1
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Simon L, Probst AV. Maintenance and dynamic reprogramming of chromatin organization during development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 118:657-670. [PMID: 36700345 DOI: 10.1111/tpj.16119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/20/2023] [Accepted: 01/23/2023] [Indexed: 06/17/2023]
Abstract
Controlled transcription of genes is critical for cell differentiation and development. Gene expression regulation therefore involves a multilayered control from nucleosome composition in histone variants and their post-translational modifications to higher-order folding of chromatin fibers and chromatin interactions in nuclear space. Recent technological advances have allowed gaining insight into these mechanisms, the interplay between local and higher-order chromatin organization, and the dynamic changes that occur during stress response and developmental transitions. In this review, we will discuss chromatin organization from the nucleosome to its three-dimensional structure in the nucleus, and consider how these different layers of organization are maintained during the cell cycle or rapidly reprogrammed during development.
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Affiliation(s)
- Lauriane Simon
- iGReD, CNRS, Inserm, Université Clermont Auvergne, 63000, Clermont-Ferrand, France
| | - Aline V Probst
- iGReD, CNRS, Inserm, Université Clermont Auvergne, 63000, Clermont-Ferrand, France
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2
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Saredi G, Carelli FN, Rolland SGM, Furlan G, Piquet S, Appert A, Sanchez-Pulido L, Price JL, Alcon P, Lampersberger L, Déclais AC, Ramakrishna NB, Toth R, Macartney T, Alabert C, Ponting CP, Polo SE, Miska EA, Gartner A, Ahringer J, Rouse J. The histone chaperone SPT2 regulates chromatin structure and function in Metazoa. Nat Struct Mol Biol 2024; 31:523-535. [PMID: 38238586 PMCID: PMC7615752 DOI: 10.1038/s41594-023-01204-3] [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: 02/13/2023] [Accepted: 12/14/2023] [Indexed: 02/15/2024]
Abstract
Histone chaperones control nucleosome density and chromatin structure. In yeast, the H3-H4 chaperone Spt2 controls histone deposition at active genes but its roles in metazoan chromatin structure and organismal physiology are not known. Here we identify the Caenorhabditis elegans ortholog of SPT2 (CeSPT-2) and show that its ability to bind histones H3-H4 is important for germline development and transgenerational epigenetic gene silencing, and that spt-2 null mutants display signatures of a global stress response. Genome-wide profiling showed that CeSPT-2 binds to a range of highly expressed genes, and we find that spt-2 mutants have increased chromatin accessibility at a subset of these loci. We also show that SPT2 influences chromatin structure and controls the levels of soluble and chromatin-bound H3.3 in human cells. Our work reveals roles for SPT2 in controlling chromatin structure and function in Metazoa.
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Affiliation(s)
- Giulia Saredi
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK.
| | - Francesco N Carelli
- Gurdon Institute, University of Cambridge, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Stéphane G M Rolland
- IBS Centre for Genomic Integrity at Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Giulia Furlan
- Gurdon Institute, University of Cambridge, Cambridge, UK
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- Transine Therapeutics, Babraham Hall, Cambridge, UK
| | - Sandra Piquet
- Laboratory of Epigenome Integrity, Epigenetics and Cell Fate Centre, UMR 7216 CNRS - Université Paris Cité, Paris, France
| | - Alex Appert
- Gurdon Institute, University of Cambridge, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Luis Sanchez-Pulido
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, UK
| | - Jonathan L Price
- Gurdon Institute, University of Cambridge, Cambridge, UK
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Pablo Alcon
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Lisa Lampersberger
- Gurdon Institute, University of Cambridge, Cambridge, UK
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- Maxion Therapeutics, Unity Campus, Cambridge, UK
| | - Anne-Cécile Déclais
- Molecular Cell and Developmental Biology Division, School of Life Sciences, University of Dundee, Dundee, UK
| | - Navin B Ramakrishna
- Gurdon Institute, University of Cambridge, Cambridge, UK
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- Genome Institute of Singapore (GIS), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Rachel Toth
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Thomas Macartney
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Constance Alabert
- Molecular Cell and Developmental Biology Division, School of Life Sciences, University of Dundee, Dundee, UK
| | - Chris P Ponting
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Sophie E Polo
- Laboratory of Epigenome Integrity, Epigenetics and Cell Fate Centre, UMR 7216 CNRS - Université Paris Cité, Paris, France
| | - Eric A Miska
- Gurdon Institute, University of Cambridge, Cambridge, UK
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, UK
| | - Anton Gartner
- IBS Centre for Genomic Integrity at Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Julie Ahringer
- Gurdon Institute, University of Cambridge, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - John Rouse
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK.
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3
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Hardtke HA, Zhang YJ. Collaborators or competitors: the communication between RNA polymerase II and the nucleosome during eukaryotic transcription. Crit Rev Biochem Mol Biol 2024; 59:1-19. [PMID: 38288999 PMCID: PMC11209794 DOI: 10.1080/10409238.2024.2306365] [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: 11/26/2023] [Accepted: 01/12/2024] [Indexed: 04/22/2024]
Abstract
Decades of scientific research have been devoted to unraveling the intricacies of eukaryotic transcription since the groundbreaking discovery of eukaryotic RNA polymerases in the late 1960s. RNA polymerase II, the polymerase responsible for mRNA synthesis, has always attracted the most attention. Despite its structural resemblance to its bacterial counterpart, eukaryotic RNA polymerase II faces a unique challenge in progressing transcription due to the presence of nucleosomes that package DNA in the nuclei. In this review, we delve into the impact of RNA polymerase II and histone signaling on the progression of eukaryotic transcription. We explore the pivotal points of interactions that bridge the RNA polymerase II and histone signaling systems. Finally, we present an analysis of recent cryo-electron microscopy structures, which captured RNA polymerase II-nucleosome complexes at different stages of the transcription cycle. The combination of the signaling crosstalk and the direct visualization of RNA polymerase II-nucleosome complexes provides a deeper understanding of the communication between these two major players in eukaryotic transcription.
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Affiliation(s)
- Haley A. Hardtke
- Department of Molecular Biosciences, University of Texas, Austin
| | - Y. Jessie Zhang
- Department of Molecular Biosciences, University of Texas, Austin
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4
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Robert F, Jeronimo C. Transcription-coupled nucleosome assembly. Trends Biochem Sci 2023; 48:978-992. [PMID: 37657993 DOI: 10.1016/j.tibs.2023.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/21/2023] [Accepted: 08/04/2023] [Indexed: 09/03/2023]
Abstract
Eukaryotic transcription occurs on chromatin, where RNA polymerase II encounters nucleosomes during elongation. These nucleosomes must unravel for the DNA to enter the active site. However, in most transcribed genes, nucleosomes remain intact due to transcription-coupled chromatin assembly mechanisms. These mechanisms primarily involve the local reassembly of displaced nucleosomes to prevent (epi)genomic instability and the emergence of cryptic transcription. As a fail-safe mechanism, cells can assemble nucleosomes de novo, particularly in highly transcribed genes, but this may result in the loss of epigenetic information. This review examines transcription-coupled chromatin assembly, with an emphasis on studies in yeast and recent structural studies. These studies shed light on how elongation factors and histone chaperones coordinate to enable nucleosome recycling during transcription.
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Affiliation(s)
- François Robert
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada; Département de Médecine, Faculté de Médecine, Université de Montréal, 2900 Boul. Édouard-Montpetit, Montréal, QC H3T 1J4, Canada; Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, QC H3A 1A3, Canada.
| | - Célia Jeronimo
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada
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5
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Jonas F, Vidavski M, Benuck E, Barkai N, Yaakov G. Nucleosome retention by histone chaperones and remodelers occludes pervasive DNA-protein binding. Nucleic Acids Res 2023; 51:8496-8513. [PMID: 37493599 PMCID: PMC10484674 DOI: 10.1093/nar/gkad615] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 06/07/2023] [Accepted: 07/11/2023] [Indexed: 07/27/2023] Open
Abstract
DNA packaging within chromatin depends on histone chaperones and remodelers that form and position nucleosomes. Cells express multiple such chromatin regulators with overlapping in-vitro activities. Defining specific in-vivo activities requires monitoring histone dynamics during regulator depletion, which has been technically challenging. We have recently generated histone-exchange sensors in Saccharomyces cerevisiae, which we now use to define the contributions of 15 regulators to histone dynamics genome-wide. While replication-independent exchange in unperturbed cells maps to promoters, regulator depletions primarily affected gene bodies. Depletion of Spt6, Spt16 or Chd1 sharply increased nucleosome replacement sequentially at the beginning, middle or end of highly expressed gene bodies. They further triggered re-localization of chaperones to affected gene body regions, which compensated for nucleosome loss during transcription complex passage, but concurred with extensive TF binding in gene bodies. We provide a unified quantitative screen highlighting regulator roles in retaining nucleosome binding during transcription and preserving genomic packaging.
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Affiliation(s)
- Felix Jonas
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Matan Vidavski
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Eli Benuck
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Naama Barkai
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Gilad Yaakov
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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6
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Dunjić M, Jonas F, Yaakov G, More R, Mayshar Y, Rais Y, Orenbuch AH, Cheng S, Barkai N, Stelzer Y. Histone exchange sensors reveal variant specific dynamics in mouse embryonic stem cells. Nat Commun 2023; 14:3791. [PMID: 37365167 DOI: 10.1038/s41467-023-39477-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 06/15/2023] [Indexed: 06/28/2023] Open
Abstract
Eviction of histones from nucleosomes and their exchange with newly synthesized or alternative variants is a central epigenetic determinant. Here, we define the genome-wide occupancy and exchange pattern of canonical and non-canonical histone variants in mouse embryonic stem cells by genetically encoded exchange sensors. While exchange of all measured variants scales with transcription, we describe variant-specific associations with transcription elongation and Polycomb binding. We found considerable exchange of H3.1 and H2B variants in heterochromatin and repeat elements, contrasting the occupancy and little exchange of H3.3 in these regions. This unexpected association between H3.3 occupancy and exchange of canonical variants is also evident in active promoters and enhancers, and further validated by reduced H3.1 dynamics following depletion of H3.3-specific chaperone, HIRA. Finally, analyzing transgenic mice harboring H3.1 or H3.3 sensors demonstrates the vast potential of this system for studying histone exchange and its impact on gene expression regulation in vivo.
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Affiliation(s)
- Marko Dunjić
- Department of Molecular Cell Biology, Weizmann Institute of Science, 7610001, Rehovot, Israel
| | - Felix Jonas
- Department of Molecular Genetics, Weizmann Institute of Science, 7610001, Rehovot, Israel
| | - Gilad Yaakov
- Department of Molecular Genetics, Weizmann Institute of Science, 7610001, Rehovot, Israel
| | - Roye More
- Department of Molecular Cell Biology, Weizmann Institute of Science, 7610001, Rehovot, Israel
| | - Yoav Mayshar
- Department of Molecular Cell Biology, Weizmann Institute of Science, 7610001, Rehovot, Israel
| | - Yoach Rais
- Department of Molecular Cell Biology, Weizmann Institute of Science, 7610001, Rehovot, Israel
| | | | - Saifeng Cheng
- Department of Molecular Cell Biology, Weizmann Institute of Science, 7610001, Rehovot, Israel
| | - Naama Barkai
- Department of Molecular Genetics, Weizmann Institute of Science, 7610001, Rehovot, Israel
| | - Yonatan Stelzer
- Department of Molecular Cell Biology, Weizmann Institute of Science, 7610001, Rehovot, Israel.
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7
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Are extraordinary nucleosome structures more ordinary than we thought? Chromosoma 2023:10.1007/s00412-023-00791-w. [PMID: 36917245 DOI: 10.1007/s00412-023-00791-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 03/16/2023]
Abstract
The nucleosome is a DNA-protein assembly that is the basic unit of chromatin. A nucleosome can adopt various structures. In the canonical nucleosome structure, 145-147 bp of DNA is wrapped around a histone heterooctamer. The strong histone-DNA interactions cause the DNA to be inaccessible for nuclear processes such as transcription. Therefore, the canonical nucleosome structure has to be altered into different, non-canonical structures to increase DNA accessibility. While it is recognised that non-canonical structures do exist, these structures are not well understood. In this review, we discuss both the evidence for various non-canonical nucleosome structures in the nucleus and the factors that are believed to induce these structures. The wide range of non-canonical structures is likely to regulate the amount of accessible DNA, and thus have important nuclear functions.
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8
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Chakraborty C, Bhattacharya M, Dhama K, Lee SS. Evaluation of differentially expressed genes during replication using gene expression landscape of monkeypox-infected MK2 cells: A bioinformatics and systems biology approach to understanding the genomic pattern of viral replication. J Infect Public Health 2023; 16:399-409. [PMID: 36724696 PMCID: PMC9874307 DOI: 10.1016/j.jiph.2023.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 01/12/2023] [Accepted: 01/18/2023] [Indexed: 01/26/2023] Open
Abstract
PURPOSE The current outbreak of monkeypox (MPX) has created colossal concerns. However, immense research gaps have been noted in our understanding of the replication process, machinery, and genomic landscape during host cell infection. To fill this gap, differentially expressed genes (DEGs) were comprehensively analyzed during viral replication in host (MK2) cells. METHODS We used a microarray GEO dataset which was divided into three groups: control, MPXV-infected MK2 cells at 3 h, and MPXV-infected MK2 cells at 7 h. Using the dataset, DEG analysis, PPI network analysis, co-expression, and pathway analysis were conducted using bioinformatics, systems biology, and statistical approaches. RESULTS We identified 250 DEGs and 24 top-ranked genes. During the DEG analysis, we identified eight up-regulated genes (LOC695323, TMEM107, LOC695427, HIST1H2AD, LOC705469, PMAIP1, HIST1H2BJ, and HIST1H3D) and 16 down-regulated genes (HOXA9, BAMBI, LMO4, PAX6, AJUBA, CREBRF, CD24, JADE1, SLC7A11, EID2, SOX4, B4GALT5, PPARGC1A, BUB3, SOS2, and CDK19). We also developed PPI networks and performed co-expression analyses using the top-ranked genes. Furthermore, five genes were listed for co-expression pattern analysis. CONCLUSIONS This study will help in better understanding the replication process, machinery, and genomic landscape of the virus. This will further aid the discovery and development of therapeutics against viruses.
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Affiliation(s)
- Chiranjib Chakraborty
- Department of Biotechnology, School of Life Science and Biotechnology, Adamas University, Kolkata, West Bengal 700126, India.
| | - Manojit Bhattacharya
- Department of Zoology, Fakir Mohan University, Vyasa Vihar, Balasore 756020, Odisha, India
| | - Kuldeep Dhama
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, Uttar Pradesh, India
| | - Sang-Soo Lee
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon 24252, Gangwon-Do, Republic of Korea.
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9
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Farnung L, Ochmann M, Garg G, Vos SM, Cramer P. Structure of a backtracked hexasomal intermediate of nucleosome transcription. Mol Cell 2022; 82:3126-3134.e7. [PMID: 35858621 DOI: 10.1016/j.molcel.2022.06.027] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/17/2022] [Accepted: 06/21/2022] [Indexed: 10/17/2022]
Abstract
During gene transcription, RNA polymerase II (RNA Pol II) passes nucleosomes with the help of various elongation factors. Here, we show that RNA Pol II achieves efficient nucleosome passage when the human elongation factors DSIF, PAF1 complex (PAF), RTF1, SPT6, and TFIIS are present. The cryo-EM structure of an intermediate of the nucleosome passage shows a partially unraveled hexasome that lacks the proximal H2A-H2B dimer and interacts with the RNA Pol II jaw, DSIF, and the CTR9trestle helix. RNA Pol II adopts a backtracked state with the RNA 3' end dislodged from the active site and bound in the RNA Pol II pore. Additional structures and biochemical data show that human TFIIS enters the RNA Pol II pore and stimulates the cleavage of the backtracked RNA and nucleosome passage.
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Affiliation(s)
- Lucas Farnung
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany.
| | - Moritz Ochmann
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Gaurika Garg
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Seychelle M Vos
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Patrick Cramer
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany.
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10
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Evrin C, Serra‐Cardona A, Duan S, Mukherjee PP, Zhang Z, Labib KPM. Spt5 histone binding activity preserves chromatin during transcription by RNA polymerase II. EMBO J 2022; 41:e109783. [PMID: 35102600 PMCID: PMC8886531 DOI: 10.15252/embj.2021109783] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 12/22/2021] [Accepted: 01/06/2022] [Indexed: 12/30/2022] Open
Abstract
Nucleosomes are disrupted transiently during eukaryotic transcription, yet the displaced histones must be retained and redeposited onto DNA, to preserve nucleosome density and associated histone modifications. Here, we show that the essential Spt5 processivity factor of RNA polymerase II (Pol II) plays a direct role in this process in budding yeast. Functional orthologues of eukaryotic Spt5 are present in archaea and bacteria, reflecting its universal role in RNA polymerase processivity. However, eukaryotic Spt5 is unique in having an acidic amino terminal tail (Spt5N) that is sandwiched between the downstream nucleosome and the upstream DNA that emerges from Pol II. We show that Spt5N contains a histone-binding motif that is required for viability in yeast cells and prevents loss of nucleosomal histones within actively transcribed regions. These findings indicate that eukaryotic Spt5 combines two essential activities, which together couple processive transcription to the efficient capture and re-deposition of nucleosomal histones.
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Affiliation(s)
- Cecile Evrin
- The MRC Protein Phosphorylation and Ubiquitylation UnitSchool of Life SciencesUniversity of DundeeDundeeUK
| | - Albert Serra‐Cardona
- Institute for Cancer GeneticsDepartment of Pediatrics and Department of Genetics and DevelopmentColumbia University Irving Medical CenterNew YorkNYUSA
| | - Shoufu Duan
- Institute for Cancer GeneticsDepartment of Pediatrics and Department of Genetics and DevelopmentColumbia University Irving Medical CenterNew YorkNYUSA
| | - Progya P Mukherjee
- The MRC Protein Phosphorylation and Ubiquitylation UnitSchool of Life SciencesUniversity of DundeeDundeeUK
| | - Zhiguo Zhang
- Institute for Cancer GeneticsDepartment of Pediatrics and Department of Genetics and DevelopmentColumbia University Irving Medical CenterNew YorkNYUSA
| | - Karim P M Labib
- The MRC Protein Phosphorylation and Ubiquitylation UnitSchool of Life SciencesUniversity of DundeeDundeeUK
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11
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Electron microscopy analysis of ATP-independent nucleosome unfolding by FACT. Commun Biol 2022; 5:2. [PMID: 35013515 PMCID: PMC8748794 DOI: 10.1038/s42003-021-02948-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 12/02/2021] [Indexed: 12/20/2022] Open
Abstract
FACT is a histone chaperone that participates in nucleosome removal and reassembly during transcription and replication. We used electron microscopy to study FACT, FACT:Nhp6 and FACT:Nhp6:nucleosome complexes, and found that all complexes adopt broad ranges of configurations, indicating high flexibility. We found unexpectedly that the DNA binding protein Nhp6 also binds to the C-terminal tails of FACT subunits, inducing more open geometries of FACT even in the absence of nucleosomes. Nhp6 therefore supports nucleosome unfolding by altering both the structure of FACT and the properties of nucleosomes. Complexes formed with FACT, Nhp6, and nucleosomes also produced a broad range of structures, revealing a large number of potential intermediates along a proposed unfolding pathway. The data suggest that Nhp6 has multiple roles before and during nucleosome unfolding by FACT, and that the process proceeds through a series of energetically similar intermediate structures, ultimately leading to an extensively unfolded form. Sivkina et al. present a biochemical and biophysical characterization of the interaction of S. cerevisiae histone chaperone FACT with the nucleosome core particle. They show that FACT adopts a more open geometry in the presence of Nhp6, and together they unfold nucleosomes to an almost extended conformation, suggesting a mechanism for FACT-facilitated disassembly of nucleosomes.
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12
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Barnes T, Korber P. The Active Mechanism of Nucleosome Depletion by Poly(dA:dT) Tracts In Vivo. Int J Mol Sci 2021; 22:ijms22158233. [PMID: 34360997 PMCID: PMC8347975 DOI: 10.3390/ijms22158233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 07/27/2021] [Accepted: 07/29/2021] [Indexed: 12/16/2022] Open
Abstract
Poly(dA:dT) tracts cause nucleosome depletion in many species, e.g., at promoters and replication origins. Their intrinsic biophysical sequence properties make them stiff and unfavorable for nucleosome assembly, as probed by in vitro nucleosome reconstitution. The mere correlation between nucleosome depletion over poly(dA:dT) tracts in in vitro reconstituted and in in vivo chromatin inspired an intrinsic nucleosome exclusion mechanism in vivo that is based only on DNA and histone properties. However, we compile here published and new evidence that this correlation does not reflect mechanistic causation. (1) Nucleosome depletion over poly(dA:dT) in vivo is not universal, e.g., very weak in S. pombe. (2) The energy penalty for incorporating poly(dA:dT) tracts into nucleosomes is modest (<10%) relative to ATP hydrolysis energy abundantly invested by chromatin remodelers. (3) Nucleosome depletion over poly(dA:dT) is much stronger in vivo than in vitro if monitored without MNase and (4) actively maintained in vivo. (5) S. cerevisiae promoters evolved a strand-biased poly(dA) versus poly(dT) distribution. (6) Nucleosome depletion over poly(dA) is directional in vivo. (7) The ATP dependent chromatin remodeler RSC preferentially and directionally displaces nucleosomes towards 5′ of poly(dA). Especially distribution strand bias and displacement directionality would not be expected for an intrinsic mechanism. Together, this argues for an in vivo mechanism where active and species-specific read out of intrinsic sequence properties, e.g., by remodelers, shapes nucleosome organization.
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13
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Ohsawa I, Kawano F. Chronic exercise training activates histone turnover in mouse skeletal muscle fibers. FASEB J 2021; 35:e21453. [PMID: 33749947 DOI: 10.1096/fj.202002027rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 01/27/2021] [Accepted: 02/02/2021] [Indexed: 11/11/2022]
Abstract
Epigenetic regulation of skeletal muscle adaptation to exercise is a recent topic for which there is limited information. This study investigated whether exercise training activates histone turnover in the skeletal muscle fibers of mice. Experiments using a tetracycline-inducible H2B-GFP expression model demonstrated that 4 weeks of running training, but not 2 weeks of training, significantly promoted the incorporation of H2B-GFP into nucleosomes and the dissociation of histone H3.3 at both transcriptionally upregulated and nonresponsive loci. Muscle-specific PGC-1α-b-overexpressing mice crossed with H2B-GFP mice showed a slight increase in H2B-GFP incorporation at transcriptionally active loci, but not in the dissociation of H3.3 from nucleosomes. Gene expression responses to a single bout of running were significantly enhanced in 4-week trained mice when compared with those in 2-week trained mice. The most drastic increase in the gene response was found in the expression of Hspa1a and Hspa1b, in which the magnitude of upregulation in response to running was significantly enhanced from 8-fold in 2 week trained mice to 97- and 121-fold in 4 week trained mice, respectively. It was also found that the HSP70 level increased during the training period. In a myonuclear immunohistochemical analysis of chromatin remodelers, we further found that the level of SPT16, an H2A-H2B-specific chaperone, was upregulated after running training. These results revealed that 4 weeks of running training activated histone turnover in skeletal muscle fibers. They also suggested that histone turnover led to loosening of the nucleosomes and enhanced gene responses to exercise.
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Affiliation(s)
- Ikumi Ohsawa
- Graduate School of Health Sciences, Matsumoto University, Matsumoto City, Nagano, Japan
| | - Fuminori Kawano
- Graduate School of Health Sciences, Matsumoto University, Matsumoto City, Nagano, Japan
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14
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Measurement of histone replacement dynamics with genetically encoded exchange timers in yeast. Nat Biotechnol 2021; 39:1434-1443. [PMID: 34239087 DOI: 10.1038/s41587-021-00959-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 05/17/2021] [Indexed: 12/15/2022]
Abstract
Histone exchange between histones carrying position-specific marks and histones bearing general marks is important for gene regulation, but understanding of histone exchange remains incomplete. To overcome the poor time resolution of conventional pulse-chase histone labeling, we present a genetically encoded histone exchange timer sensitive to the duration that two tagged histone subunits co-reside at an individual genomic locus. We apply these sensors to map genome-wide patterns of histone exchange in yeast using single samples. Comparing H3 exchange in cycling and G1-arrested cells suggests that replication-independent H3 exchange occurs at several hundred nucleosomes (<1% of all nucleosomes) per minute, with a maximal rate at histone promoters. We observed substantial differences between the two nucleosome core subcomplexes: H2A-H2B subcomplexes undergo rapid transcription-dependent replacement within coding regions, whereas H3-H4 replacement occurs predominantly within promoter nucleosomes, in association with gene activation or repression. Our timers allow the in vivo study of histone exchange dynamics with minute time scale resolution.
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15
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Morrison O, Thakur J. Molecular Complexes at Euchromatin, Heterochromatin and Centromeric Chromatin. Int J Mol Sci 2021; 22:6922. [PMID: 34203193 PMCID: PMC8268097 DOI: 10.3390/ijms22136922] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 01/19/2023] Open
Abstract
Chromatin consists of a complex of DNA and histone proteins as its core components and plays an important role in both packaging DNA and regulating DNA metabolic pathways such as DNA replication, transcription, recombination, and chromosome segregation. Proper functioning of chromatin further involves a network of interactions among molecular complexes that modify chromatin structure and organization to affect the accessibility of DNA to transcription factors leading to the activation or repression of the transcription of target DNA loci. Based on its structure and compaction state, chromatin is categorized into euchromatin, heterochromatin, and centromeric chromatin. In this review, we discuss distinct chromatin factors and molecular complexes that constitute euchromatin-open chromatin structure associated with active transcription; heterochromatin-less accessible chromatin associated with silencing; centromeric chromatin-the site of spindle binding in chromosome segregation.
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Affiliation(s)
| | - Jitendra Thakur
- Department of Biology, Emory University, 1510 Clifton Rd #2006, Atlanta, GA 30322, USA;
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16
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Morcos MNF, Zerjatke T, Glauche I, Munz CM, Ge Y, Petzold A, Reinhardt S, Dahl A, Anstee NS, Bogeska R, Milsom MD, Säwén P, Wan H, Bryder D, Roers A, Gerbaulet A. Continuous mitotic activity of primitive hematopoietic stem cells in adult mice. J Exp Med 2021; 217:151684. [PMID: 32302400 PMCID: PMC7971128 DOI: 10.1084/jem.20191284] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/23/2019] [Accepted: 03/04/2020] [Indexed: 01/04/2023] Open
Abstract
The proliferative activity of aging hematopoietic stem cells (HSCs) is controversially discussed. Inducible fluorescent histone 2B fusion protein (H2B-FP) transgenic mice are important tools for tracking the mitotic history of murine HSCs in label dilution experiments. A recent study proposed that primitive HSCs symmetrically divide only four times to then enter permanent quiescence. We observed that background fluorescence due to leaky H2B-FP expression, occurring in all H2B-FP transgenes independent of label induction, accumulated with age in HSCs with high repopulation potential. We argue that this background had been misinterpreted as stable retention of induced label. We found cell division–independent half-lives of H2B-FPs to be short, which had led to overestimation of HSC divisional activity. Our data do not support abrupt entry of HSCs into permanent quiescence or sudden loss of regeneration potential after four divisions, but show that primitive HSCs of adult mice continue to cycle rarely.
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Affiliation(s)
- Mina N F Morcos
- Institute for Immunology, Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Thomas Zerjatke
- Institute for Medical Informatics and Biometry, Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Ingmar Glauche
- Institute for Medical Informatics and Biometry, Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Clara M Munz
- Institute for Immunology, Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Yan Ge
- Institute for Immunology, Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Andreas Petzold
- DRESDEN-concept Genome Center, Center for Molecular and Cellular Bioengineering, TU Dresden, Dresden, Germany
| | - Susanne Reinhardt
- DRESDEN-concept Genome Center, Center for Molecular and Cellular Bioengineering, TU Dresden, Dresden, Germany
| | - Andreas Dahl
- DRESDEN-concept Genome Center, Center for Molecular and Cellular Bioengineering, TU Dresden, Dresden, Germany
| | - Natasha S Anstee
- Division of Experimental Hematology, Deutsches Krebsforschungszentrum and Heidelberg Institute for Stem Cell Technology and Experimental Medicine, Heidelberg, Germany
| | - Ruzhica Bogeska
- Division of Experimental Hematology, Deutsches Krebsforschungszentrum and Heidelberg Institute for Stem Cell Technology and Experimental Medicine, Heidelberg, Germany
| | - Michael D Milsom
- Division of Experimental Hematology, Deutsches Krebsforschungszentrum and Heidelberg Institute for Stem Cell Technology and Experimental Medicine, Heidelberg, Germany
| | - Petter Säwén
- Division of Molecular Hematology, Lund University, Lund, Sweden
| | - Haixia Wan
- Division of Molecular Hematology, Lund University, Lund, Sweden
| | - David Bryder
- Division of Molecular Hematology, Lund University, Lund, Sweden.,Sahlgrenska Cancer Centre, Gothenburg University, Gothenburg, Sweden
| | - Axel Roers
- Institute for Immunology, Faculty of Medicine, TU Dresden, Dresden, Germany
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17
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Moretto F, Wood NE, Chia M, Li C, Luscombe NM, van Werven FJ. Transcription levels of a noncoding RNA orchestrate opposing regulatory and cell fate outcomes in yeast. Cell Rep 2021; 34:108643. [PMID: 33472063 PMCID: PMC7816125 DOI: 10.1016/j.celrep.2020.108643] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 10/28/2020] [Accepted: 12/22/2020] [Indexed: 12/21/2022] Open
Abstract
Transcription through noncoding regions of the genome is pervasive. How these transcription events regulate gene expression remains poorly understood. Here, we report that, in S. cerevisiae, the levels of transcription through a noncoding region, IRT2, located upstream in the promoter of the inducer of meiosis, IME1, regulate opposing chromatin and transcription states. At low levels, the act of IRT2 transcription promotes histone exchange, delivering acetylated histone H3 lysine 56 to chromatin locally. The subsequent open chromatin state directs transcription factor recruitment and induces downstream transcription to repress the IME1 promoter and meiotic entry. Conversely, increasing transcription turns IRT2 into a repressor by promoting transcription-coupled chromatin assembly. The two opposing functions of IRT2 transcription shape a regulatory circuit, which ensures a robust cell-type-specific control of IME1 expression and yeast meiosis. Our data illustrate how intergenic transcription levels are key to controlling local chromatin state, gene expression, and cell fate outcomes.
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Affiliation(s)
- Fabien Moretto
- Cell Fate and Gene Regulation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion, Crete 70013, Greece
| | - N Ezgi Wood
- Department of Cell Biology, UT Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Minghao Chia
- Cell Fate and Gene Regulation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Genome Institute of Singapore, 60 Biopolis Street, Genome, #02-01, Singapore 138672, Singapore
| | - Cai Li
- Bioinformatics and Computational Biology Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Nicholas M Luscombe
- Bioinformatics and Computational Biology Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Okinawa Institute of Science and Technology Graduate University, Okinawa 904-0495, Japan; UCL Genetics Institute, University College London, London WC1E 6BT, UK
| | - Folkert J van Werven
- Cell Fate and Gene Regulation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
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18
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He Y, Lawrimore J, Cook D, Van Gorder EE, De Larimat SC, Adalsteinsson D, Forest MG, Bloom K. Statistical mechanics of chromosomes: in vivo and in silico approaches reveal high-level organization and structure arise exclusively through mechanical feedback between loop extruders and chromatin substrate properties. Nucleic Acids Res 2020; 48:11284-11303. [PMID: 33080019 PMCID: PMC7672462 DOI: 10.1093/nar/gkaa871] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 09/22/2020] [Accepted: 09/24/2020] [Indexed: 11/14/2022] Open
Abstract
The revolution in understanding higher order chromosome dynamics and organization derives from treating the chromosome as a chain polymer and adapting appropriate polymer-based physical principles. Using basic principles, such as entropic fluctuations and timescales of relaxation of Rouse polymer chains, one can recapitulate the dominant features of chromatin motion observed in vivo. An emerging challenge is to relate the mechanical properties of chromatin to more nuanced organizational principles such as ubiquitous DNA loops. Toward this goal, we introduce a real-time numerical simulation model of a long chain polymer in the presence of histones and condensin, encoding physical principles of chromosome dynamics with coupled histone and condensin sources of transient loop generation. An exact experimental correlate of the model was obtained through analysis of a model-matching fluorescently labeled circular chromosome in live yeast cells. We show that experimentally observed chromosome compaction and variance in compaction are reproduced only with tandem interactions between histone and condensin, not from either individually. The hierarchical loop structures that emerge upon incorporation of histone and condensin activities significantly impact the dynamic and structural properties of chromatin. Moreover, simulations reveal that tandem condensin–histone activity is responsible for higher order chromosomal structures, including recently observed Z-loops.
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Affiliation(s)
- Yunyan He
- Department of Mathematics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Josh Lawrimore
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Diana Cook
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | | | | | - David Adalsteinsson
- Department of Mathematics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - M Gregory Forest
- Department of Mathematics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Kerry Bloom
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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19
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Kassem S, Ferrari P, Hughes AL, Soudet J, Rando OJ, Strubin M. Histone exchange is associated with activator function at transcribed promoters and with repression at histone loci. SCIENCE ADVANCES 2020; 6:6/36/eabb0333. [PMID: 32917590 PMCID: PMC7467701 DOI: 10.1126/sciadv.abb0333] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 07/15/2020] [Indexed: 05/14/2023]
Abstract
Transcription in eukaryotes correlates with major chromatin changes, including the replacement of old nucleosomal histones by new histones at the promoters of genes. The role of these histone exchange events in transcription remains unclear. In particular, the causal relationship between histone exchange and activator binding, preinitiation complex (PIC) assembly, and/or subsequent transcription remains unclear. Here, we provide evidence that histone exchange at gene promoters is not simply a consequence of PIC assembly or transcription but instead is mediated by activators. We further show that not all activators up-regulate gene expression by inducing histone turnover. Thus, histone exchange does not simply correlate with transcriptional activity, but instead reflects the mode of action of the activator. Last, we show that histone turnover is not only associated with activator function but also plays a role in transcriptional repression at the histone loci.
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Affiliation(s)
- Sari Kassem
- Department of Microbiology and Molecular Medicine, University Medical Centre (C.M.U.), 1211 Geneva 4, Switzerland
| | - Paolo Ferrari
- Department of Microbiology and Molecular Medicine, University Medical Centre (C.M.U.), 1211 Geneva 4, Switzerland
| | - Amanda L Hughes
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Julien Soudet
- Department of Cell Biology, University of Geneva, 1211 Genève 4, Switzerland
| | - Oliver J Rando
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Michel Strubin
- Department of Microbiology and Molecular Medicine, University Medical Centre (C.M.U.), 1211 Geneva 4, Switzerland.
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20
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Scott WA, Campos EI. Interactions With Histone H3 & Tools to Study Them. Front Cell Dev Biol 2020; 8:701. [PMID: 32850821 PMCID: PMC7411163 DOI: 10.3389/fcell.2020.00701] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 07/10/2020] [Indexed: 01/12/2023] Open
Abstract
Histones are an integral part of chromatin and thereby influence its structure, dynamics, and functions. The effects of histone variants, posttranslational modifications, and binding proteins is therefore of great interest. From the moment that they are deposited on chromatin, nucleosomal histones undergo dynamic changes in function of the cell cycle, and as DNA is transcribed and replicated. In the process, histones are not only modified and bound by various proteins, but also shuffled, evicted, or replaced. Technologies and tools to study such dynamic events continue to evolve and better our understanding of chromatin and of histone proteins proper. Here, we provide an overview of H3.1 and H3.3 histone dynamics throughout the cell cycle, while highlighting some of the tools used to study their protein–protein interactions. We specifically discuss how histones are chaperoned, modified, and bound by various proteins at different stages of the cell cycle. Established and select emerging technologies that furthered (or have a high potential of furthering) our understanding of the dynamic histone–protein interactions are emphasized. This includes experimental tools to investigate spatiotemporal changes on chromatin, the role of histone chaperones, histone posttranslational modifications, and histone-binding effector proteins.
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Affiliation(s)
- William A Scott
- Genetics & Genome Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Eric I Campos
- Genetics & Genome Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
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21
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Kujirai T, Kurumizaka H. Transcription through the nucleosome. Curr Opin Struct Biol 2020; 61:42-49. [DOI: 10.1016/j.sbi.2019.10.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 10/17/2019] [Accepted: 10/22/2019] [Indexed: 11/28/2022]
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22
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Molenaar TM, Pagès-Gallego M, Meyn V, van Leeuwen F. Application of Recombination -Induced Tag Exchange (RITE) to study histone dynamics in human cells. Epigenetics 2020; 15:901-913. [PMID: 32228348 PMCID: PMC7518693 DOI: 10.1080/15592294.2020.1741777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In eukaryotes, nucleosomes form a barrier to DNA templated reactions and must be dynamically disrupted to provide access to the genome. During nucleosome (re)assembly, histones can be replaced by new histones, erasing post-translational modifications. Measuring histone turnover in mammalian cells has mostly relied on inducible overexpression of histones, which may influence and distort natural histone deposition rates. We have previously used recombination-induced tag exchange (RITE) to study histone dynamics in budding yeast. RITE is a method to follow protein turnover by genetic switching of epitope tags using Cre recombinase and does not rely on inducible overexpression. Here, we applied RITE to study the dynamics of the replication-independent histone variant H3.3 in human cells. Epitope tag-switching could be readily detected upon induction of Cre-recombinase, enabling the monitoring old and new H3.3 in the same pool of cells. However, the rate of tag-switching was lower than in yeast cells. Analysis of histone H3.3 incorporation by chromatin immunoprecipitation did not recapitulate previously reported aspects of H3.3 dynamics such as high turnover rates in active promoters and enhancers. We hypothesize that asynchronous Cre-mediated DNA recombination in the cell population leads to a low time resolution of the H3.3-RITE system in human cells. We conclude that RITE enables the detection of old and new proteins in human cells and that the time-scale of tag-switching prevents the capture of high turnover events in a population of cells. Instead, RITE might be more suited for tracking long-lived histone proteins in human cells.
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Affiliation(s)
- Thom M Molenaar
- Division of Gene Regulation, Netherlands Cancer Institute , Amsterdam, The Netherlands
| | - Marc Pagès-Gallego
- Division of Gene Regulation, Netherlands Cancer Institute , Amsterdam, The Netherlands
| | - Vanessa Meyn
- Division of Gene Regulation, Netherlands Cancer Institute , Amsterdam, The Netherlands
| | - Fred van Leeuwen
- Division of Gene Regulation, Netherlands Cancer Institute , Amsterdam, The Netherlands.,Department of Medical Biology, Amsterdam UMC, Location AMC, University of Amsterdam , Amsterdam, The Netherlands
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23
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Histone variant H3.3 residue S31 is essential for Xenopus gastrulation regardless of the deposition pathway. Nat Commun 2020; 11:1256. [PMID: 32152320 PMCID: PMC7062693 DOI: 10.1038/s41467-020-15084-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 02/09/2020] [Indexed: 01/04/2023] Open
Abstract
Vertebrates exhibit specific requirements for replicative H3 and non-replicative H3.3 variants during development. To disentangle whether this involves distinct modes of deposition or unique functions once incorporated into chromatin, we combined studies in Xenopus early development with chromatin assays. Here we investigate the extent to which H3.3 mutated at residues that differ from H3.2 rescue developmental defects caused by H3.3 depletion. Regardless of the deposition pathway, only variants at residue 31-a serine that can become phosphorylated-failed to rescue endogenous H3.3 depletion. Although an alanine substitution fails to rescue H3.3 depletion, a phospho-mimic aspartate residue at position 31 rescues H3.3 function. To explore mechanisms involving H3.3 S31 phosphorylation, we identified factors attracted or repulsed by the presence of aspartate at position 31, along with modifications on neighboring residues. We propose that serine 31-phosphorylated H3.3 acts as a signaling module that stimulates the acetylation of K27, providing a chromatin state permissive to the embryonic development program.
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24
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Yeast epigenetics: the inheritance of histone modification states. Biosci Rep 2019; 39:BSR20182006. [PMID: 30877183 PMCID: PMC6504666 DOI: 10.1042/bsr20182006] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 02/28/2019] [Accepted: 03/04/2019] [Indexed: 01/12/2023] Open
Abstract
Saccharomyces cerevisiae (budding yeast) and Schizosaccharomyces pombe (fission yeast) are two of the most recognised and well-studied model systems for epigenetic regulation and the inheritance of chromatin states. Their silent loci serve as a proxy for heterochromatic chromatin in higher eukaryotes, and as such both species have provided a wealth of information on the mechanisms behind the establishment and maintenance of epigenetic states, not only in yeast, but in higher eukaryotes. This review focuses specifically on the role of histone modifications in governing telomeric silencing in S. cerevisiae and centromeric silencing in S. pombe as examples of genetic loci that exemplify epigenetic inheritance. We discuss the recent advancements that for the first time provide a mechanistic understanding of how heterochromatin, dictated by histone modifications specifically, is preserved during S-phase. We also discuss the current state of our understanding of yeast nucleosome dynamics during DNA replication, an essential component in delineating the contribution of histone modifications to epigenetic inheritance.
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25
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Willhoft O, Ghoneim M, Lin CL, Chua EYD, Wilkinson M, Chaban Y, Ayala R, McCormack EA, Ocloo L, Rueda DS, Wigley DB. Structure and dynamics of the yeast SWR1-nucleosome complex. Science 2018; 362:362/6411/eaat7716. [PMID: 30309918 DOI: 10.1126/science.aat7716] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 08/08/2018] [Indexed: 12/31/2022]
Abstract
The yeast SWR1 complex exchanges histone H2A in nucleosomes with Htz1 (H2A.Z in humans). The cryo-electron microscopy structure of the SWR1 complex bound to a nucleosome at 3.6-angstrom resolution reveals details of the intricate interactions between components of the SWR1 complex and its nucleosome substrate. Interactions between the Swr1 motor domains and the DNA wrap at superhelical location 2 distort the DNA, causing a bulge with concomitant translocation of the DNA by one base pair, coupled to conformational changes of the histone core. Furthermore, partial unwrapping of the DNA from the histone core takes place upon binding of nucleosomes to SWR1 complex. The unwrapping, as monitored by single-molecule data, is stabilized and has its dynamics altered by adenosine triphosphate binding but does not require hydrolysis.
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Affiliation(s)
- Oliver Willhoft
- Section of Structural Biology, Department of Medicine, Imperial College London, London SW7 2AZ, UK
| | - Mohamed Ghoneim
- Single Molecule Imaging Group, MRC London Institute of Medical Sciences, London W12 0NN, UK.,Molecular Virology, Department of Medicine, Imperial College London, London W12 0NN, UK
| | - Chia-Liang Lin
- Section of Structural Biology, Department of Medicine, Imperial College London, London SW7 2AZ, UK
| | - Eugene Y D Chua
- Section of Structural Biology, Department of Medicine, Imperial College London, London SW7 2AZ, UK
| | - Martin Wilkinson
- Section of Structural Biology, Department of Medicine, Imperial College London, London SW7 2AZ, UK
| | - Yuriy Chaban
- Section of Structural Biology, Department of Medicine, Imperial College London, London SW7 2AZ, UK
| | - Rafael Ayala
- Section of Structural Biology, Department of Medicine, Imperial College London, London SW7 2AZ, UK
| | - Elizabeth A McCormack
- Section of Structural Biology, Department of Medicine, Imperial College London, London SW7 2AZ, UK
| | - Lorraine Ocloo
- Section of Structural Biology, Department of Medicine, Imperial College London, London SW7 2AZ, UK
| | - David S Rueda
- Single Molecule Imaging Group, MRC London Institute of Medical Sciences, London W12 0NN, UK. .,Molecular Virology, Department of Medicine, Imperial College London, London W12 0NN, UK
| | - Dale B Wigley
- Section of Structural Biology, Department of Medicine, Imperial College London, London SW7 2AZ, UK.
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26
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Wang T, Liu Y, Edwards G, Krzizike D, Scherman H, Luger K. The histone chaperone FACT modulates nucleosome structure by tethering its components. Life Sci Alliance 2018; 1:e201800107. [PMID: 30456370 PMCID: PMC6238592 DOI: 10.26508/lsa.201800107] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 06/29/2018] [Accepted: 06/29/2018] [Indexed: 11/24/2022] Open
Abstract
The histone chaperone FACT functions by tethering partial components of the nucleosome, thereby assisting nucleosome disassembly and reassembly during transcription. Human FAcilitates Chromatin Transcription (hFACT) is a conserved histone chaperone that was originally described as a transcription elongation factor with potential nucleosome assembly functions. Here, we show that FACT has moderate tetrasome assembly activity but facilitates H2A–H2B deposition to form hexasomes and nucleosomes. In the process, FACT tethers components of the nucleosome through interactions with H2A–H2B, resulting in a defined intermediate complex comprising FACT, a histone hexamer, and DNA. Free DNA extending from the tetrasome then competes FACT off H2A–H2B, thereby promoting hexasome and nucleosome formation. Our studies provide mechanistic insight into how FACT may stabilize partial nucleosome structures during transcription or nucleosome assembly, seemingly facilitating both nucleosome disassembly and nucleosome assembly.
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Affiliation(s)
- Tao Wang
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO, USA.,Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Yang Liu
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Garrett Edwards
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Daniel Krzizike
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO, USA.,Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Hataichanok Scherman
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA.,Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO, USA
| | - Karolin Luger
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO, USA.,Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
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27
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Abstract
Histone proteins play an important role in determining chromatin structure and gene expression. Studies in several systems have established that histones are in continuous turnover within the chromatin. It is therefore important to quantitatively measure the binding dynamics of these proteins in vivo. Photobleaching-based approaches such as fluorescence recovery after photobleaching (FRAP) are advantageous in that they are applied to living cells at a single cell level. In this chapter, I provide a detailed experimental protocol on how to perform histone FRAP experiments in Arabidopsis thaliana roots and how to analyze the most important parameters.
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Affiliation(s)
- Stefanie Rosa
- Institute of Biochemistry and Biology, Plant Physiology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, DE-14476, Potsdam-Golm, Germany.
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28
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Shaping Chromatin in the Nucleus: The Bricks and the Architects. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2017; 82:1-14. [PMID: 29208640 DOI: 10.1101/sqb.2017.82.033753] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Chromatin organization in the nucleus provides a vast repertoire of information in addition to that encoded genetically. Understanding how this organization impacts genome stability and influences cell fate and tumorigenesis is an area of rapid progress. Considering the nucleosome, the fundamental unit of chromatin structure, the study of histone variants (the bricks) and their selective loading by histone chaperones (the architects) is particularly informative. Here, we report recent advances in understanding how relationships between histone variants and their chaperones contribute to tumorigenesis using cell lines and Xenopus development as model systems. In addition to their role in histone deposition, we also document interactions between histone chaperones and other chromatin factors that govern higher-order structure and control DNA metabolism. We highlight how a fine-tuned assembly line of bricks (H3.3 and CENP-A) and architects (HIRA, HJURP, and DAXX) is key in adaptation to developmental and pathological changes. An example of this conceptual advance is the exquisite sensitivity displayed by p53-null tumor cells to modulation of HJURP, the histone chaperone for CENP-A (CenH3 variant). We discuss how these findings open avenues for novel therapeutic paradigms in cancer care.
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29
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van den Berg AA, Depken M. Crowding-induced transcriptional bursts dictate polymerase and nucleosome density profiles along genes. Nucleic Acids Res 2017; 45:7623-7632. [PMID: 28586463 PMCID: PMC5737439 DOI: 10.1093/nar/gkx513] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 06/03/2017] [Indexed: 12/20/2022] Open
Abstract
During eukaryotic transcription, RNA polymerase (RNAP) translocates along DNA molecules covered with nucleosomes and other DNA binding proteins. Though the interactions between a single nucleosome and RNAP are by now fairly well understood, this understanding has not been synthesized into a description of transcription on crowded genes, where multiple RNAP transcribe through nucleosomes while preserving the nucleosome coverage. We here take a deductive modeling approach to establish the consequences of RNAP–nucleosome interactions for transcription in crowded environments. We show that under physiologically crowded conditions, the interactions of RNAP with nucleosomes induce a strong kinetic attraction between RNAP molecules, causing them to self-organize into stable and moving pelotons. The peloton formation quantitatively explains the observed nucleosome and RNAP depletion close to the initiation site on heavily transcribed genes. Pelotons further translate into short-timescale transcriptional bursts at termination, resulting in burst characteristics consistent with instances of bursty transcription observed in vivo. To facilitate experimental testing of our proposed mechanism, we present several analytic relations that make testable quantitative predictions.
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Affiliation(s)
- Aafke A van den Berg
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Martin Depken
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
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30
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Berry S, Dean C, Howard M. Slow Chromatin Dynamics Allow Polycomb Target Genes to Filter Fluctuations in Transcription Factor Activity. Cell Syst 2017; 4:445-457.e8. [PMID: 28342717 PMCID: PMC5409831 DOI: 10.1016/j.cels.2017.02.013] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 10/10/2016] [Accepted: 02/27/2017] [Indexed: 12/18/2022]
Abstract
Genes targeted by Polycomb repressive complex 2 (PRC2) are regulated in cis by chromatin modifications and also in trans by diffusible regulators such as transcription factors. Here, we introduce a mathematical model in which transcription directly antagonizes Polycomb silencing, thereby linking these cis- and trans-regulatory inputs to gene expression. The model is parameterized by recent experimental data showing that PRC2-mediated repressive chromatin modifications accumulate extremely slowly. The model generates self-perpetuating, bistable active and repressed chromatin states that persist through DNA replication, thereby ensuring high-fidelity transmission of the current chromatin state. However, sufficiently strong, persistent activation or repression of transcription promotes switching between active and repressed chromatin states. We observe that when chromatin modification dynamics are slow, transient pulses of transcriptional activation or repression are effectively filtered, such that epigenetic memory is retained. Noise filtering thus depends on slow chromatin dynamics and may represent an important function of PRC2-based regulation.
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Affiliation(s)
- Scott Berry
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Caroline Dean
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Martin Howard
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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31
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Talbert PB, Henikoff S. Histone variants on the move: substrates for chromatin dynamics. Nat Rev Mol Cell Biol 2016; 18:115-126. [PMID: 27924075 DOI: 10.1038/nrm.2016.148] [Citation(s) in RCA: 208] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Most histones are assembled into nucleosomes behind the replication fork to package newly synthesized DNA. By contrast, histone variants, which are encoded by separate genes, are typically incorporated throughout the cell cycle. Histone variants can profoundly change chromatin properties, which in turn affect DNA replication and repair, transcription, and chromosome packaging and segregation. Recent advances in the study of histone replacement have elucidated the dynamic processes by which particular histone variants become substrates of histone chaperones, ATP-dependent chromatin remodellers and histone-modifying enzymes. Here, we review histone variant dynamics and the effects of replacing DNA synthesis-coupled histones with their replication-independent variants on the chromatin landscape.
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Affiliation(s)
- Paul B Talbert
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, Washington 98109-1024, USA
| | - Steven Henikoff
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, Washington 98109-1024, USA
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32
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Large-scale ATP-independent nucleosome unfolding by a histone chaperone. Nat Struct Mol Biol 2016; 23:1111-1116. [PMID: 27820806 DOI: 10.1038/nsmb.3321] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 10/13/2016] [Indexed: 12/13/2022]
Abstract
DNA accessibility to regulatory proteins is substantially influenced by nucleosome structure and dynamics. The facilitates chromatin transcription (FACT) complex increases the accessibility of nucleosomal DNA, but the mechanism and extent of its nucleosome reorganization activity are unknown. Here we determined the effects of FACT from the yeast Saccharomyces cerevisiae on single nucleosomes by using single-particle Förster resonance energy transfer (spFRET) microscopy. FACT binding results in dramatic ATP-independent, symmetrical and reversible DNA uncoiling that affects at least 70% of the DNA within a nucleosome, occurs without apparent loss of histones and proceeds via an 'all-or-none' mechanism. A mutated version of FACT is defective in uncoiling, and a histone mutation that suppresses phenotypes caused by this FACT mutation in vivo restores the uncoiling activity in vitro. Thus, FACT-dependent nucleosome unfolding modulates the accessibility of nucleosomal DNA, and this activity is an important function of FACT in vivo.
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33
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Structural Insights into the Association of Hif1 with Histones H2A-H2B Dimer and H3-H4 Tetramer. Structure 2016; 24:1810-1820. [DOI: 10.1016/j.str.2016.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 08/01/2016] [Accepted: 08/01/2016] [Indexed: 11/22/2022]
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34
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Aizawa M, Sugimoto N, Watanabe S, Yoshida K, Fujita M. Nucleosome assembly and disassembly activity of GRWD1, a novel Cdt1-binding protein that promotes pre-replication complex formation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2739-2748. [PMID: 27552915 DOI: 10.1016/j.bbamcr.2016.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 08/12/2016] [Accepted: 08/16/2016] [Indexed: 01/08/2023]
Abstract
GRWD1 was previously identified as a novel Cdt1-binding protein that possesses histone-binding and nucleosome assembly activities and promotes MCM loading, probably by maintaining chromatin openness at replication origins. However, the molecular mechanisms underlying these activities remain unknown. We prepared reconstituted mononucleosomes from recombinant histones and a DNA fragment containing a nucleosome positioning sequence, and investigated the effects of GRWD1 on them. GRWD1 could disassemble these preformed mononucleosomes in vitro in an ATP-independent manner. Thus, our data suggest that GRWD1 facilitates removal of H2A-H2B dimers from nucleosomes, resulting in formation of hexasomes. The activity was compromised by deletion of the acidic domain, which is required for efficient histone binding. In contrast, nucleosome assembly activity of GRWD1 was not affected by deletion of the acidic domain. In HeLa cells, the acidic domain of GRWD1 was necessary to maintain chromatin openness and promote MCM loading at replication origins. Taken together, our results suggest that GRWD1 promotes chromatin fluidity by influencing nucleosome structures, e.g., by transient eviction of H2A-H2B, and thereby promotes efficient MCM loading at replication origins.
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Affiliation(s)
- Masahiro Aizawa
- Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashiku, Fukuoka 812-8582, Japan
| | - Nozomi Sugimoto
- Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashiku, Fukuoka 812-8582, Japan
| | - Shinya Watanabe
- Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashiku, Fukuoka 812-8582, Japan
| | - Kazumasa Yoshida
- Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashiku, Fukuoka 812-8582, Japan
| | - Masatoshi Fujita
- Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashiku, Fukuoka 812-8582, Japan.
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35
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Abstract
Eukaryotic genomes are packaged into an extensively folded state known as chromatin. Analysis of the structure of eukaryotic chromosomes has been revolutionized by development of a suite of genome-wide measurement technologies, collectively termed “epigenomics.” We review major advances in epigenomic analysis of eukaryotic genomes, covering aspects of genome folding at scales ranging from whole chromosome folding down to nucleotide-resolution assays that provide structural insights into protein-DNA interactions. We then briefly outline several challenges remaining and highlight new developments such as single-cell epigenomic assays that will help provide us with a high-resolution structural understanding of eukaryotic genomes.
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Affiliation(s)
- Nir Friedman
- School of Computer Science and Engineering, The Hebrew University, Jerusalem 9190401, Israel; Institute of Life Sciences, The Hebrew University, Jerusalem 9190401, Israel
| | - Oliver J Rando
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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36
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Rea M, Jiang T, Eleazer R, Eckstein M, Marshall AG, Fondufe-Mittendorf YN. Quantitative Mass Spectrometry Reveals Changes in Histone H2B Variants as Cells Undergo Inorganic Arsenic-Mediated Cellular Transformation. Mol Cell Proteomics 2016; 15:2411-22. [PMID: 27169413 PMCID: PMC4937513 DOI: 10.1074/mcp.m116.058412] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 05/09/2016] [Indexed: 11/06/2022] Open
Abstract
Exposure to inorganic arsenic, a ubiquitous environmental toxic metalloid, leads to carcinogenesis. However, the mechanism is unknown. Several studies have shown that inorganic arsenic exposure alters specific gene expression patterns, possibly through alterations in chromatin structure. While most studies on understanding the mechanism of chromatin-mediated gene regulation have focused on histone post-translational modifications, the role of histone variants remains largely unknown. Incorporation of histone variants alters the functional properties of chromatin. To understand the global dynamics of chromatin structure and function in arsenic-mediated carcinogenesis, analysis of the histone variants incorporated into the nucleosome and their covalent modifications is required. Here we report the first global mass spectrometric analysis of histone H2B variants as cells undergo arsenic-mediated epithelial to mesenchymal transition. We used electron capture dissociation-based top-down tandem mass spectrometry analysis validated with quantitative reverse transcription real-time polymerase chain reaction to identify changes in the expression levels of H2B variants in inorganic arsenic-mediated epithelial-mesenchymal transition. We identified changes in the expression levels of specific histone H2B variants in two cell types, which are dependent on dose and length of exposure of inorganic arsenic. In particular, we found increases in H2B variants H2B1H/1K/1C/1J/1O and H2B2E/2F, and significant decreases in H2B1N/1D/1B as cells undergo inorganic arsenic-mediated epithelial-mesenchymal transition. The analysis of these histone variants provides a first step toward an understanding of the functional significance of the diversity of histone structures, especially in inorganic arsenic-mediated gene expression and carcinogenesis.
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Affiliation(s)
- Matthew Rea
- From the ‡Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky 40536
| | - Tingting Jiang
- §Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306
| | - Rebekah Eleazer
- From the ‡Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky 40536
| | - Meredith Eckstein
- From the ‡Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky 40536
| | - Alan G Marshall
- §Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306; ¶Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310
| | - Yvonne N Fondufe-Mittendorf
- From the ‡Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky 40536;
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37
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Noncoding Transcription Is a Driving Force for Nucleosome Instability in spt16 Mutant Cells. Mol Cell Biol 2016; 36:1856-67. [PMID: 27141053 DOI: 10.1128/mcb.00152-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 04/27/2016] [Indexed: 12/17/2022] Open
Abstract
FACT (facilitates chromatin transcription) consists of two essential subunits, Spt16 and Pob3, and functions as a histone chaperone. Mutation of spt16 results in a global loss of nucleosomes as well as aberrant transcription. Here, we show that the majority of nucleosome changes upon Spt16 depletion are alterations in nucleosome fuzziness and position shift. Most nucleosomal changes are suppressed by the inhibition of RNA polymerase II (Pol II) activity. Surprisingly, a small subgroup of nucleosome changes is resistant to transcriptional inhibition. Notably, Spt16 and distinct histone modifications are enriched at this subgroup of nucleosomes. We also report 1,037 Spt16-suppressed noncoding transcripts (SNTs) and found that the SNT start sites are enriched with the subgroup of nucleosomes resistant to Pol II inhibition. Finally, the nucleosomes at genes overlapping SNTs are more susceptible to changes upon Spt16 depletion than those without SNTs. Taken together, our results support a model in which Spt16 has a role in maintaining local nucleosome stability to inhibit initiation of SNT transcription, which once initiated drives additional nucleosome loss upon Spt16 depletion.
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38
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Li J, Hardy K, Phetsouphanh C, Tu WJ, Sutcliffe EL, McCuaig R, Sutton CR, Zafar A, Munier CML, Zaunders JJ, Xu Y, Theodoratos A, Tan A, Lim PS, Knaute T, Masch A, Zerweck J, Brezar V, Milburn PJ, Dunn J, Casarotto MG, Turner SJ, Seddiki N, Kelleher AD, Rao S. Nuclear PKC-θ facilitates rapid transcriptional responses in human memory CD4+ T cells through p65 and H2B phosphorylation. J Cell Sci 2016; 129:2448-61. [PMID: 27149922 PMCID: PMC4920249 DOI: 10.1242/jcs.181248] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 04/21/2016] [Indexed: 12/14/2022] Open
Abstract
Memory T cells are characterized by their rapid transcriptional programs upon re-stimulation. This transcriptional memory response is facilitated by permissive chromatin, but exactly how the permissive epigenetic landscape in memory T cells integrates incoming stimulatory signals remains poorly understood. By genome-wide ChIP-sequencing ex vivo human CD4+ T cells, here, we show that the signaling enzyme, protein kinase C theta (PKC-θ) directly relays stimulatory signals to chromatin by binding to transcriptional-memory-responsive genes to induce transcriptional activation. Flanked by permissive histone modifications, these PKC-enriched regions are significantly enriched with NF-κB motifs in ex vivo bulk and vaccinia-responsive human memory CD4+ T cells. Within the nucleus, PKC-θ catalytic activity maintains the Ser536 phosphorylation on the p65 subunit of NF-κB (also known as RelA) and can directly influence chromatin accessibility at transcriptional memory genes by regulating H2B deposition through Ser32 phosphorylation. Furthermore, using a cytoplasm-restricted PKC-θ mutant, we highlight that chromatin-anchored PKC-θ integrates activating signals at the chromatin template to elicit transcriptional memory responses in human memory T cells. Summary: Memory T cells have a rapid transcriptional program upon re-stimulation. Chromatin-anchored PKC-θ integrates activating signals at the chromatin template to elicit this transcriptional memory in T cells.
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Affiliation(s)
- Jasmine Li
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia Department of Microbiology & Immunology, The Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Kristine Hardy
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Chan Phetsouphanh
- The Kirby Institute, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Wen Juan Tu
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Elissa L Sutcliffe
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Robert McCuaig
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Christopher R Sutton
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Anjum Zafar
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - C Mee Ling Munier
- The Kirby Institute, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - John J Zaunders
- The Kirby Institute, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Yin Xu
- The Kirby Institute, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Angelo Theodoratos
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Abel Tan
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Pek Siew Lim
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Tobias Knaute
- JPT Peptide Technologies Gmbh, Berlin 12489, Germany
| | - Antonia Masch
- Department of Enzymology, Institute of Biochemistry & Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle 06108, Germany
| | | | - Vedran Brezar
- INSERM U955 Eq16 Faculte de medicine Henri Mondor and Universite Paris-Est Creteil/Vaccine Research Institute, Creteil 94010, France
| | - Peter J Milburn
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Jenny Dunn
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Marco G Casarotto
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Stephen J Turner
- Department of Microbiology & Immunology, The Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Nabila Seddiki
- INSERM U955 Eq16 Faculte de medicine Henri Mondor and Universite Paris-Est Creteil/Vaccine Research Institute, Creteil 94010, France
| | - Anthony D Kelleher
- The Kirby Institute, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Sudha Rao
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
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39
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Histone Chaperone Nap1 Is a Major Regulator of Histone H2A-H2B Dynamics at the Inducible GAL Locus. Mol Cell Biol 2016; 36:1287-96. [PMID: 26884462 DOI: 10.1128/mcb.00835-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 01/25/2016] [Indexed: 02/02/2023] Open
Abstract
Histone chaperones, like nucleosome assembly protein 1 (Nap1), play a critical role in the maintenance of chromatin architecture. Here, we use the GAL locus in Saccharomyces cerevisiae to investigate the influence of Nap1 on chromatin structure and histone dynamics during distinct transcriptional states. When the GAL locus is not expressed, cells lacking Nap1 show an accumulation of histone H2A-H2B but not histone H3-H4 at this locus. Excess H2A-H2B interacts with the linker DNA between nucleosomes, and the interaction is independent of the inherent DNA-binding affinity of H2A-H2B for these particular sequences as measured in vitro When the GAL locus is transcribed, excess H2A-H2B is reversed, and levels of all chromatin-bound histones are depleted in cells lacking Nap1. We developed an in vivo system to measure histone exchange at the GAL locus and observed considerable variability in the rate of exchange across the locus in wild-type cells. We recapitulate this variability with in vitro nucleosome reconstitutions, which suggests a contribution of DNA sequence to histone dynamics. We also find that Nap1 is required for transcription-dependent H2A-H2B exchange. Altogether, these results indicate that Nap1 is essential for maintaining proper chromatin composition and modulating the exchange of H2A-H2B in vivo.
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40
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Abstract
Short DNA fragments containing single nucleosomes have been extensively employed as simple model experimental systems for analysis of many intranuclear processes, including binding of proteins to nucleosomes, covalent histone modifications, transcription, DNA repair, and ATP-dependent chromatin remodeling. Here we describe several recently developed procedures for obtaining and analysis of mononucleosomes assembled on 200-350-bp DNA fragments.
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41
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Bondarenko MT, Maluchenko NV, Valieva ME, Gerasimova NS, Kulaeva OI, Georgiev PG, Studitsky VM. Structure and function of histone chaperone FACT. Mol Biol 2015. [DOI: 10.1134/s0026893315060023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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42
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Padavattan S, Shinagawa T, Hasegawa K, Kumasaka T, Ishii S, Kumarevel T. Structural and functional analyses of nucleosome complexes with mouse histone variants TH2a and TH2b, involved in reprogramming. Biochem Biophys Res Commun 2015; 464:929-35. [DOI: 10.1016/j.bbrc.2015.07.070] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 07/14/2015] [Indexed: 11/16/2022]
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43
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Galvani A, Thiriet C. Nucleosome Dancing at the Tempo of Histone Tail Acetylation. Genes (Basel) 2015; 6:607-21. [PMID: 26184324 PMCID: PMC4584320 DOI: 10.3390/genes6030607] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 06/26/2015] [Accepted: 07/08/2015] [Indexed: 12/12/2022] Open
Abstract
The impact of histone acetylation on transcription was revealed over 50 years ago by Allfrey and colleagues. However, it took decades for an understanding of the fine mechanism by which this posttranslational modification affects chromatin structure and promotes transcription. Here, we review breakthroughs linking histone tail acetylation, histone dynamics, and transcription. We also discuss the histone exchange during transcription and highlight the important function of a pool of non-chromatinized histones in chromatin dynamics.
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Affiliation(s)
- Angélique Galvani
- UMR CNRS 6286 UFIP, Université de Nantes, Epigénétique: Proliferation et Différenciation, 2 rue de Houssinière, 44322 Nantes Cedex 03, France.
| | - Christophe Thiriet
- UMR CNRS 6286 UFIP, Université de Nantes, Epigénétique: Proliferation et Différenciation, 2 rue de Houssinière, 44322 Nantes Cedex 03, France.
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44
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Zhou W, Zhu Y, Dong A, Shen WH. Histone H2A/H2B chaperones: from molecules to chromatin-based functions in plant growth and development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 83:78-95. [PMID: 25781491 DOI: 10.1111/tpj.12830] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 03/10/2015] [Accepted: 03/11/2015] [Indexed: 05/06/2023]
Abstract
Nucleosomal core histones (H2A, H2B, H3 and H4) must be assembled, replaced or exchanged to preserve or modify chromatin organization and function according to cellular needs. Histone chaperones escort histones, and play key functions during nucleosome assembly/disassembly and in nucleosome structure configuration. Because of their location at the periphery of nucleosome, histone H2A-H2B dimers are remarkably dynamic. Here we focus on plant histone H2A/H2B chaperones, particularly members of the NUCLEOSOME ASSEMBLY PROTEIN-1 (NAP1) and FACILITATES CHROMATIN TRANSCRIPTION (FACT) families, discussing their molecular features, properties, regulation and function. Covalent histone modifications (e.g. ubiquitination, phosphorylation, methylation, acetylation) and H2A variants (H2A.Z, H2A.X and H2A.W) are also discussed in view of their crucial importance in modulating nucleosome organization and function. We further discuss roles of NAP1 and FACT in chromatin-based processes, such as transcription, DNA replication and repair. Specific functions of NAP1 and FACT are evident when their roles are considered with respect to regulation of plant growth and development and in plant responses to environmental stresses. Future major challenges remain in order to define in more detail the overlapping and specific roles of various members of the NAP1 family as well as differences and similarities between NAP1 and FACT family members, and to identify and characterize their partners as well as new families of chaperones to understand histone variant incorporation and chromatin target specificity.
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Affiliation(s)
- Wangbin Zhou
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, International Associated Laboratory of CNRS-Fudan-HUNAU on Plant Epigenome Research, Department of Biochemistry, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 20043, China
| | - Yan Zhu
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, International Associated Laboratory of CNRS-Fudan-HUNAU on Plant Epigenome Research, Department of Biochemistry, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 20043, China
| | - Aiwu Dong
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, International Associated Laboratory of CNRS-Fudan-HUNAU on Plant Epigenome Research, Department of Biochemistry, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 20043, China
| | - Wen-Hui Shen
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, International Associated Laboratory of CNRS-Fudan-HUNAU on Plant Epigenome Research, Department of Biochemistry, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 20043, China
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, 12 rue du Général Zimmer, 67084, Strasbourg, France
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45
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Berry S, Dean C. Environmental perception and epigenetic memory: mechanistic insight through FLC. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 83:133-48. [PMID: 25929799 PMCID: PMC4691321 DOI: 10.1111/tpj.12869] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 04/13/2015] [Accepted: 04/20/2015] [Indexed: 05/18/2023]
Abstract
Chromatin plays a central role in orchestrating gene regulation at the transcriptional level. However, our understanding of how chromatin states are altered in response to environmental and developmental cues, and then maintained epigenetically over many cell divisions, remains poor. The floral repressor gene FLOWERING LOCUS C (FLC) in Arabidopsis thaliana is a useful system to address these questions. FLC is transcriptionally repressed during exposure to cold temperatures, allowing studies of how environmental conditions alter expression states at the chromatin level. FLC repression is also epigenetically maintained during subsequent development in warm conditions, so that exposure to cold may be remembered. This memory depends on molecular complexes that are highly conserved among eukaryotes, making FLC not only interesting as a paradigm for understanding biological decision-making in plants, but also an important system for elucidating chromatin-based gene regulation more generally. In this review, we summarize our understanding of how cold temperature induces a switch in the FLC chromatin state, and how this state is epigenetically remembered. We also discuss how the epigenetic state of FLC is reprogrammed in the seed to ensure a requirement for cold exposure in the next generation.
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Affiliation(s)
- Scott Berry
- John Innes Centre, Norwich Research ParkNorwich, NR4 7UH, UK
| | - Caroline Dean
- John Innes Centre, Norwich Research ParkNorwich, NR4 7UH, UK
- * For correspondence (e-mail )
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46
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Annunziato AT. The Fork in the Road: Histone Partitioning During DNA Replication. Genes (Basel) 2015; 6:353-71. [PMID: 26110314 PMCID: PMC4488668 DOI: 10.3390/genes6020353] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 06/15/2015] [Accepted: 06/16/2015] [Indexed: 12/22/2022] Open
Abstract
In the following discussion the distribution of histones at the replication fork is examined, with specific attention paid to the question of H3/H4 tetramer "splitting." After a presentation of early experiments surrounding this topic, more recent contributions are detailed. The implications of these findings with respect to the transmission of histone modifications and epigenetic models are also addressed.
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Affiliation(s)
- Anthony T Annunziato
- Biology Department, Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA.
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47
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Svensson JP, Shukla M, Menendez-Benito V, Norman-Axelsson U, Audergon P, Sinha I, Tanny JC, Allshire RC, Ekwall K. A nucleosome turnover map reveals that the stability of histone H4 Lys20 methylation depends on histone recycling in transcribed chromatin. Genome Res 2015; 25:872-83. [PMID: 25778913 PMCID: PMC4448683 DOI: 10.1101/gr.188870.114] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 03/12/2015] [Indexed: 12/16/2022]
Abstract
Nucleosome composition actively contributes to chromatin structure and accessibility. Cells have developed mechanisms to remove or recycle histones, generating a landscape of differentially aged nucleosomes. This study aimed to create a high-resolution, genome-wide map of nucleosome turnover in Schizosaccharomyces pombe. The recombination-induced tag exchange (RITE) method was used to study replication-independent nucleosome turnover through the appearance of new histone H3 and the disappearance or preservation of old histone H3. The genome-wide location of histones was determined by chromatin immunoprecipitation-exonuclease methodology (ChIP-exo). The findings were compared with diverse chromatin marks, including histone variant H2A.Z, post-translational histone modifications, and Pol II binding. Finally, genome-wide mapping of the methylation states of H4K20 was performed to determine the relationship between methylation (mono, di, and tri) of this residue and nucleosome turnover. Our analysis showed that histone recycling resulted in low nucleosome turnover in the coding regions of active genes, stably expressed at intermediate levels. High levels of transcription resulted in the incorporation of new histones primarily at the end of transcribed units. H4K20 was methylated in low-turnover nucleosomes in euchromatic regions, notably in the coding regions of long genes that were expressed at low levels. This transcription-dependent accumulation of histone methylation was dependent on the histone chaperone complex FACT. Our data showed that nucleosome turnover is highly dynamic in the genome and that several mechanisms are at play to either maintain or suppress stability. In particular, we found that FACT-associated transcription conserves histones by recycling them and is required for progressive H4K20 methylation.
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Affiliation(s)
- J Peter Svensson
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 141 57 Huddinge, Sweden
| | - Manu Shukla
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3JR, Scotland, United Kingdom
| | | | - Ulrika Norman-Axelsson
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 141 57 Huddinge, Sweden
| | - Pauline Audergon
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Indranil Sinha
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 141 57 Huddinge, Sweden
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Robin C Allshire
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Karl Ekwall
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 141 57 Huddinge, Sweden
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48
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Histone Sprocket Arginine Residues Are Important for Gene Expression, DNA Repair, and Cell Viability in Saccharomyces cerevisiae. Genetics 2015; 200:795-806. [PMID: 25971662 DOI: 10.1534/genetics.115.175885] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 05/04/2015] [Indexed: 12/26/2022] Open
Abstract
A critical feature of the intermolecular contacts that bind DNA to the histone octamer is the series of histone arginine residues that insert into the DNA minor groove at each superhelical location where the minor groove faces the histone octamer. One of these "sprocket" arginine residues, histone H4 R45, significantly affects chromatin structure in vivo and is lethal when mutated to alanine or cysteine in Saccharomyces cerevisiae (budding yeast). However, the roles of the remaining sprocket arginine residues (H3 R63, H3 R83, H2A R43, H2B R36, H2A R78, H3 R49) in chromatin structure and other cellular processes have not been well characterized. We have genetically characterized mutations in each of these histone residues when introduced either singly or in combination to yeast cells. We find that pairs of arginine residues that bind DNA adjacent to the DNA exit/entry sites in the nucleosome are lethal in yeast when mutated in combination and cause a defect in histone occupancy. Furthermore, mutations in individual residues compromise repair of UV-induced DNA lesions and affect gene expression and cryptic transcription. This study reveals simple rules for how the location and structural mode of DNA binding influence the biological function of each histone sprocket arginine residue.
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49
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Ferrari P, Strubin M. Uncoupling histone turnover from transcription-associated histone H3 modifications. Nucleic Acids Res 2015; 43:3972-85. [PMID: 25845593 PMCID: PMC4417181 DOI: 10.1093/nar/gkv282] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 03/21/2015] [Indexed: 11/14/2022] Open
Abstract
Transcription in eukaryotes is associated with two major changes in chromatin organization. Firstly, nucleosomal histones are continuously replaced by new histones, an event that in yeast occurs predominantly at transcriptionally active promoters. Secondly, histones become modified post-translationally at specific lysine residues. Some modifications, including histone H3 trimethylation at lysine 4 (H3K4me3) and acetylation at lysines 9 (H3K9ac) and 14 (H3K14ac), are specifically enriched at active promoters where histones exchange, suggesting a possible causal relationship. Other modifications accumulate within transcribed regions and one of them, H3K36me3, is thought to prevent histone exchange. Here we explored the relationship between these four H3 modifications and histone turnover at a few selected genes. Using lysine-to-arginine mutants and a histone exchange assay, we found that none of these modifications plays a major role in either promoting or preventing histone turnover. Unexpectedly, mutation of H3K56, whose acetylation occurs prior to chromatin incorporation, had an effect only when introduced into the nucleosomal histone. Furthermore, we used various genetic approaches to show that histone turnover can be experimentally altered with no major consequence on the H3 modifications tested. Together, these results suggest that transcription-associated histone turnover and H3 modification are two correlating but largely independent events.
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Affiliation(s)
- Paolo Ferrari
- Department of Microbiology and Molecular Medicine, University Medical Centre (C.M.U.), Rue Michel-Servet 1, 1211 Geneva 4, Switzerland
| | - Michel Strubin
- Department of Microbiology and Molecular Medicine, University Medical Centre (C.M.U.), Rue Michel-Servet 1, 1211 Geneva 4, Switzerland
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50
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Bowman GD, Poirier MG. Post-translational modifications of histones that influence nucleosome dynamics. Chem Rev 2015; 115:2274-95. [PMID: 25424540 PMCID: PMC4375056 DOI: 10.1021/cr500350x] [Citation(s) in RCA: 314] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Indexed: 12/12/2022]
Affiliation(s)
- Gregory D. Bowman
- T.
C. Jenkins Department of Biophysics, Johns
Hopkins University, Baltimore, Maryland 21218, United States
| | - Michael G. Poirier
- Department of Physics, and Department of
Chemistry and Biochemistry, The Ohio State
University, Columbus, Ohio 43210, United
States
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