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Picketts D, Mirzaa G, Yan K, Relator R, Timpano S, Yalcin B, Collins S, Ziegler A, Pao E, Oyama N, Brischoux-Boucher E, Piard J, Monaghan K, Sacoto MG, Dobyns W, Park K, Fernández-Mayoralas D, Fernández-Jaén A, Jayakar P, Brusco A, Antona V, Giorgio E, Kvarnung M, Isidor B, Conrad S, Cogné B, Deb W, Stuurman KE, Sterbova K, Smal N, Weckhuysen S, Oegema R, Innes M, Latsko M, Ben-Omran T, Yeh R, Kruer M, Bakhtiari S, Papavasiliou A, Moutton S, Nambot S, Chanprasert S, Paolucci S, Miller K, Burton B, Kim K, O'Heir E, Bruwer Z, Donald K, Kleefstra T, Goldstein A, Angle B, Bontempo K, Miny P, Joset P, Demurger F, Hobson E, Pang L, Carpenter L, Li D, Bonneau D, Sadikovic B. Pathogenic variants in SMARCA1 cause an X-linked neurodevelopmental disorder modulated by NURF complex composition. RESEARCH SQUARE 2023:rs.3.rs-3317938. [PMID: 37841849 PMCID: PMC10571636 DOI: 10.21203/rs.3.rs-3317938/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Pathogenic variants in ATP-dependent chromatin remodeling proteins are a recurrent cause of neurodevelopmental disorders (NDDs). The NURF complex consists of BPTF and either the SNF2H (SMARCA5) or SNF2L (SMARCA1) ISWI-chromatin remodeling enzyme. Pathogenic variants in BPTF and SMARCA5 were previously implicated in NDDs. Here, we describe 40 individuals from 30 families with de novo or maternally inherited pathogenic variants in SMARCA1. This novel NDD was associated with mild to severe ID/DD, delayed or regressive speech development, and some recurrent facial dysmorphisms. Individuals carrying SMARCA1 loss-of-function variants exhibited a mild genome-wide DNA methylation profile and a high penetrance of macrocephaly. Genetic dissection of the NURF complex using Smarca1, Smarca5, and Bptfsingle and double mouse knockouts revealed the importance of NURF composition and dosage for proper forebrain development. Finally, we propose that genetic alterations affecting different NURF components result in a NDD with a broad clinical spectrum.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Emily Pao
- Seattle Children's Research Institute
| | | | | | | | | | | | | | - Kristen Park
- University of Colorado Denver School of Medicine
| | | | - Alberto Fernández-Jaén
- Department of Pediatrics and Neurology, Hospital Universitario Quirónsalud, School of Medicine, Universidad Europea de Madrid
| | - Parul Jayakar
- Division of Genetics and Metabolism, Nicklaus Children's Hospital
| | | | | | | | | | | | | | | | | | - K E Stuurman
- Department of Clinical Genetics, Erasmus University Medical Center
| | | | | | | | | | | | - Maeson Latsko
- The Steve and Cindy Rasmussen Institute for Genomic Medicine
| | | | | | | | | | | | | | - Sophie Nambot
- Centre de Génétique et Centre de référence «Anomalies du Développement et Syndromes Malformatifs», Hôpital d'Enfants, Centre Hospitalier
| | | | | | | | | | | | | | | | - Kirsten Donald
- Division of Developmental Paediatrics, Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, Klipfontein Road/Private Bag, Rondebosch, 7700/7701, Cape Town, South A
| | | | | | | | | | | | | | | | | | | | | | - Dong Li
- The Children's Hospital of Philadelphia
| | - Dominique Bonneau
- Department of Biochemistry and Genetics, University Hospital of Angers, F-49000
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2
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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; 12:1035. [PMID: 37048108 PMCID: PMC10093269 DOI: 10.3390/cells12071035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [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
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3
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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 : THE PREPRINT SERVER FOR BIOLOGY 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] [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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4
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Goodwin LR, Zapata G, Timpano S, Marenger J, Picketts DJ. Impaired SNF2L Chromatin Remodeling Prolongs Accessibility at Promoters Enriched for Fos/Jun Binding Sites and Delays Granule Neuron Differentiation. Front Mol Neurosci 2021; 14:680280. [PMID: 34295220 PMCID: PMC8290069 DOI: 10.3389/fnmol.2021.680280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 06/10/2021] [Indexed: 11/13/2022] Open
Abstract
Chromatin remodeling proteins utilize the energy from ATP hydrolysis to mobilize nucleosomes often creating accessibility for transcription factors within gene regulatory elements. Aberrant chromatin remodeling has diverse effects on neuroprogenitor homeostasis altering progenitor competence, proliferation, survival, or cell fate. Previous work has shown that inactivation of the ISWI genes, Smarca5 (encoding Snf2h) and Smarca1 (encoding Snf2l) have dramatic effects on brain development. Smarca5 conditional knockout mice have reduced progenitor expansion and severe forebrain hypoplasia, with a similar effect on the postnatal growth of the cerebellum. In contrast, Smarca1 mutants exhibited enlarged forebrains with delayed progenitor differentiation and increased neuronal output. Here, we utilized cerebellar granule neuron precursor (GNP) cultures from Smarca1 mutant mice (Ex6DEL) to explore the requirement for Snf2l on progenitor homeostasis. The Ex6DEL GNPs showed delayed differentiation upon plating that was not attributed to changes in the Sonic Hedgehog pathway but was associated with overexpression of numerous positive effectors of proliferation, including targets of Wnt activation. Transcriptome analysis identified increased expression of Fosb and Fosl2 while ATACseq experiments identified a large increase in chromatin accessibility at promoters many enriched for Fos/Jun binding sites. Nonetheless, the elevated proliferation index was transient and the Ex6DEL cultures initiated differentiation with a high concordance in gene expression changes to the wild type cultures. Genes specific to Ex6DEL differentiation were associated with an increased activation of the ERK signaling pathway. Taken together, this data provides the first indication of how Smarca1 mutations alter progenitor cell homeostasis and contribute to changes in brain size.
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Affiliation(s)
- Laura R Goodwin
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Gerardo Zapata
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Sara Timpano
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Jacob Marenger
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - David J Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
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5
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Mallik R, Prasad P, Kundu A, Sachdev S, Biswas R, Dutta A, Roy A, Mukhopadhyay J, Bag SK, Chaudhuri S. Identification of genome-wide targets and DNA recognition sequence of the Arabidopsis HMG-box protein AtHMGB15 during cold stress response. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194644. [PMID: 33068782 DOI: 10.1016/j.bbagrm.2020.194644] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 09/12/2020] [Accepted: 10/07/2020] [Indexed: 12/27/2022]
Abstract
AtHMGB15 belongs to a group of ARID-HMG proteins which are plant specific. The presence of two known DNA binding domains: AT rich interacting domain (ARID) and High Mobility Group (HMG)-box, in one polypeptide, makes this protein intriguing. Although proteins containing individual HMG and ARID domains have been characterized, not much is known about the role of ARID-HMG proteins. Promoter analysis of AtHMGB15 showed the presence of various stress responsive cis regulatory elements along with MADS-box containing transcription factors. Our result shows that the expression of AtHMGB15 increased significantly upon application of cold stress. Using ChIP-chip approach, we have identified 6128 and 4689 significantly enriched loci having AtHMGB15 occupancy under control and cold stressed condition respectively. GO analysis shows genes belonging to abiotic stress response, cold response and root development were AtHMGB15 targets during cold stress. DNA binding and footprinting assays further identified A(A/C)--ATA---(A/T)(A/T) as AtHMGB15 binding motif. The enriched probe distribution in both control and cold condition shows a bias of AtHMGB15 binding towards the transcribed (gene body) region. Further, the expression of cold stress responsive genes decreased in athmgb15 knockout plants compared to wild-type. Taken together, binding enrichment of AtHMGB15 to the promoter and upstream to stress loci suggest an unexplored role of the protein in stress induced transcription regulation.
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Affiliation(s)
- Rwitie Mallik
- Division of Plant Biology, Bose Institute, P1/12 C.I.T Scheme VII M, Kolkata 700054, India
| | - Priti Prasad
- Academy of Scientific and Innovative Research (AcSIR), CSIR-NBRI Campus, Lucknow, India; Computational Biology Lab, Council of Scientific and Industrial Research - National Botanical Research Institute (CSIR-NBRI), Rana Pratap Marg, Lucknow, Uttar Pradesh 226001, India
| | - Anindya Kundu
- Division of Plant Biology, Bose Institute, P1/12 C.I.T Scheme VII M, Kolkata 700054, India
| | - Sonal Sachdev
- Division of Plant Biology, Bose Institute, P1/12 C.I.T Scheme VII M, Kolkata 700054, India
| | - Ruby Biswas
- Division of Plant Biology, Bose Institute, P1/12 C.I.T Scheme VII M, Kolkata 700054, India
| | - Arkajyoti Dutta
- Department of Chemistry, Bose Institute, P1/12 C.I.T Scheme VII M, Kolkata 700054, India
| | - Adrita Roy
- Division of Plant Biology, Bose Institute, P1/12 C.I.T Scheme VII M, Kolkata 700054, India
| | - Jayanta Mukhopadhyay
- Department of Chemistry, Bose Institute, P1/12 C.I.T Scheme VII M, Kolkata 700054, India
| | - Sumit K Bag
- Academy of Scientific and Innovative Research (AcSIR), CSIR-NBRI Campus, Lucknow, India; Computational Biology Lab, Council of Scientific and Industrial Research - National Botanical Research Institute (CSIR-NBRI), Rana Pratap Marg, Lucknow, Uttar Pradesh 226001, India
| | - Shubho Chaudhuri
- Division of Plant Biology, Bose Institute, P1/12 C.I.T Scheme VII M, Kolkata 700054, India.
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6
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Amato D, Bosco GL, Rizzo R. CORENup: a combination of convolutional and recurrent deep neural networks for nucleosome positioning identification. BMC Bioinformatics 2020; 21:326. [PMID: 32938377 PMCID: PMC7493859 DOI: 10.1186/s12859-020-03627-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 06/22/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Nucleosomes wrap the DNA into the nucleus of the Eukaryote cell and regulate its transcription phase. Several studies indicate that nucleosomes are determined by the combined effects of several factors, including DNA sequence organization. Interestingly, the identification of nucleosomes on a genomic scale has been successfully performed by computational methods using DNA sequence as input data. RESULTS In this work, we propose CORENup, a deep learning model for nucleosome identification. CORENup processes a DNA sequence as input using one-hot representation and combines in a parallel fashion a fully convolutional neural network and a recurrent layer. These two parallel levels are devoted to catching both non periodic and periodic DNA string features. A dense layer is devoted to their combination to give a final classification. CONCLUSIONS Results computed on public data sets of different organisms show that CORENup is a state of the art methodology for nucleosome positioning identification based on a Deep Neural Network architecture. The comparisons have been carried out using two groups of datasets, currently adopted by the best performing methods, and CORENup has shown top performance both in terms of classification metrics and elapsed computation time.
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Affiliation(s)
- Domenico Amato
- Dipartimento di Matematica e Informatica, Università degli studi di Palermo, Via Archirafi, 34, Palermo, 90123, Italy
| | - Giosue' Lo Bosco
- Dipartimento di Matematica e Informatica, Università degli studi di Palermo, Via Archirafi, 34, Palermo, 90123, Italy. .,Dipartimento di Scienze per l'Innovazione tecnologica, Istituto Euro-Mediterraneo di Scienza e Tecnologia, Via Michele Miraglia, 20, Palermo, 9039, Italy.
| | - Riccardo Rizzo
- CNR-ICAR, National Research Council of Italy, Via Ugo La Malfa, 153, Palermo, 90146, Italy
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7
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Alvarez-Saavedra M, Yan K, De Repentigny Y, Hashem LE, Chaudary N, Sarwar S, Yang D, Ioshikhes I, Kothary R, Hirayama T, Yagi T, Picketts DJ. Snf2h Drives Chromatin Remodeling to Prime Upper Layer Cortical Neuron Development. Front Mol Neurosci 2019; 12:243. [PMID: 31680852 PMCID: PMC6811508 DOI: 10.3389/fnmol.2019.00243] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 09/20/2019] [Indexed: 01/23/2023] Open
Abstract
Alterations in the homeostasis of either cortical progenitor pool, namely the apically located radial glial (RG) cells or the basal intermediate progenitors (IPCs) can severely impair cortical neuron production. Such changes are reflected by microcephaly and are often associated with cognitive defects. Genes encoding epigenetic regulators are a frequent cause of intellectual disability and many have been shown to regulate progenitor cell growth, including our inactivation of the Smarca1 gene encoding Snf2l, which is one of two ISWI mammalian orthologs. Loss of the Snf2l protein resulted in dysregulation of Foxg1 and IPC proliferation leading to macrocephaly. Here we show that inactivation of the closely related Smarca5 gene encoding the Snf2h chromatin remodeler is necessary for embryonic IPC expansion and subsequent specification of callosal projection neurons. Telencephalon-specific Smarca5 cKO embryos have impaired cell cycle kinetics and increased cell death, resulting in fewer Tbr2+ and FoxG1+ IPCs by mid-neurogenesis. These deficits give rise to adult mice with a dramatic reduction in Satb2+ upper layer neurons, and partial agenesis of the corpus callosum. Mice survive into adulthood but molecularly display reduced expression of the clustered protocadherin genes that may further contribute to altered dendritic arborization and a hyperactive behavioral phenotype. Our studies provide novel insight into the developmental function of Snf2h-dependent chromatin remodeling processes during brain development.
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Affiliation(s)
- Matías Alvarez-Saavedra
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Keqin Yan
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Yves De Repentigny
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Lukas E Hashem
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Nidhi Chaudary
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Shihab Sarwar
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Doo Yang
- Departments of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - Ilya Ioshikhes
- Departments of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - Rashmi Kothary
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Departments of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Teruyoshi Hirayama
- KOKORO-Biology Group, Integrated Biology Laboratories, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.,Department of Anatomy and Developmental Neurobiology, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan
| | - Takeshi Yagi
- KOKORO-Biology Group, Integrated Biology Laboratories, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - David J Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Departments of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
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8
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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. THE JOURNAL OF IMMUNOLOGY 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] [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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9
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Di Gangi M, Lo Bosco G, Rizzo R. Deep learning architectures for prediction of nucleosome positioning from sequences data. BMC Bioinformatics 2018; 19:418. [PMID: 30453896 PMCID: PMC6245688 DOI: 10.1186/s12859-018-2386-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Background Nucleosomes are DNA-histone complex, each wrapping about 150 pairs of double-stranded DNA. Their function is fundamental for one of the primary functions of Chromatin i.e. packing the DNA into the nucleus of the Eukaryote cells. Several biological studies have shown that the nucleosome positioning influences the regulation of cell type-specific gene activities. Moreover, computational studies have shown evidence of sequence specificity concerning the DNA fragment wrapped into nucleosomes, clearly underlined by the organization of particular DNA substrings. As the main consequence, the identification of nucleosomes on a genomic scale has been successfully performed by computational methods using a sequence features representation. Results In this work, we propose a deep learning model for nucleosome identification. Our model stacks convolutional layers and Long Short-term Memories to automatically extract features from short- and long-range dependencies in a sequence. Using this model we are able to avoid the feature extraction and selection steps while improving the classification performances. Conclusions Results computed on eleven data sets of five different organisms, from Yeast to Human, show the superiority of the proposed method with respect to the state of the art recently presented in the literature.
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Affiliation(s)
- Mattia Di Gangi
- Fondazione Bruno Kessler, Via Sommarive, 18, Trento, 38123, Italy.,ICT International Doctoral School, Via Sommarive, 9, Trento, 38123, Italy
| | - Giosuè Lo Bosco
- Dipartimento di Matematica e Informatica, Università degli studi di Palermo, Via Archirafi, 34, Palermo, 90123, Italy. .,Dipartimento di Scienze per l'Innovazione tecnologica, Istituto Euro-Mediterraneo di Scienza e Tecnologia, Via Michele Miraglia, 20, Palermo, 90139, Italy.
| | - Riccardo Rizzo
- CNR-ICAR, National Research Council of Italy, Via Ugo La Malfa, 153, Palermo, 90146, Italy
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10
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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] [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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11
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Goodwin LR, Picketts DJ. The role of ISWI chromatin remodeling complexes in brain development and neurodevelopmental disorders. Mol Cell Neurosci 2017; 87:55-64. [PMID: 29249292 DOI: 10.1016/j.mcn.2017.10.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 10/04/2017] [Accepted: 10/26/2017] [Indexed: 10/18/2022] Open
Abstract
The mammalian ISWI (Imitation Switch) genes SMARCA1 and SMARCA5 encode the ATP-dependent chromatin remodeling proteins SNF2L and SNF2H. The ISWI proteins interact with BAZ (bromodomain adjacent to PHD zinc finger) domain containing proteins to generate eight distinct remodeling complexes. ISWI complex-mediated nucleosome positioning within genes and gene regulatory elements is proving important for the transition from a committed progenitor state to a differentiated cell state. Genetic studies have implicated the involvement of many ATP-dependent chromatin remodeling proteins in neurodevelopmental disorders (NDDs), including SMARCA1. Here we review the characterization of mice inactivated for ISWI and their interacting proteins, as it pertains to brain development and disease. A better understanding of chromatin dynamics during neural development is a prerequisite to understanding disease pathologies and the development of therapeutics for these complex disorders.
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Affiliation(s)
- Laura R Goodwin
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology & Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - David J Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology & Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada; Department of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada.
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12
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Shukla A, Bhargava P. Regulation of tRNA gene transcription by the chromatin structure and nucleosome dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1861:295-309. [PMID: 29313808 DOI: 10.1016/j.bbagrm.2017.11.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 11/27/2017] [Accepted: 11/27/2017] [Indexed: 01/19/2023]
Abstract
The short, non-coding genes transcribed by the RNA polymerase (pol) III, necessary for survival of a cell, need to be repressed under the stress conditions in vivo. The pol III-transcribed genes have adopted several novel chromatin-based regulatory mechanisms to their advantage. In the budding yeast, the sub-nucleosomal size tRNA genes are found in the nucleosome-free regions, flanked by positioned nucleosomes at both the ends. With their chromosomes-wide distribution, all tRNA genes have a different chromatin context. A single nucleosome dynamics controls the accessibility of the genes for transcription. This dynamics operates under the influence of several chromatin modifiers in a gene-specific manner, giving the scope for differential regulation of even the isogenes within a tRNA gene family. The chromatin structure around the pol III-transcribed genes provides a context conducive for steady-state transcription as well as gene-specific transcriptional regulation upon signaling from the environmental cues. This article is part of a Special Issue entitled: SI: Regulation of tRNA synthesis and modification in physiological conditions and disease edited by Dr. Boguta Magdalena.
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Affiliation(s)
- Ashutosh Shukla
- Centre for Cellular and Molecular Biology (Council of Scientific and Industrial Research), Uppal Road, Hyderabad 500007, India
| | - Purnima Bhargava
- Centre for Cellular and Molecular Biology (Council of Scientific and Industrial Research), Uppal Road, Hyderabad 500007, India.
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13
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Chatterjee RN. Dosage compensation and its roles in evolution of sex chromosomes and phenotypic dimorphism: lessons from Drosophila, C.elegans and mammals. THE NUCLEUS 2017. [DOI: 10.1007/s13237-017-0223-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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14
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Phosphorylated HBO1 at UV irradiated sites is essential for nucleotide excision repair. Nat Commun 2017; 8:16102. [PMID: 28719581 PMCID: PMC5520108 DOI: 10.1038/ncomms16102] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 05/30/2017] [Indexed: 12/22/2022] Open
Abstract
HBO1, a histone acetyl transferase, is a co-activator of DNA pre-replication complex formation. We recently reported that HBO1 is phosphorylated by ATM and/or ATR and binds to DDB2 after ultraviolet irradiation. Here, we show that phosphorylated HBO1 at cyclobutane pyrimidine dimer (CPD) sites mediates histone acetylation to facilitate recruitment of XPC at the damaged DNA sites. Furthermore, HBO1 facilitates accumulation of SNF2H and ACF1, an ATP-dependent chromatin remodelling complex, to CPD sites. Depletion of HBO1 inhibited repair of CPDs and sensitized cells to ultraviolet irradiation. However, depletion of HBO1 in cells derived from xeroderma pigmentosum patient complementation groups, XPE, XPC and XPA, did not lead to additional sensitivity towards ultraviolet irradiation. Our findings suggest that HBO1 acts in concert with SNF2H-ACF1 to make the chromosome structure more accessible to canonical nucleotide excision repair factors.
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15
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Sun H, Damez-Werno DM, Scobie KN, Shao NY, Dias C, Rabkin J, Wright KN, Mouzon E, Kabbaj M, Neve R, Turecki G, Shen L, Nestler EJ. Regulation of BAZ1A and nucleosome positioning in the nucleus accumbens in response to cocaine. Neuroscience 2017; 353:1-6. [PMID: 28412501 DOI: 10.1016/j.neuroscience.2017.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 04/05/2017] [Accepted: 04/05/2017] [Indexed: 12/18/2022]
Abstract
Chromatin regulation, in particular ATP-dependent chromatin remodelers, have previously been shown to be important in the regulation of reward-related behaviors in animal models of mental illnesses. Here we demonstrate that BAZ1A, an accessory subunit of the ISWI family of chromatin remodeling complexes, is downregulated in the nucleus accumbens (NAc) of mice exposed repeatedly to cocaine and of cocaine-addicted humans. Viral-mediated overexpression of BAZ1A in mouse NAc reduces cocaine reward as assessed by conditioned place preference (CPP), but increases cocaine-induced locomotor activation. Furthermore, we investigate nucleosome repositioning genome-wide by conducting chromatin immunoprecipitation (ChIP)-sequencing for total H3 in NAc of control mice and after repeated cocaine administration, and find extensive nucleosome occupancy and shift changes across the genome in response to cocaine exposure. These findings implicate BAZ1A in molecular and behavioral plasticity to cocaine and offer new insight into the pathophysiology of cocaine addiction.
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Affiliation(s)
- HaoSheng Sun
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Diane M Damez-Werno
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Kimberly N Scobie
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ning-Yi Shao
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Caroline Dias
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jacqui Rabkin
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Katherine N Wright
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL 32306, USA
| | - Ezekiell Mouzon
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Mohamed Kabbaj
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL 32306, USA
| | - Rachael Neve
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Li Shen
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Eric J Nestler
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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16
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Li D, Liu J, Liu W, Li G, Yang Z, Qin P, Xu L. The ISWI remodeler in plants: protein complexes, biochemical functions, and developmental roles. Chromosoma 2017; 126:365-373. [PMID: 28213686 DOI: 10.1007/s00412-017-0626-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 01/15/2017] [Accepted: 01/26/2017] [Indexed: 12/01/2022]
Abstract
Imitation Switch (ISWI) is a member of the ATP-dependent chromatin remodeling factor family, whose members move or restructure nucleosomes using energy derived from ATP hydrolysis. ISWI proteins are conserved in eukaryotes and usually form complexes with DDT (DNA-binding homeobox and different transcription factors)-domain proteins. Here, we review recent research on ISWI in the model plant Arabidopsis thaliana (AtISWI). AtISWI forms complexes with AtDDT-domain proteins, many of which have domain structures that differ from those of DDT-domain proteins in yeast and animals. This might suggest that plant ISWI complexes have unique roles. In vivo studies have shown that AtISWI is involved in the formation of the evenly spaced pattern of nucleosome arrangement in gene bodies-this pattern is associated with high transcriptional levels of genes. In addition, AtISWI and the AtDDT-domain protein RINGLET (RLT) are involved in many developmental processes in A. thaliana, including meristem fate transition and organ formation. Studies on the functions of AtISWI may shed light on how chromatin remodeling functions in plants and also provide new information about the evolution of ISWI remodeling complexes in eukaryotes.
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Affiliation(s)
- Dongjie Li
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China.,College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Jie Liu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, China
| | - Wu Liu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
| | - Guang Li
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China.,Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Zhongnan Yang
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Peng Qin
- Department of Instrumentation Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
| | - Lin Xu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China.
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17
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Barutcu AR, Lajoie BR, Fritz AJ, McCord RP, Nickerson JA, van Wijnen AJ, Lian JB, Stein JL, Dekker J, Stein GS, Imbalzano AN. SMARCA4 regulates gene expression and higher-order chromatin structure in proliferating mammary epithelial cells. Genome Res 2016; 26:1188-201. [PMID: 27435934 PMCID: PMC5052043 DOI: 10.1101/gr.201624.115] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 07/08/2016] [Indexed: 01/20/2023]
Abstract
The packaging of DNA into chromatin plays an important role in transcriptional regulation and nuclear processes. Brahma-related gene-1 SMARCA4 (also known as BRG1), the essential ATPase subunit of the mammalian SWI/SNF chromatin remodeling complex, uses the energy from ATP hydrolysis to disrupt nucleosomes at target regions. Although the transcriptional role of SMARCA4 at gene promoters is well-studied, less is known about its role in higher-order genome organization. SMARCA4 knockdown in human mammary epithelial MCF-10A cells resulted in 176 up-regulated genes, including many related to lipid and calcium metabolism, and 1292 down-regulated genes, some of which encode extracellular matrix (ECM) components that can exert mechanical forces and affect nuclear structure. ChIP-seq analysis of SMARCA4 localization and SMARCA4-bound super-enhancers demonstrated extensive binding at intergenic regions. Furthermore, Hi-C analysis showed extensive SMARCA4-mediated alterations in higher-order genome organization at multiple resolutions. First, SMARCA4 knockdown resulted in clustering of intra- and inter-subtelomeric regions, demonstrating a novel role for SMARCA4 in telomere organization. SMARCA4 binding was enriched at topologically associating domain (TAD) boundaries, and SMARCA4 knockdown resulted in weakening of TAD boundary strength. Taken together, these findings provide a dynamic view of SMARCA4-dependent changes in higher-order chromatin organization and gene expression, identifying SMARCA4 as a novel component of chromatin organization.
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Affiliation(s)
- A Rasim Barutcu
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Bryan R Lajoie
- Program in Systems Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Andrew J Fritz
- Department of Biochemistry, University of Vermont College of Medicine, Burlington, Vermont 05405, USA
| | - Rachel P McCord
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Jeffrey A Nickerson
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Andre J van Wijnen
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Jane B Lian
- Department of Biochemistry, University of Vermont College of Medicine, Burlington, Vermont 05405, USA
| | - Janet L Stein
- Department of Biochemistry, University of Vermont College of Medicine, Burlington, Vermont 05405, USA
| | - Job Dekker
- Program in Systems Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA; Howard Hughes Medical Institute, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Gary S Stein
- Department of Biochemistry, University of Vermont College of Medicine, Burlington, Vermont 05405, USA
| | - Anthony N Imbalzano
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
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18
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Mazina MY, Vorobyeva NE. The role of ATP-dependent chromatin remodeling complexes in regulation of genetic processes. RUSS J GENET+ 2016. [DOI: 10.1134/s1022795416050082] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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19
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Gallach M, Betrán E. Dosage Compensation and the Distribution of Sex-Biased Gene Expression in Drosophila: Considerations and Genomic Constraints. J Mol Evol 2016; 82:199-206. [PMID: 27059220 PMCID: PMC4866998 DOI: 10.1007/s00239-016-9735-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 03/28/2016] [Indexed: 11/02/2022]
Abstract
Several studies in Drosophila have shown a paucity of male-biased genes (i.e., genes that express higher in males than in females) on the X chromosome. Dosage compensation (DC) is a regulatory mechanism of gene expression triggered in males that hypertranscribes the X-linked genes to the level of transcription in females. There are currently two different hypotheses about the effects of DC on the distribution of male-biased genes: (1) it might limit male-expression level, or (2) it might interfere with the male upregulation of gene expression. Here, we used previously published gene expression datasets to reevaluate both hypotheses and introduce a mutually exclusive prediction that helped us to reject the hypothesis that the paucity of male-biased genes in the X chromosome is due to a limit in the male-expression level. Our analysis also uncovers unanticipated details about how DC interferes with the genomic distribution of both, male-biased and female-biased genes. We suggest that DC actually interferes with female downregulation of gene expression and not male upregulation, as previously suggested.
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Affiliation(s)
- Miguel Gallach
- Center for Integrative Bioinformatics Vienna (CIBIV), Max F Perutz Laboratories (MFPL), University of Vienna and Medical University of Vienna, Dr. Bohrgasse 9, 1030, Vienna, Austria.
| | - Esther Betrán
- Department of Biology, University of Texas at Arlington, Arlington, USA
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20
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Kwon SY, Grisan V, Jang B, Herbert J, Badenhorst P. Genome-Wide Mapping Targets of the Metazoan Chromatin Remodeling Factor NURF Reveals Nucleosome Remodeling at Enhancers, Core Promoters and Gene Insulators. PLoS Genet 2016; 12:e1005969. [PMID: 27046080 PMCID: PMC4821604 DOI: 10.1371/journal.pgen.1005969] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 03/10/2016] [Indexed: 12/20/2022] Open
Abstract
NURF is a conserved higher eukaryotic ISWI-containing chromatin remodeling complex that catalyzes ATP-dependent nucleosome sliding. By sliding nucleosomes, NURF is able to alter chromatin dynamics to control transcription and genome organization. Previous biochemical and genetic analysis of the specificity-subunit of Drosophila NURF (Nurf301/Enhancer of Bithorax (E(bx)) has defined NURF as a critical regulator of homeotic, heat-shock and steroid-responsive gene transcription. It has been speculated that NURF controls pathway specific transcription by co-operating with sequence-specific transcription factors to remodel chromatin at dedicated enhancers. However, conclusive in vivo demonstration of this is lacking and precise regulatory elements targeted by NURF are poorly defined. To address this, we have generated a comprehensive map of in vivo NURF activity, using MNase-sequencing to determine at base pair resolution NURF target nucleosomes, and ChIP-sequencing to define sites of NURF recruitment. Our data show that, besides anticipated roles at enhancers, NURF interacts physically and functionally with the TRF2/DREF basal transcription factor to organize nucleosomes downstream of active promoters. Moreover, we detect NURF remodeling and recruitment at distal insulator sites, where NURF functionally interacts with and co-localizes with DREF and insulator proteins including CP190 to establish nucleosome-depleted domains. This insulator function of NURF is most apparent at subclasses of insulators that mark the boundaries of chromatin domains, where multiple insulator proteins co-associate. By visualizing the complete repertoire of in vivo NURF chromatin targets, our data provide new insights into how chromatin remodeling can control genome organization and regulatory interactions.
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Affiliation(s)
- So Yeon Kwon
- Institute of Biomedical Research, University of Birmingham, Edgbaston, United Kingdom
| | - Valentina Grisan
- Institute of Biomedical Research, University of Birmingham, Edgbaston, United Kingdom
| | - Boyun Jang
- Institute of Biomedical Research, University of Birmingham, Edgbaston, United Kingdom
| | - John Herbert
- Institute of Biomedical Research, University of Birmingham, Edgbaston, United Kingdom
| | - Paul Badenhorst
- Institute of Biomedical Research, University of Birmingham, Edgbaston, United Kingdom
- * E-mail:
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21
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Abstract
Base Excision Repair (BER) is a conserved, intracellular DNA repair system that recognizes and removes chemically modified bases to insure genomic integrity and prevent mutagenesis. Aberrant BER has been tightly linked with a broad spectrum of human pathologies, such as several types of cancer, neurological degeneration, developmental abnormalities, immune dysfunction and aging. In the cell, BER must recognize and remove DNA lesions from the tightly condensed, protein-coated chromatin. Because chromatin is necessarily refractory to DNA metabolic processes, like transcription and replication, the compaction of the genomic material is also inhibitory to the repair systems necessary for its upkeep. Multiple ATP-dependent chromatin remodelling (ACR) complexes play essential roles in modulating the protein-DNA interactions within chromatin, regulating transcription and promoting activities of some DNA repair systems, including double-strand break repair and nucleotide excision repair. However, it remains unclear how BER operates in the context of chromatin, and if the chromatin remodelling processes that govern transcription and replication also actively regulate the efficiency of BER. In this review we highlight the emerging role of ACR in regulation of BER.
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Affiliation(s)
- John M Hinz
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164-7520, USA.
| | - Wioletta Czaja
- Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602-7229, USA
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22
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ACF chromatin-remodeling complex mediates stress-induced depressive-like behavior. Nat Med 2015; 21:1146-53. [PMID: 26390241 PMCID: PMC4598281 DOI: 10.1038/nm.3939] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 08/11/2015] [Indexed: 02/08/2023]
Abstract
Improved treatment for major depressive disorder (MDD) remains elusive because of the limited understanding of its underlying biological mechanisms. It is likely that stress-induced maladaptive transcriptional regulation in limbic neural circuits contributes to the development of MDD, possibly through epigenetic factors that regulate chromatin structure. We establish that persistent upregulation of the ACF (ATP-utilizing chromatin assembly and remodeling factor) ATP-dependent chromatin-remodeling complex, occurring in the nucleus accumbens of stress-susceptible mice and depressed humans, is necessary for stress-induced depressive-like behaviors. We found that altered ACF binding after chronic stress was correlated with altered nucleosome positioning, particularly around the transcription start sites of affected genes. These alterations in ACF binding and nucleosome positioning were associated with repressed expression of genes implicated in susceptibility to stress. Together, our findings identify the ACF chromatin-remodeling complex as a critical component in the development of susceptibility to depression and in regulating stress-related behaviors.
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23
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Ramachandran P, Palidwor GA, Perkins TJ. BIDCHIPS: bias decomposition and removal from ChIP-seq data clarifies true binding signal and its functional correlates. Epigenetics Chromatin 2015; 8:33. [PMID: 26388941 PMCID: PMC4574076 DOI: 10.1186/s13072-015-0028-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 09/07/2015] [Indexed: 12/24/2022] Open
Abstract
Background Unraveling transcriptional regulatory networks is a central problem in molecular biology and, in this quest, chromatin immunoprecipitation and sequencing (ChIP-seq) technology has given us the unprecedented ability to identify sites of protein-DNA binding and histone modification genome wide. However, multiple systemic and procedural biases hinder harnessing the full potential of this technology. Previous studies have addressed this problem, but a thorough characterization of different, interacting biases on ChIP-seq signals is still lacking. Results Here, we present a novel framework where the genome-wide ChIP-seq signal is viewed as being quantifiably influenced by different, measurable sources of bias, which can then be computationally subtracted away. We use a compendium of 123 human ENCODE ChIP-seq datasets to build regression models that tell us how much of a ChIP-seq signal can be attributed to mappability, GC-content, chromatin accessibility, and factors represented in input DNA and IgG controls. When we use the model to separate out these non-binding influences from the ChIP-seq signal, we obtain a purified signal that associates better to TF-DNA-binding motifs than do other measures of peak significance. We also carry out a multiscale analysis that reveals how ChIP-seq signal biases differ across different scales. Finally, we investigate previously reported associations between gene expression and ChIP-seq signals at transcription start sites. We show that our model can be used to discriminate ChIP-seq signals that are truly related to gene expression from those that are merely correlated by virtue of bias—in particular, chromatin accessibility bias, which shows up in ChIP-seq signals and also relates to gene expression. Conclusions Our study provides new insights into the behavior of ChIP-seq signal biases and proposes a novel mitigation framework that improves results compared to existing techniques. With ChIP-seq now being the central technology for studying transcriptional regulation, it is most crucial to accurately characterize, quantify, and adjust for the genome-wide effects of biases affecting ChIP-seq. Our study also emphasizes that properly accounting for confounders in ChIP-seq data is of paramount importance for obtaining biologically accurate insights into the workings of the complex regulatory mechanisms in living organisms. R and MATLAB packages implementing the framework can be obtained from http://www.perkinslab.ca/Software.html. Electronic supplementary material The online version of this article (doi:10.1186/s13072-015-0028-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Parameswaran Ramachandran
- Regenerative Medicine Program, Ottawa Hospital Research Institute, K1H 8L6 Ottawa, Canada ; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, K1H 8M5 Ottawa, Canada
| | - Gareth A Palidwor
- Regenerative Medicine Program, Ottawa Hospital Research Institute, K1H 8L6 Ottawa, Canada
| | - Theodore J Perkins
- Regenerative Medicine Program, Ottawa Hospital Research Institute, K1H 8L6 Ottawa, Canada ; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, K1H 8M5 Ottawa, Canada
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24
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Jain D, Baldi S, Zabel A, Straub T, Becker PB. Active promoters give rise to false positive 'Phantom Peaks' in ChIP-seq experiments. Nucleic Acids Res 2015; 43:6959-68. [PMID: 26117547 PMCID: PMC4538825 DOI: 10.1093/nar/gkv637] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 06/08/2015] [Indexed: 02/07/2023] Open
Abstract
Chromatin immunoprecipitation (ChIP) is widely used to identify chromosomal binding sites. Chromatin proteins are cross-linked to their target sequences in living cells. The purified chromatin is sheared and the relevant protein is enriched by immunoprecipitation with specific antibodies. The co-purifying genomic DNA is then determined by massive parallel sequencing (ChIP-seq). We applied ChIP-seq to map the chromosomal binding sites for two ISWI-containing nucleosome remodeling factors, ACF and RSF, in Drosophila embryos. Employing several polyclonal and monoclonal antibodies directed against their signature subunits, ACF1 and RSF-1, robust profiles were obtained indicating that both remodelers co-occupied a large set of active promoters. Further validation included controls using chromatin of mutant embryos that do not express ACF1 or RSF-1. Surprisingly, the ChIP-seq profiles were unchanged, suggesting that they were not due to specific immunoprecipitation. Conservative analysis lists about 3000 chromosomal loci, mostly active promoters that are prone to non-specific enrichment in ChIP and appear as ‘Phantom Peaks’. These peaks are not obtained with pre-immune serum and are not prominent in input chromatin. Mining the modENCODE ChIP-seq profiles identifies potential Phantom Peaks in many profiles of epigenetic regulators. These profiles and other ChIP-seq data featuring prominent Phantom Peaks must be validated with chromatin from cells in which the protein of interest has been depleted.
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Affiliation(s)
- Dhawal Jain
- Biomedical Center and Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, Munich, Germany
| | - Sandro Baldi
- Biomedical Center and Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, Munich, Germany
| | - Angelika Zabel
- Biomedical Center and Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, Munich, Germany
| | - Tobias Straub
- Biomedical Center and Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, Munich, Germany
| | - Peter B Becker
- Biomedical Center and Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, Munich, Germany
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Abstract
Dosage compensation in Drosophila increases the transcription of genes on the single X chromosome in males to equal that of both X chromosomes in females. Site-specific histone acetylation by the male-specific lethal (MSL) complex is thought to play a fundamental role in the increased transcriptional output of the male X. Nucleation and sequence-independent spreading of the complex to active genes serves as a model for understanding the targeting and function of epigenetic chromatin-modifying complexes. Interestingly, two noncoding RNAs are key for MSL assembly and spreading to active genes along the length of the X chromosome.
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Affiliation(s)
- John C Lucchesi
- Department of Biology, O. W. Rollins Research Center, Emory University, Atlanta, Georgia 30322
| | - Mitzi I Kuroda
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115
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Alexander JM, Hota SK, He D, Thomas S, Ho L, Pennacchio LA, Bruneau BG. Brg1 modulates enhancer activation in mesoderm lineage commitment. Development 2015; 142:1418-30. [PMID: 25813539 PMCID: PMC4392595 DOI: 10.1242/dev.109496] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 02/27/2015] [Indexed: 12/28/2022]
Abstract
The interplay between different levels of gene regulation in modulating developmental transcriptional programs, such as histone modifications and chromatin remodeling, is not well understood. Here, we show that the chromatin remodeling factor Brg1 is required for enhancer activation in mesoderm induction. In an embryonic stem cell-based directed differentiation assay, the absence of Brg1 results in a failure of cardiomyocyte differentiation and broad deregulation of lineage-specific gene expression during mesoderm induction. We find that Brg1 co-localizes with H3K27ac at distal enhancers and is required for robust H3K27 acetylation at distal enhancers that are activated during mesoderm induction. Brg1 is also required to maintain Polycomb-mediated repression of non-mesodermal developmental regulators, suggesting cooperativity between Brg1 and Polycomb complexes. Thus, Brg1 is essential for modulating active and repressive chromatin states during mesoderm lineage commitment, in particular the activation of developmentally important enhancers. These findings demonstrate interplay between chromatin remodeling complexes and histone modifications that, together, ensure robust and broad gene regulation during crucial lineage commitment decisions. SUMMARY: The chromatin remodeling factor Brg1 is essential for mesoderm induction and, by modulating active and repressive chromatin states, is involved in promoting the activation of dynamic enhancers.
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Affiliation(s)
- Jeffrey M Alexander
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA
| | - Swetansu K Hota
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA
| | - Daniel He
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA
| | - Sean Thomas
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA
| | - Lena Ho
- Institute of Medical Biology, A*STAR, Singapore 138648
| | - Len A Pennacchio
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA United States Department of Energy, Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Benoit G Bruneau
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA Department of Pediatrics, University of California, San Francisco, CA 94143, USA Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA
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27
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Jimeno-González S, Ceballos-Chávez M, Reyes JC. A positioned +1 nucleosome enhances promoter-proximal pausing. Nucleic Acids Res 2015; 43:3068-78. [PMID: 25735750 PMCID: PMC4381062 DOI: 10.1093/nar/gkv149] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 02/13/2015] [Indexed: 02/07/2023] Open
Abstract
Chromatin distribution is not uniform along the human genome. In most genes there is a promoter-associated nucleosome free region (NFR) followed by an array of nucleosomes towards the gene body in which the first (+1) nucleosome is strongly positioned. The function of this characteristic chromatin distribution in transcription is not fully understood. Here we show in vivo that the +1 nucleosome plays a role in modulating RNA polymerase II (RNAPII) promoter-proximal pausing. When a +1 nucleosome is strongly positioned, elongating RNAPII has a tendency to stall at the promoter-proximal region, recruits more negative elongation factor (NELF) and produces less mRNA. The nucleosome-induced pause favors pre-mRNA quality control by promoting the addition of the cap to the nascent RNA. Moreover, the uncapped RNAs produced in the absence of a positioned nucleosome are degraded by the 5′-3′ exonuclease XRN2. Interestingly, reducing the levels of the chromatin remodeler ISWI factor SNF2H decreases +1 nucleosome positioning and increases RNAPII pause release. This work demonstrates a function for +1 nucleosome in regulation of transcription elongation, pre-mRNA processing and gene expression.
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Affiliation(s)
- Silvia Jimeno-González
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Consejo Superior de Investigaciones Científicas (CSIC), E-41012, Seville, Spain
| | - María Ceballos-Chávez
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Consejo Superior de Investigaciones Científicas (CSIC), E-41012, Seville, Spain
| | - José C Reyes
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Consejo Superior de Investigaciones Científicas (CSIC), E-41012, Seville, Spain
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29
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Abstract
Gene expression frequently requires chromatin-remodeling complexes, and it is assumed that these complexes have common gene targets across cell types. Contrary to this belief, we show by genome-wide expression profiling that Bptf, an essential and unique subunit of the nucleosome-remodeling factor (NURF), predominantly regulates the expression of a unique set of genes between diverse cell types. Coincident with its functions in gene expression, we observed that Bptf is also important for regulating nucleosome occupancy at nucleosome-free regions (NFRs), many of which are located at sites occupied by the multivalent factors Ctcf and cohesin. NURF function at Ctcf binding sites could be direct, because Bptf occupies Ctcf binding sites in vivo and has physical interactions with CTCF and the cohesin subunit SA2. Assays of several Ctcf binding sites using reporter assays showed that their regulatory activity requires Bptf in two different cell types. Focused studies at H2-K1 showed that Bptf regulates the ability of Klf4 to bind near an upstream Ctcf site, possibly influencing gene expression. In combination, these studies demonstrate that gene expression as regulated by NURF occurs partly through physical and functional interactions with the ubiquitous and multivalent factors Ctcf and cohesin.
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30
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Petruk S, Black KL, Kovermann SK, Brock HW, Mazo A. Stepwise histone modifications are mediated by multiple enzymes that rapidly associate with nascent DNA during replication. Nat Commun 2014; 4:2841. [PMID: 24276476 PMCID: PMC3874871 DOI: 10.1038/ncomms3841] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 10/29/2013] [Indexed: 11/10/2022] Open
Abstract
The mechanism of epigenetic inheritance following DNA replication may involve dissociation of chromosomal proteins from parental DNA and reassembly on daughter strands in a specific order. Here we investigated the behavior of different types of chromosomal proteins using newly developed methods that allow assessment of the assembly of proteins during DNA replication. Unexpectedly, most chromatin-modifying proteins tested, including methylases, demethylases, acetyltransferases and a deacetylase, are found in close proximity to PCNA or associate with short nascent DNA. Histone modifications occur in a temporal order following DNA replication, mediated by complex activities of different enzymes. In contrast, components of several major nucleosome remodeling complexes are dissociated from parental DNA, and are later recruited to nascent DNA following replication. Epigenetic inheritance of gene expression patterns may require many aspects of chromatin structure to remain in close proximity to the replication complex followed by re-assembly on nascent DNA shortly after replication.
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Affiliation(s)
- Svetlana Petruk
- Department of Biochemistry and Molecular Biology and Kimmel Cancer Center, Thomas Jefferson University, 1020 Locust Street, Philadelphia, Pennsylvania 19107, USA
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31
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Genome-wide mapping of yeast histone chaperone anti-silencing function 1 reveals its role in condensin binding with chromatin. PLoS One 2014; 9:e108652. [PMID: 25264624 PMCID: PMC4181348 DOI: 10.1371/journal.pone.0108652] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 09/01/2014] [Indexed: 12/23/2022] Open
Abstract
Genome-wide participation and importance of the histone chaperone Asf1 (Anti-Silencing Function 1) in diverse DNA transactions like replication, repair, heterochromatic silencing and transcription are well documented. Yet its genome-wide targets have not been reported. Using ChIP-seq method, we found that yeast Asf1 associates with 590 unique targets including centromeres, telomeres and condensin-binding sites. It is found selectively on highly transcribed regions, which include replication fork pause sites. Asf1 preferentially associates with the genes transcribed by RNA polymerase (pol) III where its presence affects RNA production and replication-independent histone exchange. On pol II-transcribed genes, a negative correlation is found between Asf1 and nucleosome occupancy. It is not enriched on most of the reported sites of histone exchange or on the genes, which are misregulated in the asf1Δ cells. Interestingly, chromosome-wide distributions of Asf1 and one of the condensin subunits, Brn1 show a nearly identical pattern. Moreover, Brn1 shows reduced occupancy at various condensin-binding sites in asf1Δ cells. These results along with high association of Asf1 with heterochromatic centromeres and telomeres ascribe novel roles to Asf1 in condensin loading and chromatin dynamics.
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32
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Herb BR. Epigenetics as an answer to Darwin's "special difficulty". Front Genet 2014; 5:321. [PMID: 25309578 PMCID: PMC4162389 DOI: 10.3389/fgene.2014.00321] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 08/27/2014] [Indexed: 11/24/2022] Open
Abstract
Epigenetic modifications produce distinct phenotypes from the same genome through genome-wide transcriptional control. Recently, DNA methylation in honeybees and histone modifications in ants were found to assist the formation of caste phenotypes during development and adulthood. This insight allows us to revisit one of Darwin’s greatest challenges to his natural selection theory; the derivation of multiple forms of sterile workers within eusocial species. Differential feeding of larvae creates two distinct developmental paths between queens and workers, with workers further refined by pheromone cues. Flexible epigenetic control provides a mechanism to interpret the milieu of social cues that create distinct worker sub-caste phenotypes. Recent findings suggest a distinct use for DNA methylation before and after adult emergence. Further, a comparison of genes that are differentially methylated and transcriptionally altered upon pheromone signaling suggests that epigenetics can play a key role in mediating pheromone signals to derive sub-caste phenotypes. Epigenetic modifications may provide a molecular mechanism to Darwin’s ”special difficulty” and explain the emergence of multiple sub-phenotypes among sterile individuals.
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Affiliation(s)
- Brian R Herb
- Center for Epigenetics and Department of Medicine, Johns Hopkins University School of Medicine Baltimore, MD, USA
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33
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Aydin ÖZ, Marteijn JA, Ribeiro-Silva C, Rodríguez López A, Wijgers N, Smeenk G, van Attikum H, Poot RA, Vermeulen W, Lans H. Human ISWI complexes are targeted by SMARCA5 ATPase and SLIDE domains to help resolve lesion-stalled transcription. Nucleic Acids Res 2014; 42:8473-85. [PMID: 24990377 PMCID: PMC4117783 DOI: 10.1093/nar/gku565] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chromatin compaction of deoxyribonucleic acid (DNA) presents a major challenge to the detection and removal of DNA damage. Helix-distorting DNA lesions that block transcription are specifically repaired by transcription-coupled nucleotide excision repair, which is initiated by binding of the CSB protein to lesion-stalled RNA polymerase II. Using live cell imaging, we identify a novel function for two distinct mammalian ISWI adenosine triphosphate (ATP)-dependent chromatin remodeling complexes in resolving lesion-stalled transcription. Human ISWI isoform SMARCA5/SNF2H and its binding partners ACF1 and WSTF are rapidly recruited to UV-C induced DNA damage to specifically facilitate CSB binding and to promote transcription recovery. SMARCA5 targeting to UV-C damage depends on transcription and histone modifications and requires functional SWI2/SNF2-ATPase and SLIDE domains. After initial recruitment to UV damage, SMARCA5 re-localizes away from the center of DNA damage, requiring its HAND domain. Our studies support a model in which SMARCA5 targeting to DNA damage-stalled transcription sites is controlled by an ATP-hydrolysis-dependent scanning and proofreading mechanism, highlighting how SWI2/SNF2 chromatin remodelers identify and bind nucleosomes containing damaged DNA.
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Affiliation(s)
- Özge Z Aydin
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Jurgen A Marteijn
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Cristina Ribeiro-Silva
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Aida Rodríguez López
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Nils Wijgers
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Godelieve Smeenk
- Department of Toxicogenetics, Leiden University Medical Center, Leiden, 2333 ZC, The Netherlands
| | - Haico van Attikum
- Department of Toxicogenetics, Leiden University Medical Center, Leiden, 2333 ZC, The Netherlands
| | - Raymond A Poot
- Department of Cell Biology, Medical Genetics Cluster, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Wim Vermeulen
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Hannes Lans
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
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34
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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] [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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Li G, Liu S, Wang J, He J, Huang H, Zhang Y, Xu L. ISWI proteins participate in the genome-wide nucleosome distribution in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 78:706-14. [PMID: 24606212 DOI: 10.1111/tpj.12499] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 01/28/2014] [Accepted: 02/24/2014] [Indexed: 05/25/2023]
Abstract
Chromatin is a highly organized structure with repetitive nucleosome subunits. Nucleosome distribution patterns, which contain information on epigenetic controls, are dynamically affected by ATP-dependent chromatin remodeling factors (remodelers). However, whether plants have specific nucleosome distribution patterns and how plant remodelers contribute to the pattern formation are not clear. In this study we used the micrococcal nuclease digestion followed by deep sequencing (MNase-seq) assay to show the genome-wide nucleosome pattern in Arabidopsis thaliana. We demonstrated that the nucleosome distribution patterns of Arabidopsis are associated with the gene expression level, and have several specific characteristics that are different from those of animals and yeast. In addition, we found that remodelers in the A. thaliana imitation switch (AtISWI) subfamily are important for the formation of the nucleosome distribution pattern. Double mutations in the AtISWI genes, CHROMATIN REMODELING 11 (CHR11) and CHR17, resulted in the loss of the evenly spaced nucleosome pattern in gene bodies, but did not affect nucleosome density, supporting a previous idea that the primary role of ISWI is to slide nucleosomes in gene bodies for pattern formation.
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Affiliation(s)
- Guang Li
- National Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
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36
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Regulation of ISWI chromatin remodelling activity. Chromosoma 2014; 123:91-102. [PMID: 24414837 DOI: 10.1007/s00412-013-0447-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 11/20/2013] [Accepted: 11/25/2013] [Indexed: 12/22/2022]
Abstract
The packaging of the eukaryotic genome into chromatin facilitates the storage of the genetic information within the nucleus, but prevents the access to the underlying DNA sequences. Structural changes in chromatin are mediated by several mechanisms. Among them, ATP-dependent remodelling complexes belonging to ISWI family provides one of the best examples that eukaryotic cells evolved to finely regulate these changes. ISWI-containing complexes use the energy derived from ATP hydrolysis to rearrange nucleosomes on chromatin in order to favour specific nuclear reactions. The combination of regulatory nuclear factors associated with the ATPase subunit as well as its modulation by specific histone modifications, specializes the nuclear function of each ISWI-containing complex. Here we review the different ways by which ISWI enzymatic activity can be modulated and regulated in the nucleus of eukaryotic cells.
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37
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Morris SA, Baek S, Sung MH, John S, Wiench M, Johnson TA, Schiltz RL, Hager GL. Overlapping chromatin-remodeling systems collaborate genome wide at dynamic chromatin transitions. Nat Struct Mol Biol 2013; 21:73-81. [PMID: 24317492 PMCID: PMC3947387 DOI: 10.1038/nsmb.2718] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 10/17/2013] [Indexed: 12/24/2022]
Abstract
ATP-dependent chromatin remodeling is an essential process required for the dynamic organization of chromatin structure. Here we describe the genome-wide location and activity of three remodeler proteins with diverse physiological functions in the mouse genome: Brg1, Chd4, and Snf2h. The localization patterns of all three proteins significantly overlap with one another and with regions of accessible chromatin. Furthermore, using inducible mutant variants, we demonstrate that the catalytic activity of these proteins contributes to the remodeling of chromatin genome-wide, and that each of these remodelers can independently regulate chromatin reorganization at distinct sites. Many regions require the activity of more than one remodeler to regulate accessibility. These findings provide a dynamic view of chromatin organization, and highlight the differential contributions of remodelers to chromatin maintenance in higher eukaryotes.
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Affiliation(s)
- Stephanie A Morris
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Songjoon Baek
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Myong-Hee Sung
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Sam John
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Malgorzata Wiench
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Thomas A Johnson
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - R Louis Schiltz
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Gordon L Hager
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
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38
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Epigenetic regulation of transcription by RNA polymerase III. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2013; 1829:1015-25. [DOI: 10.1016/j.bbagrm.2013.05.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 05/11/2013] [Accepted: 05/15/2013] [Indexed: 01/11/2023]
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Balancing chromatin remodeling and histone modifications in transcription. Trends Genet 2013; 29:621-9. [PMID: 23870137 DOI: 10.1016/j.tig.2013.06.006] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 05/29/2013] [Accepted: 06/18/2013] [Indexed: 11/24/2022]
Abstract
Chromatin remodelers use the energy of ATP hydrolysis to reposition or evict nucleosomes or to replace canonical histones with histone variants. By regulating nucleosome dynamics, remodelers gate access to the underlying DNA for replication, repair, and transcription. Nucleosomes are subject to extensive post-translational modifications that can recruit regulatory proteins or alter the local chromatin structure. Just as extensive crosstalk has been observed between different histone post-translational modifications, there is growing evidence for both coordinated and antagonistic functional relations between nucleosome remodeling and modifying machineries. Defining the combined functions of the complexes that alter nucleosome interactions, position, and stability is key to understanding processes that require access to DNA, particularly with growing appreciation of their contributions to human health and disease. Here, we highlight recent advances in the interactions between histone modifications and the imitation-switch (ISWI) and chromodomain helicase DNA-binding protein 1 (CHD1) chromatin remodelers from studies in budding yeast, fission yeast, flies, and mammalian cells, with a focus on yeast.
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Yajima M, Fairbrother WG, Wessel GM. ISWI contributes to ArsI insulator function in development of the sea urchin. Development 2012; 139:3613-22. [PMID: 22949616 DOI: 10.1242/dev.081828] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Insulators are genomic elements that regulate transcriptional activity by forming chromatin boundaries. Various DNA insulators have been identified or are postulated in many organisms, and the paradigmatic CTCF-dependent insulators are perhaps the best understood and most widespread in function. The diversity of DNA insulators is, however, understudied, especially in the context of embryonic development, when many new gene territories undergo transitions in functionality. Here we report the functional analysis of the arylsulfatase insulator (ArsI) derived from the sea urchin, which has conserved insulator activity throughout the many metazoans tested, but for which the molecular mechanism of function is unknown. Using a rapid in vivo assay system and a high-throughput mega-shift assay, we identified a minimal region in ArsI that is responsible for its insulator function. We discovered a small set of proteins specifically bound to the minimal ArsI region, including ISWI, a known chromatin-remodeling protein. During embryogenesis, ISWI was found to interact with select ArsI sites throughout the genome, and when inactivated led to misregulation of select gene expression, loss of insulator activity and aberrant morphogenesis. These studies reveal a mechanistic basis for ArsI function in the gene regulatory network of early development.
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Affiliation(s)
- Mamiko Yajima
- MCB Department, Brown University, 185 Meeting Street, BOX-GL173, Providence, RI 02912, USA.
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Erdel F, Rippe K. Quantifying transient binding of ISWI chromatin remodelers in living cells by pixel-wise photobleaching profile evolution analysis. Proc Natl Acad Sci U S A 2012; 109:E3221-30. [PMID: 23129662 PMCID: PMC3511136 DOI: 10.1073/pnas.1209579109] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Interactions between nuclear proteins and chromatin frequently occur on the time scale of seconds and below. These transient binding events are important for the fast identification of target sites as concluded from our previous analysis of the human chromatin remodelers Snf2H and Snf2L from the imitation switch (ISWI) family. Both ATP-driven molecular motor proteins are able to translocate nucleosomes along the DNA and appear to exert this activity only on a small number of nucleosomes to which they bind more tightly. For mechanistic studies, one needs to distinguish such translocation reactions or other long-lived interactions associated with conformational changes and/or ATP hydrolysis from nonproductive chromatin sampling during target search. These processes can be separated by measuring the duration of nucleosome binding with subsecond time resolution. To reach this goal, we have developed a fluorescence bleaching technique termed pixel-wise photobleaching profile evolution analysis (3PEA). It exploits the inherent time structure of confocal microscopy images and yields millisecond resolution. 3PEA represents a generally applicable approach to quantitate transient chromatin interactions in the 2- to 500-ms time regime within only ∼1 s needed for a measurement. The green autofluorescent protein (GFP)-tagged Snf2H and Snf2L and the inactive Snf2L+13 splice variant were studied by 3PEA in comparison to the isolated GFP or red autofluorescent protein and a GFP pentamer. Our results reveal that the residence time for transient chromatin binding of Snf2H and Snf2L is <2 ms, and strongly support the view that ISWI-type remodelers are only rarely active in unperturbed cells during G1 phase.
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Affiliation(s)
- Fabian Erdel
- Research Group Genome Organization and Function, Deutsches Krebsforschungszentrum (DKFZ) and BioQuant, 69120 Heidelberg, Germany
| | - Karsten Rippe
- Research Group Genome Organization and Function, Deutsches Krebsforschungszentrum (DKFZ) and BioQuant, 69120 Heidelberg, Germany
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Dunlap D, Yokoyama R, Ling H, Sun HY, McGill K, Cugusi S, Lucchesi JC. Distinct contributions of MSL complex subunits to the transcriptional enhancement responsible for dosage compensation in Drosophila. Nucleic Acids Res 2012; 40:11281-91. [PMID: 23047951 PMCID: PMC3526317 DOI: 10.1093/nar/gks890] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The regulatory mechanism of dosage compensation is the paramount example of epigenetic regulation at the chromosomal level. In Drosophila, this mechanism, designed to compensate for the difference in the dosage of X-linked genes between the sexes, depends on the MSL complex that enhances the transcription of the single dose of these genes in males. We have investigated the function of various subunits of the complex in mediating dosage compensation. Our results confirm that the highly enriched specific acetylation of histone H4 at lysine 16 of compensated genes by the histone acetyl transferase subunit MOF induces a more disorganized state of their chromatin. We have determined that the association of the MSL complex reduces the level of negative supercoiling of the deoxyribonucleic acid of compensated genes, and we have defined the role that the other subunits of the complex play in this topological modification. Lastly, we have analyzed the potential contribution of ISWI-containing remodeling complexes to the architecture of compensated chromatin, and we suggest a role for this remodeling factor in dosage compensation.
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Affiliation(s)
- David Dunlap
- Department of Cell Biology and Department of Biology, Emory University, Atlanta, GA 30322, USA
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The emerging roles of ATP-dependent chromatin remodeling enzymes in nucleotide excision repair. Int J Mol Sci 2012; 13:11954-11973. [PMID: 23109894 PMCID: PMC3472786 DOI: 10.3390/ijms130911954] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 08/30/2012] [Accepted: 08/31/2012] [Indexed: 12/14/2022] Open
Abstract
DNA repair in eukaryotic cells takes place in the context of chromatin, where DNA, including damaged DNA, is tightly packed into nucleosomes and higher order chromatin structures. Chromatin intrinsically restricts accessibility of DNA repair proteins to the damaged DNA and impacts upon the overall rate of DNA repair. Chromatin is highly responsive to DNA damage and undergoes specific remodeling to facilitate DNA repair. How damaged DNA is accessed, repaired and restored to the original chromatin state, and how chromatin remodeling coordinates these processes in vivo, remains largely unknown. ATP-dependent chromatin remodelers (ACRs) are the master regulators of chromatin structure and dynamics. Conserved from yeast to humans, ACRs utilize the energy of ATP to reorganize packing of chromatin and control DNA accessibility by sliding, ejecting or restructuring nucleosomes. Several studies have demonstrated that ATP-dependent remodeling activity of ACRs plays important roles in coordination of spatio-temporal steps of different DNA repair pathways in chromatin. This review focuses on the role of ACRs in regulation of various aspects of nucleotide excision repair (NER) in the context of chromatin. We discuss current understanding of ATP-dependent chromatin remodeling by various subfamilies of remodelers and regulation of the NER pathway in vivo.
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New insights into nucleosome and chromatin structure: an ordered state or a disordered affair? Nat Rev Mol Cell Biol 2012; 13:436-47. [PMID: 22722606 DOI: 10.1038/nrm3382] [Citation(s) in RCA: 473] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The compaction of genomic DNA into chromatin has profound implications for the regulation of key processes such as transcription, replication and DNA repair. Nucleosomes, the repeating building blocks of chromatin, vary in the composition of their histone protein components. This is the result of the incorporation of variant histones and post-translational modifications of histone amino acid side chains. The resulting changes in nucleosome structure, stability and dynamics affect the compaction of nucleosomal arrays into higher-order structures. It is becoming clear that chromatin structures are not nearly as uniform and regular as previously assumed. This implies that chromatin structure must also be viewed in the context of specific biological functions.
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Nucleosome remodeler SNF2L suppresses cell proliferation and migration and attenuates Wnt signaling. Mol Cell Biol 2012; 32:2359-71. [PMID: 22508985 DOI: 10.1128/mcb.06619-11] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
ISWI is an evolutionarily conserved ATPase that catalyzes nucleosome remodeling in different macromolecular complexes. Two mammalian ISWI orthologs, SNF2H and SNF2L, are thought to have specialized functions despite their high sequence similarity. To date, the function of SNF2L in human cells has not been a focus of research. Newly established specific monoclonal antibodies and selective RNA interference protocols have now enabled a comprehensive characterization of loss-of-function phenotypes in human cells. In contrast to earlier results, we found SNF2L to be broadly expressed in primary human tissues. Depletion of SNF2L in HeLa cells led to enhanced proliferation and increased migration. These phenomena were explained by transcriptome profiling, which identified SNF2L as a modulator of the Wnt signaling network. The cumulative effects of SNF2L depletion on gene expression portray the cell in a state of activated Wnt signaling characterized by increased proliferation and chemotactic locomotion. Accordingly, high levels of SNF2L expression in normal melanocytes contrast with undetectable expression in malignant melanoma. In summary, our data document an inverse relationship between SNF2L expression and features characteristic of malignant cells.
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Berger N, Dubreucq B. Evolution goes GAGA: GAGA binding proteins across kingdoms. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:863-8. [PMID: 22425673 DOI: 10.1016/j.bbagrm.2012.02.022] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 02/17/2012] [Accepted: 02/22/2012] [Indexed: 01/21/2023]
Abstract
Chromatin-associated proteins (CAP) play a crucial role in the regulation of gene expression and development in higher organisms. They are involved in the control of chromatin structure and dynamics. CAP have been extensively studied over the past years and are classified into two major groups: enzymes that modify histone stability and organization by post-translational modification of histone N-Terminal tails; and proteins that use ATP hydrolysis to modify chromatin structure. All of these proteins show a relatively high degree of sequence conservation across the animal and plant kingdoms. The essential Drosophila melanogaster GAGA factor (dGAF) interacts with these two types of CAP to regulate homeobox genes and thus contributes to a wide range of developmental events. Surprisingly, however, it is not conserved in plants. In this review, following an overview of fly GAF functions, we discuss the role of plant BBR/BPC proteins. These appear to functionally converge with dGAF despite a completely divergent amino acid sequence. Some suggestions are given for further investigation into the function of BPC proteins in plants.
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Dechassa ML, Hota SK, Sen P, Chatterjee N, Prasad P, Bartholomew B. Disparity in the DNA translocase domains of SWI/SNF and ISW2. Nucleic Acids Res 2012; 40:4412-21. [PMID: 22298509 PMCID: PMC3378860 DOI: 10.1093/nar/gks007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
An ATP-dependent DNA translocase domain consisting of seven conserved motifs is a general feature of all ATP-dependent chromatin remodelers. While motifs on the ATPase domains of the yeast SWI/SNF and ISWI families of remodelers are highly conserved, the ATPase domains of these complexes appear not to be functionally interchangeable. We found one reason that may account for this is the ATPase domains interact differently with nucleosomes even though both associate with nucleosomal DNA 17–18 bp from the dyad axis. The cleft formed between the two lobes of the ISW2 ATPase domain is bound to nucleosomal DNA and Isw2 associates with the side of nucleosomal DNA away from the histone octamer. The ATPase domain of SWI/SNF binds to the same region of nucleosomal DNA, but is bound outside of the cleft region. The catalytic subunit of SWI/SNF also appears to intercalate between the DNA gyre and histone octamer. The altered interactions of SWI/SNF with DNA are specific to nucleosomes and do not occur with free DNA. These differences are likely mediated through interactions with the histone surface. The placement of SWI/SNF between the octamer and DNA could make it easier to disrupt histone–DNA interactions.
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Affiliation(s)
- Mekonnen Lemma Dechassa
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL 62901-4413, USA
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Remodelers organize cellular chromatin by counteracting intrinsic histone-DNA sequence preferences in a class-specific manner. Mol Cell Biol 2011; 32:675-88. [PMID: 22124157 DOI: 10.1128/mcb.06365-11] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The nucleosome is the fundamental repeating unit of eukaryotic chromatin. Here, we assessed the interplay between DNA sequence and ATP-dependent chromatin-remodeling factors (remodelers) in the nucleosomal organization of a eukaryotic genome. We compared the genome-wide distribution of Drosophila NURD, (P)BAP, INO80, and ISWI, representing the four major remodeler families. Each remodeler has a unique set of genomic targets and generates distinct chromatin signatures. Remodeler loci have characteristic DNA sequence features, predicted to influence nucleosome formation. Strikingly, remodelers counteract DNA sequence-driven nucleosome distribution in two distinct ways. NURD, (P)BAP, and INO80 increase histone density at their target sequences, which intrinsically disfavor positioned nucleosome formation. In contrast, ISWI promotes open chromatin at sites that are propitious for precise nucleosome placement. Remodelers influence nucleosome organization genome-wide, reflecting their high genomic density and the propagation of nucleosome redistribution beyond remodeler binding sites. In transcriptionally silent early embryos, nucleosome organization correlates with intrinsic histone-DNA sequence preferences. Following differential expression of the genome, however, this relationship diminishes and eventually disappears. We conclude that the cellular nucleosome landscape is the result of the balance between DNA sequence-driven nucleosome placement and active nucleosome repositioning by remodelers and the transcription machinery.
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Piatti P, Zeilner A, Lusser A. ATP-dependent chromatin remodeling factors and their roles in affecting nucleosome fiber composition. Int J Mol Sci 2011; 12:6544-65. [PMID: 22072904 PMCID: PMC3210995 DOI: 10.3390/ijms12106544] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 09/20/2011] [Accepted: 09/28/2011] [Indexed: 01/03/2023] Open
Abstract
ATP-dependent chromatin remodeling factors of the SNF2 family are key components of the cellular machineries that shape and regulate chromatin structure and function. Members of this group of proteins have broad and heterogeneous functions ranging from controlling gene activity, facilitating DNA damage repair, promoting homologous recombination to maintaining genomic stability. Several chromatin remodeling factors are critical components of nucleosome assembly processes, and recent reports have identified specific functions of distinct chromatin remodeling factors in the assembly of variant histones into chromatin. In this review we will discuss the specific roles of ATP-dependent chromatin remodeling factors in determining nucleosome composition and, thus, chromatin fiber properties.
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Affiliation(s)
- Paolo Piatti
- Division of Molecular Biology, Innsbruck Medical University, Biocenter, Fritz-Pregl Strasse 3, 6020 Innsbruck, Austria; E-Mails: (P.P.); (A.Z.)
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