitive checkpoints, phenotypes that we show are explained by an increase in the amount of signaling generated at each DNA break. Furthermore, the decrease in H1 leads to a general increase in telomere length, an as of yet unrecognized role for H1 in the regulation of chromosome structure. We propose that slight differences in the epigenetic configuration might account for the cell-to-cell variation in the strength of the DDR observed when groups of cells are challenged with DNA breaks.
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Affiliation(s)
- Matilde Murga
- Genomic Instability Group, Molecular Oncology Programme, Spanish National Cancer Center, Madrid 28029, Spain
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33
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Long JM, LaPorte P, Merscher S, Funke B, Saint-Jore B, Puech A, Kucherlapati R, Morrow BE, Skoultchi AI, Wynshaw-Boris A. Behavior of mice with mutations in the conserved region deleted in velocardiofacial/DiGeorge syndrome. Neurogenetics 2006; 7:247-57. [PMID: 16900388 DOI: 10.1007/s10048-006-0054-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Accepted: 06/20/2006] [Indexed: 11/28/2022]
Abstract
Velocardiofacial/DiGeorge syndrome (VCFS/DGS) is a developmental disorder caused by a 1.5 to 3-Mb hemizygous 22q11.2 deletion. VCFS/DGS patients display malformations in multiple systems, as well as an increased frequency of neuropsychiatric defects including schizophrenia. Haploinsufficiency of TBX1 appears to be responsible for these physical malformations in humans and mice, but the genes responsible for the neuropsychiatric defects are unknown. In this study, two mouse models of VCFS/DGS, a deletion mouse model (Lgdel/+) and a single gene model (Tbx1 +/-), as well as a third mouse mutant (Gscl -/-) for a gene within the Lgdel deletion, were tested in a large behavioral battery designed to assess gross physical features, sensorimotor reflexes, motor activity nociception, acoustic startle, sensorimotor gating, and learning and memory. Lgdel/+ mice contain a 1.5-Mb hemizygous deletion of 27 genes in the orthologous region on MMU 16 and present with impairment in sensorimotor gating, grip strength, and nociception. Tbx1 +/- mice were impaired in grip strength similar to Lgdel/+ mice and movement initiation. Gscl -/- mice were not impaired in any of the administered tests, suggesting that redundant function of other Gsc family members may compensate for the loss of Gscl. Thus, although deletion of the genes in the Lgdel region in mice may recapitulate some of the behavioral phenotypes seen in humans with VCFS/DGS, these phenotypes are not found in mice with complete loss of Gscl or in mice with heterozygous loss of Tbx1, suggesting that the neuropsychiatric and physical malformations of VCFS/DGS may act by different genetic mechanisms.
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Affiliation(s)
- Jeffrey M Long
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, CA 92093-0627, USA
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34
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Yang Y, Stopka T, Golestaneh N, Wang Y, Wu K, Li A, Chauhan BK, Gao CY, Cveklová K, Duncan MK, Pestell RG, Chepelinsky AB, Skoultchi AI, Cvekl A. Regulation of alphaA-crystallin via Pax6, c-Maf, CREB and a broad domain of lens-specific chromatin. EMBO J 2006; 25:2107-18. [PMID: 16675956 PMCID: PMC1462985 DOI: 10.1038/sj.emboj.7601114] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Accepted: 04/04/2006] [Indexed: 11/08/2022] Open
Abstract
Pax6 and c-Maf regulate multiple stages of mammalian lens development. Here, we identified novel distal control regions (DCRs) of the alphaA-crystallin gene, a marker of lens fiber cell differentiation induced by FGF-signaling. DCR1 stimulated reporter gene expression in primary lens explants treated with FGF2 linking FGF-signaling with alphaA-crystallin synthesis. A DCR1/alphaA-crystallin promoter (including DCR2) coupled with EGFP virtually recapitulated the expression pattern of alphaA-crystallin in lens epithelium and fibers. In contrast, the DCR3/alphaA/EGFP reporter was expressed only in 'late' lens fibers. Chromatin immunoprecipitations showed binding of Pax6 to DCR1 and the alphaA-crystallin promoter in lens chromatin and demonstrated that high levels of alphaA-crystallin expression correlate with increased binding of c-Maf and CREB to the promoter and of CREB to DCR3, a broad domain of histone H3K9-hyperacetylation extending from DCR1 to DCR3, and increased abundance of chromatin remodeling enzymes Brg1 and Snf2h at the alphaA-crystallin locus. Our data demonstrate a novel mechanism of Pax6, c-Maf and CREB function, through regulation of chromatin-remodeling enzymes, and suggest a multistage model for the activation of alphaA-crystallin during lens differentiation.
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Affiliation(s)
- Ying Yang
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Tomáš Stopka
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | | | - Yan Wang
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Kongming Wu
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Anping Li
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Bharesh K Chauhan
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | | | - Květa Cveklová
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Melinda K Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Richard G Pestell
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Aleš Cvekl
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Ophthalmology and Visual Sciences and Molecular Genetics, Albert Einstein College of Medicine, 123 Ullmann, 1300 Morris Park Ave, Bronx, NY 10461, USA. Tel: +1 718 430 3217; Fax: +1 718 430 8778; E-mail:
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35
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Fan Y, Nikitina T, Zhao J, Fleury TJ, Bhattacharyya R, Bouhassira EE, Stein A, Woodcock CL, Skoultchi AI. Histone H1 depletion in mammals alters global chromatin structure but causes specific changes in gene regulation. Cell 2006; 123:1199-212. [PMID: 16377562 DOI: 10.1016/j.cell.2005.10.028] [Citation(s) in RCA: 419] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Revised: 08/05/2005] [Accepted: 10/06/2005] [Indexed: 01/05/2023]
Abstract
Linker histone H1 plays an important role in chromatin folding in vitro. To study the role of H1 in vivo, mouse embryonic stem cells null for three H1 genes were derived and were found to have 50% of the normal level of H1. H1 depletion caused dramatic chromatin structure changes, including decreased global nucleosome spacing, reduced local chromatin compaction, and decreases in certain core histone modifications. Surprisingly, however, microarray analysis revealed that expression of only a small number of genes is affected. Many of the affected genes are imprinted or are on the X chromosome and are therefore normally regulated by DNA methylation. Although global DNA methylation is not changed, methylation of specific CpGs within the regulatory regions of some of the H1 regulated genes is reduced. These results indicate that linker histones can participate in epigenetic regulation of gene expression by contributing to the maintenance or establishment of specific DNA methylation patterns.
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Affiliation(s)
- Yuhong Fan
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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36
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Abstract
Despite a great deal of attention over many years, the structural and functional roles of the linker histone H1 remain enigmatic. The earlier concepts of H1 as a general transcriptional inhibitor have had to be reconsidered in the light of experiments demonstrating a minor effect of H1 deletion in unicellular organisms. More recent work analysing the results of depleting H1 in mammals through genetic knockouts of selected H1 subtypes in the mouse has shown that cells and tissues can tolerate a surprisingly low H1 content. One common feature of H1-depleted nuclei is a reduction in nucleosome repeat length (NRL). Moreover, there is a robust linear relationship between H1 stoichiometry and NRL, suggesting an inherent homeostatic mechanism that maintains intranuclear electrostatic balance. It is also clear that the 1 H1 per nucleosome paradigm for higher eukaryotes is the exception rather than the rule. This, together with the high mobility of H1 within the nucleus, prompts a reappraisal of the role of linker histone as an obligatory chromatin architectural protein.
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Affiliation(s)
- Christopher L Woodcock
- Biology Department and Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, 01003, USA.
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37
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Stopka T, Amanatullah DF, Papetti M, Skoultchi AI. PU.1 inhibits the erythroid program by binding to GATA-1 on DNA and creating a repressive chromatin structure. EMBO J 2005; 24:3712-23. [PMID: 16222338 PMCID: PMC1276718 DOI: 10.1038/sj.emboj.7600834] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Accepted: 09/12/2005] [Indexed: 11/08/2022] Open
Abstract
Transcriptional repression mechanisms are important during differentiation of multipotential hematopoietic progenitors, where they are thought to regulate lineage commitment and to extinguish alternative differentiation programs. PU.1 and GATA-1 are two critical hematopoietic transcription factors that physically interact and mutually antagonize each other's transcriptional activity and ability to promote myeloid and erythroid differentiation, respectively. We find that PU.1 inhibits the erythroid program by binding to GATA-1 on its target genes and organizing a complex of proteins that creates a repressive chromatin structure containing lysine-9 methylated H3 histones and heterochromatin protein 1. Although these features are thought to be stable aspects of repressed chromatin, we find that silencing of PU.1 expression leads to removal of the repression complex, loss of the repressive chromatin marks and reactivation of the erythroid program. This process involves incorporation of the replacement histone variant H3.3 into nucleosomes. Repression of one transcription factor bound to DNA by another transcription factor not on the DNA represents a new mechanism for downregulating an alternative gene expression program during lineage commitment of multipotential hematopoietic progenitors.
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Affiliation(s)
- Tomas Stopka
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Derek F Amanatullah
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Michael Papetti
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA. Tel.: +1 718 430 2169; Fax: +1 718 430 8574; E-mail:
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38
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Yu YL, Chiang YJ, Chen YC, Papetti M, Juo CG, Skoultchi AI, Yen JJY. MAPK-mediated phosphorylation of GATA-1 promotes Bcl-XL expression and cell survival. J Biol Chem 2005; 280:29533-42. [PMID: 15967790 PMCID: PMC3193074 DOI: 10.1074/jbc.m506514200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the interleukin 3-dependent hematopoietic cell line Ba/F3, inhibition of mitogen-activated protein kinase, a member of the MAPK/c-Jun N-terminal kinase/stress-activated protein kinase kinase family that plays an important role in cell growth and death control, rapidly leads to severe apoptosis. However, most of the antiapoptotic substrates of MAPK remain to be identified. Here we report that, upon interleukin-3 stimulation of Ba/F3 cells, the transcription factor GATA-1 is strongly phosphorylated at residue serine 26 by a MAPK-dependent pathway. Phosphorylation of GATA-1 increases GATA-1-mediated transcription of the E4bp4 survival gene without significantly changing the DNA-binding affinity of GATA-1. Further characterization of GATA-1 phosphorylation site mutants revealed that the antiapoptotic function of GATA-1 is strongly dependent upon its phosphorylation at the Ser-26 position and is probably mediated through its up-regulation of Bcl-X(L) expression. Taken together, our data demonstrate that MAPK-dependent GATA-1 phosphorylation is important for its transactivation of the E4bp4 gene, Bcl-X(L) expression and cell survival. Therefore, GATA-1 may represent a novel MAPK substrate that plays an essential role in a cytokine-mediated antiapoptotic response.
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Affiliation(s)
- Yung-Luen Yu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan 11529
| | - Yun-Jung Chiang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan 11529
| | - Yu-Chun Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan 11529
| | - Michael Papetti
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Chiun-Gung Juo
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan 11529
| | - Arthur I. Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Jeffrey J. Y. Yen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan 11529
- To whom correspondence should be addressed: Institute of Biomedical Sciences, Academia Sinica. No. 128, Sec. 2, Yen-Jiou-Yuan Rd., Taipei, Taiwan 11529. Tel.: 886-2-2652-3077; Fax: 886-2-2782-9142;
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39
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Lin Q, Inselman A, Han X, Xu H, Zhang W, Handel MA, Skoultchi AI. Reductions in Linker Histone Levels Are Tolerated in Developing Spermatocytes but Cause Changes in Specific Gene Expression. J Biol Chem 2004; 279:23525-35. [PMID: 15039436 DOI: 10.1074/jbc.m400925200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
H1 linker histones are involved in packaging chromatin into 30-nm fibers and higher order structures. Most eukaryotic cells contain nearly one H1 molecule for each nucleosome core particle. Male germ cells in mammals contain large amounts of a germ cell-specific linker histone, HIST1HT, herein denoted H1t, which is particularly abundant in pachytene spermatocytes. Despite its abundance in male germ cells and significant divergence in primary sequence from other H1 subtypes, inactivation of the H1t gene in mice showed that it is not required for spermatogenesis. Analysis of germ cell chromatin from H1t null mice showed that other H1 subtypes, especially the testis-enriched HIST1H1A, herein denoted as the H1a subtype, were able to compensate for the absence of H1t to maintain a normal total H1 to nucleosome core ratio. To disrupt the compensation, we generated H1t and H1a double null mice by two sequential gene-targeting steps in embryonic stem cells. Elimination of both H1t and H1a led to a 25% decrease in the ratio of H1 to nucleosome cores in double null germ cells. Surprisingly, the reduction in H1 did not perturb spermatogenesis or produce detectable defects in meiotic processes. Microarray analysis of gene expression showed that the reduced linker histone levels did not affect global gene expression, but it did cause changes in expression of specific genes. Our results indicate that a partial reduction in linker histone-nucleosome core particle stoichiometry is tolerated in developing male germ cells.
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Affiliation(s)
- Qingcong Lin
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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40
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Affiliation(s)
- Yuhong Fan
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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41
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Rekhtman N, Choe KS, Matushansky I, Murray S, Stopka T, Skoultchi AI. PU.1 and pRB interact and cooperate to repress GATA-1 and block erythroid differentiation. Mol Cell Biol 2003; 23:7460-74. [PMID: 14559995 PMCID: PMC207581 DOI: 10.1128/mcb.23.21.7460-7474.2003] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PU.1 and GATA-1 are two hematopoietic specific transcription factors that play key roles in development of the myeloid and erythroid lineages, respectively. The two proteins bind to one another and inhibit each other's function in transcriptional activation and promotion of their respective differentiation programs. This mutual antagonism may be an important aspect of lineage commitment decisions. PU.1 can also act as an oncoprotein since deregulated expression of PU.1 in erythroid precursors causes erythroleukemias in mice. Studies of cultured mouse erythroleukemia cell lines indicate that one aspect of PU.1 function in erythroleukemogenesis is its ability to block erythroid differentiation by repressing GATA-1 (N. Rekhtman, F. Radparvar, T. Evans, and A. I. Skoultchi, Genes Dev. 13:1398-1411, 1999). We have investigated the mechanism of PU.1-mediated repression of GATA-1. We report here that PU.1 binds to GATA-1 on DNA. We localized the repression activity of PU.1 to a small acidic N-terminal domain that interacts with the C pocket of pRB, a well-known transcriptional corepressor. Repression of GATA-1 by PU.1 requires pRB, and pRB colocalizes with PU.1 and GATA-1 at repressed GATA-1 target genes. PU.1 and pRB also cooperate to block erythroid differentiation. Our results suggest that one of the mechanisms by which PU.1 antagonizes GATA-1 is by binding to it at GATA-1 target genes and tethering to these sites a corepressor that blocks transcriptional activity and thereby erythroid differentiation.
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Affiliation(s)
- Natasha Rekhtman
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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42
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Abstract
Chromatin assembly and remodeling complexes alter histone-DNA interactions by using the energy of ATP hydrolysis catalyzed by nucleosome-dependent ATPase subunits. Several classes of ATP-dependent chromatin remodeling complexes exist, including the ISWI family. ISWI complexes disrupt histone-DNA interactions in vitro by facilitating nucleosome sliding. Snf2h is a widely expressed ISWI ATPase. We investigated the role of the Snf2h gene in mammalian development by generating a null mutation in mice. Snf2h heterozygous mutant mice are born at the expected frequency and appear normal. Snf2h-/- embryos die during the periimplantation stage. Blastocyst outgrowth experiments indicate that loss of Snf2h results in growth arrest and cell death of both the trophectoderm and inner cell mass. To investigate the effect of decreased Snf2h levels in adult cells, we performed antisense inhibition of Snf2h in human hematopoietic progenitors. Reducing Snf2h levels inhibited CD34+ progenitors from undergoing cytokine-induced erythropoiesis in vitro. Our results indicate that Snf2h is required for proliferation of early blastocyst-derived stem cells and adult human hematopoietic progenitors. Cells lacking Snf2h are thus prevented from further embryonic development and differentiation.
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Affiliation(s)
- Tomas Stopka
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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43
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Choe KS, Radparvar F, Matushansky I, Rekhtman N, Han X, Skoultchi AI. Reversal of tumorigenicity and the block to differentiation in erythroleukemia cells by GATA-1. Cancer Res 2003; 63:6363-9. [PMID: 14559825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Oncogenic transformation usually inhibits normal cell differentiation processes. Certain chemical agents can force some tumor cells to resume their differentiation program and undergo cell cycle arrest, an approach termed differentiation therapy. Mouse erythroleukemia (MEL) cells represent an important cell culture model system for investigating the principles of differentiation therapy. MEL cells are malignant erythroblasts that are blocked from differentiating into mature erythroid cells because of inappropriate expression of the transcription factor PU.1, which binds to and represses GATA-1, a key transcriptional stimulator of red blood cell differentiation. We report here that the block to differentiation in MEL cells can be overcome by providing the cells with additional GATA-1. A conditionally active form of GATA-1 can trigger the cells to differentiate, undergo terminal cell division, and lose their tumorigenicity. We also show that the gene for the cell cycle inhibitor p21 is transcriptionally regulated by GATA-1 and is a likely downstream effector of GATA-1 that helps to promote differentiation and proliferation arrest.
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MESH Headings
- Animals
- Cell Differentiation/genetics
- Cell Differentiation/physiology
- Cyclin-Dependent Kinase Inhibitor p21
- Cyclins/biosynthesis
- Cyclins/genetics
- DNA-Binding Proteins/biosynthesis
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/physiology
- Down-Regulation
- Erythroid-Specific DNA-Binding Factors
- GATA1 Transcription Factor
- Genetic Therapy
- Leukemia, Erythroblastic, Acute/genetics
- Leukemia, Erythroblastic, Acute/metabolism
- Leukemia, Erythroblastic, Acute/pathology
- Leukemia, Erythroblastic, Acute/therapy
- Male
- Mice
- Mice, Inbred DBA
- Receptors, Estrogen/biosynthesis
- Receptors, Estrogen/genetics
- Recombinant Fusion Proteins/biosynthesis
- Recombinant Fusion Proteins/genetics
- Transcription Factors/biosynthesis
- Transcription Factors/genetics
- Transcription Factors/physiology
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Affiliation(s)
- Kevin S Choe
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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44
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Konishi A, Shimizu S, Hirota J, Takao T, Fan Y, Matsuoka Y, Zhang L, Yoneda Y, Fujii Y, Skoultchi AI, Tsujimoto Y. Involvement of Histone H1.2 in Apoptosis Induced by DNA Double-Strand Breaks. Cell 2003; 114:673-88. [PMID: 14505568 DOI: 10.1016/s0092-8674(03)00719-0] [Citation(s) in RCA: 232] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
It is poorly understood how apoptotic signals arising from DNA damage are transmitted to mitochondria, which release apoptogenic factors into the cytoplasm that activate downstream destruction programs. Here, we identify histone H1.2 as a cytochrome c-releasing factor that appears in the cytoplasm after exposure to X-ray irradiation. While all nuclear histone H1 forms are released into the cytoplasm in a p53-dependent manner after irradiation, only H1.2, but not other H1 forms, induced cytochrome c release from isolated mitochondria in a Bak-dependent manner. Reducing H1.2 expression enhanced cellular resistance to apoptosis induced by X-ray irradiation or etoposide, but not that induced by other stimuli including TNF-alpha and UV irradiation. H1.2-deficient mice exhibited increased cellular resistance in thymocytes and the small intestine to X-ray-induced apoptosis. These results indicate that histone H1.2 plays an important role in transmitting apoptotic signals from the nucleus to the mitochondria following DNA double-strand breaks.
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Affiliation(s)
- Akimitsu Konishi
- Department of Post-Genomics and Diseases, Osaka University Medical School, 2-2 Yamadaoka, Suita, 565-0871, Osaka, Japan
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45
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Abstract
Cell proliferation and differentiation are highly coordinated during normal development. Many tumor cells exhibit both uncontrolled proliferation and a block to terminal differentiation. To understand the mechanisms coordinating these two processes, we have investigated the relation between cyclin-dependent kinase (CDK) activities and the block to differentiation in murine erythroleukemia (MEL) cells. We found that CDK6 (but not CDK4) is rapidly downregulated as MEL cells are induced to re-enter erythroid differentiation and that maintenance of CDK6 (but not CDK4) activity by transfection blocks differentiation. Moreover, we found that PU.1, an Ets transcription factor that is oncogenic in erythroid cells and also can block their differentiation, controls the synthesis of CDK6 mRNA. These results suggest a mechanism for coupling proliferation and the block to differentiation in these leukemic cells through the action of an oncogenic transcription factor (PU.1) on a key cell cycle regulator (CDK6). Our findings suggest that studying the relative roles of CDK6 and CDK4 in other types of malignant cells will be important in designing approaches for cell cycle inhibition and differentiation therapy in cancer.
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Affiliation(s)
- Igor Matushansky
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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46
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Fan Y, Nikitina T, Morin-Kensicki EM, Zhao J, Magnuson TR, Woodcock CL, Skoultchi AI. H1 linker histones are essential for mouse development and affect nucleosome spacing in vivo. Mol Cell Biol 2003; 23:4559-72. [PMID: 12808097 PMCID: PMC164858 DOI: 10.1128/mcb.23.13.4559-4572.2003] [Citation(s) in RCA: 235] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Most eukaryotic cells contain nearly equimolar amounts of nucleosomes and H1 linker histones. Despite their abundance and the potential functional specialization of H1 subtypes in multicellular organisms, gene inactivation studies have failed to reveal essential functions for linker histones in vivo. Moreover, in vitro studies suggest that H1 subtypes may not be absolutely required for assembly of chromosomes or nuclei. By sequentially inactivating the genes for three mouse H1 subtypes (H1c, H1d, and H1e), we showed that linker histones are essential for mammalian development. Embryos lacking the three H1 subtypes die by mid-gestation with a broad range of defects. Triple-H1-null embryos have about 50% of the normal ratio of H1 to nucleosomes. Mice null for five of these six H1 alleles are viable but are underrepresented in litters and are much smaller than their littermates. Marked reductions in H1 content were found in certain tissues of these mice and in another compound H1 mutant. These results demonstrate that the total amount of H1 is crucial for proper embryonic development. Extensive reduction of H1 in certain tissues did not lead to changes in nuclear size, but it did result in global shortening of the spacing between nucleosomes.
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Affiliation(s)
- Yuhong Fan
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Alami R, Fan Y, Pack S, Sonbuchner TM, Besse A, Lin Q, Greally JM, Skoultchi AI, Bouhassira EE. Mammalian linker-histone subtypes differentially affect gene expression in vivo. Proc Natl Acad Sci U S A 2003; 100:5920-5. [PMID: 12719535 PMCID: PMC156302 DOI: 10.1073/pnas.0736105100] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2002] [Indexed: 01/26/2023] Open
Abstract
Posttranslational modifications and remodeling of nucleosomes are critical factors in the regulation of transcription. Higher-order folding of chromatin also is likely to contribute to the control of gene expression, but the absence of a detailed description of the structure of the chromatin fiber has impaired progress in this area. Mammalian somatic cells contain a set of H1 linker-histone subtypes, H1 (0) and H1a to H1e, that bind to nucleosome core particles and to the linker DNA between nucleosomes. To determine whether the H1 histone subtypes play differential roles in the regulation of gene expression, we combined mice lacking specific H1 histone subtypes with mice carrying transgenes subject to position effects. Because position effects result from the unique chromatin structure created by the juxtaposition of regulatory elements in the transgene and at the site of integration, transgenes can serve as exquisitely sensitive indicators of chromatin structure. We report that some, but not all, linker histones can attenuate or accentuate position effects. The results suggest that the linker-histone subtypes play differential roles in the control of gene expression and that the sequential arrangement of the linker histones on the chromatin fiber might regulate higher-order chromatin structure and fine-tune expression levels.
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Affiliation(s)
- Raouf Alami
- Department of Medicine, Division of Hematology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Abstract
Oocytes and embryos of many species, including mammals, contain a unique linker (H1) histone, termed H1oo in mammals. It is uncertain, however, whether other H1 histones also contribute to the linker histone complement of these cells. Using immunofluorescence and radiolabeling, we have examined whether histone H10, which frequently accumulates in the chromatin of nondividing cells, and the somatic subtypes of H1 are present in mouse oocytes and early embryos. We report that oocytes and embryos contain mRNA encoding H10. A polymerase chain reaction-based test indicated that the poly(A) tail did not lengthen during meiotic maturation, although it did so beginning at the four-cell stage. Antibodies raised against histone H10 stained the nucleus of wild-type prophase-arrested oocytes but not of mice lacking the H10 gene. Following fertilization, H10 was detected in the nuclei of two-cell embryos and less strongly at the four-cell stage. No signal was detected in H10 -/- embryos. Radiolabeling revealed that species comigrating with the somatic H1 subtypes H1a and H1c were synthesized in maturing oocytes and in one- and two-cell embryos. Beginning at the four-cell stage in both wild-type and H10 -/- embryos, species comigrating with subtypes H1b, H1d, and H1e were additionally synthesized. These results establish that histone H10 constitutes a portion of the linker histone complement in oocytes and early embryos and that changes in the pattern of somatic H1 synthesis occur during early embryonic development. Taken together with previous results, these findings suggest that multiple H1 subtypes are present on oocyte chromatin and that following fertilization changes in the histone H1 complement accompany the establishment of regulated embryonic gene expression.
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Affiliation(s)
- Germaine Fu
- Department of Obstetrics and Gynecology, McGill University, Montréal, Québec, Canada
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Gabrilovich DI, Cheng P, Fan Y, Yu B, Nikitina E, Sirotkin A, Shurin M, Oyama T, Adachi Y, Nadaf S, Carbone DP, Skoultchi AI. H1° histone and differentiation of dendritic cells. A molecular target for tumor‐derived factors. J Leukoc Biol 2002. [DOI: 10.1189/jlb.72.2.285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
| | - Pingyan Cheng
- H. Lee Moffitt Cancer Center, University of South Florida, Tampa
| | - Yuhong Fan
- Department of Cell Biology and Cancer Center, Albert Einstein College of Medicine, Bronx, New York
| | - Bin Yu
- H. Lee Moffitt Cancer Center, University of South Florida, Tampa
| | | | - Allen Sirotkin
- Department of Cell Biology and Cancer Center, Albert Einstein College of Medicine, Bronx, New York
| | - Michael Shurin
- Department of Surgery, University of Pittsburgh, Pennsylvania; and
| | - Tsunehiro Oyama
- Department of Medicine and Cancer Center, Vanderbilt University, Nashville, Tennessee
| | - Yasushi Adachi
- Department of Medicine and Cancer Center, Vanderbilt University, Nashville, Tennessee
| | - Sorena Nadaf
- Department of Medicine and Cancer Center, Vanderbilt University, Nashville, Tennessee
| | - David P. Carbone
- Department of Medicine and Cancer Center, Vanderbilt University, Nashville, Tennessee
| | - Arthur I. Skoultchi
- Department of Cell Biology and Cancer Center, Albert Einstein College of Medicine, Bronx, New York
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Gabrilovich DI, Cheng P, Fan Y, Yu B, Nikitina E, Sirotkin A, Shurin M, Oyama T, Adachi Y, Nadaf S, Carbone DP, Skoultchi AI. H1(0) histone and differentiation of dendritic cells. A molecular target for tumor-derived factors. J Leukoc Biol 2002; 72:285-96. [PMID: 12149419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023] Open
Abstract
Dendritic cells (DC) play a central role in antitumor immune responses. Abnormal differentiation of DC and their inability to stimulate T cells are important factors in tumor escape from immune-system control. However, the mechanisms of this process remain elusive. Here, we have described one possible molecular mechanism that involves replacement linker histone H1 (0). A close association between expression of H1(0) and DC differentiation in vitro has been found. DC production in H1(0) -deficient mice was decreased significantly, whereas generation and function of macrophages, granulocytes, and lymphocytes appear to be normal. However, these mice had a significantly reduced response to vaccination with antigens. Tumor-derived factors considerably reduced H1(0) expression in hematopoietic progenitor cells. We have demonstrated that transcription factor NF-kappaB is involved actively in regulation of H1(0). Thus, H1(0) histone may be an important factor in normal DC differentiation. Tumor-derived factors may inhibit DC differentiation by affecting H1(0) expression.
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