1
|
Lou J, Deng Q, Zhang X, Bell CC, Das AB, Bediaga NG, Zlatic CO, Johanson TM, Allan RS, Griffin MDW, Paradkar P, Harvey KF, Dawson MA, Hinde E. Heterochromatin protein 1 alpha (HP1α) undergoes a monomer to dimer transition that opens and compacts live cell genome architecture. Nucleic Acids Res 2024:gkae720. [PMID: 39193905 DOI: 10.1093/nar/gkae720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 07/29/2024] [Accepted: 08/07/2024] [Indexed: 08/29/2024] Open
Abstract
Our understanding of heterochromatin nanostructure and its capacity to mediate gene silencing in a living cell has been prevented by the diffraction limit of optical microscopy. Thus, here to overcome this technical hurdle, and directly measure the nucleosome arrangement that underpins this dense chromatin state, we coupled fluorescence lifetime imaging microscopy (FLIM) of Förster resonance energy transfer (FRET) between histones core to the nucleosome, with molecular editing of heterochromatin protein 1 alpha (HP1α). Intriguingly, this super-resolved readout of nanoscale chromatin structure, alongside fluorescence fluctuation spectroscopy (FFS) and FLIM-FRET analysis of HP1α protein-protein interaction, revealed nucleosome arrangement to be differentially regulated by HP1α oligomeric state. Specifically, we found HP1α monomers to impart a previously undescribed global nucleosome spacing throughout genome architecture that is mediated by trimethylation on lysine 9 of histone H3 (H3K9me3) and locally reduced upon HP1α dimerisation. Collectively, these results demonstrate HP1α to impart a dual action on chromatin that increases the dynamic range of nucleosome proximity. We anticipate that this finding will have important implications for our understanding of how live cell heterochromatin structure regulates genome function.
Collapse
Affiliation(s)
- Jieqiong Lou
- School of Physics, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Qiji Deng
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
| | - Xiaomeng Zhang
- School of Physics, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Charles C Bell
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
| | - Andrew B Das
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Naiara G Bediaga
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
| | - Courtney O Zlatic
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Timothy M Johanson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Rhys S Allan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Michael D W Griffin
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC 3010, Australia
| | - PrasadN Paradkar
- CSIRO Health & Biosecurity, Australian Centre for Disease Preparedness, 5 Portarlington Road, Geelong3220, Australia
| | - Kieran F Harvey
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia
- Department of Anatomy and Developmental Biology and Biomedicine Discovery Institute, Monash University, Clayton, VIC 3168, Australia
| | - Mark A Dawson
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia
- Centre for Cancer Research, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Elizabeth Hinde
- School of Physics, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC 3010, Australia
| |
Collapse
|
2
|
Wong LH, Tremethick DJ. Multifunctional histone variants in genome function. Nat Rev Genet 2024:10.1038/s41576-024-00759-1. [PMID: 39138293 DOI: 10.1038/s41576-024-00759-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2024] [Indexed: 08/15/2024]
Abstract
Histones are integral components of eukaryotic chromatin that have a pivotal role in the organization and function of the genome. The dynamic regulation of chromatin involves the incorporation of histone variants, which can dramatically alter its structural and functional properties. Contrary to an earlier view that limited individual histone variants to specific genomic functions, new insights have revealed that histone variants exert multifaceted roles involving all aspects of genome function, from governing patterns of gene expression at precise genomic loci to participating in genome replication, repair and maintenance. This conceptual change has led to a new understanding of the intricate interplay between chromatin and DNA-dependent processes and how this connection translates into normal and abnormal cellular functions.
Collapse
Affiliation(s)
- Lee H Wong
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - David J Tremethick
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capial Territory, Australia.
| |
Collapse
|
3
|
Serra-Bardenys G, Blanco E, Escudero-Iriarte C, Serra-Camprubí Q, Querol J, Pascual-Reguant L, Morancho B, Escorihuela M, Tissera NS, Sabé A, Martín L, Segura-Bayona S, Verde G, Aiese Cigliano R, Millanes-Romero A, Jerónimo C, Cebrià-Costa JP, Nuciforo P, Simonetti S, Viaplana C, Dienstmann R, Oliveira M, Peg V, Stracker TH, Arribas J, Canals F, Villanueva J, Di Croce L, García de Herreros A, Tian TV, Peiró S. LOXL2-mediated chromatin compaction is required to maintain the oncogenic properties of triple-negative breast cancer cells. FEBS J 2024; 291:2423-2448. [PMID: 38451841 DOI: 10.1111/febs.17112] [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: 06/01/2023] [Revised: 01/02/2024] [Accepted: 02/23/2024] [Indexed: 03/09/2024]
Abstract
Oxidation of histone H3 at lysine 4 (H3K4ox) is catalyzed by lysyl oxidase homolog 2 (LOXL2). This histone modification is enriched in heterochromatin in triple-negative breast cancer (TNBC) cells and has been linked to the maintenance of compacted chromatin. However, the molecular mechanism underlying this maintenance is still unknown. Here, we show that LOXL2 interacts with RuvB-Like 1 (RUVBL1), RuvB-Like 2 (RUVBL2), Actin-like protein 6A (ACTL6A), and DNA methyltransferase 1associated protein 1 (DMAP1), a complex involved in the incorporation of the histone variant H2A.Z. Our experiments indicate that this interaction and the active form of RUVBL2 are required to maintain LOXL2-dependent chromatin compaction. Genome-wide experiments showed that H2A.Z, RUVBL2, and H3K4ox colocalize in heterochromatin regions. In the absence of LOXL2 or RUVBL2, global levels of the heterochromatin histone mark H3K9me3 were strongly reduced, and the ATAC-seq signal in the H3K9me3 regions was increased. Finally, we observed that the interplay between these series of events is required to maintain H3K4ox-enriched heterochromatin regions, which in turn is key for maintaining the oncogenic properties of the TNBC cell line tested (MDA-MB-231).
Collapse
Affiliation(s)
- Gemma Serra-Bardenys
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
- Institut Bonanova FP Sanitaria, Consorci Mar Parc de Salut de Barcelona, Spain
| | - Enrique Blanco
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Spain
| | | | | | - Jessica Querol
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Laura Pascual-Reguant
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Spain
| | | | | | | | - Anna Sabé
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Luna Martín
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | | | - Gaetano Verde
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | | | - Alba Millanes-Romero
- Institute for Research in Biomedicine (IRB Barcelona) and Barcelona Institute of Science and Technology, Spain
| | - Celia Jerónimo
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Spain
- Institut de Recherches Cliniques de Montréal, Canada
| | | | - Paolo Nuciforo
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Sara Simonetti
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | | | | | - Mafalda Oliveira
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
- Medical Oncology Department, Vall d'Hebron University Hospital, Barcelona, Spain
| | - Vicente Peg
- Medical Oncology Department, Vall d'Hebron University Hospital, Barcelona, Spain
- Centro de Investigación Biomédica en Red en Oncología (CIBERONC), Barcelona, Spain
- Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Travis H Stracker
- Radiation Oncology Branch, National Cancer Institute, Bethesda, MD, USA
| | - Joaquín Arribas
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
- Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
- Programa de Recerca en Càncer, Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain
| | - Francesc Canals
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | | | - Luciano Di Croce
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Antonio García de Herreros
- Programa de Recerca en Càncer, Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain
- Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Tian V Tian
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Sandra Peiró
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| |
Collapse
|
4
|
Singh S, Anderson N, Chu D, Roy SW. Nematode histone H2A variant evolution reveals diverse histories of retention and loss and evidence for conserved core-like variant histone genes. PLoS One 2024; 19:e0300190. [PMID: 38814971 PMCID: PMC11139335 DOI: 10.1371/journal.pone.0300190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 02/22/2024] [Indexed: 06/01/2024] Open
Abstract
Histone variants are paralogs that replace canonical histones in nucleosomes, often imparting novel functions. However, how histone variants arise and evolve is poorly understood. Reconstruction of histone protein evolution is challenging due to large differences in evolutionary rates across gene lineages and sites. Here we used intron position data from 108 nematode genomes in combination with amino acid sequence data to find disparate evolutionary histories of the three H2A variants found in Caenorhabditis elegans: the ancient H2A.ZHTZ-1, the sperm-specific HTAS-1, and HIS-35, which differs from the canonical S-phase H2A by a single glycine-to-alanine C-terminal change. Although the H2A.ZHTZ-1 protein sequence is highly conserved, its gene exhibits recurrent intron gain and loss. This pattern suggests that specific intron sequences or positions may not be important to H2A.Z functionality. For HTAS-1 and HIS-35, we find variant-specific intron positions that are conserved across species. Patterns of intron position conservation indicate that the sperm-specific variant HTAS-1 arose more recently in the ancestor of a subset of Caenorhabditis species, while HIS-35 arose in the ancestor of Caenorhabditis and its sister group, including the genus Diploscapter. HIS-35 exhibits gene retention in some descendent lineages but gene loss in others, suggesting that histone variant use or functionality can be highly flexible. Surprisingly, we find the single amino acid differentiating HIS-35 from core H2A is ancestral and common across canonical Caenorhabditis H2A sequences. Thus, we speculate that the role of HIS-35 lies not in encoding a functionally distinct protein, but instead in enabling H2A expression across the cell cycle or in distinct tissues. This work illustrates how genes encoding such partially-redundant functions may be advantageous yet relatively replaceable over evolutionary timescales, consistent with the patchwork pattern of retention and loss of both genes. Our study shows the utility of intron positions for reconstructing evolutionary histories of gene families, particularly those undergoing idiosyncratic sequence evolution.
Collapse
Affiliation(s)
- Swadha Singh
- Quantitative & Systems Biology, University of California, Merced, Merced, California, United States of America
| | - Noelle Anderson
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Diana Chu
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Scott W. Roy
- Quantitative & Systems Biology, University of California, Merced, Merced, California, United States of America
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| |
Collapse
|
5
|
Belotti E, Lacoste N, Iftikhar A, Simonet T, Papin C, Osseni A, Streichenberger N, Mari PO, Girard E, Graies M, Giglia-Mari G, Dimitrov S, Hamiche A, Schaeffer L. H2A.Z is involved in premature aging and DSB repair initiation in muscle fibers. Nucleic Acids Res 2024; 52:3031-3049. [PMID: 38281187 PMCID: PMC11014257 DOI: 10.1093/nar/gkae020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 12/13/2023] [Accepted: 01/19/2024] [Indexed: 01/30/2024] Open
Abstract
Histone variants are key epigenetic players, but their functional and physiological roles remain poorly understood. Here, we show that depletion of the histone variant H2A.Z in mouse skeletal muscle causes oxidative stress, oxidation of proteins, accumulation of DNA damages, and both neuromuscular junction and mitochondria lesions that consequently lead to premature muscle aging and reduced life span. Investigation of the molecular mechanisms involved shows that H2A.Z is required to initiate DNA double strand break repair by recruiting Ku80 at DNA lesions. This is achieved via specific interactions of Ku80 vWA domain with H2A.Z. Taken as a whole, our data reveal that H2A.Z containing nucleosomes act as a molecular platform to bring together the proteins required to initiate and process DNA double strand break repair.
Collapse
Affiliation(s)
- Edwige Belotti
- Laboratoire Physiopathologie et Génétique du Neurone et du Muscle (PGNM), Institut NeuroMyoGène, Université Claude Bernard Lyon 1, INSERM U1315, CNRS UMR 5261, 8 avenue Rockefeller, 69008 Lyon, France
| | - Nicolas Lacoste
- Laboratoire Physiopathologie et Génétique du Neurone et du Muscle (PGNM), Institut NeuroMyoGène, Université Claude Bernard Lyon 1, INSERM U1315, CNRS UMR 5261, 8 avenue Rockefeller, 69008 Lyon, France
| | - Arslan Iftikhar
- For Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS/INSERM/ULP, Parc d’innovation, 1 rue Laurent Fries, 67404 Ilkirch Cedex, France
| | - Thomas Simonet
- Laboratoire Physiopathologie et Génétique du Neurone et du Muscle (PGNM), Institut NeuroMyoGène, Université Claude Bernard Lyon 1, INSERM U1315, CNRS UMR 5261, 8 avenue Rockefeller, 69008 Lyon, France
| | - Christophe Papin
- For Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS/INSERM/ULP, Parc d’innovation, 1 rue Laurent Fries, 67404 Ilkirch Cedex, France
| | - Alexis Osseni
- Laboratoire Physiopathologie et Génétique du Neurone et du Muscle (PGNM), Institut NeuroMyoGène, Université Claude Bernard Lyon 1, INSERM U1315, CNRS UMR 5261, 8 avenue Rockefeller, 69008 Lyon, France
| | - Nathalie Streichenberger
- Laboratoire Physiopathologie et Génétique du Neurone et du Muscle (PGNM), Institut NeuroMyoGène, Université Claude Bernard Lyon 1, INSERM U1315, CNRS UMR 5261, 8 avenue Rockefeller, 69008 Lyon, France
| | - Pierre-Olivier Mari
- Laboratoire Physiopathologie et Génétique du Neurone et du Muscle (PGNM), Institut NeuroMyoGène, Université Claude Bernard Lyon 1, INSERM U1315, CNRS UMR 5261, 8 avenue Rockefeller, 69008 Lyon, France
| | - Emmanuelle Girard
- Laboratoire Physiopathologie et Génétique du Neurone et du Muscle (PGNM), Institut NeuroMyoGène, Université Claude Bernard Lyon 1, INSERM U1315, CNRS UMR 5261, 8 avenue Rockefeller, 69008 Lyon, France
| | - Mohamed Graies
- Institute for Advanced Biosciences (IAB), Université Grenoble Alpes, CNRS UMR 5309, INSERM U1209, Site Santé - Allée des Alpes, 38700 La Tronche, France
| | - Giuseppina Giglia-Mari
- Laboratoire Physiopathologie et Génétique du Neurone et du Muscle (PGNM), Institut NeuroMyoGène, Université Claude Bernard Lyon 1, INSERM U1315, CNRS UMR 5261, 8 avenue Rockefeller, 69008 Lyon, France
| | - Stefan Dimitrov
- Institute for Advanced Biosciences (IAB), Université Grenoble Alpes, CNRS UMR 5309, INSERM U1209, Site Santé - Allée des Alpes, 38700 La Tronche, France
| | - Ali Hamiche
- For Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS/INSERM/ULP, Parc d’innovation, 1 rue Laurent Fries, 67404 Ilkirch Cedex, France
| | - Laurent Schaeffer
- Laboratoire Physiopathologie et Génétique du Neurone et du Muscle (PGNM), Institut NeuroMyoGène, Université Claude Bernard Lyon 1, INSERM U1315, CNRS UMR 5261, 8 avenue Rockefeller, 69008 Lyon, France
- Centre de Biotechnologie Cellulaire, Hospices Civils de Lyon, Lyon, France
| |
Collapse
|
6
|
Gopinathan G, Xu Q, Luan X, Diekwisch TGH. CFDP1 regulates the stability of pericentric heterochromatin thereby affecting RAN GTPase activity and mitotic spindle formation. PLoS Biol 2024; 22:e3002574. [PMID: 38630655 PMCID: PMC11023358 DOI: 10.1371/journal.pbio.3002574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 03/02/2024] [Indexed: 04/19/2024] Open
Abstract
The densely packed centromeric heterochromatin at minor and major satellites is comprised of H3K9me2/3 histones, the heterochromatin protein HP1α, and histone variants. In the present study, we sought to determine the mechanisms by which condensed heterochromatin at major and minor satellites stabilized by the chromatin factor CFDP1 affects the activity of the small GTPase Ran as a requirement for spindle formation. CFDP1 colocalized with heterochromatin at major and minor satellites and was essential for the structural stability of centromeric heterochromatin. Loss of CENPA, HP1α, and H2A.Z heterochromatin components resulted in decreased binding of the spindle nucleation facilitator RCC1 to minor and major satellite repeats. Decreased RanGTP levels as a result of diminished RCC1 binding interfered with chromatin-mediated microtubule nucleation at the onset of mitotic spindle formation. Rescuing chromatin H2A.Z levels in cells and mice lacking CFDP1 through knock-down of the histone chaperone ANP32E not only partially restored RCC1-dependent RanGTP levels but also alleviated CFDP1-knockout-related craniofacial defects and increased microtubule nucleation in CFDP1/ANP32E co-silenced cells. Together, these studies provide evidence for a direct link between condensed heterochromatin at major and minor satellites and microtubule nucleation through the chromatin protein CFDP1.
Collapse
Affiliation(s)
- Gokul Gopinathan
- School of Medicine and Dentistry, University of Rochester, Rochester, New York, United States of America
| | - Qian Xu
- School of Medicine and Dentistry, University of Rochester, Rochester, New York, United States of America
| | - Xianghong Luan
- School of Medicine and Dentistry, University of Rochester, Rochester, New York, United States of America
| | - Thomas G. H. Diekwisch
- School of Medicine and Dentistry, University of Rochester, Rochester, New York, United States of America
| |
Collapse
|
7
|
Atanasoff-Kardjalieff AK, Berger H, Steinert K, Janevska S, Ponts N, Humpf HU, Kalinina S, Studt-Reinhold L. Incorporation of the histone variant H2A.Z counteracts gene silencing mediated by H3K27 trimethylation in Fusarium fujikuroi. Epigenetics Chromatin 2024; 17:7. [PMID: 38509556 PMCID: PMC10953111 DOI: 10.1186/s13072-024-00532-y] [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: 09/23/2023] [Accepted: 02/15/2024] [Indexed: 03/22/2024] Open
Abstract
BACKGROUND Fusarium fujikuroi is a pathogen of rice causing diverse disease symptoms such as 'bakanae' or stunting, most likely due to the production of various natural products (NPs) during infection. Fusaria have the genetic potential to synthesize a plethora of these compounds with often diverse bioactivity. The capability to synthesize NPs exceeds the number of those being produced by far, implying a gene regulatory network decisive to induce production. One such regulatory layer is the chromatin structure and chromatin-based modifications associated with it. One prominent example is the exchange of histones against histone variants such as the H2A variant H2A.Z. Though H2A.Z already is well studied in several model organisms, its regulatory functions are not well understood. Here, we used F. fujikuroi as a model to explore the role of the prominent histone variant FfH2A.Z in gene expression within euchromatin and facultative heterochromatin. RESULTS Through the combination of diverse '-omics' methods, we show the global distribution of FfH2A.Z and analyze putative crosstalks between the histone variant and two prominent histone marks, i.e., H3K4me3 and H3K27me3, important for active gene transcription and silencing, respectively. We demonstrate that, if FfH2A.Z is positioned at the + 1-nucleosome, it poises chromatin for gene transcription, also within facultative heterochromatin. Lastly, functional characterization of FfH2A.Z overexpression and depletion mutants revealed that FfH2A.Z is important for wild type-like fungal development and secondary metabolism. CONCLUSION In this study, we show that the histone variant FfH2A.Z is a mark of positive gene transcription and acts independently of the chromatin state most likely through the stabilization of the + 1-nucleosome. Furthermore, we demonstrate that FfH2A.Z depletion does not influence the establishment of both H3K27me3 and H3K4me3, thus indicating no crosstalk between FfH2A.Z and both histone marks. These results highlight the manifold functions of the histone variant FfH2A.Z in the phytopathogen F. fujikuroi, which are distinct regarding gene transcription and crosstalk with the two prominent histone marks H3K27me3 and H3K4me3, as proposed for other model organisms.
Collapse
Affiliation(s)
- Anna K Atanasoff-Kardjalieff
- Department of Applied Genetics and Cell Biology, Institute of Microbial Genetics, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz Strasse 24, Tulln an der Donau, 3430, Austria
| | - Harald Berger
- Department of Applied Genetics and Cell Biology, Institute of Microbial Genetics, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz Strasse 24, Tulln an der Donau, 3430, Austria
| | - Katharina Steinert
- Institute of Food Chemistry, University of Münster, Corrensstraße 45, 48149, Münster, Germany
| | - Slavica Janevska
- (Epi-)Genetic Regulation of Fungal Virulence, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, 07745, Jena, Germany
| | - Nadia Ponts
- INRAE, UR1264 Mycology and Food Safety (MycSA), Villenave d'Ornon, 33882, France
| | - Hans-Ulrich Humpf
- Institute of Food Chemistry, University of Münster, Corrensstraße 45, 48149, Münster, Germany
| | - Svetlana Kalinina
- Institute of Food Chemistry, University of Münster, Corrensstraße 45, 48149, Münster, Germany
| | - Lena Studt-Reinhold
- Department of Applied Genetics and Cell Biology, Institute of Microbial Genetics, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz Strasse 24, Tulln an der Donau, 3430, Austria.
| |
Collapse
|
8
|
Paniri A, Hosseini MM, Akhavan-Niaki H. Alzheimer's Disease-Related Epigenetic Changes: Novel Therapeutic Targets. Mol Neurobiol 2024; 61:1282-1317. [PMID: 37700216 DOI: 10.1007/s12035-023-03626-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 08/30/2023] [Indexed: 09/14/2023]
Abstract
Aging is a significant risk factor for Alzheimer's disease (AD), although the precise mechanism and molecular basis of AD are not yet fully understood. Epigenetic mechanisms, such as DNA methylation and hydroxymethylation, mitochondrial DNA methylation, histone modifications, and non-coding RNAs (ncRNAs), play a role in regulating gene expression related to neuron plasticity and integrity, which are closely associated with learning and memory development. This review describes the impact of dynamic and reversible epigenetic modifications and factors on memory and plasticity throughout life, emphasizing their potential as target for therapeutic intervention in AD. Additionally, we present insight from postmortem and animal studies on abnormal epigenetics regulation in AD, as well as current strategies aiming at targeting these factors in the context of AD therapy.
Collapse
Affiliation(s)
- Alireza Paniri
- Genetics Department, Faculty of Medicine, Babol University of Medical Sciences, Babol, Iran
- Zoonoses Research Center, Pasteur Institute of Iran, Amol, Iran
| | | | - Haleh Akhavan-Niaki
- Genetics Department, Faculty of Medicine, Babol University of Medical Sciences, Babol, Iran.
- Zoonoses Research Center, Pasteur Institute of Iran, Amol, Iran.
| |
Collapse
|
9
|
Choi J, Kim T, Cho EJ. HIRA vs. DAXX: the two axes shaping the histone H3.3 landscape. Exp Mol Med 2024; 56:251-263. [PMID: 38297159 PMCID: PMC10907377 DOI: 10.1038/s12276-023-01145-3] [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: 09/27/2023] [Revised: 11/20/2023] [Accepted: 11/23/2023] [Indexed: 02/02/2024] Open
Abstract
H3.3, the most common replacement variant for histone H3, has emerged as an important player in chromatin dynamics for controlling gene expression and genome integrity. While replicative variants H3.1 and H3.2 are primarily incorporated into nucleosomes during DNA synthesis, H3.3 is under the control of H3.3-specific histone chaperones for spatiotemporal incorporation throughout the cell cycle. Over the years, there has been progress in understanding the mechanisms by which H3.3 affects domain structure and function. Furthermore, H3.3 distribution and relative abundance profoundly impact cellular identity and plasticity during normal development and pathogenesis. Recurrent mutations in H3.3 and its chaperones have been identified in neoplastic transformation and developmental disorders, providing new insights into chromatin biology and disease. Here, we review recent findings emphasizing how two distinct histone chaperones, HIRA and DAXX, take part in the spatial and temporal distribution of H3.3 in different chromatin domains and ultimately achieve dynamic control of chromatin organization and function. Elucidating the H3.3 deposition pathways from the available histone pool will open new avenues for understanding the mechanisms by which H3.3 epigenetically regulates gene expression and its impact on cellular integrity and pathogenesis.
Collapse
Affiliation(s)
- Jinmi Choi
- Sungkyunkwan University School of Pharmacy, Seoburo 2066, Jangan-gu Suwon, Gyeonggi-do, 16419, Republic of Korea
| | - Taewan Kim
- Sungkyunkwan University School of Pharmacy, Seoburo 2066, Jangan-gu Suwon, Gyeonggi-do, 16419, Republic of Korea
| | - Eun-Jung Cho
- Sungkyunkwan University School of Pharmacy, Seoburo 2066, Jangan-gu Suwon, Gyeonggi-do, 16419, Republic of Korea.
| |
Collapse
|
10
|
Park S, Athreya A, Carrizo GE, Benning NA, Mitchener MM, Bhanu NV, Garcia BA, Zhang B, Muir TW, Pearce EL, Ha T. Electrostatic encoding of genome organization principles within single native nucleosomes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.08.570828. [PMID: 38106048 PMCID: PMC10723453 DOI: 10.1101/2023.12.08.570828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
The eukaryotic genome, first packed into nucleosomes of about 150 bp around the histone core, is organized into euchromatin and heterochromatin, corresponding to the A and B compartments, respectively. Here, we asked if individual nucleosomes in vivo know where to go. That is, do mono-nucleosomes by themselves contain A/B compartment information, associated with transcription activity, in their biophysical properties? We purified native mono-nucleosomes to high monodispersity and used physiological concentrations of biological polyamines to determine their condensability. The chromosomal regions known to partition into A compartments have low condensability and vice versa. In silico chromatin polymer simulations using condensability as the only input showed that biophysical information needed to form compartments is all contained in single native nucleosomes and no other factors are needed. Condensability is also strongly anticorrelated with gene expression, and especially so near the promoter region and in a cell type dependent manner. Therefore, individual nucleosomes in the promoter know whether the gene is on or off, and that information is contained in their biophysical properties. Comparison with genetic and epigenetic features suggest that nucleosome condensability is a very meaningful axis onto which to project the high dimensional cellular chromatin state. Analysis of condensability using various condensing agents including those that are protein-based suggests that genome organization principle encoded into individual nucleosomes is electrostatic in nature. Polyamine depletion in mouse T cells, by either knocking out ornithine decarboxylase (ODC) or inhibiting ODC, results in hyperpolarized condensability, suggesting that when cells cannot rely on polyamines to translate biophysical properties of nucleosomes to control gene expression and 3D genome organization, they accentuate condensability contrast, which may explain dysfunction known to occur with polyamine deficiency.
Collapse
Affiliation(s)
- Sangwoo Park
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Advait Athreya
- Computational and Systems Biology Program, MIT, Cambridge, MA, 02139, USA
| | - Gustavo Ezequiel Carrizo
- Department of Oncology, The Bloomberg–Kimmel Institute for Cancer Immunotherapy, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Nils A. Benning
- Department of Biology, Johns Hopkins University. Baltimore, MD 21218, USA
| | | | - Natarajan V. Bhanu
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine St. Louis, St. Louis, MO 63110, USA
| | - Benjamin A. Garcia
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine St. Louis, St. Louis, MO 63110, USA
| | - Bin Zhang
- Department of Chemistry, MIT, Cambridge, MA 02139, USA
| | - Tom W. Muir
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Erika L. Pearce
- Department of Oncology, The Bloomberg–Kimmel Institute for Cancer Immunotherapy, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Biochemistry and Molecular Biology Department, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Boston, MA 02115, USA
| |
Collapse
|
11
|
Lin F, Zhang R, Shao W, Lei C, Ma M, Zhang Y, Wen Z, Li W. Structural basis of nucleosomal H4K20 recognition and methylation by SUV420H1 methyltransferase. Cell Discov 2023; 9:120. [PMID: 38052811 DOI: 10.1038/s41421-023-00620-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 10/29/2023] [Indexed: 12/07/2023] Open
Abstract
Histone lysine methyltransferase SUV420H1, which is responsible for site-specific di-/tri-methylation of histone H4 lysine 20 (H4K20), has crucial roles in DNA-templated processes, including DNA replication, DNA damage repair, and chromatin compaction. Its mutations frequently occur in human cancers. Nucleosomes containing the histone variant H2A.Z enhance the catalytic activities of SUV420H1 on H4K20 di-methylation deposition, regulating early replication origins. However, the molecular mechanism by which SUV420H1 specifically recognizes and deposits H4K20 methyl marks on nucleosomes remains poorly understood. Here we report the cryo-electron microscopy structures of SUV420H1 associated with H2A-containing nucleosome core particles (NCPs), and H2A.Z-containing NCPs. We find that SUV420H1 makes extensive site-specific contacts with histone and DNA regions. SUV420H1 C-terminal domain recognizes the H2A-H2B acidic patch of NCPs through its two arginine anchors, thus enabling H4K20 insertion for catalysis specifically. We also identify important residues increasing the catalytic activities of SUV420H1 bound to H2A.Z NCPs. In vitro and in vivo functional analyses reveal that multiple disease-associated mutations at the interfaces are essential for its catalytic activity and chromatin state regulation. Together, our study provides molecular insights into the nucleosome-based recognition and methylation mechanisms of SUV420H1, and a structural basis for understanding SUV420H1-related human disease.
Collapse
Affiliation(s)
- Folan Lin
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Ruxin Zhang
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, Guangdong, China
| | - Weihan Shao
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Cong Lei
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Mingxi Ma
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Ying Zhang
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Zengqi Wen
- School of Medicine, Shenzhen Campus of Sun Yat-Sen University, Sun Yat-Sen University, Shenzhen, Guangdong, China.
| | - Wanqiu Li
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, China.
- Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, Guangdong, China.
| |
Collapse
|
12
|
Sokolova V, Miratsky J, Svetlov V, Brenowitz M, Vant J, Lewis T, Dryden K, Lee G, Sarkar S, Nudler E, Singharoy A, Tan D. Structural mechanism of HP1α-dependent transcriptional repression and chromatin compaction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.30.569387. [PMID: 38076844 PMCID: PMC10705452 DOI: 10.1101/2023.11.30.569387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Heterochromatin protein 1 (HP1) plays a central role in establishing and maintaining constitutive heterochromatin. However, the mechanisms underlying HP1-nucleosome interactions and their contributions to heterochromatin functions remain elusive. In this study, we employed a multidisciplinary approach to unravel the interactions between human HP1α and nucleosomes. We have elucidated the cryo-EM structure of an HP1α dimer bound to an H2A.Z nucleosome, revealing that the HP1α dimer interfaces with nucleosomes at two distinct sites. The primary binding site is located at the N-terminus of histone H3, specifically at the trimethylated K9 (K9me3) region, while a novel secondary binding site is situated near histone H2B, close to nucleosome superhelical location 4 (SHL4). Our biochemical data further demonstrates that HP1α binding influences the dynamics of DNA on the nucleosome. It promotes DNA unwrapping near the nucleosome entry and exit sites while concurrently restricting DNA accessibility in the vicinity of SHL4. This study offers a model that explains how HP1α functions in heterochromatin maintenance and gene silencing, particularly in the context of H3K9me-dependent mechanisms. Additionally, it sheds light on the H3K9me-independent role of HP1 in responding to DNA damage.
Collapse
Affiliation(s)
- Vladyslava Sokolova
- Department of Pharmacological Sciences, Stony Brook University; Stony Brook, NY, USA
| | - Jacob Miratsky
- School of Molecular Sciences, Arizona State University; Tempe, AZ, USA
| | - Vladimir Svetlov
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Michael Brenowitz
- Departments of Biochemistry and Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - John Vant
- School of Molecular Sciences, Arizona State University; Tempe, AZ, USA
| | - Tyler Lewis
- Department of Pharmacological Sciences, Stony Brook University; Stony Brook, NY, USA
| | - Kelly Dryden
- Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22903 USA
| | - Gahyun Lee
- Department of Pharmacological Sciences, Stony Brook University; Stony Brook, NY, USA
| | - Shayan Sarkar
- Department of Pathology, Stony Brook University; Stony Brook, New York, 11794 USA
| | - Evgeny Nudler
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | | | - Dongyan Tan
- Department of Pharmacological Sciences, Stony Brook University; Stony Brook, NY, USA
| |
Collapse
|
13
|
González J, Bosch-Presegué L, Marazuela-Duque A, Guitart-Solanes A, Espinosa-Alcantud M, Fernandez AF, Brown JP, Ausió J, Vazquez BN, Singh PB, Fraga MF, Vaquero A. A complex interplay between H2A.Z and HP1 isoforms regulates pericentric heterochromatin. Front Cell Dev Biol 2023; 11:1293122. [PMID: 38020886 PMCID: PMC10665487 DOI: 10.3389/fcell.2023.1293122] [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: 09/12/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023] Open
Abstract
Pericentric heterochromatin (PCH) plays an essential role in the maintenance of genome integrity and alterations in PCH have been linked to cancer and aging. HP1 α, β, and γ, are hallmarks of constitutive heterochromatin that are thought to promote PCH structure through binding to heterochromatin-specific histone modifications and interaction with a wide range of factors. Among the less understood components of PCH is the histone H2A variant H2A.Z, whose role in the organization and maintenance of PCH is poorly defined. Here we show that there is a complex interplay between H2A.Z and HP1 isoforms in PCH. While the loss of HP1α results in the accumulation of H2A.Z.1 in PCH, which is associated with a significant decrease in its mobile fraction, H2A.Z.1 binds preferentially to HP1β in these regions. Of note, H2A.Z.1 downregulation results in increased heterochromatinization and instability of PCH, reflected by accumulation of the major epigenetic hallmarks of heterochromatin in these regions and increased frequency of chromosome aberrations related to centromeric/pericentromeric defects. Our studies support a role for H2A.Z in genome stability and unveil a key role of H2A.Z in the regulation of heterochromatin-specific epigenetic modifications through a complex interplay with the HP1 isoforms.
Collapse
Affiliation(s)
- Jessica González
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
| | - Laia Bosch-Presegué
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
- Tissue Repair and Regeneration Laboratory (TR2Lab), Institut de Recerca I Innovació en Ciències de La Vida i de La Salut a La Catalunya Central (IrisCC), Barcelona, Spain
| | - Anna Marazuela-Duque
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
| | - Anna Guitart-Solanes
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
| | - María Espinosa-Alcantud
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
| | - Agustín F. Fernandez
- Nanomaterials and Nanotechnology Research Center (CINN), Spanish National Research Council (CSIC), El Entrego, Spain
- Institute of Oncology of Asturias (IUOPA), University of Oviedo, Oviedo, Spain
- Health Research Institute of the Principality of Asturias (ISPA), Oviedo, Spain
- Spanish Biomedical Research Network in Rare Diseases (CIBERER), Madrid, Spain
| | - Jeremy P. Brown
- Department of Immunology and Inflammation, Imperial College London, Commonwealth Building, The Hammersmith Hospital, London, United Kingdom
| | - Juan Ausió
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Berta N. Vazquez
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
- Cytology and Histology Unit. Department of Cell Biology, Physiology, and Immunology, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - Prim B. Singh
- Nazarbayev University School of Medicine, Astana, Kazakhstan
| | - Mario F. Fraga
- Nanomaterials and Nanotechnology Research Center (CINN), Spanish National Research Council (CSIC), El Entrego, Spain
- Institute of Oncology of Asturias (IUOPA), University of Oviedo, Oviedo, Spain
- Health Research Institute of the Principality of Asturias (ISPA), Oviedo, Spain
- Spanish Biomedical Research Network in Rare Diseases (CIBERER), Madrid, Spain
| | - Alejandro Vaquero
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
| |
Collapse
|
14
|
Meng FW, Murphy KE, Makowski CE, Delatte B, Murphy PJ. Competition for H2A.Z underlies the developmental impacts of repetitive element de-repression. Development 2023; 150:dev202338. [PMID: 37938830 PMCID: PMC10651094 DOI: 10.1242/dev.202338] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 10/10/2023] [Indexed: 11/10/2023]
Abstract
The histone variant H2A.Z is central to early embryonic development, determining transcriptional competency through chromatin regulation of gene promoters and enhancers. In addition to genic loci, we find that H2A.Z resides at a subset of evolutionarily young repetitive elements, including DNA transposons, long interspersed nuclear elements and long terminal repeats, during early zebrafish development. Moreover, increases in H2A.Z occur when repetitive elements become transcriptionally active. Acquisition of H2A.Z corresponds with a reduction in the levels of the repressive histone modification H3K9me3 and a moderate increase in chromatin accessibility. Notably, however, de-repression of repetitive elements also leads to a significant reduction in H2A.Z over non-repetitive genic loci. Genic loss of H2A.Z is accompanied by transcriptional silencing at adjacent coding sequences, but remarkably, these impacts are mitigated by augmentation of total H2A.Z protein via transgenic overexpression. Our study reveals that levels of H2A.Z protein determine embryonic sensitivity to de-repression of repetitive elements, that repetitive elements can function as a nuclear sink for epigenetic factors and that competition for H2A.Z greatly influences overall transcriptional output during development. These findings uncover general mechanisms in which counteractive biological processes underlie phenotypic outcomes.
Collapse
Affiliation(s)
- Fanju W. Meng
- University of Rochester Medical Center, Rochester, NY 14642, USA
| | | | | | - Benjamin Delatte
- Advanced Research Laboratory, Active Motif, 1914 Palomar Oaks Way STE 150, Carlsbad, CA 92008, USA
| | | |
Collapse
|
15
|
Kang Z, Fu P, Ma H, Li T, Lu K, Liu J, Ginjala V, Romanienko P, Feng Z, Guan M, Ganesan S, Xia B. Distinct functions of EHMT1 and EHMT2 in cancer chemotherapy and immunotherapy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.03.560719. [PMID: 37873068 PMCID: PMC10592889 DOI: 10.1101/2023.10.03.560719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
EHTM1 (GLP) and EHMT2 (G9a) are closely related protein lysine methyltransferases often thought to function together as a heterodimer to methylate histone H3 and non-histone substrates in diverse cellular processes including transcriptional regulation, genome methylation, and DNA repair. Here we show that EHMT1/2 inhibitors cause ATM-mediated slowdown of replication fork progression, accumulation of single-stranded replication gaps, emergence of cytosolic DNA, and increased expression of STING. EHMT1/2 inhibition strongly potentiates the efficacy of alkylating chemotherapy and anti-PD-1 immunotherapy in mouse models of tripe negative breast cancer. The effects on DNA replication and alkylating agent sensitivity are largely caused by the loss of EHMT1-mediated methylation of LIG1, whereas the elevated STING expression and remarkable response to immunotherapy appear mainly elicited by the loss of EHMT2 activity. Depletion of UHRF1, a protein known to be associated with EHMT1/2 and LIG1, also induces STING expression, and depletion of either EHMT2 or UHRF1 leads to demethylation of specific CpG sites in the STING1 promoter, suggestive of a distinct EHMT2-UHRF1 axis that regulates DNA methylation and gene transcription. These results highlight distinct functions of the two EHMT paralogs and provide enlightening paradigms and corresponding molecular basis for combination therapies involving alkylating agents and immune checkpoint inhibitors.
Collapse
Affiliation(s)
- Zhihua Kang
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
- Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Pan Fu
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
- Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
- Department of Clinical Microbiology Laboratory, Children’s Hospital of Fudan University, Shanghai, China
| | - Hui Ma
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
- Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Tao Li
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
- Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Kevin Lu
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
- Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Juan Liu
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
- Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Vasudeva Ginjala
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
- Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | | | - Zhaohui Feng
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
- Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Ming Guan
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Shridar Ganesan
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
- Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Bing Xia
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
- Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
- Lead contact
| |
Collapse
|
16
|
Smerdon MJ, Wyrick JJ, Delaney S. A half century of exploring DNA excision repair in chromatin. J Biol Chem 2023; 299:105118. [PMID: 37527775 PMCID: PMC10498010 DOI: 10.1016/j.jbc.2023.105118] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/23/2023] [Accepted: 07/25/2023] [Indexed: 08/03/2023] Open
Abstract
DNA in eukaryotic cells is packaged into the compact and dynamic structure of chromatin. This packaging is a double-edged sword for DNA repair and genomic stability. Chromatin restricts the access of repair proteins to DNA lesions embedded in nucleosomes and higher order chromatin structures. However, chromatin also serves as a signaling platform in which post-translational modifications of histones and other chromatin-bound proteins promote lesion recognition and repair. Similarly, chromatin modulates the formation of DNA damage, promoting or suppressing lesion formation depending on the chromatin context. Therefore, the modulation of DNA damage and its repair in chromatin is crucial to our understanding of the fate of potentially mutagenic and carcinogenic lesions in DNA. Here, we survey many of the landmark findings on DNA damage and repair in chromatin over the last 50 years (i.e., since the beginning of this field), focusing on excision repair, the first repair mechanism studied in the chromatin landscape. For example, we highlight how the impact of chromatin on these processes explains the distinct patterns of somatic mutations observed in cancer genomes.
Collapse
Affiliation(s)
- Michael J Smerdon
- Biochemistry and Biophysics, School of Molecular Biosciences, Washington State University, Pullman, Washington, USA.
| | - John J Wyrick
- Genetics and Cell Biology, School of Molecular Biosciences, Washington State University, Pullman, Washington, USA
| | - Sarah Delaney
- Department of Chemistry, Brown University, Providence, Rhode Island, USA
| |
Collapse
|
17
|
Mechetin GV, Zharkov DO. DNA Damage Response and Repair in Boron Neutron Capture Therapy. Genes (Basel) 2023; 14:127. [PMID: 36672868 PMCID: PMC9859301 DOI: 10.3390/genes14010127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 01/03/2023] Open
Abstract
Boron neutron capture therapy (BNCT) is an approach to the radiotherapy of solid tumors that was first outlined in the 1930s but has attracted considerable attention recently with the advent of a new generation of neutron sources. In BNCT, tumor cells accumulate 10B atoms that react with epithermal neutrons, producing energetic α particles and 7Li atoms that damage the cell's genome. The damage inflicted by BNCT appears not to be easily repairable and is thus lethal for the cell; however, the molecular events underlying the action of BNCT remain largely unaddressed. In this review, the chemistry of DNA damage during BNCT is outlined, the major mechanisms of DNA break sensing and repair are summarized, and the specifics of the repair of BNCT-induced DNA lesions are discussed.
Collapse
Affiliation(s)
- Grigory V. Mechetin
- Department of Natural Sciences, Novosibirsk State University, 2 Pirogova St., 630090 Novosibirsk, Russia
- Siberian Branch of the Russian Academy of Sciences Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia
| | - Dmitry O. Zharkov
- Department of Natural Sciences, Novosibirsk State University, 2 Pirogova St., 630090 Novosibirsk, Russia
- Siberian Branch of the Russian Academy of Sciences Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia
| |
Collapse
|
18
|
Ayala-Guerrero L, Claudio-Galeana S, Furlan-Magaril M, Castro-Obregón S. Chromatin Structure from Development to Ageing. Subcell Biochem 2023; 102:7-51. [PMID: 36600128 DOI: 10.1007/978-3-031-21410-3_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Nuclear structure influences genome architecture, which contributes to determine patterns of gene expression. Global changes in chromatin dynamics are essential during development and differentiation, and are one of the hallmarks of ageing. This chapter describes the molecular dynamics of chromatin structure that occur during development and ageing. In the first part, we introduce general information about the nuclear lamina, the chromatin structure, and the 3D organization of the genome. Next, we detail the molecular hallmarks found during development and ageing, including the role of DNA and histone modifications, 3D genome dynamics, and changes in the nuclear lamina. Within the chapter we discuss the implications that genome structure has on the mechanisms that drive development and ageing, and the physiological consequences when these mechanisms fail.
Collapse
Affiliation(s)
- Lorelei Ayala-Guerrero
- Departamento de Neurodesarrollo y Fisiología, Instituto de Fisiología Celular, UNAM, Mexico City, Mexico
| | - Sherlyn Claudio-Galeana
- Departamento de Genética Molecular, Instituto de Fisiología Celular, UNAM, Mexico City, Mexico
| | - Mayra Furlan-Magaril
- Departamento de Genética Molecular, Instituto de Fisiología Celular, UNAM, Mexico City, Mexico.
| | - Susana Castro-Obregón
- Departamento de Neurodesarrollo y Fisiología, Instituto de Fisiología Celular, UNAM, Mexico City, Mexico.
| |
Collapse
|
19
|
Sun X, Klingbeil O, Lu B, Wu C, Ballon C, Ouyang M, Wu XS, Jin Y, Hwangbo Y, Huang YH, Somerville TDD, Chang K, Park J, Chung T, Lyons SK, Shi J, Vogel H, Schulder M, Vakoc CR, Mills AA. BRD8 maintains glioblastoma by epigenetic reprogramming of the p53 network. Nature 2023; 613:195-202. [PMID: 36544023 PMCID: PMC10189659 DOI: 10.1038/s41586-022-05551-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 11/10/2022] [Indexed: 12/24/2022]
Abstract
Inhibition of the tumour suppressive function of p53 (encoded by TP53) is paramount for cancer development in humans. However, p53 remains unmutated in the majority of cases of glioblastoma (GBM)-the most common and deadly adult brain malignancy1,2. Thus, how p53-mediated tumour suppression is countered in TP53 wild-type (TP53WT) GBM is unknown. Here we describe a GBM-specific epigenetic mechanism in which the chromatin regulator bromodomain-containing protein 8 (BRD8) maintains H2AZ occupancy at p53 target loci through the EP400 histone acetyltransferase complex. This mechanism causes a repressive chromatin state that prevents transactivation by p53 and sustains proliferation. Notably, targeting the bromodomain of BRD8 displaces H2AZ, enhances chromatin accessibility and engages p53 transactivation. This in turn enforces cell cycle arrest and tumour suppression in TP53WT GBM. In line with these findings, BRD8 is highly expressed with H2AZ in proliferating single cells of patient-derived GBM, and is inversely correlated with CDKN1A, a canonical p53 target that encodes p21 (refs. 3,4). This work identifies BRD8 as a selective epigenetic vulnerability for a malignancy for which treatment has not improved for decades. Moreover, targeting the bromodomain of BRD8 may be a promising therapeutic strategy for patients with TP53WT GBM.
Collapse
Affiliation(s)
- Xueqin Sun
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Olaf Klingbeil
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Bin Lu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Caizhi Wu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Carlos Ballon
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Meng Ouyang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Xiaoli S Wu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
- Genetics Program, Stony Brook University, Stony Brook, NY, USA
| | - Ying Jin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Yon Hwangbo
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Yu-Han Huang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | | | - Kenneth Chang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Jung Park
- Department of Neurosurgery, Zucker School of Medicine at Hofstra Northwell, Lake Success, NY, USA
| | - Taemoon Chung
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Scott K Lyons
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Junwei Shi
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Hannes Vogel
- Department of Pathology, Stanford University, Stanford, CA, USA
| | - Michael Schulder
- Department of Neurosurgery, Zucker School of Medicine at Hofstra Northwell, Lake Success, NY, USA
| | | | - Alea A Mills
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
| |
Collapse
|
20
|
Centromere Chromatin Dynamics at a Glance. EPIGENOMES 2022; 6:epigenomes6040039. [PMID: 36412794 PMCID: PMC9680212 DOI: 10.3390/epigenomes6040039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 10/27/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
The centromere is a specialized DNA locus that ensures the faithful segregation of chromosomes during cell division. It does so by directing the assembly of an essential proteinaceous structure called the kinetochore. The centromere identity is primarily epigenetically defined by a nucleosome containing an H3 variant called CENP-A as well as by the interplay of several factors such as differential chromatin organization driven by CENP-A and H2A.Z, centromere-associated proteins, and post-translational modifications. At the centromere, CENP-A is not just a driving force for kinetochore assembly but also modifies the structural and dynamic properties of the centromeric chromatin, resulting in a distinctive chromatin organization. An additional level of regulation of the centromeric chromatin conformation is provided by post-translational modifications of the histones in the CENP-A nucleosomes. Further, H2A.Z is present in the regions flanking the centromere for heterochromatinization. In this review, we focus on the above-mentioned factors to describe how they contribute to the organization of the centromeric chromatin: CENP-A at the core centromere, post-translational modifications that decorate CENP-A, and the variant H2A.Z.
Collapse
|
21
|
Feng Y, Zhang Y, Lin Z, Ye X, Lin X, Lv L, Lin Y, Sun S, Qi Y, Lin X. Chromatin remodeler Dmp18 regulates apoptosis by controlling H2Av incorporation in Drosophila imaginal disc development. PLoS Genet 2022; 18:e1010395. [PMID: 36166470 PMCID: PMC9514664 DOI: 10.1371/journal.pgen.1010395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 08/23/2022] [Indexed: 11/18/2022] Open
Abstract
Programmed Cell Death (PCD) or apoptosis is a highly conserved biological process and plays essential roles both in the development and stress context. In Drosophila, expression of pro-apoptotic genes, including reaper (rpr), head involution defective (hid), grim, and sickle (skl), is sufficient to induce cell death. Here, we demonstrate that the chromatin remodeler Dmp18, the homolog of mammalian Znhit1, plays a crucial role in regulating apoptosis in eye and wing development. We showed that loss of Dmp18 disrupted eye and wing development, up-regulated transcription of pro-apoptotic genes, and induced apoptosis. Inhibition of apoptosis suppressed the eye defects caused by Dmp18 deletion. Furthermore, loss of Dmp18 disrupted H2Av incorporation into chromatin, promoted H3K4me3, but reduced H3K27me3 modifications on the TSS regions of pro-apoptotic genes. These results indicate that Dmp18 negatively regulates apoptosis by mediating H2Av incorporation and histone H3 modifications at pro-apoptotic gene loci for transcriptional regulation. Our study uncovers the role of Dmp18 in regulating apoptosis in Drosophila eye and wing development and provides insights into chromatin remodeling regulating apoptosis at the epigenetic levels.
Collapse
Affiliation(s)
- Ying Feng
- State Key Laboratory of Optometry, Ophthalmology and Vision Science, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
- * E-mail: (YF); (YQ); (XL)
| | - Yan Zhang
- State Key Laboratory of Optometry, Ophthalmology and Vision Science, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zhiqing Lin
- State Key Laboratory of Optometry, Ophthalmology and Vision Science, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiaolei Ye
- State Key Laboratory of Optometry, Ophthalmology and Vision Science, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xue Lin
- State Key Laboratory of Optometry, Ophthalmology and Vision Science, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Lixiu Lv
- The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yi Lin
- State Key Laboratory of Optometry, Ophthalmology and Vision Science, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Shenfei Sun
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Greater Bay Area Institute of Precision Medicine (Guangzhou), Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yun Qi
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
- * E-mail: (YF); (YQ); (XL)
| | - Xinhua Lin
- State Key Laboratory of Optometry, Ophthalmology and Vision Science, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Greater Bay Area Institute of Precision Medicine (Guangzhou), Zhongshan Hospital, Fudan University, Shanghai, China
- * E-mail: (YF); (YQ); (XL)
| |
Collapse
|
22
|
Dijkwel Y, Tremethick DJ. The Role of the Histone Variant H2A.Z in Metazoan Development. J Dev Biol 2022; 10:jdb10030028. [PMID: 35893123 PMCID: PMC9326617 DOI: 10.3390/jdb10030028] [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: 05/17/2022] [Revised: 06/12/2022] [Accepted: 06/23/2022] [Indexed: 12/10/2022] Open
Abstract
During the emergence and radiation of complex multicellular eukaryotes from unicellular ancestors, transcriptional systems evolved by becoming more complex to provide the basis for this morphological diversity. The way eukaryotic genomes are packaged into a highly complex structure, known as chromatin, underpins this evolution of transcriptional regulation. Chromatin structure is controlled by a variety of different epigenetic mechanisms, including the major mechanism for altering the biochemical makeup of the nucleosome by replacing core histones with their variant forms. The histone H2A variant H2A.Z is particularly important in early metazoan development because, without it, embryos cease to develop and die. However, H2A.Z is also required for many differentiation steps beyond the stage that H2A.Z-knockout embryos die. H2A.Z can facilitate the activation and repression of genes that are important for pluripotency and differentiation, and acts through a variety of different molecular mechanisms that depend upon its modification status, its interaction with histone and nonhistone partners, and where it is deposited within the genome. In this review, we discuss the current knowledge about the different mechanisms by which H2A.Z regulates chromatin function at various developmental stages and the chromatin remodeling complexes that determine when and where H2A.Z is deposited.
Collapse
|
23
|
Foroozani M, Holder DH, Deal RB. Histone Variants in the Specialization of Plant Chromatin. ANNUAL REVIEW OF PLANT BIOLOGY 2022; 73:149-172. [PMID: 35167758 PMCID: PMC9133179 DOI: 10.1146/annurev-arplant-070221-050044] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The basic unit of chromatin, the nucleosome, is an octamer of four core histone proteins (H2A, H2B, H3, and H4) and serves as a fundamental regulatory unit in all DNA-templated processes. The majority of nucleosome assembly occurs during DNA replication when these core histones are produced en masse to accommodate the nascent genome. In addition, there are a number of nonallelic sequence variants of H2A and H3 in particular, known as histone variants, that can be incorporated into nucleosomes in a targeted and replication-independent manner. By virtue of their sequence divergence from the replication-coupled histones, these histone variants can impart unique properties onto the nucleosomes they occupy and thereby influence transcription and epigenetic states, DNA repair, chromosome segregation, and other nuclear processes in ways that profoundly affect plant biology. In this review, we discuss the evolutionary origins of these variants in plants, their known roles in chromatin, and their impacts on plant development and stress responses. We focus on the individual and combined roles of histone variants in transcriptional regulation within euchromatic and heterochromatic genome regions. Finally, we highlight gaps in our understanding of plant variants at the molecular, cellular, and organismal levels, and we propose new directions for study in the field of plant histone variants.
Collapse
Affiliation(s)
| | - Dylan H Holder
- Department of Biology, Emory University, Atlanta, Georgia, USA;
- Graduate Program in Genetics and Molecular Biology, Emory University, Atlanta, Georgia, USA
| | - Roger B Deal
- Department of Biology, Emory University, Atlanta, Georgia, USA;
| |
Collapse
|
24
|
Zhang C, Tian Y, Song S, Zhang L, Dang Y, He Q. H3K56 deacetylation and H2A.Z deposition are required for aberrant heterochromatin spreading. Nucleic Acids Res 2022; 50:3852-3866. [PMID: 35333354 PMCID: PMC9023284 DOI: 10.1093/nar/gkac196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 03/10/2022] [Accepted: 03/15/2022] [Indexed: 11/21/2022] Open
Abstract
Crucial mechanisms are required to restrict self-propagating heterochromatin spreading within defined boundaries and prevent euchromatic gene silencing. In the filamentous fungus Neurospora crassa, the JmjC domain protein DNA METHYLATION MODULATOR-1 (DMM-1) prevents aberrant spreading of heterochromatin, but the molecular details remain unknown. Here, we revealed that DMM-1 is highly enriched in a well-defined 5-kb heterochromatin domain upstream of the cat-3 gene, hereby called 5H-cat-3 domain, to constrain aberrant heterochromatin spreading. Interestingly, aberrant spreading of the 5H-cat-3 domain observed in the dmm-1KO strain is accompanied by robust deposition of histone variant H2A.Z, and deletion of H2A.Z abolishes aberrant spreading of the 5H-cat-3 domain into adjacent euchromatin. Furthermore, lysine 56 of histone H3 is deacetylated at the expanded heterochromatin regions, and mimicking H3K56 acetylation with an H3K56Q mutation effectively blocks H2A.Z-mediated aberrant spreading of the 5H-cat-3 domain. Importantly, genome-wide analyses demonstrated the general roles of H3K56 deacetylation and H2A.Z deposition in aberrant spreading of heterochromatin. Together, our results illustrate a previously unappreciated regulatory process that mediates aberrant heterochromatin spreading.
Collapse
Affiliation(s)
- Chengcheng Zhang
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yuan Tian
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Shuang Song
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Center for Life Science, School of Life Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Lu Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Center for Life Science, School of Life Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Yunkun Dang
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Center for Life Science, School of Life Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Qun He
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| |
Collapse
|
25
|
Wootton J, Soutoglou E. Chromatin and Nuclear Dynamics in the Maintenance of Replication Fork Integrity. Front Genet 2022; 12:773426. [PMID: 34970302 PMCID: PMC8712883 DOI: 10.3389/fgene.2021.773426] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/24/2021] [Indexed: 11/13/2022] Open
Abstract
Replication of the eukaryotic genome is a highly regulated process and stringent control is required to maintain genome integrity. In this review, we will discuss the many aspects of the chromatin and nuclear environment that play key roles in the regulation of both unperturbed and stressed replication. Firstly, the higher order organisation of the genome into A and B compartments, topologically associated domains (TADs) and sub-nuclear compartments has major implications in the control of replication timing. In addition, the local chromatin environment defined by non-canonical histone variants, histone post-translational modifications (PTMs) and enrichment of factors such as heterochromatin protein 1 (HP1) plays multiple roles in normal S phase progression and during the repair of replicative damage. Lastly, we will cover how the spatial organisation of stalled replication forks facilitates the resolution of replication stress.
Collapse
Affiliation(s)
- Jack Wootton
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Evi Soutoglou
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| |
Collapse
|
26
|
Tsukii K, Takahata S, Murakami Y. Histone variant H2A.Z plays multiple roles in the maintenance of heterochromatin integrity. Genes Cells 2021; 27:93-112. [PMID: 34910346 DOI: 10.1111/gtc.12911] [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: 11/05/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 01/04/2023]
Abstract
H2A.Z, an evolutionally well-conserved histone H2A variant, is involved in many biological processes. Although the function of H2A.Z in euchromatic gene regulation is well known, its function and deposition mechanism in heterochromatin are still unclear. Here, we report that H2A.Z plays multiple roles in fission yeast heterochromatin. While a small amount of H2A.Z localizes at pericentromeric heterochromatin, loss of methylation of histone H3 at Lys9 (H3K9me) induces the accumulation of H2A.Z, which is dependent on the H2A.Z loader, SWR complex. The accumulated H2A.Z suppresses heterochromatic non-coding RNA transcription. This transcriptional repression activity requires the N-terminal tail of H2A.Z, which is involved in the regulation of euchromatic gene transcription. RNAi-defective cells, in which a substantial amount of H3K9me is retained by RNAi-independent heterochromatin assembly, also accumulate H2A.Z at heterochromatin, and the additional loss of H2A.Z in these cells triggers a further decrease in H3K9me. Our results suggest that H2A.Z facilitates RNAi-independent heterochromatin assembly by antagonizing the demethylation activity of Epe1, an eraser of H3K9me. Furthermore, H2A.Z suppresses Epe1-mediated transcriptional activation, which is required for subtelomeric gene repression. Our results provide novel evidence that H2A.Z plays diverse roles in chromatin silencing.
Collapse
Affiliation(s)
- Kazuki Tsukii
- Laboratory of Bioorganic Chemistry, Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
| | - Shinya Takahata
- Laboratory of Bioorganic Chemistry, Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan.,Laboratory of Bioorganic Chemistry, Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Japan
| | - Yota Murakami
- Laboratory of Bioorganic Chemistry, Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan.,Laboratory of Bioorganic Chemistry, Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Japan
| |
Collapse
|
27
|
Lewis TS, Sokolova V, Jung H, Ng H, Tan D. Structural basis of chromatin regulation by histone variant H2A.Z. Nucleic Acids Res 2021; 49:11379-11391. [PMID: 34643712 PMCID: PMC8565303 DOI: 10.1093/nar/gkab907] [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: 04/23/2021] [Revised: 09/20/2021] [Accepted: 09/23/2021] [Indexed: 02/06/2023] Open
Abstract
The importance of histone variant H2A.Z in transcription regulation has been well established, yet its mechanism-of-action remains enigmatic. Conflicting evidence exists in support of both an activating and a repressive role of H2A.Z in transcription. Here we report cryo-electron microscopy (cryo-EM) structures of nucleosomes and chromatin fibers containing H2A.Z and those containing canonical H2A. The structures show that H2A.Z incorporation results in substantial structural changes in both nucleosome and chromatin fiber. While H2A.Z increases the mobility of DNA terminus in nucleosomes, it simultaneously enables nucleosome arrays to form a more regular and condensed chromatin fiber. We also demonstrated that H2A.Z’s ability to enhance nucleosomal DNA mobility is largely attributed to its characteristic shorter C-terminus. Our study provides the structural basis for H2A.Z-mediated chromatin regulation, showing that the increase flexibility of the DNA termini in H2A.Z nucleosomes is central to its dual-functions in chromatin regulation and in transcription.
Collapse
Affiliation(s)
- Tyler S Lewis
- Department of Pharmacological Sciences, Stony Brook University; Stony Brook, NY 11794, USA
| | - Vladyslava Sokolova
- Department of Pharmacological Sciences, Stony Brook University; Stony Brook, NY 11794, USA
| | - Harry Jung
- Department of Pharmacological Sciences, Stony Brook University; Stony Brook, NY 11794, USA
| | - Honkit Ng
- Department of Pharmacological Sciences, Stony Brook University; Stony Brook, NY 11794, USA.,Cryo Electron Microscopy Resource Center, Rockefeller University; New York, NY 10065, USA
| | - Dongyan Tan
- Department of Pharmacological Sciences, Stony Brook University; Stony Brook, NY 11794, USA
| |
Collapse
|
28
|
Sales-Gil R, Kommer DC, de Castro IJ, Amin HA, Vinciotti V, Sisu C, Vagnarelli P. Non-redundant functions of H2A.Z.1 and H2A.Z.2 in chromosome segregation and cell cycle progression. EMBO Rep 2021; 22:e52061. [PMID: 34423893 PMCID: PMC8567233 DOI: 10.15252/embr.202052061] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 07/26/2021] [Accepted: 08/03/2021] [Indexed: 12/30/2022] Open
Abstract
H2A.Z is a H2A‐type histone variant essential for many aspects of cell biology, ranging from gene expression to genome stability. From deuterostomes, H2A.Z evolved into two paralogues, H2A.Z.1 and H2A.Z.2, that differ by only three amino acids and are encoded by different genes (H2AFZ and H2AFV, respectively). Despite the importance of this histone variant in development and cellular homeostasis, very little is known about the individual functions of each paralogue in mammals. Here, we have investigated the distinct roles of the two paralogues in cell cycle regulation and unveiled non‐redundant functions for H2A.Z.1 and H2A.Z.2 in cell division. Our findings show that H2A.Z.1 regulates the expression of cell cycle genes such as Myc and Ki‐67 and its depletion leads to a G1 arrest and cellular senescence. On the contrary, H2A.Z.2, in a transcription‐independent manner, is essential for centromere integrity and sister chromatid cohesion regulation, thus playing a key role in chromosome segregation.
Collapse
Affiliation(s)
- Raquel Sales-Gil
- College of Health, Medicine and Life Science, Brunel University London, London, UK
| | - Dorothee C Kommer
- College of Health, Medicine and Life Science, Brunel University London, London, UK
| | - Ines J de Castro
- College of Health, Medicine and Life Science, Brunel University London, London, UK
| | - Hasnat A Amin
- College of Health, Medicine and Life Science, Brunel University London, London, UK
| | - Veronica Vinciotti
- College of Engineering, Design and Physical Sciences, Research Institute for Environment Health and Society, Brunel University London, London, UK
| | - Cristina Sisu
- College of Health, Medicine and Life Science, Brunel University London, London, UK
| | - Paola Vagnarelli
- College of Health, Medicine and Life Science, Brunel University London, London, UK
| |
Collapse
|
29
|
Fu I, Geacintov NE, Broyde S. Molecular dynamics simulations reveal how H3K56 acetylation impacts nucleosome structure to promote DNA exposure for lesion sensing. DNA Repair (Amst) 2021; 107:103201. [PMID: 34399316 PMCID: PMC8526387 DOI: 10.1016/j.dnarep.2021.103201] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/12/2021] [Accepted: 08/02/2021] [Indexed: 01/04/2023]
Abstract
The first order of DNA packaging is the nucleosome with the DNA wrapped around the histone octamer. This leaves the nucleosomal DNA with access restrictions, which impose a significant barrier to repair of damaged DNA. The efficiency of DNA repair has been related to nucleosome structure and chromatin status, which is modulated in part by post-translational modifications (PTMs) of histones. Numerous studies have suggested a role for acetylation of lysine at position 56 of the H3 histone (H3K56ac) in various DNA transactions, including the response to DNA damage and its association with human cancer. Biophysical studies have revealed that H3K56ac increases DNA accessibility by facilitating spontaneous and transient unwrapping motions of the DNA ends. However, how this acetylation mark modulates nucleosome structure and dynamics to promote accessibility to the damaged DNA for repair factors and other proteins is still poorly understood. Here, we utilize approximately 5-6 microseconds of atomistic molecular dynamics simulations to delineate the impact of H3K56 acetylation on the nucleosome structure and dynamics, and to elucidate how these nucleosome properties are further impacted when a bulky benzo[a]pyrene-derived DNA lesion is placed near the acetylation site. Our findings reveal that H3K56ac alone induces considerable disturbance to the histone-DNA/histone-histone interactions, and amplifies the distortions imposed by the presence of the lesion. Our work highlights the important role of H3K56 acetylation in response to DNA damage and depicts how access to DNA lesions by the repair machinery can be facilitated within the nucleosome via a key acetylation event.
Collapse
Affiliation(s)
- Iwen Fu
- Department of Biology, New York University, 100 Washington Square East, New York, NY, 10003, United States.
| | - Nicholas E Geacintov
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY, 10003, United States.
| | - Suse Broyde
- Department of Biology, New York University, 100 Washington Square East, New York, NY, 10003, United States.
| |
Collapse
|
30
|
Jiang X, Wen J, Paver E, Wu Y, Sun G, Bullman A, Dahlstrom J, Tremethick DJ, Soboleva TA. H2A.B is a cancer/testis factor involved in the activation of ribosome biogenesis in Hodgkin lymphoma. EMBO Rep 2021; 22:e52462. [PMID: 34350706 PMCID: PMC8339673 DOI: 10.15252/embr.202152462] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 06/02/2021] [Accepted: 06/15/2021] [Indexed: 12/12/2022] Open
Abstract
Testis-specific regulators of chromatin function are commonly ectopically expressed in human cancers, but their roles are poorly understood. Examination of 81 primary Hodgkin lymphoma (HL) samples showed that the ectopic expression of the eutherian testis-specific histone variant H2A.B is an inherent feature of HL. In experiments using two HL cell lines derived from different subtypes of HL, H2A.B knockdown inhibited cell proliferation. H2A.B was enriched in both nucleoli of these HL cell lines and primary HL samples. We found that H2A.B enhanced ribosomal DNA (rDNA) transcription, was enriched at the rDNA promoter and transcribed regions, and interacted with RNA Pol I. Depletion of H2A.B caused the loss of RNA Pol I from rDNA chromatin. Remarkably, H2A.B was also required for high levels of ribosomal protein gene expression being located at the transcriptional start site and within the gene body. H2A.B knockdown reduced gene body chromatin accessibility of active RNA Pol II genes concurrent with a decrease in transcription. Taken together, our data show that in HL H2A.B has acquired a new function, the ability to increase ribosome biogenesis.
Collapse
Affiliation(s)
- Xuanzhao Jiang
- The John Curtin School of Medical ResearchThe Australian National UniversityCanberraACTAustralia
| | - Jiayu Wen
- The John Curtin School of Medical ResearchThe Australian National UniversityCanberraACTAustralia
| | - Elizabeth Paver
- Department of Tissue Pathology and Diagnostic OncologyRoyal Prince Alfred HospitalSydneyNSWAustralia
| | - Yu‐Huan Wu
- The John Curtin School of Medical ResearchThe Australian National UniversityCanberraACTAustralia
- Present address:
IQVIA Solutions Taiwan Ltd.Taipei CityTaiwan
| | - Gege Sun
- The John Curtin School of Medical ResearchThe Australian National UniversityCanberraACTAustralia
- Present address:
Department of Applied Biology and Chemical Technology and State Key Laboratory of Chemical Biology and Drug DiscoveryHong Kong Polytechnic UniversityHong KongChina
| | - Amanda Bullman
- Department of Anatomical PathologyACT PathologyThe Canberra HospitalCanberraACTAustralia
| | - Jane E Dahlstrom
- Department of Anatomical PathologyACT PathologyThe Canberra HospitalCanberraACTAustralia
- Australian National University Medical SchoolThe Australian National UniversityCanberraACTAustralia
| | - David J Tremethick
- The John Curtin School of Medical ResearchThe Australian National UniversityCanberraACTAustralia
| | - Tatiana A Soboleva
- The John Curtin School of Medical ResearchThe Australian National UniversityCanberraACTAustralia
| |
Collapse
|
31
|
Borg M, Jiang D, Berger F. Histone variants take center stage in shaping the epigenome. CURRENT OPINION IN PLANT BIOLOGY 2021; 61:101991. [PMID: 33434757 DOI: 10.1016/j.pbi.2020.101991] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/09/2020] [Accepted: 12/17/2020] [Indexed: 05/28/2023]
Abstract
The dynamic properties of the nucleosome are central to genomic activity. Variants of the core histones that form the nucleosome play a pivotal role in modulating nucleosome structure and function. Despite often small differences in sequence, histone variants display remarkable diversity in genomic deposition and post-translational modification. Here, we summarize the roles played by histone variants in the establishment, maintenance and reprogramming of plant chromatin landscapes, with a focus on histone H3 variants. Deposition of replicative H3.1 during DNA replication controls epigenetic inheritance, while local replacement of H3.1 with H3.3 marks cells undergoing terminal differentiation. Deposition of specialized H3 variants in specific cell types is emerging as a novel mechanism of selective epigenetic reprogramming during the plant life cycle.
Collapse
Affiliation(s)
- Michael Borg
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Danhua Jiang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Frédéric Berger
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria.
| |
Collapse
|
32
|
Abstract
In eukaryotes, genomic DNA is packaged into chromatin in the nucleus. The accessibility of DNA is dependent on the chromatin structure and dynamics, which essentially control DNA-related processes, including transcription, DNA replication, and repair. All of the factors that affect the structure and dynamics of nucleosomes, the nucleosome-nucleosome interaction interfaces, and the binding of linker histones or other chromatin-binding proteins need to be considered to understand the organization and function of chromatin fibers. In this review, we provide a summary of recent progress on the structure of chromatin fibers in vitro and in the nucleus, highlight studies on the dynamic regulation of chromatin fibers, and discuss their related biological functions and abnormal organization in diseases.
Collapse
Affiliation(s)
- Ping Chen
- Department of Immunology, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; .,National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China;
| | - Wei Li
- National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; .,Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Guohong Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; .,University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
33
|
Farr SE, Woods EJ, Joseph JA, Garaizar A, Collepardo-Guevara R. Nucleosome plasticity is a critical element of chromatin liquid-liquid phase separation and multivalent nucleosome interactions. Nat Commun 2021; 12:2883. [PMID: 34001913 PMCID: PMC8129070 DOI: 10.1038/s41467-021-23090-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 03/23/2021] [Indexed: 12/19/2022] Open
Abstract
Liquid-liquid phase separation (LLPS) is an important mechanism that helps explain the membraneless compartmentalization of the nucleus. Because chromatin compaction and LLPS are collective phenomena, linking their modulation to the physicochemical features of nucleosomes is challenging. Here, we develop an advanced multiscale chromatin model-integrating atomistic representations, a chemically-specific coarse-grained model, and a minimal model-to resolve individual nucleosomes within sub-Mb chromatin domains and phase-separated systems. To overcome the difficulty of sampling chromatin at high resolution, we devise a transferable enhanced-sampling Debye-length replica-exchange molecular dynamics approach. We find that nucleosome thermal fluctuations become significant at physiological salt concentrations and destabilize the 30-nm fiber. Our simulations show that nucleosome breathing favors stochastic folding of chromatin and promotes LLPS by simultaneously boosting the transient nature and heterogeneity of nucleosome-nucleosome contacts, and the effective nucleosome valency. Our work puts forward the intrinsic plasticity of nucleosomes as a key element in the liquid-like behavior of nucleosomes within chromatin, and the regulation of chromatin LLPS.
Collapse
Affiliation(s)
- Stephen E Farr
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, UK
| | - Esmae J Woods
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, UK
| | - Jerelle A Joseph
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, UK
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Adiran Garaizar
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, UK
| | - Rosana Collepardo-Guevara
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, UK.
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK.
- Department of Genetics, University of Cambridge, Cambridge, UK.
| |
Collapse
|
34
|
Cole L, Kurscheid S, Nekrasov M, Domaschenz R, Vera DL, Dennis JH, Tremethick DJ. Multiple roles of H2A.Z in regulating promoter chromatin architecture in human cells. Nat Commun 2021; 12:2524. [PMID: 33953180 PMCID: PMC8100287 DOI: 10.1038/s41467-021-22688-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Accepted: 03/25/2021] [Indexed: 01/02/2023] Open
Abstract
Chromatin accessibility of a promoter is fundamental in regulating transcriptional activity. The histone variant H2A.Z has been shown to contribute to this regulation, but its role has remained poorly understood. Here, we prepare high-depth maps of the position and accessibility of H2A.Z-containing nucleosomes for all human Pol II promoters in epithelial, mesenchymal and isogenic cancer cell lines. We find that, in contrast to the prevailing model, many different types of active and inactive promoter structures are observed that differ in their nucleosome organization and sensitivity to MNase digestion. Key aspects of an active chromatin structure include positioned H2A.Z MNase resistant nucleosomes upstream or downstream of the TSS, and a MNase sensitive nucleosome at the TSS. Furthermore, the loss of H2A.Z leads to a dramatic increase in the accessibility of transcription factor binding sites. Collectively, these results suggest that H2A.Z has multiple and distinct roles in regulating gene expression dependent upon its location in a promoter.
Collapse
Affiliation(s)
- Lauren Cole
- College of Arts and Sciences, Department of Biological Sciences, Florida State University, Tallahassee, FL, USA
| | - Sebastian Kurscheid
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Maxim Nekrasov
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Renae Domaschenz
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Daniel L Vera
- College of Arts and Sciences, Department of Biological Sciences, Florida State University, Tallahassee, FL, USA
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for Biology of Aging Research, Harvard Medical School, Boston, MA, USA
| | - Jonathan H Dennis
- College of Arts and Sciences, Department of Biological Sciences, Florida State University, Tallahassee, FL, USA.
| | - David J Tremethick
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australia.
| |
Collapse
|
35
|
Seier JA, Reinhardt J, Saraf K, Ng SS, Layer JP, Corvino D, Althoff K, Giordano FA, Schramm A, Fischer M, Hölzel M. Druggable epigenetic suppression of interferon-induced chemokine expression linked to MYCN amplification in neuroblastoma. J Immunother Cancer 2021; 9:e001335. [PMID: 34016720 PMCID: PMC8141444 DOI: 10.1136/jitc-2020-001335] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2021] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Amplification of the MYCN oncogene is a molecular hallmark of aggressive neuroblastoma (NB), a childhood cancer of the sympathetic nervous system. There is evidence that MYCN promotes a non-inflamed and T-cell infiltration-poor ('cold') tumor microenvironment (TME) by suppressing interferon signaling. This may explain, at least in part, why patients with NB seem to have little benefit from single-agent immune checkpoint blockade (ICB) therapy. Targeting MYCN or its effectors could be a strategy to convert a cold TME into a 'hot' (inflamed) TME and improve the efficacy of ICB therapy. METHODS NB transcriptome analyses were used to identify epigenetic drivers of a T-cell infiltration-poor TME. Biological and molecular responses of NB cells to epigenetic drugs and interferon (IFN)-γ exposure were assessed by proliferation assays, immunoblotting, ELISA, qRT-PCR, RNA-seq and ChIP-qPCR as well as co-culture assays with T cells. RESULTS We identified H3K9 euchromatic histone-lysine methyltransferases EHMT2 and EHMT1, also known as G9a and GLP, as epigenetic effectors of the MYCN-driven malignant phenotype and repressors of IFN-γ transcriptional responses in NB cells. EHMT inhibitors enhanced IFN-γ-induced expression of the Th1-type chemokines CXCL9 and CXCL10, key factors of T-cell recruitment into the TME. In MYCN-amplified NB cells, co-inhibition of EZH2 (enhancer of zeste homologue 2), a H3K27 histone methyltransferase cooperating with EHMTs, was needed for strong transcriptional responses to IFN-γ, in line with histone mark changes at CXCL9 and CXCL10 chemokine gene loci. EHMT and EZH2 inhibitor response gene signatures from NB cells were established as surrogate measures and revealed high EHMT and EZH2 activity in MYCN-amplified high-risk NBs with a cold immune phenotype. CONCLUSION Our results delineate a strategy for targeted epigenetic immunomodulation of high-risk NBs, whereby EHMT inhibitors alone or in combination with EZH2 inhibitors (in particular, MYCN-amplified NBs) could promote a T-cell-infiltrated TME via enhanced Th1-type chemokine expression.
Collapse
Affiliation(s)
- Johanna A Seier
- Institute of Experimental Oncology, Medical Faculty, University Hospital Bonn, Bonn, Germany
| | - Julia Reinhardt
- Institute of Experimental Oncology, Medical Faculty, University Hospital Bonn, Bonn, Germany
| | - Kritika Saraf
- Institute of Experimental Oncology, Medical Faculty, University Hospital Bonn, Bonn, Germany
| | - Susanna S Ng
- Institute of Experimental Oncology, Medical Faculty, University Hospital Bonn, Bonn, Germany
| | - Julian P Layer
- Institute of Experimental Oncology, Medical Faculty, University Hospital Bonn, Bonn, Germany
- Department of Radiation Oncology, University Hospital Bonn, Bonn, Germany
| | - Dillon Corvino
- Institute of Experimental Oncology, Medical Faculty, University Hospital Bonn, Bonn, Germany
| | - Kristina Althoff
- Department of Medical Oncology, West German Cancer Center, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Frank A Giordano
- Department of Radiation Oncology, University Hospital Bonn, Bonn, Germany
| | - Alexander Schramm
- Department of Medical Oncology, West German Cancer Center, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Matthias Fischer
- Department of Experimental Pediatric Oncology, University Children's Hospital of Cologne, Faculty of Medicine, University Hospital Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Medical Faculty, University Hospital Cologne, Cologne, Germany
| | - Michael Hölzel
- Institute of Experimental Oncology, Medical Faculty, University Hospital Bonn, Bonn, Germany
| |
Collapse
|
36
|
Ferrand J, Rondinelli B, Polo SE. Histone Variants: Guardians of Genome Integrity. Cells 2020; 9:E2424. [PMID: 33167489 PMCID: PMC7694513 DOI: 10.3390/cells9112424] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/30/2020] [Accepted: 11/03/2020] [Indexed: 12/12/2022] Open
Abstract
Chromatin integrity is key for cell homeostasis and for preventing pathological development. Alterations in core chromatin components, histone proteins, recently came into the spotlight through the discovery of their driving role in cancer. Building on these findings, in this review, we discuss how histone variants and their associated chaperones safeguard genome stability and protect against tumorigenesis. Accumulating evidence supports the contribution of histone variants and their chaperones to the maintenance of chromosomal integrity and to various steps of the DNA damage response, including damaged chromatin dynamics, DNA damage repair, and damage-dependent transcription regulation. We present our current knowledge on these topics and review recent advances in deciphering how alterations in histone variant sequence, expression, and deposition into chromatin fuel oncogenic transformation by impacting cell proliferation and cell fate transitions. We also highlight open questions and upcoming challenges in this rapidly growing field.
Collapse
Affiliation(s)
| | | | - Sophie E. Polo
- Epigenetics & Cell Fate Centre, UMR7216 CNRS, Université de Paris, 75013 Paris, France; (J.F.); (B.R.)
| |
Collapse
|
37
|
Creighton SD, Stefanelli G, Reda A, Zovkic IB. Epigenetic Mechanisms of Learning and Memory: Implications for Aging. Int J Mol Sci 2020; 21:E6918. [PMID: 32967185 PMCID: PMC7554829 DOI: 10.3390/ijms21186918] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/16/2020] [Accepted: 09/17/2020] [Indexed: 12/15/2022] Open
Abstract
The neuronal epigenome is highly sensitive to external events and its function is vital for producing stable behavioral outcomes, such as the formation of long-lasting memories. The importance of epigenetic regulation in memory is now well established and growing evidence points to altered epigenome function in the aging brain as a contributing factor to age-related memory decline. In this review, we first summarize the typical role of epigenetic factors in memory processing in a healthy young brain, then discuss the aspects of this system that are altered with aging. There is general agreement that many epigenetic marks are modified with aging, but there are still substantial inconsistencies in the precise nature of these changes and their link with memory decline. Here, we discuss the potential source of age-related changes in the epigenome and their implications for therapeutic intervention in age-related cognitive decline.
Collapse
Affiliation(s)
- Samantha D. Creighton
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada; (S.D.C.); (G.S.)
| | - Gilda Stefanelli
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada; (S.D.C.); (G.S.)
| | - Anas Reda
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S, Canada;
| | - Iva B. Zovkic
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada; (S.D.C.); (G.S.)
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S, Canada;
| |
Collapse
|
38
|
Abstract
Pioneer transcription factors have the intrinsic biochemical ability to scan partial DNA sequence motifs that are exposed on the surface of a nucleosome and thus access silent genes that are inaccessible to other transcription factors. Pioneer factors subsequently enable other transcription factors, nucleosome remodeling complexes, and histone modifiers to engage chromatin, thereby initiating the formation of an activating or repressive regulatory sequence. Thus, pioneer factors endow the competence for fate changes in embryonic development, are essential for cellular reprogramming, and rewire gene networks in cancer cells. Recent studies with reconstituted nucleosomes in vitro and chromatin binding in vivo reveal that pioneer factors can directly perturb nucleosome structure and chromatin accessibility in different ways. This review focuses on our current understanding of the mechanisms by which pioneer factors initiate gene network changes and will ultimately contribute to our ability to control cell fates at will.
Collapse
Affiliation(s)
- Kenneth S Zaret
- Institute for Regenerative Medicine, Epigenetics Institute, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-5157, USA;
| |
Collapse
|
39
|
Martire S, Banaszynski LA. The roles of histone variants in fine-tuning chromatin organization and function. Nat Rev Mol Cell Biol 2020; 21:522-541. [PMID: 32665685 PMCID: PMC8245300 DOI: 10.1038/s41580-020-0262-8] [Citation(s) in RCA: 200] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2020] [Indexed: 12/15/2022]
Abstract
Histones serve to both package and organize DNA within the nucleus. In addition to histone post-translational modification and chromatin remodelling complexes, histone variants contribute to the complexity of epigenetic regulation of the genome. Histone variants are characterized by a distinct protein sequence and a selection of designated chaperone systems and chromatin remodelling complexes that regulate their localization in the genome. In addition, histone variants can be enriched with specific post-translational modifications, which in turn can provide a scaffold for recruitment of variant-specific interacting proteins to chromatin. Thus, through these properties, histone variants have the capacity to endow specific regions of chromatin with unique character and function in a regulated manner. In this Review, we provide an overview of recent advances in our understanding of the contribution of histone variants to chromatin function in mammalian systems. First, we discuss new molecular insights into chaperone-mediated histone variant deposition. Next, we discuss mechanisms by which histone variants influence chromatin properties such as nucleosome stability and the local chromatin environment both through histone variant sequence-specific effects and through their role in recruiting different chromatin-associated complexes. Finally, we focus on histone variant function in the context of both embryonic development and human disease, specifically developmental syndromes and cancer.
Collapse
Affiliation(s)
- Sara Martire
- Green Center for Reproductive Biology Sciences, Department of Obstetrics and Gynecology, Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Laura A Banaszynski
- Green Center for Reproductive Biology Sciences, Department of Obstetrics and Gynecology, Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| |
Collapse
|
40
|
Abstract
Nucleosome dynamics and properties are central to all forms of genomic activities. Among the core histones, H3 variants play a pivotal role in modulating nucleosome structure and function. Here, we focus on the impact of H3 variants on various facets of development. The deposition of the replicative H3 variant following DNA replication is essential for the transmission of the epigenomic information encoded in posttranscriptional modifications. Through this process, replicative H3 maintains cell fate while, in contrast, the replacement H3.3 variant opposes cell differentiation during early embryogenesis. In later steps of development, H3.3 and specialized H3 variants are emerging as new, important regulators of terminal cell differentiation, including neurons and gametes. The specific pathways that regulate the dynamics of the deposition of H3.3 are paramount during reprogramming events that drive zygotic activation and the initiation of a new cycle of development.
Collapse
Affiliation(s)
- Benjamin Loppin
- Laboratoire de Biologie et de Modélisation de la Cellule, CNRS UMR 5239, Ecole Normale Supérieure de Lyon, University of Lyon, F-69007 Lyon, France;
| | - Frédéric Berger
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), 1030 Vienna, Austria;
| |
Collapse
|
41
|
How HP1 Post-Translational Modifications Regulate Heterochromatin Formation and Maintenance. Cells 2020; 9:cells9061460. [PMID: 32545538 PMCID: PMC7349378 DOI: 10.3390/cells9061460] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 12/12/2022] Open
Abstract
Heterochromatin Protein 1 (HP1) is a highly conserved protein that has been used as a classic marker for heterochromatin. HP1 binds to di- and tri-methylated histone H3K9 and regulates heterochromatin formation, functions and structure. Besides the well-established phosphorylation of histone H3 Ser10 that has been shown to modulate HP1 binding to chromatin, several studies have recently highlighted the importance of HP1 post-translational modifications and additional epigenetic features for the modulation of HP1-chromatin binding ability and heterochromatin formation. In this review, we summarize the recent literature of HP1 post-translational modifications that have contributed to understand how heterochromatin is formed, regulated and maintained.
Collapse
|
42
|
Sanulli S, J Narlikar G. Liquid-like interactions in heterochromatin: Implications for mechanism and regulation. Curr Opin Cell Biol 2020; 64:90-96. [PMID: 32434105 DOI: 10.1016/j.ceb.2020.03.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/12/2020] [Accepted: 03/29/2020] [Indexed: 12/14/2022]
Abstract
A large portion of the eukaryotic genome is packed into heterochromatin, a versatile platform that is essential to maintain genome stability. Often associated with a compact and transcriptionally repressed chromatin state, heterochromatin was earlier considered a static and locked compartment. However, cumulative findings over the last 17 years have suggested that heterochromatin displays dynamics at different timescales and size scales. These dynamics are thought to be essential for the regulation of heterochromatin. This review illustrates how the key principles underlying heterochromatin structure and function have evolved along the years and summarizes the discoveries that have led to the continuous revision of these principles. Using heterochromatin protein 1-mediated heterochromatin as a context, we discuss a novel paradigm for heterochromatin organization based on two emerging concepts, phase separation and nucleosome structural plasticity. We also examine the broader implications of this paradigm for chromatin organization and regulation beyond heterochromatin.
Collapse
Affiliation(s)
- Serena Sanulli
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, 94158, USA.
| | - Geeta J Narlikar
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, 94158, USA
| |
Collapse
|
43
|
Short Histone H2A Variants: Small in Stature but not in Function. Cells 2020; 9:cells9040867. [PMID: 32252453 PMCID: PMC7226823 DOI: 10.3390/cells9040867] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 03/24/2020] [Accepted: 03/31/2020] [Indexed: 12/19/2022] Open
Abstract
The dynamic packaging of DNA into chromatin regulates all aspects of genome function by altering the accessibility of DNA and by providing docking pads to proteins that copy, repair and express the genome. Different epigenetic-based mechanisms have been described that alter the way DNA is organised into chromatin, but one fundamental mechanism alters the biochemical composition of a nucleosome by substituting one or more of the core histones with their variant forms. Of the core histones, the largest number of histone variants belong to the H2A class. The most divergent class is the designated “short H2A variants” (H2A.B, H2A.L, H2A.P and H2A.Q), so termed because they lack a H2A C-terminal tail. These histone variants appeared late in evolution in eutherian mammals and are lineage-specific, being expressed in the testis (and, in the case of H2A.B, also in the brain). To date, most information about the function of these peculiar histone variants has come from studies on the H2A.B and H2A.L family in mice. In this review, we describe their unique protein characteristics, their impact on chromatin structure, and their known functions plus other possible, even non-chromatin, roles in an attempt to understand why these peculiar histone variants evolved in the first place.
Collapse
|
44
|
Kumar A, Kono H. Heterochromatin protein 1 (HP1): interactions with itself and chromatin components. Biophys Rev 2020; 12:387-400. [PMID: 32144738 PMCID: PMC7242596 DOI: 10.1007/s12551-020-00663-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 02/23/2020] [Indexed: 12/12/2022] Open
Abstract
Isoforms of heterochromatin protein 1 (HP1) have been known to perform a multitude of functions ranging from gene silencing, gene activation to cell cycle regulation, and cell differentiation. This functional diversity arises from the dissimilarities coded in protein sequence which confers different biophysical and biochemical properties to individual structural elements of HP1 and thereby different behavior and interaction patterns. Hence, an understanding of various interactions of the structural elements of HP1 will be of utmost importance to better elucidate chromatin dynamics in its presence. In this review, we have gathered available information about interactions of HP1 both within and with itself as well as with chromatin elements. Also, the possible implications of these interactions are discussed.
Collapse
Affiliation(s)
- Amarjeet Kumar
- Molecular Modelling and Simulation (MMS) Group, Institute for Quantum Life Science (iQLS), National Institutes for Quantum and Radiological Science and Technology (QST), Kizugawa, Kyoto, 619-0215, Japan
| | - Hidetoshi Kono
- Molecular Modelling and Simulation (MMS) Group, Institute for Quantum Life Science (iQLS), National Institutes for Quantum and Radiological Science and Technology (QST), Kizugawa, Kyoto, 619-0215, Japan.
| |
Collapse
|
45
|
Abstract
In eukaryotes, DNA is highly compacted within the nucleus into a structure known as chromatin. Modulation of chromatin structure allows for precise regulation of gene expression, and thereby controls cell fate decisions. Specific chromatin organization is established and preserved by numerous factors to generate desired cellular outcomes. In embryonic stem (ES) cells, chromatin is precisely regulated to preserve their two defining characteristics: self-renewal and pluripotent state. This action is accomplished by a litany of nucleosome remodelers, histone variants, epigenetic marks, and other chromatin regulatory factors. These highly dynamic regulatory factors come together to precisely define a chromatin state that is conducive to ES cell maintenance and development, where dysregulation threatens the survival and fitness of the developing organism.
Collapse
Affiliation(s)
- David C Klein
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sarah J Hainer
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, United States.
| |
Collapse
|
46
|
H2A.Z facilitates licensing and activation of early replication origins. Nature 2019; 577:576-581. [PMID: 31875854 DOI: 10.1038/s41586-019-1877-9] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 10/31/2019] [Indexed: 12/31/2022]
Abstract
DNA replication is a tightly regulated process that ensures the precise duplication of the genome during the cell cycle1. In eukaryotes, the licensing and activation of replication origins are regulated by both DNA sequence and chromatin features2. However, the chromatin-based regulatory mechanisms remain largely uncharacterized. Here we show that, in HeLa cells, nucleosomes containing the histone variant H2A.Z are enriched with histone H4 that is dimethylated on its lysine 20 residue (H4K20me2) and with bound origin-recognition complex (ORC). In vitro studies show that H2A.Z-containing nucleosomes bind directly to the histone lysine methyltransferase enzyme SUV420H1, promoting H4K20me2 deposition, which is in turn required for ORC1 binding. Genome-wide studies show that signals from H4K20me2, ORC1 and nascent DNA strands co-localize with H2A.Z, and that depletion of H2A.Z results in decreased H4K20me2, ORC1 and nascent-strand signals throughout the genome. H2A.Z-regulated replication origins have a higher firing efficiency and early replication timing compared with other origins. Our results suggest that the histone variant H2A.Z epigenetically regulates the licensing and activation of early replication origins and maintains replication timing through the SUV420H1-H4K20me2-ORC1 axis.
Collapse
|
47
|
Ryan DP, Tremethick DJ. The interplay between H2A.Z and H3K9 methylation in regulating HP1α binding to linker histone-containing chromatin. Nucleic Acids Res 2019; 46:9353-9366. [PMID: 30007360 PMCID: PMC6182156 DOI: 10.1093/nar/gky632] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 07/04/2018] [Indexed: 12/14/2022] Open
Abstract
One of the most intensively studied chromatin binding factors is HP1α. HP1α is associated with silenced, heterochromatic regions of the genome and binds to H3K9me3. While H3K9me3 is necessary for HP1α recruitment to heterochromatin, it is becoming apparent that it is not sufficient suggesting that additional factors are involved. One candidate proposed as a potential regulator of HP1α recruitment is the linker histone H1.4. Changes to the underlying make-up of chromatin, such as the incorporation of the histone variant H2A.Z, has also been linked with regulating HP1 binding to chromatin. Here, we rigorously dissected the effects of H1.4, H2A.Z and H3K9me3 on the nucleosome binding activity of HP1α in vitro employing arrays, mononucleosomes and nucleosome core particles. Unexpectedly, histone H1.4 impedes the binding of HP1α but strikingly, this inhibition is partially relieved by the incorporation of both H2A.Z and H3K9me3 but only in the context of arrays or nucleosome core particles. Our data suggests that there are two modes of interaction of HP1α with nucleosomes. The first primary mode is through interactions with linker DNA. However, when linker DNA is missing or occluded by linker histones, HP1α directly interacts with the nucleosome core and this interaction is enhanced by H2A.Z with H3K9me3.
Collapse
Affiliation(s)
- Daniel P Ryan
- Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, ACT 2601, Australia
| | - David J Tremethick
- Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, ACT 2601, Australia
| |
Collapse
|
48
|
Giaimo BD, Ferrante F, Herchenröther A, Hake SB, Borggrefe T. The histone variant H2A.Z in gene regulation. Epigenetics Chromatin 2019; 12:37. [PMID: 31200754 PMCID: PMC6570943 DOI: 10.1186/s13072-019-0274-9] [Citation(s) in RCA: 173] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 04/23/2019] [Indexed: 01/04/2023] Open
Abstract
The histone variant H2A.Z is involved in several processes such as transcriptional control, DNA repair, regulation of centromeric heterochromatin and, not surprisingly, is implicated in diseases such as cancer. Here, we review the recent developments on H2A.Z focusing on its role in transcriptional activation and repression. H2A.Z, as a replication-independent histone, has been studied in several model organisms and inducible mammalian model systems. Its loading machinery and several modifying enzymes have been recently identified, and some of the long-standing discrepancies in transcriptional activation and/or repression are about to be resolved. The buffering functions of H2A.Z, as supported by genome-wide localization and analyzed in several dynamic systems, are an excellent example of transcriptional control. Posttranslational modifications such as acetylation and ubiquitination of H2A.Z, as well as its specific binding partners, are in our view central players in the control of gene expression. Understanding the key-mechanisms in either turnover or stabilization of H2A.Z-containing nucleosomes as well as defining the H2A.Z interactome will pave the way for therapeutic applications in the future.
Collapse
Affiliation(s)
| | - Francesca Ferrante
- Institute of Biochemistry, University of Giessen, Friedrichstrasse 24, 35392, Giessen, Germany
| | - Andreas Herchenröther
- Institute for Genetics, University of Giessen, Heinrich-Buff-Ring 58-62, 35392, Giessen, Germany
| | - Sandra B Hake
- Institute for Genetics, University of Giessen, Heinrich-Buff-Ring 58-62, 35392, Giessen, Germany
| | - Tilman Borggrefe
- Institute of Biochemistry, University of Giessen, Friedrichstrasse 24, 35392, Giessen, Germany.
| |
Collapse
|
49
|
Unraveling the multiplex folding of nucleosome chains in higher order chromatin. Essays Biochem 2019; 63:109-121. [PMID: 31015386 DOI: 10.1042/ebc20180066] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 02/25/2019] [Accepted: 03/01/2019] [Indexed: 12/19/2022]
Abstract
The DNA of eukaryotic chromatin and chromosomes is repeatedly supercoiled around histone octamers forming 'beads-on-a-string' chains of nucleosomes. The extent of nucleosome chain folding and DNA accessibility vary between different functional and epigenetic states of nuclear chromatin and change dramatically upon cell differentiation, but the molecular mechanisms that direct 3D folding of the nucleosome chain in vivo are still enigmatic. Recent advances in cell imaging and chromosome capture techniques have radically challenged the established paradigm of regular and hierarchical chromatin fibers by highlighting irregular chromatin organization and the importance of the nuclear skeletal structures hoisting the nucleosome chains. Here, we argue that, by analyzing individual structural elements of the nucleosome chain - nucleosome spacing, linker DNA conformations, internucleosomal interactions, and nucleosome chain flexibility - and integrating these elements in multiplex 3D structural models, we can predict the features of the multiplex chromatin folding assemblies underlying distinct developmental and epigenetic states in living cells. Furthermore, partial disassembly of the nuclear structures suspending chromatin fibers may reveal the intrinsic mechanisms of nucleosome chain folding. These mechanisms and structures are expected to provide molecular cues to modify chromatin structure and functions related to developmental and disease processes.
Collapse
|
50
|
Abstract
Budding yeast harbors a simple point centromere, which is originally believed to be sequence dependent without much epigenetic regulation and is transcription incompatible, as inserting a strong promoter upstream inactivates the centromere completely. Here, we demonstrate that an optimal level centromeric noncoding RNA is required for budding yeast centromere activity. Centromeric transcription is induced in S phase, coinciding with the assembly of new centromeric proteins. Too much or too little centromeric noncoding RNA leads to centromere malfunction. Overexpression of centromeric noncoding RNA reduces the protein levels and chromatin localization of inner centromere and kinetochore proteins, such as CENP-A, CENP-C, and the chromosome passenger complex. This work shows that point centromere is epigenetically regulated by noncoding RNA. In budding yeast, which possesses simple point centromeres, we discovered that all of its centromeres express long noncoding RNAs (cenRNAs), especially in S phase. Induction of cenRNAs coincides with CENP-ACse4 loading time and is dependent on DNA replication. Centromeric transcription is repressed by centromere-binding factor Cbf1 and histone H2A variant H2A.ZHtz1. Deletion of CBF1 and H2A.ZHTZ1 results in an up-regulation of cenRNAs; an increased loss of a minichromosome; elevated aneuploidy; a down-regulation of the protein levels of centromeric proteins CENP-ACse4, CENP-A chaperone HJURPScm3, CENP-CMif2, SurvivinBir1, and INCENPSli15; and a reduced chromatin localization of CENP-ACse4, CENP-CMif2, and Aurora BIpl1. When the RNA interference system was introduced to knock down all cenRNAs from the endogenous chromosomes, but not the cenRNA from the circular minichromosome, an increase in minichromosome loss was still observed, suggesting that cenRNA functions in trans to regulate centromere activity. CenRNA knockdown partially alleviates minichromosome loss in cbf1Δ, htz1Δ, and cbf1Δ htz1Δ in a dose-dependent manner, demonstrating that cenRNA level is tightly regulated to epigenetically control point centromere function.
Collapse
|