1
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Thamkachy R, Medina-Pritchard B, Park SH, Chiodi CG, Zou J, de la Torre-Barranco M, Shimanaka K, Abad MA, Gallego Páramo C, Feederle R, Ruksenaite E, Heun P, Davies OR, Rappsilber J, Schneidman-Duhovny D, Cho US, Jeyaprakash AA. Structural basis for Mis18 complex assembly and its implications for centromere maintenance. EMBO Rep 2024:10.1038/s44319-024-00183-w. [PMID: 38951710 DOI: 10.1038/s44319-024-00183-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 05/06/2024] [Accepted: 06/06/2024] [Indexed: 07/03/2024] Open
Abstract
The centromere, defined by the enrichment of CENP-A (a Histone H3 variant) containing nucleosomes, is a specialised chromosomal locus that acts as a microtubule attachment site. To preserve centromere identity, CENP-A levels must be maintained through active CENP-A loading during the cell cycle. A central player mediating this process is the Mis18 complex (Mis18α, Mis18β and Mis18BP1), which recruits the CENP-A-specific chaperone HJURP to centromeres for CENP-A deposition. Here, using a multi-pronged approach, we characterise the structure of the Mis18 complex and show that multiple hetero- and homo-oligomeric interfaces facilitate the hetero-octameric Mis18 complex assembly composed of 4 Mis18α, 2 Mis18β and 2 Mis18BP1. Evaluation of structure-guided/separation-of-function mutants reveals structural determinants essential for cell cycle controlled Mis18 complex assembly and centromere maintenance. Our results provide new mechanistic insights on centromere maintenance, highlighting that while Mis18α can associate with centromeres and deposit CENP-A independently of Mis18β, the latter is indispensable for the optimal level of CENP-A loading required for preserving the centromere identity.
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Affiliation(s)
- Reshma Thamkachy
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | | | - Sang Ho Park
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Carla G Chiodi
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Juan Zou
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | | | - Kazuma Shimanaka
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Maria Alba Abad
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | | | - Regina Feederle
- Monoclonal Antibody Core Facility, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764, Neuherberg, Germany
| | - Emilija Ruksenaite
- Institute Novo Nordisk Foundation Centre for Protein Research, Copenhagen, Denmark
| | - Patrick Heun
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Owen R Davies
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Juri Rappsilber
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
- Institute of Biotechnology, Technische Universität Berlin, 13355, Berlin, Germany
| | - Dina Schneidman-Duhovny
- School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Uhn-Soo Cho
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - A Arockia Jeyaprakash
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK.
- Gene Center, Department of Biochemistry, Ludwig Maximilians Universität, Munich, Germany.
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2
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Nakase Y, Murakami H, Suma M, Nagano K, Wakuda A, Kitagawa T, Matsumoto T. Cdc48 and its co-factor Ufd1 extract CENP-A from centromeric chromatin and can induce chromosome elimination in the fission yeast Schizosaccharomyces pombe. Biol Open 2024; 13:bio060287. [PMID: 38526189 PMCID: PMC11033524 DOI: 10.1242/bio.060287] [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: 12/19/2023] [Accepted: 03/14/2024] [Indexed: 03/26/2024] Open
Abstract
CENP-A determines the identity of the centromere. Because the position and size of the centromere and its number per chromosome must be maintained, the distribution of CENP-A is strictly regulated. In this study, we have aimed to understand mechanisms to regulate the distribution of CENP-A (Cnp1SP) in fission yeast. A mutant of the ufd1+ gene (ufd1-73) encoding a cofactor of Cdc48 ATPase is sensitive to Cnp1 expressed at a high level and allows mislocalization of Cnp1. The level of Cnp1 in centromeric chromatin is increased in the ufd1-73 mutant even when Cnp1 is expressed at a normal level. A preexisting mutant of the cdc48+ gene (cdc48-353) phenocopies the ufd1-73 mutant. We have also shown that Cdc48 and Ufd1 proteins interact physically with centromeric chromatin. Finally, Cdc48 ATPase with Ufd1 artificially recruited to the centromere of a mini-chromosome (Ch16) induce a loss of Cnp1 from Ch16, leading to an increased rate of chromosome loss. It appears that Cdc48 ATPase, together with its cofactor Ufd1 remove excess Cnp1 from chromatin, likely in a direct manner. This mechanism may play a role in centromere disassembly, a process to eliminate Cnp1 to inactivate the kinetochore function during development, differentiation, and stress response.
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Affiliation(s)
- Yukiko Nakase
- Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Yoshida-Konoe cho, Sakyo ku, Kyoto 606-8501, Japan
| | - Hiroaki Murakami
- Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Yoshida-Konoe cho, Sakyo ku, Kyoto 606-8501, Japan
| | - Michiko Suma
- Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Yoshida-Konoe cho, Sakyo ku, Kyoto 606-8501, Japan
| | - Kaho Nagano
- Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Yoshida-Konoe cho, Sakyo ku, Kyoto 606-8501, Japan
| | - Airi Wakuda
- Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Yoshida-Konoe cho, Sakyo ku, Kyoto 606-8501, Japan
| | - Teppei Kitagawa
- Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Yoshida-Konoe cho, Sakyo ku, Kyoto 606-8501, Japan
| | - Tomohiro Matsumoto
- Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Yoshida-Konoe cho, Sakyo ku, Kyoto 606-8501, Japan
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3
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Scott WA, Campos EI. Interactions With Histone H3 & Tools to Study Them. Front Cell Dev Biol 2020; 8:701. [PMID: 32850821 PMCID: PMC7411163 DOI: 10.3389/fcell.2020.00701] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 07/10/2020] [Indexed: 01/12/2023] Open
Abstract
Histones are an integral part of chromatin and thereby influence its structure, dynamics, and functions. The effects of histone variants, posttranslational modifications, and binding proteins is therefore of great interest. From the moment that they are deposited on chromatin, nucleosomal histones undergo dynamic changes in function of the cell cycle, and as DNA is transcribed and replicated. In the process, histones are not only modified and bound by various proteins, but also shuffled, evicted, or replaced. Technologies and tools to study such dynamic events continue to evolve and better our understanding of chromatin and of histone proteins proper. Here, we provide an overview of H3.1 and H3.3 histone dynamics throughout the cell cycle, while highlighting some of the tools used to study their protein–protein interactions. We specifically discuss how histones are chaperoned, modified, and bound by various proteins at different stages of the cell cycle. Established and select emerging technologies that furthered (or have a high potential of furthering) our understanding of the dynamic histone–protein interactions are emphasized. This includes experimental tools to investigate spatiotemporal changes on chromatin, the role of histone chaperones, histone posttranslational modifications, and histone-binding effector proteins.
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Affiliation(s)
- William A Scott
- Genetics & Genome Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Eric I Campos
- Genetics & Genome Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
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4
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Killinger K, Böhm M, Steinbach P, Hagemann G, Blüggel M, Jänen K, Hohoff S, Bayer P, Herzog F, Westermann S. Auto-inhibition of Mif2/CENP-C ensures centromere-dependent kinetochore assembly in budding yeast. EMBO J 2020; 39:e102938. [PMID: 32515113 PMCID: PMC7360964 DOI: 10.15252/embj.2019102938] [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: 07/12/2019] [Revised: 04/27/2020] [Accepted: 05/12/2020] [Indexed: 11/28/2022] Open
Abstract
Kinetochores are chromatin‐bound multi‐protein complexes that allow high‐fidelity chromosome segregation during mitosis and meiosis. Kinetochore assembly is exclusively initiated at chromatin containing Cse4/CENP‐A nucleosomes. The molecular mechanisms ensuring that subcomplexes assemble efficiently into kinetochores only at centromeres, but not anywhere else, are incompletely understood. Here, we combine biochemical and genetic experiments to demonstrate that auto‐inhibition of the conserved kinetochore subunit Mif2/CENP‐C contributes to preventing unscheduled kinetochore assembly in budding yeast cells. We show that wild‐type Mif2 is attenuated in its ability to bind a key downstream component in the assembly pathway, the Mtw1 complex, and that addition of Cse4 nucleosomes overcomes this inhibition. By exchanging the N‐terminus of Mif2 with its functional counterpart from Ame1/CENP‐U, we have created a Mif2 mutant which bypasses the Cse4 requirement for Mtw1 binding in vitro, thereby shortcutting kinetochore assembly. Expression of this Mif2 mutant in cells leads to mis‐localization of the Mtw1 complex and causes pronounced chromosome segregation defects. We propose that auto‐inhibition of Mif2/CENP‐C constitutes a key concept underlying the molecular logic of kinetochore assembly.
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Affiliation(s)
- Kerstin Killinger
- Department of Molecular Genetics, Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Miriam Böhm
- Department of Molecular Genetics, Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Philine Steinbach
- Department of Molecular Genetics, Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Götz Hagemann
- Department of Biochemistry, Gene Center, Ludwig-Maximilians-Universität München, München, Germany
| | - Mike Blüggel
- Structural and Medicinal Biochemistry, Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Karolin Jänen
- Department of Molecular Genetics, Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Simone Hohoff
- Department of Molecular Genetics, Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Peter Bayer
- Structural and Medicinal Biochemistry, Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Franz Herzog
- Department of Biochemistry, Gene Center, Ludwig-Maximilians-Universität München, München, Germany
| | - Stefan Westermann
- Department of Molecular Genetics, Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
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5
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Fission Yeast CENP-C (Cnp3) Plays a Role in Restricting the Site of CENP-A Accumulation. G3-GENES GENOMES GENETICS 2018; 8:2723-2733. [PMID: 29925533 PMCID: PMC6071599 DOI: 10.1534/g3.118.200486] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The centromere is a chromosomal locus where a microtubule attachment site, termed kinetochore, is assembled in mitosis. In most eukaryotes, with the exception of holocentric species, each chromosome contains a single distinct centromere. A chromosome with an additional centromere undergoes successive rounds of anaphase bridge formation and breakage, or triggers a cell cycle arrest imposed by DNA damage and replication checkpoints. We report here a study in Schizosaccharomyces pombe to characterize a mutant (cnp3-1) in a gene encoding a homolog of mammalian centromere-specific protein, CENP-C. At the restrictive temperature 36°, the Cnp3-1 mutant protein loses its localization at the centromere. In the cnp3-1 mutant, the level of the Cnp1 (a homolog of a centromere-specific histone CENP-A) also decreases at the centromere. Interestingly, the cnp3-1 mutant is prone to promiscuous accumulation of Cnp1 at non-centromeric regions, when Cnp1 is present in excess. Unlike the wild type protein, Cnp3-1 mutant protein is found at the sites of promiscuous accumulation of Cnp1, suggesting that Cnp3-1 may stabilize or promote accumulation of Cnp1 at non-centromeric regions. From these results, we infer the role of Cnp3 in restricting the site of accumulation of Cnp1 and thus to prevent formation of de novo centromeres.
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6
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Using human artificial chromosomes to study centromere assembly and function. Chromosoma 2017; 126:559-575. [DOI: 10.1007/s00412-017-0633-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/12/2017] [Accepted: 06/13/2017] [Indexed: 12/13/2022]
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7
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Spiller F, Medina-Pritchard B, Abad MA, Wear MA, Molina O, Earnshaw WC, Jeyaprakash AA. Molecular basis for Cdk1-regulated timing of Mis18 complex assembly and CENP-A deposition. EMBO Rep 2017; 18:894-905. [PMID: 28377371 PMCID: PMC5452045 DOI: 10.15252/embr.201643564] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 03/13/2017] [Accepted: 03/15/2017] [Indexed: 12/26/2022] Open
Abstract
The centromere, a chromosomal locus that acts as a microtubule attachment site, is epigenetically specified by the enrichment of CENP‐A nucleosomes. Centromere maintenance during the cell cycle requires HJURP‐mediated CENP‐A deposition, a process regulated by the Mis18 complex (Mis18α/Mis18β/Mis18BP1). Spatial and temporal regulation of Mis18 complex assembly is crucial for its centromere association and function. Here, we provide the molecular basis for the assembly and regulation of the Mis18 complex. We show that the N‐terminal region of Mis18BP1 spanning amino acid residues 20–130 directly interacts with Mis18α/β to form the Mis18 complex. Within Mis18α/β, the Mis18α MeDiY domain can directly interact with Mis18BP1. Mis18α/β forms a hetero‐hexamer with 4 Mis18α and 2 Mis18β. However, only two copies of Mis18BP1 interact with Mis18α/β to form a hetero‐octameric assembly, highlighting the role of Mis18 oligomerization in limiting the number of Mis18BP1 within the Mis18 complex. Furthermore, we demonstrate the involvement of consensus Cdk1 phosphorylation sites on Mis18 complex assembly and thus provide a rationale for cell cycle‐regulated timing of Mis18 assembly and CENP‐A deposition.
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Affiliation(s)
- Frances Spiller
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Bethan Medina-Pritchard
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Maria Alba Abad
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Martin A Wear
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Oscar Molina
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - A Arockia Jeyaprakash
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
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8
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9
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Abstract
Centromeric chromatin undergoes major changes in composition and architecture during each cell cycle. These changes in specialized chromatin facilitate kinetochore formation in mitosis to ensure proper chromosome segregation. Thus, proper orchestration of centromeric chromatin dynamics during interphase, including replication in S phase, is crucial. We provide the current view concerning the centromeric architecture associated with satellite repeat sequences in mammals and its dynamics during the cell cycle. We summarize the contributions of deposited histone variants and their chaperones, other centromeric components - including proteins and their post-translational modifications, and RNAs - and we link the expression and deposition timing of each component during the cell cycle. Because neocentromeres occur at ectopic sites, we highlight how cell cycle processes can go wrong, leading to neocentromere formation and potentially disease.
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Affiliation(s)
- Sebastian Müller
- Institut Curie, PSL Research University, CNRS, UMR3664, Equipe Labellisée Ligue contre le Cancer, F-75005 Paris, France.,Sorbonne Universités, UPMC Université Paris 06, CNRS, UMR3664, F-75005 Paris, France
| | - Geneviève Almouzni
- Institut Curie, PSL Research University, CNRS, UMR3664, Equipe Labellisée Ligue contre le Cancer, F-75005 Paris, France.,Sorbonne Universités, UPMC Université Paris 06, CNRS, UMR3664, F-75005 Paris, France
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10
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Musacchio A, Desai A. A Molecular View of Kinetochore Assembly and Function. BIOLOGY 2017; 6:E5. [PMID: 28125021 PMCID: PMC5371998 DOI: 10.3390/biology6010005] [Citation(s) in RCA: 310] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 01/16/2017] [Accepted: 01/17/2017] [Indexed: 12/15/2022]
Abstract
Kinetochores are large protein assemblies that connect chromosomes to microtubules of the mitotic and meiotic spindles in order to distribute the replicated genome from a mother cell to its daughters. Kinetochores also control feedback mechanisms responsible for the correction of incorrect microtubule attachments, and for the coordination of chromosome attachment with cell cycle progression. Finally, kinetochores contribute to their own preservation, across generations, at the specific chromosomal loci devoted to host them, the centromeres. They achieve this in most species by exploiting an epigenetic, DNA-sequence-independent mechanism; notable exceptions are budding yeasts where a specific sequence is associated with centromere function. In the last 15 years, extensive progress in the elucidation of the composition of the kinetochore and the identification of various physical and functional modules within its substructure has led to a much deeper molecular understanding of kinetochore organization and the origins of its functional output. Here, we provide a broad summary of this progress, focusing primarily on kinetochores of humans and budding yeast, while highlighting work from other models, and present important unresolved questions for future studies.
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Affiliation(s)
- Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn Straße 11, Dortmund 44227, Germany.
- Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen 45117, Germany.
| | - Arshad Desai
- Ludwig Institute for Cancer Research, La Jolla, CA 92093, USA.
- Department of Cellular & Molecular Medicine, 9500 Gilman Dr., La Jolla, CA 92093, USA.
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11
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Weir JR, Faesen AC, Klare K, Petrovic A, Basilico F, Fischböck J, Pentakota S, Keller J, Pesenti ME, Pan D, Vogt D, Wohlgemuth S, Herzog F, Musacchio A. Insights from biochemical reconstitution into the architecture of human kinetochores. Nature 2016; 537:249-253. [PMID: 27580032 DOI: 10.1038/nature19333] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 07/25/2016] [Indexed: 12/15/2022]
Abstract
Chromosomes are carriers of genetic material and their accurate transfer from a mother cell to its two daughters during cell division is of paramount importance for life. Kinetochores are crucial for this process, as they connect chromosomes with microtubules in the mitotic spindle. Kinetochores are multi-subunit complexes that assemble on specialized chromatin domains, the centromeres, that are able to enrich nucleosomes containing the histone H3 variant centromeric protein A (CENP-A). A group of several additional CENPs, collectively known as constitutive centromere associated network (CCAN), establish the inner kinetochore, whereas a ten-subunit assembly known as the KMN network creates a microtubule-binding site in the outer kinetochore. Interactions between CENP-A and two CCAN subunits, CENP-C and CENP-N, have been previously described, but a comprehensive understanding of CCAN organization and of how it contributes to the selective recognition of CENP-A has been missing. Here we use biochemical reconstitution to unveil fundamental principles of kinetochore organization and function. We show that cooperative interactions of a seven-subunit CCAN subcomplex, the CHIKMLN complex, determine binding selectivity for CENP-A over H3-nucleosomes. The CENP-A:CHIKMLN complex binds directly to the KMN network, resulting in a 21-subunit complex that forms a minimal high-affinity linkage between CENP-A nucleosomes and microtubules in vitro. This structural module is related to fungal point kinetochores, which bind a single microtubule. Its convolution with multiple CENP-A proteins may give rise to the regional kinetochores of higher eukaryotes, which bind multiple microtubules. Biochemical reconstitution paves the way for mechanistic and quantitative analyses of kinetochores.
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Affiliation(s)
- John R Weir
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Alex C Faesen
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Kerstin Klare
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Arsen Petrovic
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Federica Basilico
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Josef Fischböck
- Gene Center Munich, Ludwig-Maximilians-Universität München, Feodor-Lynen-Straße 25, 81377 Munich, Germany
| | - Satyakrishna Pentakota
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Jenny Keller
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Marion E Pesenti
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Dongqing Pan
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Doro Vogt
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Sabine Wohlgemuth
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Franz Herzog
- Gene Center Munich, Ludwig-Maximilians-Universität München, Feodor-Lynen-Straße 25, 81377 Munich, Germany
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany.,Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Universitätsstraße, 45141 Essen, Germany
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12
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Subramanian L, Medina-Pritchard B, Barton R, Spiller F, Kulasegaran-Shylini R, Radaviciute G, Allshire RC, Arockia Jeyaprakash A. Centromere localization and function of Mis18 requires Yippee-like domain-mediated oligomerization. EMBO Rep 2016; 17:496-507. [PMID: 26921242 PMCID: PMC4818781 DOI: 10.15252/embr.201541520] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 02/03/2016] [Indexed: 11/09/2022] Open
Abstract
Mis18 is a key regulator responsible for the centromere localization of the CENP-A chaperone Scm3 in Schizosaccharomyces pombe and HJURP in humans, which establishes CENP-A chromatin that defines centromeres. The molecular and structural determinants of Mis18 centromere targeting remain elusive. Here, by combining structural, biochemical, and yeast genetic studies, we show that the oligomerization of S. pombe Mis18, mediated via its conserved N-terminal Yippee-like domain, is crucial for its centromere localization and function. The crystal structure of the N-terminal Yippee-like domain reveals a fold containing a cradle-shaped pocket that is implicated in protein/nucleic acid binding, which we show is required for Mis18 function. While the N-terminal Yippee-like domain forms a homodimer in vitro and in vivo, full-length Mis18, including the C-terminal α-helical domain, forms a homotetramer in vitro We also show that the Yippee-like domains of human Mis18α/Mis18β interact to form a heterodimer, implying a conserved structural theme for Mis18 regulation.
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Affiliation(s)
- Lakxmi Subramanian
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Bethan Medina-Pritchard
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Rachael Barton
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Frances Spiller
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | | | - Guoda Radaviciute
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Robin C Allshire
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - A Arockia Jeyaprakash
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
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13
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Subirana JA, Albà MM, Messeguer X. High evolutionary turnover of satellite families in Caenorhabditis. BMC Evol Biol 2015; 15:218. [PMID: 26438045 PMCID: PMC4595182 DOI: 10.1186/s12862-015-0495-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 09/22/2015] [Indexed: 02/07/2023] Open
Abstract
Background The high density of tandem repeat sequences (satellites) in nematode genomes and the availability of genome sequences from several species in the group offer a unique opportunity to better understand the evolutionary dynamics and the functional role of these sequences. We take advantage of the previously developed SATFIND program to study the satellites in four Caenorhabditis species and investigate these questions. Methods The identification and comparison of satellites is carried out in three steps. First we find all the satellites present in each species with the SATFIND program. Each satellite is defined by its length, number of repeats, and repeat sequence. Only satellites with at least ten repeats are considered. In the second step we build satellite families with a newly developed alignment program. Satellite families are defined by a consensus sequence and the number of satellites in the family. Finally we compare the consensus sequence of satellite families in different species. Results We give a catalog of individual satellites in each species. We have also identified satellite families with a related sequence and compare them in different species. We analyze the turnover of satellites: they increased in size through duplications of fragments of 100-300 bases. It appears that in many cases they have undergone an explosive expansion. In C. elegans we have identified a subset of large satellites that have strong affinity for the centromere protein CENP-A. We have also compared our results with those obtained from other species, including one nematode and three mammals. Conclusions Most satellite families found in Caenorhabditis are species-specific; in particular those with long repeats. A subset of these satellites may facilitate the formation of kinetochores in mitosis. Other satellite families in C. elegans are either related to Helitron transposons or to meiotic pairing centers. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0495-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Juan A Subirana
- Department of Computer Science, Universitat Politècnica de Catalunya, Jordi Girona 31, Barcelona, 08034, Spain. .,Evolutionary Genomics Group, Research Programme on Biomedical Informatics (GRIB) - Hospital del Mar Research Institute (IMIM), Universitat Pompeu Fabra (UPF), Dr. Aiguader 86, Barcelona, 08003, Spain.
| | - M Mar Albà
- Evolutionary Genomics Group, Research Programme on Biomedical Informatics (GRIB) - Hospital del Mar Research Institute (IMIM), Universitat Pompeu Fabra (UPF), Dr. Aiguader 86, Barcelona, 08003, Spain.
| | - Xavier Messeguer
- Department of Computer Science, Universitat Politècnica de Catalunya, Jordi Girona 31, Barcelona, 08034, Spain.
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Regional centromeres in the yeast Candida lusitaniae lack pericentromeric heterochromatin. Proc Natl Acad Sci U S A 2015; 112:12139-44. [PMID: 26371315 DOI: 10.1073/pnas.1508749112] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Point centromeres are specified by a short consensus sequence that seeds kinetochore formation, whereas regional centromeres lack a conserved sequence and instead are epigenetically inherited. Regional centromeres are generally flanked by heterochromatin that ensures high levels of cohesin and promotes faithful chromosome segregation. However, it is not known whether regional centromeres require pericentromeric heterochromatin. In the yeast Candida lusitaniae, we identified a distinct type of regional centromere that lacks pericentromeric heterochromatin. Centromere locations were determined by ChIP-sequencing of two key centromere proteins, Cse4 and Mif2, and are consistent with bioinformatic predictions. The centromeric DNA sequence was unique for each chromosome and spanned 4-4.5 kbp, consistent with regional epigenetically inherited centromeres. However, unlike other regional centromeres, there was no evidence of pericentromeric heterochromatin in C. lusitaniae. In particular, flanking genes were expressed at a similar level to the rest of the genome, and a URA3 reporter inserted adjacent to a centromere was not repressed. In addition, regions flanking the centromeric core were not associated with hypoacetylated histones or a sirtuin deacetylase that generates heterochromatin in other yeast. Interestingly, the centromeric chromatin had a distinct pattern of histone modifications, being enriched for methylated H3K79 and H3R2 but lacking methylation of H3K4, which is found at other regional centromeres. Thus, not all regional centromeres require flanking heterochromatin.
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15
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Mandáková T, Schranz ME, Sharbel TF, de Jong H, Lysak MA. Karyotype evolution in apomictic Boechera and the origin of the aberrant chromosomes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 82:785-93. [PMID: 25864414 DOI: 10.1111/tpj.12849] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 03/24/2015] [Accepted: 04/01/2015] [Indexed: 05/19/2023]
Abstract
Chromosome rearrangements may result in both decrease and increase of chromosome numbers. Here we have used comparative chromosome painting (CCP) to reconstruct the pathways of descending and ascending dysploidy in the genus Boechera (tribe Boechereae, Brassicaceae). We describe the origin and structure of three Boechera genomes and establish the origin of the previously described aberrant Het and Del chromosomes found in Boechera apomicts with euploid (2n = 14) and aneuploid (2n = 15) chromosome number. CCP analysis allowed us to reconstruct the origin of seven chromosomes in sexual B. stricta and apomictic B. divaricarpa from the ancestral karyotype (n = 8) of Brassicaceae lineage I. Whereas three chromosomes (BS4, BS6, and BS7) retained their ancestral structure, five chromosomes were reshuffled by reciprocal translocations to form chromosomes BS1-BS3 and BS5. The reduction of the chromosome number (from x = 8 to x = 7) was accomplished through the inactivation of a paleocentromere on chromosome BS5. In apomictic 2n = 14 plants, CCP identifies the largely heterochromatic chromosome (Het) being one of the BS1 homologues with the expansion of pericentromeric heterochromatin. In apomictic B. polyantha (2n = 15), the Het has undergone a centric fission resulting in two smaller chromosomes - the submetacentric Het' and telocentric Del. Here we show that new chromosomes can be formed by a centric fission and can be fixed in populations due to the apomictic mode of reproduction.
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Affiliation(s)
- Terezie Mandáková
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, CZ-62500, Czech Republic
| | - M Eric Schranz
- Plant Systematics Group, Wageningen University (WU), Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands
| | - Timothy F Sharbel
- Apomixis Research Group, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, D-06466, Germany
| | - Hans de Jong
- Laboratory of Genetics, Wageningen UR PSG, P.O. Box 16, Wageningen, 6700 AA, The Netherlands
| | - Martin A Lysak
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, CZ-62500, Czech Republic
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16
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Discovering centromere proteins: from cold white hands to the A, B, C of CENPs. Nat Rev Mol Cell Biol 2015; 16:443-9. [PMID: 25991376 DOI: 10.1038/nrm4001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The kinetochore is a complex molecular machine that directs chromosome segregation during mitosis. It is one of the most elaborate subcellular protein structures in eukaryotes, comprising more than 100 different proteins. Inner kinetochore proteins associate with specialized centromeric chromatin containing the histone H3 variant centromere protein A (CENP-A) in place of H3. Outer kinetochore proteins bind to microtubules and signal to delay anaphase onset when microtubules are absent. Since the first kinetochore proteins were discovered and cloned 30 years ago using autoimmune sera from patients with scleroderma-spectrum disease, much has been learnt about the composition, functions and regulation of this remarkable structure.
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17
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Catania S, Pidoux AL, Allshire RC. Sequence features and transcriptional stalling within centromere DNA promote establishment of CENP-A chromatin. PLoS Genet 2015; 11:e1004986. [PMID: 25738810 PMCID: PMC4349457 DOI: 10.1371/journal.pgen.1004986] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 01/06/2015] [Indexed: 11/19/2022] Open
Abstract
Centromere sequences are not conserved between species, and there is compelling evidence for epigenetic regulation of centromere identity, with location being dictated by the presence of chromatin containing the histone H3 variant CENP-A. Paradoxically, in most organisms CENP-A chromatin generally occurs on particular sequences. To investigate the contribution of primary DNA sequence to establishment of CENP-A chromatin in vivo, we utilised the fission yeast Schizosaccharomyces pombe. CENP-ACnp1 chromatin is normally assembled on ∼10 kb of central domain DNA within these regional centromeres. We demonstrate that overproduction of S. pombe CENP-ACnp1 bypasses the usual requirement for adjacent heterochromatin in establishing CENP-ACnp1 chromatin, and show that central domain DNA is a preferred substrate for de novo establishment of CENP-ACnp1 chromatin. When multimerised, a 2 kb sub-region can establish CENP-ACnp1 chromatin and form functional centromeres. Randomization of the 2 kb sequence to generate a sequence that maintains AT content and predicted nucleosome positioning is unable to establish CENP-ACnp1 chromatin. These analyses indicate that central domain DNA from fission yeast centromeres contains specific information that promotes CENP-ACnp1 incorporation into chromatin. Numerous transcriptional start sites were detected on the forward and reverse strands within the functional 2 kb sub-region and active promoters were identified. RNAPII is enriched on central domain DNA in wild-type cells, but only low levels of transcripts are detected, consistent with RNAPII stalling during transcription of centromeric DNA. Cells lacking factors involved in restarting transcription-TFIIS and Ubp3-assemble CENP-ACnp1 on central domain DNA when CENP-ACnp1 is at wild-type levels, suggesting that persistent stalling of RNAPII on centromere DNA triggers chromatin remodelling events that deposit CENP-ACnp1. Thus, sequence-encoded features of centromeric DNA create an environment of pervasive low quality RNAPII transcription that is an important determinant of CENP-ACnp1 assembly. These observations emphasise roles for both genetic and epigenetic processes in centromere establishment.
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Affiliation(s)
- Sandra Catania
- Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Alison L. Pidoux
- Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Robin C. Allshire
- Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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18
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Folco HD, Campbell CS, May KM, Espinoza CA, Oegema K, Hardwick KG, Grewal SIS, Desai A. The CENP-A N-tail confers epigenetic stability to centromeres via the CENP-T branch of the CCAN in fission yeast. Curr Biol 2015; 25:348-356. [PMID: 25619765 PMCID: PMC4318777 DOI: 10.1016/j.cub.2014.11.060] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 11/17/2014] [Accepted: 11/21/2014] [Indexed: 12/29/2022]
Abstract
In most eukaryotes, centromeres are defined epigenetically by presence of the histone H3 variant CENP-A [1-3]. CENP-A-containing chromatin recruits the constitutive centromere-associated network (CCAN) of proteins, which in turn directs assembly of the outer kinetochore to form microtubule attachments and ensure chromosome segregation fidelity [4-6]. Whereas the mechanisms that load CENP-A at centromeres are being elucidated, the functions of its divergent N-terminal tail remain enigmatic [7-12]. Here, we employ the well-studied fission yeast centromere [13-16] to investigate the function of the CENP-A (Cnp1) N-tail. We show that alteration of the N-tail does not affect Cnp1 loading at centromeres, outer kinetochore formation, or spindle checkpoint signaling but nevertheless elevates chromosome loss. N-tail mutants exhibited synthetic lethality with an altered centromeric DNA sequence, with rare survivors harboring chromosomal fusions in which the altered centromere was epigenetically inactivated. Elevated centromere inactivation was also observed for N-tail mutants with unaltered centromeric DNA sequences. N-tail mutants specifically reduced localization of the CCAN proteins Cnp20/CENP-T and Mis6/CENP-I, but not Cnp3/CENP-C. Overexpression of Cnp20/CENP-T suppressed defects in an N-tail mutant, suggesting a link between reduced CENP-T recruitment and the observed centromere inactivation phenotype. Thus, the Cnp1 N-tail promotes epigenetic stability of centromeres in fission yeast, at least in part via recruitment of the CENP-T branch of the CCAN.
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Affiliation(s)
- H Diego Folco
- Ludwig Institute for Cancer Research, Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Christopher S Campbell
- Ludwig Institute for Cancer Research, Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Karen M May
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Celso A Espinoza
- Ludwig Institute for Cancer Research, Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Karen Oegema
- Ludwig Institute for Cancer Research, Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kevin G Hardwick
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Shiv I S Grewal
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Arshad Desai
- Ludwig Institute for Cancer Research, Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
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Arimura Y, Shirayama K, Horikoshi N, Fujita R, Taguchi H, Kagawa W, Fukagawa T, Almouzni G, Kurumizaka H. Crystal structure and stable property of the cancer-associated heterotypic nucleosome containing CENP-A and H3.3. Sci Rep 2014; 4:7115. [PMID: 25408271 PMCID: PMC4236741 DOI: 10.1038/srep07115] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 11/03/2014] [Indexed: 12/11/2022] Open
Abstract
The centromere-specific histone H3 variant, CENP-A, is overexpressed in particular aggressive cancer cells, where it can be mislocalized ectopically in the form of heterotypic nucleosomes containing H3.3. In the present study, we report the crystal structure of the heterotypic CENP-A/H3.3 particle and reveal its “hybrid structure”, in which the physical characteristics of CENP-A and H3.3 are conserved independently within the same particle. The CENP-A/H3.3 nucleosome forms an unexpectedly stable structure as compared to the CENP-A nucleosome, and allows the binding of the essential centromeric protein, CENP-C, which is ectopically mislocalized in the chromosomes of CENP-A overexpressing cells.
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Affiliation(s)
- Yasuhiro Arimura
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Kazuyoshi Shirayama
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Naoki Horikoshi
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Risa Fujita
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Hiroyuki Taguchi
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Wataru Kagawa
- 1] Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan [2] Program in Chemistry and Life Science, School of Science and Engineering, Meisei University, 2-1-1 Hodokubo, Hino-shi, Tokyo 191-8506, Japan
| | - Tatsuo Fukagawa
- Department of Molecular Genetics, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Geneviève Almouzni
- 1] Institut Curie, Centre de Recherche, Paris, F-75248 France [2] CNRS, UMR3664, Paris, F-75248 France
| | - Hitoshi Kurumizaka
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
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20
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Subramanian L, Toda NRT, Rappsilber J, Allshire RC. Eic1 links Mis18 with the CCAN/Mis6/Ctf19 complex to promote CENP-A assembly. Open Biol 2014; 4:140043. [PMID: 24789708 PMCID: PMC4043117 DOI: 10.1098/rsob.140043] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
CENP-A chromatin forms the foundation for kinetochore assembly. Replication-independent incorporation of CENP-A at centromeres depends on its chaperone HJURPScm3, and Mis18 in vertebrates and fission yeast. The recruitment of Mis18 and HJURPScm3 to centromeres is cell cycle regulated. Vertebrate Mis18 associates with Mis18BP1KNL2, which is critical for the recruitment of Mis18 and HJURPScm3. We identify two novel fission yeast Mis18-interacting proteins (Eic1 and Eic2), components of the Mis18 complex. Eic1 is essential to maintain Cnp1CENP-A at centromeres and is crucial for kinetochore integrity; Eic2 is dispensable. Eic1 also associates with Fta7CENP-Q/Okp1, Cnl2Nkp2 and Mal2CENP-O/Mcm21, components of the constitutive CCAN/Mis6/Ctf19 complex. No Mis18BP1KNL2 orthologue has been identified in fission yeast, consequently it remains unknown how the key Cnp1CENP-A loading factor Mis18 is recruited. Our findings suggest that Eic1 serves a function analogous to that of Mis18BP1KNL2, thus representing the functional counterpart of Mis18BP1KNL2 in fission yeast that connects with a module within the CCAN/Mis6/Ctf19 complex to allow the temporally regulated recruitment of the Mis18/Scm3HJURP Cnp1CENP-A loading factors. The novel interactions identified between CENP-A loading factors and the CCAN/Mis6/Ctf19 complex are likely to also contribute to CENP-A maintenance in other organisms.
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Affiliation(s)
- Lakxmi Subramanian
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3JR, UK
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Mitra S, Gómez-Raja J, Larriba G, Dubey DD, Sanyal K. Rad51-Rad52 mediated maintenance of centromeric chromatin in Candida albicans. PLoS Genet 2014; 10:e1004344. [PMID: 24762765 PMCID: PMC3998917 DOI: 10.1371/journal.pgen.1004344] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 03/19/2014] [Indexed: 11/29/2022] Open
Abstract
Specification of the centromere location in most eukaryotes is not solely dependent on the DNA sequence. However, the non-genetic determinants of centromere identity are not clearly defined. While multiple mechanisms, individually or in concert, may specify centromeres epigenetically, most studies in this area are focused on a universal factor, a centromere-specific histone H3 variant CENP-A, often considered as the epigenetic determinant of centromere identity. In spite of variable timing of its loading at centromeres across species, a replication coupled early S phase deposition of CENP-A is found in most yeast centromeres. Centromeres are the earliest replicating chromosomal regions in a pathogenic budding yeast Candida albicans. Using a 2-dimensional agarose gel electrophoresis assay, we identify replication origins (ORI7-LI and ORI7-RI) proximal to an early replicating centromere (CEN7) in C. albicans. We show that the replication forks stall at CEN7 in a kinetochore dependent manner and fork stalling is reduced in the absence of the homologous recombination (HR) proteins Rad51 and Rad52. Deletion of ORI7-RI causes a significant reduction in the stalled fork signal and an increased loss rate of the altered chromosome 7. The HR proteins, Rad51 and Rad52, have been shown to play a role in fork restart. Confocal microscopy shows declustered kinetochores in rad51 and rad52 mutants, which are evidence of kinetochore disintegrity. CENP-ACaCse4 levels at centromeres, as determined by chromatin immunoprecipitation (ChIP) experiments, are reduced in absence of Rad51/Rad52 resulting in disruption of the kinetochore structure. Moreover, western blot analysis reveals that delocalized CENP-A molecules in HR mutants degrade in a similar fashion as in other kinetochore mutants described before. Finally, co-immunoprecipitation assays indicate that Rad51 and Rad52 physically interact with CENP-ACaCse4in vivo. Thus, the HR proteins Rad51 and Rad52 epigenetically maintain centromere functioning by regulating CENP-ACaCse4 levels at the programmed stall sites of early replicating centromeres. The epigenetic mark of centromeres, CENP-A, is deposited in S phase in most yeasts by a mechanism that is not completely understood. Here, we identify two CEN7 flanking replication origins, ORI7-L1 and ORI7-RI, proximal to an early replicating centromere (CEN7) in a budding yeast Candida albicans. Replication forks starting from these origins stall randomly at CEN7 by the kinetochore that serves as a barrier to fork progression. We observe that centromeric fork stalling is reduced in absence of the HR proteins, Rad51 and Rad52, known to play a role in restarting stalled forks. Further, we demonstrate that Rad51 and Rad52 physically interact with CENP-ACaCse4in vivo. CENP-ACaCse4 levels are reduced in absence of Rad51 or Rad52, which results in disruption of the kinetochore structure. Here we propose a novel DNA replication-coupled mechanism mediated by HR proteins which epigenetically maintains centromere identity by regulating CENP-A deposition. A direct role of DNA repair proteins in centromere function offers insights into the mechanisms of centromere mis-regulation that leads to widespread aneuploidy in cancer cells.
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Affiliation(s)
- Sreyoshi Mitra
- Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India
| | - Jonathan Gómez-Raja
- Departamento Ciencias Biomédicas Área de Microbiología, Universidad de Extremadura, Badajoz, Spain
| | - Germán Larriba
- Departamento Ciencias Biomédicas Área de Microbiología, Universidad de Extremadura, Badajoz, Spain
| | | | - Kaustuv Sanyal
- Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India
- * E-mail:
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