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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.
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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.
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2
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Rogers AM, Neri NR, Chigweshe L, Holmes SG. Histone variant H2A.Z and linker histone H1 influence chromosome condensation in Saccharomyces cerevisiae. Genetics 2024; 226:iyae022. [PMID: 38366024 PMCID: PMC10990423 DOI: 10.1093/genetics/iyae022] [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: 10/15/2023] [Revised: 10/15/2023] [Accepted: 01/17/2024] [Indexed: 02/18/2024] Open
Abstract
Chromosome condensation is essential for the fidelity of chromosome segregation during mitosis and meiosis. Condensation is associated both with local changes in nucleosome structure and larger-scale alterations in chromosome topology mediated by the condensin complex. We examined the influence of linker histone H1 and variant histone H2A.Z on chromosome condensation in budding yeast cells. Linker histone H1 has been implicated in local and global compaction of chromatin in multiple eukaryotes, but we observe normal condensation of the rDNA locus in yeast strains lacking H1. However, deletion of the yeast HTZ1 gene, coding for variant histone H2A.Z, causes a significant defect in rDNA condensation. Loss of H2A.Z does not change condensin association with the rDNA locus or significantly affect condensin mRNA levels. Prior studies reported that several phenotypes caused by loss of H2A.Z are suppressed by eliminating Swr1, a key component of the SWR complex that deposits H2A.Z in chromatin. We observe that an htz1Δ swr1Δ strain has near-normal rDNA condensation. Unexpectedly, we find that elimination of the linker histone H1 can also suppress the rDNA condensation defect of htz1Δ strains. Our experiments demonstrate that histone H2A.Z promotes chromosome condensation, in part by counteracting activities of histone H1 and the SWR complex.
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Affiliation(s)
- Anna M Rogers
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06459, USA
| | - Nola R Neri
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06459, USA
| | - Lorencia Chigweshe
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06459, USA
| | - Scott G Holmes
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06459, USA
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3
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Ragusa D, Vagnarelli P. Contribution of histone variants to aneuploidy: a cancer perspective. Front Genet 2023; 14:1290903. [PMID: 38075697 PMCID: PMC10702394 DOI: 10.3389/fgene.2023.1290903] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 10/27/2023] [Indexed: 07/29/2024] Open
Abstract
Histone variants, which generally differ in few amino acid residues, can replace core histones (H1, H2A, H2B, and H3) to confer specific structural and functional features to regulate cellular functions. In addition to their role in DNA packaging, histones modulate key processes such as gene expression regulation and chromosome segregation, which are frequently dysregulated in cancer cells. During the years, histones variants have gained significant attention as gatekeepers of chromosome stability, raising interest in understanding how structural and functional alterations can contribute to tumourigenesis. Beside the well-established role of the histone H3 variant CENP-A in centromere specification and maintenance, a growing body of literature has described mutations, aberrant expression patterns and post-translational modifications of a variety of histone variants in several cancers, also coining the term "oncohistones." At the molecular level, mechanistic studies have been dissecting the biological mechanisms behind histones and missegregation events, with the potential to uncover novel clinically-relevant targets. In this review, we focus on the current understanding and highlight knowledge gaps of the contribution of histone variants to aneuploidy, and we have compiled a database (HistoPloidyDB) of histone gene alterations linked to aneuploidy in cancers of the The Cancer Genome Atlas project.
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Affiliation(s)
- Denise Ragusa
- College of Health, Medicine and Life Sciences, Department of Life Sciences, Brunel University London, London, United Kingdom
| | - Paola Vagnarelli
- College of Health, Medicine and Life Sciences, Department of Life Sciences, Brunel University London, London, United Kingdom
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4
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Chigweshe L, MacQueen AJ, Holmes SG. Histone variant H2A.Z promotes meiotic chromosome axis organization in Saccharomyces cerevisiae. G3 GENES|GENOMES|GENETICS 2022; 12:6591205. [PMID: 35608312 PMCID: PMC9339299 DOI: 10.1093/g3journal/jkac128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 05/07/2022] [Indexed: 11/14/2022]
Abstract
Progression through meiosis is associated with significant reorganization of chromosome structure, regulated in part by changes in histones and chromatin. Prior studies observed defects in meiotic progression in yeast strains lacking the linker histone H1 or variant histone H2A.Z. To further define the contributions of these chromatin factors, we have conducted genetic and cytological analysis of cells undergoing meiosis in the absence of H1 and H2A.Z. We find that a spore viability defect observed in strains lacking H2A.Z can be partially suppressed if cells also lack histone H1, while the combined loss of both H1 and H2A.Z is associated with elevated gene conversion events. Cytological analysis of Red1 and Rec8 staining patterns indicates that a subset of cells lacking H2A.Z fail to assemble a proper chromosome axis, and the staining pattern of the synaptonemal complex protein Zip1 in htz1Δ/htz1Δ cells mimics that of cells deficient for Rec8-dependent meiotic cohesion. Our results suggest a role for H2A.Z in the establishment or maintenance of the meiotic chromosome axis, possibly by promoting the efficient chromosome cohesion.
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Affiliation(s)
- Lorencia Chigweshe
- Department of Molecular Biology and Biochemistry, Wesleyan University , Middletown, CT 06459, USA
| | - Amy J MacQueen
- Department of Molecular Biology and Biochemistry, Wesleyan University , Middletown, CT 06459, USA
| | - Scott G Holmes
- Department of Molecular Biology and Biochemistry, Wesleyan University , Middletown, CT 06459, USA
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5
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Cameron B, Lehrmann E, Chih T, Walters J, Buksch R, Snyder S, Goffena J, Lefcort F, Becker KG, George L. Loss of Elp1 perturbs histone H2A.Z and the Notch signaling pathway. Biol Open 2021; 10:272332. [PMID: 34590699 PMCID: PMC8496692 DOI: 10.1242/bio.058979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 08/17/2021] [Indexed: 12/12/2022] Open
Abstract
Elongator dysfunction is increasingly recognized as a contributor to multiple neurodevelopmental and neurodegenerative disorders including familial dysautonomia, intellectual disability, amyotrophic lateral sclerosis, and autism spectrum disorder. Although numerous cellular processes are perturbed in the context of Elongator loss, converging evidence from multiple studies has resolved Elongator's primary function in the cell to the modification of tRNA wobble uridines and the translational regulation of codon-biased genes. Here we characterize H2a.z, encoding the variant H2a histone H2A.Z, as an indirect Elongator target. We further show that canonical Notch signaling, a pathway directed by H2A.Z, is perturbed as a consequence of Elp1 loss. Finally, we demonstrate that hyperacetylation of H2A.Z and other histones via exposure to the histone deacetylase inhibitor Trichostatin A during neurogenesis corrects the expression of Notch3 and rescues the development of sensory neurons in embryos lacking the Elp1 Elongator subunit. Summary: The maldevelopment of sensory neurons in Elongator knockout embryos is associated with elevated H2A.Z and perturbed Notch signaling that can be rescued by Trichostatin A.
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Affiliation(s)
- BreAnna Cameron
- Department of Biological and Physical Sciences, Montana State University Billings, Billings, MT 59101, USA
| | - Elin Lehrmann
- Computational Biology & Genomics Core (CBGC), Laboratory of Genetics and Genomics (LGG), Department of Health and Human Services (DHHS), National Institute on Aging, Intramural Research Program (NIA IRP), National Institutes of Health (NIH), Biomedical Research Center, Baltimore, MD 21224, USA
| | - Tien Chih
- Department of Biological and Physical Sciences, Montana State University Billings, Billings, MT 59101, USA
| | - Joseph Walters
- Department of Biological and Physical Sciences, Montana State University Billings, Billings, MT 59101, USA
| | - Richard Buksch
- Department of Biological and Physical Sciences, Montana State University Billings, Billings, MT 59101, USA
| | - Sara Snyder
- Department of Biological and Physical Sciences, Montana State University Billings, Billings, MT 59101, USA
| | - Joy Goffena
- Department of Biological and Physical Sciences, Montana State University Billings, Billings, MT 59101, USA
| | - Frances Lefcort
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Kevin G Becker
- Gene Expression and Genomics Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Lynn George
- Department of Biological and Physical Sciences, Montana State University Billings, Billings, MT 59101, USA
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6
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Wu PS, Grosser J, Cameron DP, Baranello L, Ström L. Deficiency of Polη in Saccharomyces cerevisiae reveals the impact of transcription on damage-induced cohesion. PLoS Genet 2021; 17:e1009763. [PMID: 34499654 PMCID: PMC8454932 DOI: 10.1371/journal.pgen.1009763] [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: 03/15/2021] [Revised: 09/21/2021] [Accepted: 08/05/2021] [Indexed: 11/18/2022] Open
Abstract
The structural maintenance of chromosome (SMC) complex cohesin mediates sister chromatid cohesion established during replication, and damage-induced cohesion formed in response to DSBs post-replication. The translesion synthesis polymerase Polη is required for damage-induced cohesion through a hitherto unknown mechanism. Since Polη is functionally associated with transcription, and transcription triggers de novo cohesion in Schizosaccharomyces pombe, we hypothesized that transcription facilitates damage-induced cohesion in Saccharomyces cerevisiae. Here, we show dysregulated transcriptional profiles in the Polη null mutant (rad30Δ), where genes involved in chromatin assembly and positive transcription regulation were downregulated. In addition, chromatin association of RNA polymerase II was reduced at promoters and coding regions in rad30Δ compared to WT cells, while occupancy of the H2A.Z variant (Htz1) at promoters was increased in rad30Δ cells. Perturbing histone exchange at promoters inactivated damage-induced cohesion, similarly to deletion of the RAD30 gene. Conversely, altering regulation of transcription elongation suppressed the deficient damage-induced cohesion in rad30Δ cells. Furthermore, transcription inhibition negatively affected formation of damage-induced cohesion. These results indicate that the transcriptional deregulation of the Polη null mutant is connected with its reduced capacity to establish damage-induced cohesion. This also suggests a linkage between regulation of transcription and formation of damage-induced cohesion after replication.
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Affiliation(s)
- Pei-Shang Wu
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
| | - Jan Grosser
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
| | - Donald P. Cameron
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
| | - Laura Baranello
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
| | - Lena Ström
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
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7
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Hsu CL, Chong SY, Lin CY, Kao CF. Histone dynamics during DNA replication stress. J Biomed Sci 2021; 28:48. [PMID: 34144707 PMCID: PMC8214274 DOI: 10.1186/s12929-021-00743-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/08/2021] [Indexed: 01/20/2023] Open
Abstract
Accurate and complete replication of the genome is essential not only for genome stability but also for cell viability. However, cells face constant threats to the replication process, such as spontaneous DNA modifications and DNA lesions from endogenous and external sources. Any obstacle that slows down replication forks or perturbs replication dynamics is generally considered to be a form of replication stress, and the past decade has seen numerous advances in our understanding of how cells respond to and resolve such challenges. Furthermore, recent studies have also uncovered links between defects in replication stress responses and genome instability or various diseases, such as cancer. Because replication stress takes place in the context of chromatin, histone dynamics play key roles in modulating fork progression and replication stress responses. Here, we summarize the current understanding of histone dynamics in replication stress, highlighting recent advances in the characterization of fork-protective mechanisms.
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Affiliation(s)
- Chia-Ling Hsu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Shin Yen Chong
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Chia-Yeh Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Cheng-Fu Kao
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan.
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8
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Ming Sun S, Batté A, Elmer M, van der Horst SC, van Welsem T, Bean G, Ideker T, van Leeuwen F, van Attikum H. A genetic interaction map centered on cohesin reveals auxiliary factors involved in sister chromatid cohesion in S. cerevisiae. J Cell Sci 2020; 133:jcs237628. [PMID: 32299836 PMCID: PMC7325435 DOI: 10.1242/jcs.237628] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 03/26/2020] [Indexed: 12/15/2022] Open
Abstract
Eukaryotic chromosomes are replicated in interphase and the two newly duplicated sister chromatids are held together by the cohesin complex and several cohesin auxiliary factors. Sister chromatid cohesion is essential for accurate chromosome segregation during mitosis, yet has also been implicated in other processes, including DNA damage repair, transcription and DNA replication. To assess how cohesin and associated factors functionally interconnect and coordinate with other cellular processes, we systematically mapped the genetic interactions of 17 cohesin genes centered on quantitative growth measurements of >52,000 gene pairs in the budding yeast Saccharomyces cerevisiae Integration of synthetic genetic interactions unveiled a cohesin functional map that constitutes 373 genetic interactions, revealing novel functional connections with post-replication repair, microtubule organization and protein folding. Accordingly, we show that the microtubule-associated protein Irc15 and the prefoldin complex members Gim3, Gim4 and Yke2 are new factors involved in sister chromatid cohesion. Our genetic interaction map thus provides a unique resource for further identification and functional interrogation of cohesin proteins. Since mutations in cohesin proteins have been associated with cohesinopathies and cancer, it may also help in identifying cohesin interactions relevant in disease etiology.
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Affiliation(s)
- Su Ming Sun
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, Netherlands
| | - Amandine Batté
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, Netherlands
| | - Mireille Elmer
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, Netherlands
- Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, 2600 AA, Delft, Netherlands
| | - Sophie C van der Horst
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, Netherlands
| | - Tibor van Welsem
- Division of Gene Regulation, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, Netherlands
| | - Gordon Bean
- Bioinformatics and Systems Biology Program, University of California, San Diego; La Jolla, CA, 92093, USA
| | - Trey Ideker
- Bioinformatics and Systems Biology Program, University of California, San Diego; La Jolla, CA, 92093, USA
- Department of Medicine, Division of Genetics, University of California, San Diego; La Jolla, CA, 92093, USA
- Department of Bioengineering, University of California, San Diego; La Jolla, CA, 92093, USA
- Cancer Cell Map Initiative (CCMI), Moores UCSD Cancer Center, La Jolla, CA, 92093, USA
| | - Fred van Leeuwen
- Division of Gene Regulation, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, Netherlands
| | - Haico van Attikum
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, Netherlands
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9
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Cheema MS, Good KV, Kim B, Soufari H, O’Sullivan C, Freeman ME, Stefanelli G, Casas CR, Zengeler KE, Kennedy AJ, Eirin Lopez JM, Howard PL, Zovkic IB, Shabanowitz J, Dryhurst DD, Hunt DF, Mackereth CD, Ausió J. Deciphering the Enigma of the Histone H2A.Z-1/H2A.Z-2 Isoforms: Novel Insights and Remaining Questions. Cells 2020; 9:cells9051167. [PMID: 32397240 PMCID: PMC7290884 DOI: 10.3390/cells9051167] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 12/20/2022] Open
Abstract
The replication independent (RI) histone H2A.Z is one of the more extensively studied variant members of the core histone H2A family, which consists of many replication dependent (RD) members. The protein has been shown to be indispensable for survival, and involved in multiple roles from DNA damage to chromosome segregation, replication, and transcription. However, its functional involvement in gene expression is controversial. Moreover, the variant in several groups of metazoan organisms consists of two main isoforms (H2A.Z-1 and H2A.Z-2) that differ in a few (3–6) amino acids. They comprise the main topic of this review, starting from the events that led to their identification, what is currently known about them, followed by further experimental, structural, and functional insight into their roles. Despite their structural differences, a direct correlation to their functional variability remains enigmatic. As all of this is being elucidated, it appears that a strong functional involvement of isoform variability may be connected to development.
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Affiliation(s)
- Manjinder S. Cheema
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Katrina V. Good
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Bohyun Kim
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Heddy Soufari
- Institut Européen de Chimie et Biologie, Univ. Bordeaux, 2 rue Robert Escarpit, F-33607 Pessac, France; (H.S.); (C.D.M.)
- Inserm U1212, CNRS UMR 5320, ARNA Laboratory, Univ. Bordeaux, 146 rue Léo Saignat, F-33076 Bordeaux, France
| | - Connor O’Sullivan
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Melissa E. Freeman
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Gilda Stefanelli
- Department of Neurosciences & Mental Health, the Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; (G.S.); (I.B.Z.)
| | - Ciro Rivera Casas
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International UniversityNorth Miami, FL 33181, USA; (C.R.C.); (J.M.E.L.)
| | - Kristine E. Zengeler
- Department of Chemistry and Biochemistry, Bates College, 2 Andrews Road, Lewiston, ME 04240, USA; (K.E.Z.); (A.J.K.)
| | - Andrew J. Kennedy
- Department of Chemistry and Biochemistry, Bates College, 2 Andrews Road, Lewiston, ME 04240, USA; (K.E.Z.); (A.J.K.)
| | - Jose Maria Eirin Lopez
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International UniversityNorth Miami, FL 33181, USA; (C.R.C.); (J.M.E.L.)
| | - Perry L. Howard
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Iva B. Zovkic
- Department of Neurosciences & Mental Health, the Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; (G.S.); (I.B.Z.)
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Jeffrey Shabanowitz
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA; (J.S.); (D.F.H.)
| | - Deanna D. Dryhurst
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Donald F. Hunt
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA; (J.S.); (D.F.H.)
- Department of Pathology, University of Virginia, Charlottesville, VA 22903, USA
| | - Cameron D. Mackereth
- Institut Européen de Chimie et Biologie, Univ. Bordeaux, 2 rue Robert Escarpit, F-33607 Pessac, France; (H.S.); (C.D.M.)
- Inserm U1212, CNRS UMR 5320, ARNA Laboratory, Univ. Bordeaux, 146 rue Léo Saignat, F-33076 Bordeaux, France
| | - Juan Ausió
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
- Correspondence: ; Tel.: +1-250-721-8863; Fax: +1-250-721-8855
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10
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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.
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11
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Morillo-Huesca M, Murillo-Pineda M, Barrientos-Moreno M, Gómez-Marín E, Clemente-Ruiz M, Prado F. Actin and Nuclear Envelope Components Influence Ectopic Recombination in the Absence of Swr1. Genetics 2019; 213:819-834. [PMID: 31533921 PMCID: PMC6827384 DOI: 10.1534/genetics.119.302580] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 09/17/2019] [Indexed: 12/11/2022] Open
Abstract
The accuracy of most DNA processes depends on chromatin integrity and dynamics. Our analyses in the yeast Saccharomyces cerevisiae show that an absence of Swr1 (the catalytic and scaffold subunit of the chromatin-remodeling complex SWR) leads to the formation of long-duration Rad52, but not RPA, foci and to an increase in intramolecular recombination. These phenotypes are further increased by MMS, zeocin, and ionizing radiation, but not by double-strand breaks, HU, or transcription/replication collisions, suggesting that they are associated with specific DNA lesions. Importantly, these phenotypes can be specifically suppressed by mutations in: (1) chromatin-anchorage internal nuclear membrane components (mps3∆75-150 and src1∆); (2) actin and actin regulators (act1-157, act1-159, crn1∆, and cdc42-6); or (3) the SWR subunit Swc5 and the SWR substrate Htz1 However, they are not suppressed by global disruption of actin filaments or by the absence of Csm4 (a component of the external nuclear membrane that forms a bridging complex with Mps3, thus connecting the actin cytoskeleton with chromatin). Moreover, swr1∆-induced Rad52 foci and intramolecular recombination are not associated with tethering recombinogenic DNA lesions to the nuclear periphery. In conclusion, the absence of Swr1 impairs efficient recombinational repair of specific DNA lesions by mechanisms that are influenced by SWR subunits, including actin, and nuclear envelope components. We suggest that these recombinational phenotypes might be associated with a pathological effect on homologous recombination of actin-containing complexes.
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Affiliation(s)
- Macarena Morillo-Huesca
- Department of Genome Biology, Andalusian Molecular Biology and Regenerative Medicine Center (CABIMER), Consejo Superior de Investigaciones Científicas-University of Seville-University Pablo de Olavide, Spain
| | - Marina Murillo-Pineda
- Department of Genome Biology, Andalusian Molecular Biology and Regenerative Medicine Center (CABIMER), Consejo Superior de Investigaciones Científicas-University of Seville-University Pablo de Olavide, Spain
| | - Marta Barrientos-Moreno
- Department of Genome Biology, Andalusian Molecular Biology and Regenerative Medicine Center (CABIMER), Consejo Superior de Investigaciones Científicas-University of Seville-University Pablo de Olavide, Spain
| | - Elena Gómez-Marín
- Department of Genome Biology, Andalusian Molecular Biology and Regenerative Medicine Center (CABIMER), Consejo Superior de Investigaciones Científicas-University of Seville-University Pablo de Olavide, Spain
| | - Marta Clemente-Ruiz
- Department of Genome Biology, Andalusian Molecular Biology and Regenerative Medicine Center (CABIMER), Consejo Superior de Investigaciones Científicas-University of Seville-University Pablo de Olavide, Spain
| | - Félix Prado
- Department of Genome Biology, Andalusian Molecular Biology and Regenerative Medicine Center (CABIMER), Consejo Superior de Investigaciones Científicas-University of Seville-University Pablo de Olavide, Spain
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12
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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.
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13
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Cdc48/VCP Promotes Chromosome Morphogenesis by Releasing Condensin from Self-Entrapment in Chromatin. Mol Cell 2019; 69:664-676.e5. [PMID: 29452641 DOI: 10.1016/j.molcel.2018.01.030] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 11/04/2017] [Accepted: 01/22/2018] [Indexed: 01/26/2023]
Abstract
The morphological transformation of amorphous chromatin into distinct chromosomes is a hallmark of mitosis. To achieve this, chromatin must be compacted and remodeled by a ring-shaped enzyme complex known as condensin. However, the mechanistic basis underpinning condensin's role in chromosome remodeling has remained elusive. Here we show that condensin has a strong tendency to trap itself in its own reaction product during chromatin compaction and yet is capable of interacting with chromatin in a highly dynamic manner in vivo. To resolve this apparent paradox, we identified specific chromatin remodelers and AAA-class ATPases that act in a coordinated manner to release condensin from chromatin entrapment. The Cdc48 segregase is the central linchpin of this regulatory mechanism and promotes ubiquitin-dependent cycling of condensin on mitotic chromatin as well as effective chromosome condensation. Collectively, our results show that condensin inhibition by its own reaction product is relieved by forceful enzyme extraction from chromatin.
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14
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Srivatsan A, Li BZ, Szakal B, Branzei D, Putnam CD, Kolodner RD. The Swr1 chromatin-remodeling complex prevents genome instability induced by replication fork progression defects. Nat Commun 2018; 9:3680. [PMID: 30206225 PMCID: PMC6134005 DOI: 10.1038/s41467-018-06131-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 08/09/2018] [Indexed: 01/05/2023] Open
Abstract
Genome instability is associated with tumorigenesis. Here, we identify a role for the histone Htz1, which is deposited by the Swr1 chromatin-remodeling complex (SWR-C), in preventing genome instability in the absence of the replication fork/replication checkpoint proteins Mrc1, Csm3, or Tof1. When combined with deletion of SWR1 or HTZ1, deletion of MRC1, CSM3, or TOF1 or a replication-defective mrc1 mutation causes synergistic increases in gross chromosomal rearrangement (GCR) rates, accumulation of a broad spectrum of GCRs, and hypersensitivity to replication stress. The double mutants have severe replication defects and accumulate aberrant replication intermediates. None of the individual mutations cause large increases in GCR rates; however, defects in MRC1, CSM3 or TOF1 cause activation of the DNA damage checkpoint and replication defects. We propose a model in which Htz1 deposition and retention in chromatin prevents transiently stalled replication forks that occur in mrc1, tof1, or csm3 mutants from being converted to DNA double-strand breaks that trigger genome instability.
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Affiliation(s)
- Anjana Srivatsan
- Ludwig Institute for Cancer Research, University of California School of Medicine, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0669, USA
| | - Bin-Zhong Li
- Ludwig Institute for Cancer Research, University of California School of Medicine, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0669, USA
| | - Barnabas Szakal
- The FIRC Institute of Molecular Oncology Foundation, Via Adamello 16, 20139, Milan, Italy
| | - Dana Branzei
- The FIRC Institute of Molecular Oncology Foundation, Via Adamello 16, 20139, Milan, Italy.,Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche (IGM-CNR), Via Abbiategrasso 207, 27100, Pavia, Italy
| | - Christopher D Putnam
- Ludwig Institute for Cancer Research, University of California School of Medicine, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0669, USA.,Departments of Medicine, University of California School of Medicine, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0669, USA
| | - Richard D Kolodner
- Ludwig Institute for Cancer Research, University of California School of Medicine, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0669, USA. .,Cellular and Molecular Medicine, University of California School of Medicine, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0669, USA. .,Moores-UCSD Cancer Center, University of California School of Medicine, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0669, USA. .,Institute of Genomic Medicine, University of California School of Medicine, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0669, USA.
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15
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Champroux A, Cocquet J, Henry-Berger J, Drevet JR, Kocer A. A Decade of Exploring the Mammalian Sperm Epigenome: Paternal Epigenetic and Transgenerational Inheritance. Front Cell Dev Biol 2018; 6:50. [PMID: 29868581 PMCID: PMC5962689 DOI: 10.3389/fcell.2018.00050] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 04/18/2018] [Indexed: 12/12/2022] Open
Abstract
The past decade has seen a tremendous increase in interest and progress in the field of sperm epigenetics. Studies have shown that chromatin regulation during male germline development is multiple and complex, and that the spermatozoon possesses a unique epigenome. Its DNA methylation profile, DNA-associated proteins, nucleo-protamine distribution pattern and non-coding RNA set up a unique epigenetic landscape which is delivered, along with its haploid genome, to the oocyte upon fertilization, and therefore can contribute to embryogenesis and to the offspring health. An emerging body of compelling data demonstrates that environmental exposures and paternal lifestyle can change the sperm epigenome and, consequently, may affect both the embryonic developmental program and the health of future generations. This short review will attempt to provide an overview of what is currently known about sperm epigenome and the existence of transgenerational epigenetic inheritance of paternally acquired traits that may contribute to the offspring phenotype.
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Affiliation(s)
- Alexandre Champroux
- GReD, Laboratoire “Génétique, Reproduction and Développement,” UMR Centre National de la Recherche Scientifique 6293, INSERM U1103, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Julie Cocquet
- INSERM U1016, Institut Cochin, Centre National de la Recherche Scientifique UMR8104, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Joëlle Henry-Berger
- GReD, Laboratoire “Génétique, Reproduction and Développement,” UMR Centre National de la Recherche Scientifique 6293, INSERM U1103, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Joël R. Drevet
- GReD, Laboratoire “Génétique, Reproduction and Développement,” UMR Centre National de la Recherche Scientifique 6293, INSERM U1103, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Ayhan Kocer
- GReD, Laboratoire “Génétique, Reproduction and Développement,” UMR Centre National de la Recherche Scientifique 6293, INSERM U1103, Université Clermont Auvergne, Clermont-Ferrand, France
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16
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The Nuts and Bolts of Transcriptionally Silent Chromatin in Saccharomyces cerevisiae. Genetics 2017; 203:1563-99. [PMID: 27516616 DOI: 10.1534/genetics.112.145243] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/30/2016] [Indexed: 12/31/2022] Open
Abstract
Transcriptional silencing in Saccharomyces cerevisiae occurs at several genomic sites including the silent mating-type loci, telomeres, and the ribosomal DNA (rDNA) tandem array. Epigenetic silencing at each of these domains is characterized by the absence of nearly all histone modifications, including most prominently the lack of histone H4 lysine 16 acetylation. In all cases, silencing requires Sir2, a highly-conserved NAD(+)-dependent histone deacetylase. At locations other than the rDNA, silencing also requires additional Sir proteins, Sir1, Sir3, and Sir4 that together form a repressive heterochromatin-like structure termed silent chromatin. The mechanisms of silent chromatin establishment, maintenance, and inheritance have been investigated extensively over the last 25 years, and these studies have revealed numerous paradigms for transcriptional repression, chromatin organization, and epigenetic gene regulation. Studies of Sir2-dependent silencing at the rDNA have also contributed to understanding the mechanisms for maintaining the stability of repetitive DNA and regulating replicative cell aging. The goal of this comprehensive review is to distill a wide array of biochemical, molecular genetic, cell biological, and genomics studies down to the "nuts and bolts" of silent chromatin and the processes that yield transcriptional silencing.
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17
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Borrie MS, Campor JS, Joshi H, Gartenberg MR. Binding, sliding, and function of cohesin during transcriptional activation. Proc Natl Acad Sci U S A 2017; 114:E1062-E1071. [PMID: 28137853 PMCID: PMC5320966 DOI: 10.1073/pnas.1617309114] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The ring-shaped cohesin complex orchestrates long-range DNA interactions to mediate sister chromatid cohesion and other aspects of chromosome structure and function. In the yeast Saccharomyces cerevisiae, the complex binds discrete sites along chromosomes, including positions within and around genes. Transcriptional activity redistributes the complex to the 3' ends of convergently oriented gene pairs. Despite the wealth of information about where cohesin binds, little is known about cohesion at individual chromosomal binding sites and how transcription affects cohesion when cohesin complexes redistribute. In this study, we generated extrachromosomal DNA circles to study cohesion in response to transcriptional induction of a model gene, URA3. Functional cohesin complexes loaded onto the locus via a poly(dA:dT) tract in the gene promoter and mediated cohesion before induction. Upon transcription, the fate of these complexes depended on whether the DNA was circular or not. When gene activation occurred before DNA circularization, cohesion was lost. When activation occurred after DNA circularization, cohesion persisted. The presence of a convergently oriented gene also prevented transcription-driven loss of functional cohesin complexes, at least in M phase-arrested cells. The results are consistent with cohesin binding chromatin in a topological embrace and with transcription mobilizing functional complexes by sliding them along DNA.
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MESH Headings
- Adenosine Triphosphatases/metabolism
- Binding Sites
- Cell Cycle Proteins/metabolism
- Chromosomal Proteins, Non-Histone/metabolism
- Chromosomes, Fungal/metabolism
- Chromosomes, Fungal/ultrastructure
- DNA, Circular/metabolism
- DNA, Fungal/genetics
- DNA-Binding Proteins/metabolism
- Extrachromosomal Inheritance
- Gene Expression Regulation, Fungal
- Genes, Fungal
- Genes, Reporter
- Genes, Synthetic
- Metaphase
- Multiprotein Complexes/metabolism
- Poly dA-dT/pharmacology
- Promoter Regions, Genetic/genetics
- Protein Binding
- Regulatory Sequences, Nucleic Acid
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae Proteins/genetics
- Saccharomyces cerevisiae Proteins/metabolism
- Transcriptional Activation/physiology
- Cohesins
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Affiliation(s)
- Melinda S Borrie
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854
| | - John S Campor
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854
| | - Hansa Joshi
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854
| | - Marc R Gartenberg
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854;
- The Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08901
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18
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Chen YF, Chou CC, Gartenberg MR. Determinants of Sir2-Mediated, Silent Chromatin Cohesion. Mol Cell Biol 2016; 36:2039-50. [PMID: 27185881 PMCID: PMC4946433 DOI: 10.1128/mcb.00057-16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 02/26/2016] [Accepted: 05/09/2016] [Indexed: 11/20/2022] Open
Abstract
Cohesin associates with distinct sites on chromosomes to mediate sister chromatid cohesion. Single cohesin complexes are thought to bind by encircling both sister chromatids in a topological embrace. Transcriptionally repressed chromosomal domains in the yeast Saccharomyces cerevisiae represent specialized sites of cohesion where cohesin binds silent chromatin in a Sir2-dependent fashion. In this study, we investigated the molecular basis for Sir2-mediated cohesion. We identified a cluster of charged surface residues of Sir2, collectively termed the EKDK motif, that are required for cohesin function. In addition, we demonstrated that Esc8, a Sir2-interacting factor, is also required for silent chromatin cohesion. Esc8 was previously shown to associate with Isw1, the enzymatic core of ISW1 chromatin remodelers, to form a variant of the ISW1a chromatin remodeling complex. When ESC8 was deleted or the EKDK motif was mutated, cohesin binding at silenced chromatin domains persisted but cohesion of the domains was abolished. The data are not consistent with cohesin embracing both sister chromatids within silent chromatin domains. Transcriptional silencing remains largely intact in strains lacking ESC8 or bearing EKDK mutations, indicating that silencing and cohesion are separable functions of Sir2 and silent chromatin.
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Affiliation(s)
- Yu-Fan Chen
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Chia-Ching Chou
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Marc R Gartenberg
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
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19
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Vernì F, Cenci G. The Drosophila histone variant H2A.V works in concert with HP1 to promote kinetochore-driven microtubule formation. Cell Cycle 2015; 14:577-88. [PMID: 25591068 DOI: 10.4161/15384101.2014.991176] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Unlike other organisms that have evolved distinct H2A variants for different functions, Drosophila melanogaster has just one variant which is capable of filling many roles. This protein, H2A.V, combines the features of the conserved variants H2A.Z and H2A.X in transcriptional control/heterochromatin assembly and DNA damage response, respectively. Here we show that mutations in the gene encoding H2A.V affect chromatin compaction and perturb chromosome segregation in Drosophila mitotic cells. A microtubule (MT) regrowth assay after cold exposure revealed that loss of H2A.V impairs the formation of kinetochore-driven (k) fibers, which can account for defects in chromosome segregation. All defects are rescued by a transgene encoding H2A.V that lacks the H2A.X function in the DNA damage response, suggesting that the H2A.Z (but not H2A.X) functionality of H2A.V is required for chromosome segregation. We also found that loss of H2A.V weakens HP1 localization, specifically at the pericentric heterochromatin of metaphase chromosomes. Interestingly, loss of HP1 yielded not only telomeric fusions but also mitotic defects similar to those seen in H2A.V null mutants, suggesting a role for HP1 in chromosome segregation. We also show that H2A.V precipitates HP1 from larval brain extracts indicating that both proteins are part of the same complex. Moreover, we found that the overexpression of HP1 rescues chromosome missegregation and defects in the kinetochore-driven k-fiber regrowth of H2A.V mutants indicating that both phenotypes are influenced by unbalanced levels of HP1. Collectively, our results suggest that H2A.V and HP1 work in concert to ensure kinetochore-driven MT growth.
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Affiliation(s)
- Fiammetta Vernì
- a Dipartimento di Biologia e Biotecnologie "C. Darwin" ; Sapienza Università di Roma ; Roma , Italy
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20
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Melters DP, Nye J, Zhao H, Dalal Y. Chromatin Dynamics in Vivo: A Game of Musical Chairs. Genes (Basel) 2015; 6:751-76. [PMID: 26262644 PMCID: PMC4584328 DOI: 10.3390/genes6030751] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 07/17/2015] [Accepted: 07/28/2015] [Indexed: 01/30/2023] Open
Abstract
Histones are a major component of chromatin, the nucleoprotein complex fundamental to regulating transcription, facilitating cell division, and maintaining genome integrity in almost all eukaryotes. In addition to canonical, replication-dependent histones, replication-independent histone variants exist in most eukaryotes. In recent years, steady progress has been made in understanding how histone variants assemble, their involvement in development, mitosis, transcription, and genome repair. In this review, we will focus on the localization of the major histone variants H3.3, CENP-A, H2A.Z, and macroH2A, as well as how these variants have evolved, their structural differences, and their functional significance in vivo.
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Affiliation(s)
- Daniël P Melters
- Chromatin Structure and Epigenetics Mechanisms Unit, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 41 Library Drive, Bethesda, MD 20892, USA.
| | - Jonathan Nye
- Chromatin Structure and Epigenetics Mechanisms Unit, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 41 Library Drive, Bethesda, MD 20892, USA.
| | - Haiqing Zhao
- Chromatin Structure and Epigenetics Mechanisms Unit, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 41 Library Drive, Bethesda, MD 20892, USA.
- Biophysics Graduate Program, University of Maryland, College Park, MD 20742, USA.
| | - Yamini Dalal
- Chromatin Structure and Epigenetics Mechanisms Unit, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 41 Library Drive, Bethesda, MD 20892, USA.
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21
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Chemical “Diversity” of Chromatin Through Histone Variants and Histone Modifications. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s40610-015-0005-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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22
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Tong K, Skibbens RV. Cohesin without cohesion: a novel role for Pds5 in Saccharomyces cerevisiae. PLoS One 2014; 9:e100470. [PMID: 24963665 PMCID: PMC4070927 DOI: 10.1371/journal.pone.0100470] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 05/18/2014] [Indexed: 11/18/2022] Open
Abstract
High fidelity chromosome segregation during mitosis requires that cells identify the products of DNA replication during S-phase and then maintain that identity until anaphase onset. Sister chromatid identity is achieved through cohesin complexes (Smc1, Smc3, and Mcd1 and Irr1/Scc3), but the structure through which cohesins perform this task remains enigmatic. In the absence of unambiguous data, a popular model is that a subset of cohesin subunits form a huge ring-like structure that embraces both sister chromatids. This 'one-ring two-sister chromatid embrace' model makes clear predictions--including that premature cohesion loss in mitotic cells must occur through a substantial reduction in cohesin-DNA associations. We used chromatin immunoprecipitation to directly test for cohesin dissociation from well-established cohesin binding sites in mitotic cells inactivated for Pds5--a key cohesin regulatory protein. The results reveal little if any chromatin dissociation from cohesins, despite a regimen that produces both massive loss of sister chromatid tethering and cell inviability. We further excluded models that cohesion loss in mitotic cells inactivated for Pds5 arises through either cohesin subunit degradation, premature Hos1-dependent Smc3 de-acetylation or Rad61/WAPL-dependent regulation of cohesin dynamics. In combination, our findings support a model that cohesin complexes associate with each sister and that sister chromatid cohesion likely results from cohesin-cohesin interactions. We further assessed the role that Pds5 plays in cohesion establishment during S-phase. The results show that Pds5 inactivation can result in establishment defects despite normal cohesion loading and Smc3 acetylation, revealing a novel establishment role for Pds5 that is independent of these processes. The combination of findings provides important new insights that significantly impact current models of both cohesion establishment reactions and maintenance.
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Affiliation(s)
- Kevin Tong
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania, United States of America
| | - Robert V. Skibbens
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania, United States of America
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23
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Boyarchuk E, Filipescu D, Vassias I, Cantaloube S, Almouzni G. The histone variant composition of centromeres is controlled by the pericentric heterochromatin state during the cell cycle. J Cell Sci 2014; 127:3347-59. [PMID: 24906798 DOI: 10.1242/jcs.148189] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Correct chromosome segregation requires a unique chromatin environment at centromeres and in their vicinity. Here, we address how the deposition of canonical H2A and H2A.Z histone variants is controlled at pericentric heterochromatin (PHC). Whereas in euchromatin newly synthesized H2A and H2A.Z are deposited throughout the cell cycle, we reveal two discrete waves of deposition at PHC - during mid to late S phase in a replication-dependent manner for H2A and during G1 phase for H2A.Z. This G1 cell cycle restriction is lost when heterochromatin features are altered, leading to the accumulation of H2A.Z at the domain. Interestingly, compromising PHC integrity also impacts upon neighboring centric chromatin, increasing the amount of centromeric CENP-A without changing the timing of its deposition. We conclude that the higher-order chromatin structure at the pericentric domain influences dynamics at the nucleosomal level within centromeric chromatin. The two different modes of rearrangement of the PHC during the cell cycle provide distinct opportunities to replenish one or the other H2A variant, highlighting PHC integrity as a potential signal to regulate the deposition timing and stoichiometry of histone variants at the centromere.
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Affiliation(s)
- Ekaterina Boyarchuk
- Institut Curie, Centre de Recherche, Paris, 75248 France CNRS, UMR3664, Paris, 75248 France Equipe Labellisée Ligue contre le Cancer, UMR3664, Paris, 75248 France UPMC, UMR3664, Paris, 75248 France Sorbonne University, PSL, 75006 Paris, France
| | - Dan Filipescu
- Institut Curie, Centre de Recherche, Paris, 75248 France CNRS, UMR3664, Paris, 75248 France Equipe Labellisée Ligue contre le Cancer, UMR3664, Paris, 75248 France UPMC, UMR3664, Paris, 75248 France Sorbonne University, PSL, 75006 Paris, France
| | - Isabelle Vassias
- Institut Curie, Centre de Recherche, Paris, 75248 France CNRS, UMR3664, Paris, 75248 France Equipe Labellisée Ligue contre le Cancer, UMR3664, Paris, 75248 France UPMC, UMR3664, Paris, 75248 France Sorbonne University, PSL, 75006 Paris, France
| | - Sylvain Cantaloube
- Institut Curie, Centre de Recherche, Paris, 75248 France CNRS, UMR3664, Paris, 75248 France Equipe Labellisée Ligue contre le Cancer, UMR3664, Paris, 75248 France UPMC, UMR3664, Paris, 75248 France Sorbonne University, PSL, 75006 Paris, France
| | - Geneviève Almouzni
- Institut Curie, Centre de Recherche, Paris, 75248 France CNRS, UMR3664, Paris, 75248 France Equipe Labellisée Ligue contre le Cancer, UMR3664, Paris, 75248 France UPMC, UMR3664, Paris, 75248 France Sorbonne University, PSL, 75006 Paris, France
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24
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Tapia-Alveal C, Lin SJ, Yeoh A, Jabado OJ, O'Connell MJ. H2A.Z-dependent regulation of cohesin dynamics on chromosome arms. Mol Cell Biol 2014; 34:2092-104. [PMID: 24687850 PMCID: PMC4019066 DOI: 10.1128/mcb.00193-14] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 02/25/2014] [Accepted: 03/21/2014] [Indexed: 11/20/2022] Open
Abstract
Structural maintenance of chromosomes (SMC) complexes and DNA topoisomerases are major determinants of chromosome structure and dynamics. The cohesin complex embraces sister chromatids throughout interphase, but during mitosis most cohesin is stripped from chromosome arms by early prophase, while the remaining cohesin at kinetochores is cleaved at anaphase. This two-step removal of cohesin is required for sister chromatids to separate. The cohesin-related Smc5/6 complex has been studied mostly as a determinant of DNA repair via homologous recombination. However, chromosome segregation fails in Smc5/6 null mutants or cells treated with small interfering RNAs. This also occurs in Smc5/6 hypomorphs in the fission yeast Schizosaccharomyces pombe following genotoxic and replication stress, or topoisomerase II dysfunction, and these mitotic defects are due to the postanaphase retention of cohesin on chromosome arms. Here we show that mitotic and repair roles for Smc5/6 are genetically separable in S. pombe. Further, we identified the histone variant H2A.Z as a critical factor to modulate cohesin dynamics, and cells lacking H2A.Z suppress the mitotic defects conferred by Smc5/6 dysfunction. Together, H2A.Z and the SMC complexes ensure genome integrity through accurate chromosome segregation.
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Affiliation(s)
- Claudia Tapia-Alveal
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Su-Jiun Lin
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Aaron Yeoh
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Omar J. Jabado
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Matthew J. O'Connell
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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Duffy MF, Selvarajah SA, Josling GA, Petter M. Epigenetic regulation of the Plasmodium falciparum genome. Brief Funct Genomics 2013; 13:203-16. [PMID: 24326119 DOI: 10.1093/bfgp/elt047] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Recent research has highlighted some unique aspects of chromatin biology in the malaria parasite Plasmodium falciparum. During its erythrocytic lifecycle P. falciparum maintains its genome primarily as unstructured euchromatin. Indeed there is no clear role for chromatin-mediated silencing of the majority of the developmentally expressed genes in P. falciparum. However discontinuous stretches of heterochromatin are critical for variegated expression of contingency genes that mediate key pathogenic processes in malaria. These range from invasion of erythrocytes and antigenic variation to solute transport and growth adaptation in response to environmental changes. Despite lack of structure within euchromatin the nucleus maintains functional compartments that regulate expression of many genes at the nuclear periphery, particularly genes with clonally variant expression. The typical components of the chromatin regulatory machinery are present in P. falciparum; however, some of these appear to have evolved novel species-specific functions, e.g. the dynamic regulation of histone variants at virulence gene promoters. The parasite also appears to have repeatedly acquired chromatin regulatory proteins through lateral transfer from endosymbionts and from the host. P. falciparum chromatin regulators have been successfully targeted with multiple drugs in laboratory studies; hopefully their functional divergence from human counterparts will allow the development of parasite-specific inhibitors.
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