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Di Nardo M, Musio A. Cohesin - bridging the gap among gene transcription, genome stability, and human diseases. FEBS Lett 2024. [PMID: 38852996 DOI: 10.1002/1873-3468.14949] [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: 02/19/2024] [Revised: 04/15/2024] [Accepted: 05/08/2024] [Indexed: 06/11/2024]
Abstract
The intricate landscape of cellular processes governing gene transcription, chromatin organization, and genome stability is a fascinating field of study. A key player in maintaining this delicate equilibrium is the cohesin complex, a molecular machine with multifaceted roles. This review presents an in-depth exploration of these intricate connections and their significant impact on various human diseases.
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Affiliation(s)
- Maddalena Di Nardo
- Institute for Biomedical Technologies (ITB), National Research Council (CNR), Pisa, Italy
| | - Antonio Musio
- Institute for Biomedical Technologies (ITB), National Research Council (CNR), Pisa, Italy
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2
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Golov AK, Gavrilov AA. Cohesin-Dependent Loop Extrusion: Molecular Mechanics and Role in Cell Physiology. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:601-625. [PMID: 38831499 DOI: 10.1134/s0006297924040023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 12/29/2023] [Accepted: 02/15/2024] [Indexed: 06/05/2024]
Abstract
The most prominent representatives of multisubunit SMC complexes, cohesin and condensin, are best known as structural components of mitotic chromosomes. It turned out that these complexes, as well as their bacterial homologues, are molecular motors, the ATP-dependent movement of these complexes along DNA threads leads to the formation of DNA loops. In recent years, we have witnessed an avalanche-like accumulation of data on the process of SMC dependent DNA looping, also known as loop extrusion. This review briefly summarizes the current understanding of the place and role of cohesin-dependent extrusion in cell physiology and presents a number of models describing the potential molecular mechanism of extrusion in a most compelling way. We conclude the review with a discussion of how the capacity of cohesin to extrude DNA loops may be mechanistically linked to its involvement in sister chromatid cohesion.
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Affiliation(s)
- Arkadiy K Golov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
- Technion - Israel Institute of Technology, Haifa, 3525433, Israel
| | - Alexey A Gavrilov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
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3
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Bailey MLP, Surovtsev I, Williams JF, Yan H, Yuan T, Li K, Duseau K, Mochrie SGJ, King MC. Loops and the activity of loop extrusion factors constrain chromatin dynamics. Mol Biol Cell 2023; 34:ar78. [PMID: 37126401 PMCID: PMC10398873 DOI: 10.1091/mbc.e23-04-0119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 05/02/2023] Open
Abstract
The chromosomes-DNA polymers and their binding proteins-are compacted into a spatially organized, yet dynamic, three-dimensional structure. Recent genome-wide chromatin conformation capture experiments reveal a hierarchical organization of the DNA structure that is imposed, at least in part, by looping interactions arising from the activity of loop extrusion factors. The dynamics of chromatin reflects the response of the polymer to a combination of thermal fluctuations and active processes. However, how chromosome structure and enzymes acting on chromatin together define its dynamics remains poorly understood. To gain insight into the structure-dynamics relationship of chromatin, we combine high-precision microscopy in living Schizosaccharomyces pombe cells with systematic genetic perturbations and Rouse model polymer simulations. We first investigated how the activity of two loop extrusion factors, the cohesin and condensin complexes, influences chromatin dynamics. We observed that deactivating cohesin, or to a lesser extent condensin, increased chromatin mobility, suggesting that loop extrusion constrains rather than agitates chromatin motion. Our corresponding simulations reveal that the introduction of loops is sufficient to explain the constraining activity of loop extrusion factors, highlighting that the conformation adopted by the polymer plays a key role in defining its dynamics. Moreover, we find that the number of loops or residence times of loop extrusion factors influence the dynamic behavior of the chromatin polymer. Last, we observe that the activity of the INO80 chromatin remodeler, but not the SWI/SNF or RSC complexes, is critical for ATP-dependent chromatin mobility in fission yeast. Taking the data together, we suggest that thermal and INO80-dependent activities exert forces that drive chromatin fluctuations, which are constrained by the organization of the chromosome into loops.
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Affiliation(s)
- Mary Lou P. Bailey
- Department of Applied Physics, Yale University, New Haven, CT 06511
- Integrated Graduate Program in Physics Engineering Biology, Yale University, New Haven, CT 06511
| | - Ivan Surovtsev
- Department of Physics, Yale University, New Haven, CT 06511
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| | | | - Hao Yan
- Integrated Graduate Program in Physics Engineering Biology, Yale University, New Haven, CT 06511
- Department of Physics, Yale University, New Haven, CT 06511
| | - Tianyu Yuan
- Integrated Graduate Program in Physics Engineering Biology, Yale University, New Haven, CT 06511
- Department of Physics, Yale University, New Haven, CT 06511
| | - Kevin Li
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| | - Katherine Duseau
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| | - Simon G. J. Mochrie
- Department of Applied Physics, Yale University, New Haven, CT 06511
- Integrated Graduate Program in Physics Engineering Biology, Yale University, New Haven, CT 06511
- Department of Physics, Yale University, New Haven, CT 06511
| | - Megan C. King
- Integrated Graduate Program in Physics Engineering Biology, Yale University, New Haven, CT 06511
- Department of Molecular, Cell and Developmental Biology, Yale University, New Haven, CT 06511
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
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4
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González-Martín E, Jiménez J, Tallada VA. BiFCo: visualizing cohesin assembly/disassembly cycle in living cells. Life Sci Alliance 2023; 6:e202301945. [PMID: 37160310 PMCID: PMC10172768 DOI: 10.26508/lsa.202301945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 04/13/2023] [Accepted: 04/17/2023] [Indexed: 05/11/2023] Open
Abstract
Cohesin is a highly conserved, ring-shaped protein complex found in all eukaryotes. It consists of at least two structural maintenance of chromosomes (SMC) proteins, SMC1 and SMC3 in humans (Psm1 and Psm3 in fission yeast), and the kleisin RAD21 (Rad21 in fission yeast). Mutations in its components or regulators can lead to genetic syndromes, known as cohesinopathies, and various types of cancer. Studies in several organisms have shown that only a small fraction of each subunit assembles into complexes, making it difficult to investigate dynamic chromatin loading and unloading using fluorescent fusions in vivo because of excess soluble components. In this study, we introduce bimolecular fluorescent cohesin (BiFCo), based on bimolecular fluorescent complementation in the fission yeast Schizosaccharomyces pombe BiFCo selectively excludes signals from individual proteins, enabling the monitoring of complex assembly and disassembly within a physiological context throughout the entire cell cycle in living cells. This versatile system can be expanded and adapted for various genetic backgrounds and other eukaryotic models, including human cells.
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Affiliation(s)
- Emilio González-Martín
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Seville, Spain
| | - Juan Jiménez
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Seville, Spain
| | - Víctor A Tallada
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Seville, Spain
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5
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Haase J, Chen R, Parker WM, Bonner MK, Jenkins LM, Kelly AE. The TFIIH complex is required to establish and maintain mitotic chromosome structure. eLife 2022; 11:75475. [PMID: 35293859 PMCID: PMC8956287 DOI: 10.7554/elife.75475] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 03/15/2022] [Indexed: 11/13/2022] Open
Abstract
Condensins compact chromosomes to promote their equal segregation during mitosis, but the mechanism of condensin engagement with and action on chromatin is incompletely understood. Here, we show that the general transcription factor TFIIH complex is continuously required to establish and maintain a compacted chromosome structure in transcriptionally silent Xenopus egg extracts. Inhibiting the DNA-dependent ATPase activity of the TFIIH complex subunit XPB rapidly and reversibly induces a complete loss of chromosome structure and prevents the enrichment of condensins I and II, but not topoisomerase II, on chromatin. In addition, inhibiting TFIIH prevents condensation of both mouse and Xenopus nuclei in Xenopus egg extracts, which suggests an evolutionarily conserved mechanism of TFIIH action. Reducing nucleosome density through partial histone depletion restores chromosome structure and condensin enrichment in the absence of TFIIH activity. We propose that the TFIIH complex promotes mitotic chromosome condensation by dynamically altering the chromatin environment to facilitate condensin loading and condensin-dependent loop extrusion.
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Affiliation(s)
- Julian Haase
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, Bethesda, United States
| | - Richard Chen
- Graduate School of Biomedical Sciences, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Wesley M Parker
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, Bethesda, United States
| | - Mary Kate Bonner
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, Bethesda, United States
| | - Lisa M Jenkins
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, Bethesda, United States
| | - Alexander E Kelly
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, Bethesda, United States
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6
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Higashi TL, Uhlmann F. SMC complexes: Lifting the lid on loop extrusion. Curr Opin Cell Biol 2022; 74:13-22. [PMID: 35016058 PMCID: PMC9089308 DOI: 10.1016/j.ceb.2021.12.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 01/02/2023]
Abstract
Loop extrusion has emerged as a prominent hypothesis for how SMC complexes shape chromosomes - single molecule in vitro observations have yielded fascinating images of this process. When not extruding loops, SMC complexes are known to topologically entrap one or more DNAs. Here, we review how structural insight into the SMC complex cohesin has led to a molecular framework for both activities: a Brownian ratchet motion, associated with topological DNA entry, might repeat itself to elicit loop extrusion. After contrasting alternative loop extrusion models, we explore whether topological loading or loop extrusion is more adept at explaining in vivo SMC complex function. SMC variants that experimentally separate topological loading from loop extrusion will in the future probe their respective contributions to chromosome biology.
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Affiliation(s)
- Torahiko L Higashi
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, NW1 1AT, UK; Department of Cellular Biochemistry, Kyushu University, Fukuoka, 812-8582, Japan
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, NW1 1AT, UK.
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7
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Yan H, Surovtsev I, Williams JF, Bailey MLP, King MC, Mochrie SGJ. Extrusion of chromatin loops by a composite loop extrusion factor. Phys Rev E 2021; 104:024414. [PMID: 34525654 DOI: 10.1103/physreve.104.024414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 06/16/2021] [Indexed: 12/26/2022]
Abstract
Chromatin loop extrusion by structural maintenance of chromosome (SMC) complexes is thought to underlie intermediate-scale chromatin organization inside cells. Motivated by a number of experiments suggesting that nucleosomes may block loop extrusion by SMCs, such as cohesin and condensin complexes, we introduce and characterize theoretically a composite loop extrusion factor (composite LEF) model. In addition to an SMC complex that creates a chromatin loop by encircling two threads of DNA, this model includes a remodeling complex that relocates or removes nucleosomes as it progresses along the chromatin, and nucleosomes that block SMC translocation along the DNA. Loop extrusion is enabled by SMC motion along nucleosome-free DNA, created in the wake of the remodeling complex, while nucleosome rebinding behind the SMC acts as a ratchet, holding the SMC close to the remodeling complex. We show that, for a wide range of parameter values, this collection of factors constitutes a composite LEF that extrudes loops with a velocity, comparable to the velocity of remodeling complex translocation on chromatin in the absence of SMC, and much faster than loop extrusion by an isolated SMC that is blocked by nucleosomes.
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Affiliation(s)
- Hao Yan
- Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, Connecticut 06511, USA.,Department of Physics, Yale University, New Haven, Connecticut 06511, USA
| | - Ivan Surovtsev
- Department of Physics, Yale University, New Haven, Connecticut 06511, USA.,Department of Cell Biology, Yale School of Medicine, New Haven, Connecticut 06520, USA
| | - Jessica F Williams
- Department of Cell Biology, Yale School of Medicine, New Haven, Connecticut 06520, USA
| | - Mary Lou P Bailey
- Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, Connecticut 06511, USA.,Department of Applied Physics, Yale University, New Haven, Connecticut 06511, USA
| | - Megan C King
- Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, Connecticut 06511, USA.,Department of Cell Biology, Yale School of Medicine, New Haven, Connecticut 06520, USA.,Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06511, USA
| | - Simon G J Mochrie
- Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, Connecticut 06511, USA.,Department of Physics, Yale University, New Haven, Connecticut 06511, USA.,Department of Applied Physics, Yale University, New Haven, Connecticut 06511, USA
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8
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Higashi TL, Pobegalov G, Tang M, Molodtsov MI, Uhlmann F. A Brownian ratchet model for DNA loop extrusion by the cohesin complex. eLife 2021; 10:e67530. [PMID: 34309513 PMCID: PMC8313234 DOI: 10.7554/elife.67530] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 06/10/2021] [Indexed: 12/12/2022] Open
Abstract
The cohesin complex topologically encircles DNA to promote sister chromatid cohesion. Alternatively, cohesin extrudes DNA loops, thought to reflect chromatin domain formation. Here, we propose a structure-based model explaining both activities. ATP and DNA binding promote cohesin conformational changes that guide DNA through a kleisin N-gate into a DNA gripping state. Two HEAT-repeat DNA binding modules, associated with cohesin's heads and hinge, are now juxtaposed. Gripping state disassembly, following ATP hydrolysis, triggers unidirectional hinge module movement, which completes topological DNA entry by directing DNA through the ATPase head gate. If head gate passage fails, hinge module motion creates a Brownian ratchet that, instead, drives loop extrusion. Molecular-mechanical simulations of gripping state formation and resolution cycles recapitulate experimentally observed DNA loop extrusion characteristics. Our model extends to asymmetric and symmetric loop extrusion, as well as z-loop formation. Loop extrusion by biased Brownian motion has important implications for chromosomal cohesin function.
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Affiliation(s)
- Torahiko L Higashi
- Chromosome Segregation Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Georgii Pobegalov
- Mechanobiology and Biophysics Laboratory, The Francis Crick InstituteLondonUnited Kingdom
- Department of Physics and Astronomy, University College LondonLondonUnited Kingdom
| | - Minzhe Tang
- Chromosome Segregation Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Maxim I Molodtsov
- Mechanobiology and Biophysics Laboratory, The Francis Crick InstituteLondonUnited Kingdom
- Department of Physics and Astronomy, University College LondonLondonUnited Kingdom
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick InstituteLondonUnited Kingdom
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9
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Paulson JR, Hudson DF, Cisneros-Soberanis F, Earnshaw WC. Mitotic chromosomes. Semin Cell Dev Biol 2021; 117:7-29. [PMID: 33836947 PMCID: PMC8406421 DOI: 10.1016/j.semcdb.2021.03.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/23/2021] [Accepted: 03/23/2021] [Indexed: 01/25/2023]
Abstract
Our understanding of the structure and function of mitotic chromosomes has come a long way since these iconic objects were first recognized more than 140 years ago, though many details remain to be elucidated. In this chapter, we start with the early history of chromosome studies and then describe the path that led to our current understanding of the formation and structure of mitotic chromosomes. We also discuss some of the remaining questions. It is now well established that each mitotic chromatid consists of a central organizing region containing a so-called "chromosome scaffold" from which loops of DNA project radially. Only a few key non-histone proteins and protein complexes are required to form the chromosome: topoisomerase IIα, cohesin, condensin I and condensin II, and the chromokinesin KIF4A. These proteins are concentrated along the axis of the chromatid. Condensins I and II are primarily responsible for shaping the chromosome and the scaffold, and they produce the loops of DNA by an ATP-dependent process known as loop extrusion. Modelling of Hi-C data suggests that condensin II adopts a spiral staircase arrangement with an extruded loop extending out from each step in a roughly helical pattern. Condensin I then forms loops nested within these larger condensin II loops, thereby giving rise to the final compaction of the mitotic chromosome in a process that requires Topo IIα.
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Affiliation(s)
- James R Paulson
- Department of Chemistry, University of Wisconsin Oshkosh, 800 Algoma Boulevard, Oshkosh, WI 54901, USA.
| | - Damien F Hudson
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, VIC 3052, Australia
| | - Fernanda Cisneros-Soberanis
- Wellcome Trust Centre for Cell Biology, ICB, University of Edinburgh, Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, ICB, University of Edinburgh, Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK.
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10
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Lambing C, Tock AJ, Topp SD, Choi K, Kuo PC, Zhao X, Osman K, Higgins JD, Franklin FCH, Henderson IR. Interacting Genomic Landscapes of REC8-Cohesin, Chromatin, and Meiotic Recombination in Arabidopsis. THE PLANT CELL 2020; 32:1218-1239. [PMID: 32024691 PMCID: PMC7145502 DOI: 10.1105/tpc.19.00866] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/03/2020] [Accepted: 02/03/2020] [Indexed: 05/20/2023]
Abstract
Meiosis recombines genetic variation and influences eukaryote genome evolution. During meiosis, DNA double-strand breaks (DSBs) enter interhomolog repair to yield crossovers and noncrossovers. DSB repair occurs as replicated sister chromatids are connected to a polymerized axis. Cohesin rings containing the REC8 kleisin subunit bind sister chromatids and anchor chromosomes to the axis. Here, we report the genomic landscape of REC8 using chromatin immunoprecipitation sequencing (ChIP-seq) in Arabidopsis (Arabidopsis thaliana). REC8 associates with regions of high nucleosome occupancy in multiple chromatin states, including histone methylation at H3K4 (expressed genes), H3K27 (silent genes), and H3K9 (silent transposons). REC8 enrichment is associated with suppression of meiotic DSBs and crossovers at the chromosome and fine scales. As REC8 enrichment is greatest in transposon-dense heterochromatin, we repeated ChIP-seq in kyp suvh5 suvh6 H3K9me2 mutants. Surprisingly, REC8 enrichment is maintained in kyp suvh5 suvh6 heterochromatin and no defects in centromeric cohesion were observed. REC8 occupancy within genes anti-correlates with transcription and is reduced in COPIA transposons that reactivate expression in kyp suvh5 suvh6 Abnormal axis structures form in rec8 that recruit DSB-associated protein foci and undergo synapsis, which is followed by chromosome fragmentation. Therefore, REC8 occupancy correlates with multiple chromatin states and is required to organize meiotic chromosome architecture and interhomolog recombination.
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Affiliation(s)
- Christophe Lambing
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
| | - Andrew J Tock
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
| | - Stephanie D Topp
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
| | - Kyuha Choi
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
| | - Pallas C Kuo
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
| | - Xiaohui Zhao
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
| | - Kim Osman
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - James D Higgins
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, United Kingdom
| | - F Chris H Franklin
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Ian R Henderson
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
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11
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Birot A, Tormos-Pérez M, Vaur S, Feytout A, Jaegy J, Alonso Gil D, Vazquez S, Ekwall K, Javerzat JP. The CDK Pef1 and protein phosphatase 4 oppose each other for regulating cohesin binding to fission yeast chromosomes. eLife 2020; 9:e50556. [PMID: 31895039 PMCID: PMC6954021 DOI: 10.7554/elife.50556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 01/02/2020] [Indexed: 12/19/2022] Open
Abstract
Cohesin has essential roles in chromosome structure, segregation and repair. Cohesin binding to chromosomes is catalyzed by the cohesin loader, Mis4 in fission yeast. How cells fine tune cohesin deposition is largely unknown. Here, we provide evidence that Mis4 activity is regulated by phosphorylation of its cohesin substrate. A genetic screen for negative regulators of Mis4 yielded a CDK called Pef1, whose closest human homologue is CDK5. Inhibition of Pef1 kinase activity rescued cohesin loader deficiencies. In an otherwise wild-type background, Pef1 ablation stimulated cohesin binding to its regular sites along chromosomes while ablating Protein Phosphatase 4 had the opposite effect. Pef1 and PP4 control the phosphorylation state of the cohesin kleisin Rad21. The CDK phosphorylates Rad21 on Threonine 262. Pef1 ablation, non-phosphorylatable Rad21-T262 or mutations within a Rad21 binding domain of Mis4 alleviated the effect of PP4 deficiency. Such a CDK/PP4-based regulation of cohesin loader activity could provide an efficient mechanism for translating cellular cues into a fast and accurate cohesin response.
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Affiliation(s)
- Adrien Birot
- Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS - Université de BordeauxBordeauxFrance
| | - Marta Tormos-Pérez
- Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS - Université de BordeauxBordeauxFrance
| | - Sabine Vaur
- Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS - Université de BordeauxBordeauxFrance
| | - Amélie Feytout
- Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS - Université de BordeauxBordeauxFrance
| | - Julien Jaegy
- Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS - Université de BordeauxBordeauxFrance
| | - Dácil Alonso Gil
- Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS - Université de BordeauxBordeauxFrance
| | - Stéphanie Vazquez
- Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS - Université de BordeauxBordeauxFrance
| | - Karl Ekwall
- Department of Biosciences and NutritionKarolinska InstitutetHuddingeSweden
| | - Jean-Paul Javerzat
- Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS - Université de BordeauxBordeauxFrance
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12
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Zhurinsky J, Salas-Pino S, Iglesias-Romero AB, Torres-Mendez A, Knapp B, Flor-Parra I, Wang J, Bao K, Jia S, Chang F, Daga RR. Effects of the microtubule nucleator Mto1 on chromosomal movement, DNA repair, and sister chromatid cohesion in fission yeast. Mol Biol Cell 2019; 30:2695-2708. [PMID: 31483748 PMCID: PMC6761766 DOI: 10.1091/mbc.e19-05-0301] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 08/27/2019] [Accepted: 08/30/2019] [Indexed: 11/11/2022] Open
Abstract
Although the function of microtubules (MTs) in chromosomal segregation during mitosis is well characterized, much less is known about the role of MTs in chromosomal functions during interphase. In the fission yeast Schizosaccharomyces pombe, dynamic cytoplasmic MT bundles move chromosomes in an oscillatory manner during interphase via linkages through the nuclear envelope (NE) at the spindle pole body (SPB) and other sites. Mto1 is a cytoplasmic factor that mediates the nucleation and attachment of cytoplasmic MTs to the nucleus. Here, we test the function of these cytoplasmic MTs and Mto1 on DNA repair and recombination during interphase. We find that mto1Δ cells exhibit defects in DNA repair and homologous recombination (HR) and abnormal DNA repair factory dynamics. In these cells, sister chromatids are not properly paired, and binding of Rad21 cohesin subunit along chromosomal arms is reduced. Our findings suggest a model in which cytoplasmic MTs and Mto1 facilitate efficient DNA repair and HR by promoting dynamic chromosomal organization and cohesion in the nucleus.
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Affiliation(s)
- Jacob Zhurinsky
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Silvia Salas-Pino
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Ana B. Iglesias-Romero
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Antonio Torres-Mendez
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Benjamin Knapp
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY 10032
| | - Ignacio Flor-Parra
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Jiyong Wang
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143
| | - Kehan Bao
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143
| | - Songtao Jia
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143
| | - Fred Chang
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY 10032
| | - Rafael R. Daga
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
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13
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Folco HD, McCue A, Balachandran V, Grewal SIS. Cohesin Impedes Heterochromatin Assembly in Fission Yeast Cells Lacking Pds5. Genetics 2019; 213:127-141. [PMID: 31278118 PMCID: PMC6727797 DOI: 10.1534/genetics.119.302256] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 06/24/2019] [Indexed: 01/05/2023] Open
Abstract
The fission yeast Schizosaccharomyces pombe is a powerful genetic model system for uncovering fundamental principles of heterochromatin assembly and epigenetic inheritance of chromatin states. Heterochromatin defined by histone H3 lysine 9 methylation and HP1 proteins coats large chromosomal domains at centromeres, telomeres, and the mating-type (mat) locus. Although genetic and biochemical studies have provided valuable insights into heterochromatin assembly, many key mechanistic details remain unclear. Here, we use a sensitized reporter system at the mat locus to screen for factors affecting heterochromatic silencing. In addition to known components of heterochromatin assembly pathways, our screen identified eight new factors including the cohesin-associated protein Pds5. We find that Pds5 enriched throughout heterochromatin domains is required for proper maintenance of heterochromatin. This function of Pds5 requires its associated Eso1 acetyltransferase, which is implicated in the acetylation of cohesin. Indeed, introducing an acetylation-mimicking mutation in a cohesin subunit suppresses defects in heterochromatin assembly in pds5∆ and eso1∆ cells. Our results show that in cells lacking Pds5, cohesin interferes with heterochromatin assembly. Supporting this, eliminating cohesin from the mat locus in the pds5∆ mutant restores both heterochromatin assembly and gene silencing. These analyses highlight an unexpected requirement for Pds5 in ensuring proper coordination between cohesin and heterochromatin factors to effectively maintain gene silencing.
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Affiliation(s)
- H Diego Folco
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Andrea McCue
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Vanivilasini Balachandran
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Shiv I S Grewal
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
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14
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Pagé V, Chen JJ, Durand-Dubief M, Grabowski D, Oya E, Sansô M, Martin RD, Hébert TE, Fisher RP, Ekwall K, Tanny JC. Histone H2B Ubiquitylation Regulates Histone Gene Expression by Suppressing Antisense Transcription in Fission Yeast. Genetics 2019; 213:161-172. [PMID: 31345994 PMCID: PMC6727805 DOI: 10.1534/genetics.119.302499] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 07/23/2019] [Indexed: 02/08/2023] Open
Abstract
Histone H2B monoubiquitylation (H2Bub1) is tightly linked to RNA polymerase II transcription elongation, and is also directly implicated in DNA replication and repair. Loss of H2Bub1 is associated with defects in cell cycle progression, but how these are related to its various functions, and the underlying mechanisms involved, is not understood. Here we describe a role for H2Bub1 in the regulation of replication-dependent histone genes in the fission yeast Schizosaccharomyces pombe H2Bub1 activates histone genes indirectly by suppressing antisense transcription of ams2+ -a gene encoding a GATA-type transcription factor that activates histone genes and is required for assembly of centromeric chromatin. Mutants lacking the ubiquitylation site in H2B or the H2B-specific E3 ubiquitin ligase Brl2 had elevated levels of ams2+ antisense transcripts and reduced Ams2 protein levels. These defects were reversed upon inhibition of Cdk9-an ortholog of the kinase component of positive transcription elongation factor b (P-TEFb)-indicating that they likely resulted from aberrant transcription elongation. Reduced Cdk9 activity also partially rescued chromosome segregation phenotypes of H2Bub1 mutants. In a genome-wide analysis, loss of H2Bub1 led to increased antisense transcripts at over 500 protein-coding genes in H2Bub1 mutants; for a subset of these, including several genes involved in chromosome segregation and chromatin assembly, antisense derepression was Cdk9-dependent. Our results highlight antisense suppression as a key feature of cell cycle-dependent gene regulation by H2Bub1, and suggest that aberrant transcription elongation may underlie the effects of H2Bub1 loss on cell cycle progression.
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Affiliation(s)
- Viviane Pagé
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Jennifer J Chen
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Mickael Durand-Dubief
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm 17177, Sweden
| | - David Grabowski
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Eriko Oya
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm 17177, Sweden
| | - Miriam Sansô
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, Mount Sinai School of Medicine, New York, New York 10029
| | - Ryan D Martin
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Robert P Fisher
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, Mount Sinai School of Medicine, New York, New York 10029
| | - Karl Ekwall
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm 17177, Sweden
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
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15
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Moronta-Gines M, van Staveren TRH, Wendt KS. One ring to bind them - Cohesin's interaction with chromatin fibers. Essays Biochem 2019; 63:167-176. [PMID: 31015387 DOI: 10.1042/ebc20180064] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/26/2019] [Accepted: 03/01/2019] [Indexed: 12/17/2023]
Abstract
In the nuclei of eukaryotic cells, the genetic information is organized at several levels. First, the DNA is wound around the histone proteins, to form a structure termed as chromatin fiber. This fiber is then arranged into chromatin loops that can cluster together and form higher order structures. This packaging of chromatin provides on one side compaction but also functional compartmentalization. The cohesin complex is a multifunctional ring-shaped multiprotein complex that organizes the chromatin fiber to establish functional domains important for transcriptional regulation, help with DNA damage repair, and ascertain stable inheritance of the genome during cell division. Our current model for cohesin function suggests that cohesin tethers chromatin strands by topologically entrapping them within its ring. To achieve this, cohesin's association with chromatin needs to be very precisely regulated in timing and position on the chromatin strand. Here we will review the current insight in when and where cohesin associates with chromatin and which factors regulate this. Further, we will discuss the latest insights into where and how the cohesin ring opens to embrace chromatin and also the current knowledge about the 'exit gates' when cohesin is released from chromatin.
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Affiliation(s)
| | | | - Kerstin S Wendt
- Department of Cell Biology, Erasmus MC, Rotterdam, The Netherlands
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16
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Amitai A, Holcman D. Encounter times of chromatin loci influenced by polymer decondensation. Phys Rev E 2018; 97:032417. [PMID: 29776075 DOI: 10.1103/physreve.97.032417] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Indexed: 12/24/2022]
Abstract
The time for a DNA sequence to find its homologous counterpart depends on a long random search inside the cell nucleus. Using polymer models, we compute here the mean first encounter time (MFET) between two sites located on two different polymer chains and confined locally by potential wells. We find that reducing tethering forces acting on the polymers results in local decondensation, and numerical simulations of the polymer model show that these changes are associated with a reduction of the MFET by several orders of magnitude. We derive here new asymptotic formula for the MFET, confirmed by Brownian simulations. We conclude from the present modeling approach that the fast search for homology is mediated by a local chromatin decondensation due to the release of multiple chromatin tethering forces. The present scenario could explain how the homologous recombination pathway for double-stranded DNA repair is controlled by its random search step.
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Affiliation(s)
- A Amitai
- Department of Chemical Engineering and Institute for Medical Engineering & Science, Massachusetts Institute of Technology, Cambridge 02139, Massachusetts, USA
| | - D Holcman
- Group of Applied Mathematics and Computational Biology, Ecole Normale Supérieure, 75005 Paris, France
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17
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Hocquet C, Robellet X, Modolo L, Sun XM, Burny C, Cuylen-Haering S, Toselli E, Clauder-Münster S, Steinmetz L, Haering CH, Marguerat S, Bernard P. Condensin controls cellular RNA levels through the accurate segregation of chromosomes instead of directly regulating transcription. eLife 2018; 7:38517. [PMID: 30230473 PMCID: PMC6173581 DOI: 10.7554/elife.38517] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 09/18/2018] [Indexed: 12/15/2022] Open
Abstract
Condensins are genome organisers that shape chromosomes and promote their accurate transmission. Several studies have also implicated condensins in gene expression, although any mechanisms have remained enigmatic. Here, we report on the role of condensin in gene expression in fission and budding yeasts. In contrast to previous studies, we provide compelling evidence that condensin plays no direct role in the maintenance of the transcriptome, neither during interphase nor during mitosis. We further show that the changes in gene expression in post-mitotic fission yeast cells that result from condensin inactivation are largely a consequence of chromosome missegregation during anaphase, which notably depletes the RNA-exosome from daughter cells. Crucially, preventing karyotype abnormalities in daughter cells restores a normal transcriptome despite condensin inactivation. Thus, chromosome instability, rather than a direct role of condensin in the transcription process, changes gene expression. This knowledge challenges the concept of gene regulation by canonical condensin complexes.
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Affiliation(s)
- Clémence Hocquet
- CNRS Laboratory of Biology and Modelling of the Cell, Lyon, France.,Université de Lyon, ENSL, UCBL, Lyon, France
| | - Xavier Robellet
- CNRS Laboratory of Biology and Modelling of the Cell, Lyon, France.,Université de Lyon, ENSL, UCBL, Lyon, France
| | - Laurent Modolo
- CNRS Laboratory of Biology and Modelling of the Cell, Lyon, France.,Université de Lyon, ENSL, UCBL, Lyon, France
| | - Xi-Ming Sun
- MRC London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Claire Burny
- CNRS Laboratory of Biology and Modelling of the Cell, Lyon, France.,Université de Lyon, ENSL, UCBL, Lyon, France
| | - Sara Cuylen-Haering
- Cell Biology and Biophysics Unit, Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Esther Toselli
- CNRS Laboratory of Biology and Modelling of the Cell, Lyon, France.,Université de Lyon, ENSL, UCBL, Lyon, France
| | | | - Lars Steinmetz
- Genome Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Christian H Haering
- Cell Biology and Biophysics Unit, Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Samuel Marguerat
- MRC London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Pascal Bernard
- CNRS Laboratory of Biology and Modelling of the Cell, Lyon, France.,Université de Lyon, ENSL, UCBL, Lyon, France
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18
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Wang X, Hughes AC, Brandão HB, Walker B, Lierz C, Cochran JC, Oakley MG, Kruse AC, Rudner DZ. In Vivo Evidence for ATPase-Dependent DNA Translocation by the Bacillus subtilis SMC Condensin Complex. Mol Cell 2018; 71:841-847.e5. [PMID: 30100265 PMCID: PMC6591583 DOI: 10.1016/j.molcel.2018.07.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 06/27/2018] [Accepted: 07/03/2018] [Indexed: 11/16/2022]
Abstract
Structural maintenance of chromosomes (SMC) complexes shape the genomes of virtually all organisms, but how they function remains incompletely understood. Recent studies in bacteria and eukaryotes have led to a unifying model in which these ring-shaped ATPases act along contiguous DNA segments, processively enlarging DNA loops. In support of this model, single-molecule imaging experiments indicate that Saccharomyces cerevisiae condensin complexes can extrude DNA loops in an ATP-hydrolysis-dependent manner in vitro. Here, using time-resolved high-throughput chromosome conformation capture (Hi-C), we investigate the interplay between ATPase activity of the Bacillus subtilis SMC complex and loop formation in vivo. We show that point mutants in the SMC nucleotide-binding domain that impair but do not eliminate ATPase activity not only exhibit delays in de novo loop formation but also have reduced rates of processive loop enlargement. These data provide in vivo evidence that SMC complexes function as loop extruders.
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Affiliation(s)
- Xindan Wang
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA.
| | - Anna C Hughes
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Hugo B Brandão
- Graduate Program in Biophysics, Harvard University, Cambridge, MA 02138, USA
| | - Benjamin Walker
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Carrie Lierz
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Jared C Cochran
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Martha G Oakley
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Andrew C Kruse
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - David Z Rudner
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA.
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19
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Kakui Y, Uhlmann F. SMC complexes orchestrate the mitotic chromatin interaction landscape. Curr Genet 2018; 64:335-339. [PMID: 28936767 PMCID: PMC5851691 DOI: 10.1007/s00294-017-0755-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 09/14/2017] [Accepted: 09/16/2017] [Indexed: 12/24/2022]
Abstract
Chromatin is a very long DNA-protein complex that controls the expression and inheritance of the genetic information. Chromatin is stored within the nucleus in interphase and further compacted into chromosomes during mitosis. This process, known as chromosome condensation, is essential for faithful segregation of genomic DNA into daughter cells. Condensin and cohesin, members of the structural maintenance of chromosomes (SMC) family, are fundamental for chromosome architecture, both for establishment of chromatin structure in the interphase nucleus and for the formation of condensed chromosomes in mitosis. These ring-shaped SMC complexes are thought to regulate the interactions between DNA strands by topologically entrapping DNA. How this activity shapes chromosomes is not yet understood. Recent high throughput chromosome conformation capture studies revealed how chromatin is reorganized during the cell cycle and have started to explore the role of SMC complexes in mitotic chromatin architecture. Here, we summarize these findings and discuss the conserved nature of chromosome condensation in eukaryotes. We highlight the unexpected finding that condensin-dependent intra-chromosomal interactions in mitosis increase within a distinctive distance range that is characteristic for an organism, while longer and shorter-range interactions are suppressed. This reveals important molecular insight into chromosome architecture.
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Affiliation(s)
- Yasutaka Kakui
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK.
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK.
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20
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Litwin I, Wysocki R. New insights into cohesin loading. Curr Genet 2018; 64:53-61. [PMID: 28631016 DOI: 10.1007/s00294-017-0723-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 06/12/2017] [Accepted: 06/13/2017] [Indexed: 01/13/2023]
Abstract
Cohesin is a conserved, ring-shaped protein complex that encircles sister chromatids and ensures correct chromosome segregation during mitosis and meiosis. It also plays a crucial role in the regulation of gene expression, DNA condensation, and DNA repair through both non-homologous end joining and homologous recombination. Cohesins are spatiotemporally regulated by the Scc2-Scc4 complex which facilitates cohesin loading onto chromatin at specific chromosomal sites. Over the last few years, much attention has been paid to cohesin and cohesin loader as it became clear that even minor disruptions of these complexes may lead to developmental disorders and cancers. Here we summarize recent developments in the structure of Scc2-Scc4 complex, cohesin loading process, and mediators that determine the Scc2-Scc4 binding patterns to chromatin.
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Affiliation(s)
- Ireneusz Litwin
- Institute of Experimental Biology, University of Wroclaw, 50-328, Wroclaw, Poland.
| | - Robert Wysocki
- Institute of Experimental Biology, University of Wroclaw, 50-328, Wroclaw, Poland
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21
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Abstract
The three-dimensional (3D) genome structure is highly ordered by a hierarchy of organizing events ranging from enhancer-promoter or gene-gene contacts to chromosomal territorial arrangement. It is becoming clear that the cohesin and condensin complexes are key molecular machines that organize the 3D genome structure. These complexes are highly conserved from simple systems, e.g., yeast cells, to the much more complex human system. Therefore, knowledge from the budding and fission yeast systems illuminates highly conserved molecular mechanisms of how cohesin and condensin establish the functional 3D genome structures. Here I discuss how these complexes are recruited across the yeast genomes, mediate distinct genome-organizing events such as gene contacts and topological domain formation, and participate in important nuclear activities including transcriptional regulation and chromosomal dynamics.
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Affiliation(s)
- Ken-Ichi Noma
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, Pennsylvania 19104, USA;
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22
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Lin L, Chen L, Tran PT. Fission yeast neddylation ligase Dcn1 facilitates cohesin cleavage and chromosome segregation at anaphase. Biol Open 2017; 6:844-849. [PMID: 28455357 PMCID: PMC5483010 DOI: 10.1242/bio.021238] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Post-translational protein modification such as phosphorylation and ubiquitination are critical during mitosis to ensure proper timing and progression of chromosome segregation. It has been recently recognized that another type of protein modification – neddylation – may also regulate mitosis and chromosome segregation. The conserved protein DCN1 (defective cullin neddylation 1) has been shown, when knocked-down by RNAi, to result in multinucleated cells and/or blockage of cell proliferation. However, how DCN1 functions in mitosis and chromosome segregation is not known. We report here the fission yeast dcn1+ and its role in mitosis and chromosome segregation. Dcn1-GFP localizes to the nucleus throughout the cell cycle. dcn1-deletion (dcn1Δ) leads to chromosome and kinetochore lagging at anaphase, resulting from delayed and attenuated cohesin cleavage and sister chromatids separation. These results put Dcn1 upstream of the anaphase promoting complex/cyclosome (APC/C) pathway. We propose a mechanism for Dcn1 function at mitosis. Summary: The fission yeast neddylation ligase Dcn1 plays a role in chromosome segregation. dcn1-deletion results in activation of the Mad2-dependent spindle assembly checkpoint, and lagging chromosomes at anaphase.
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Affiliation(s)
- Lan Lin
- School of Medicine, Southeast University, Nanjing, Jiangsu 210009, People's Republic of China.,Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Li Chen
- Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Phong T Tran
- Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104, USA .,Institut Curie, PSL Research Universities, CNRS, UMR144, Paris F-75005, France
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23
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Birot A, Eguienta K, Vazquez S, Claverol S, Bonneu M, Ekwall K, Javerzat JP, Vaur S. A second Wpl1 anti-cohesion pathway requires dephosphorylation of fission yeast kleisin Rad21 by PP4. EMBO J 2017; 36:1364-1378. [PMID: 28438891 PMCID: PMC5430217 DOI: 10.15252/embj.201696050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 03/10/2017] [Accepted: 03/27/2017] [Indexed: 01/06/2023] Open
Abstract
Cohesin mediates sister chromatid cohesion which is essential for chromosome segregation and repair. Sister chromatid cohesion requires an acetyl-transferase (Eso1 in fission yeast) counteracting Wpl1, promoting cohesin release from DNA We report here that Wpl1 anti-cohesion function includes an additional mechanism. A genetic screen uncovered that Protein Phosphatase 4 (PP4) mutants allowed cell survival in the complete absence of Eso1. PP4 co-immunoprecipitated Wpl1 and cohesin and Wpl1 triggered Rad21 de-phosphorylation in a PP4-dependent manner. Relevant residues were identified and mapped within the central domain of Rad21. Phospho-mimicking alleles dampened Wpl1 anti-cohesion activity, while alanine mutants were neutral indicating that Rad21 phosphorylation would shelter cohesin from Wpl1 unless erased by PP4. Experiments in post-replicative cells lacking Eso1 revealed two cohesin populations. Type 1 was released from DNA by Wpl1 in a PP4-independent manner. Type 2 cohesin, however, remained DNA-bound and lost its cohesiveness in a manner depending on Wpl1- and PP4-mediated Rad21 de-phosphorylation. These results reveal that Wpl1 antagonizes sister chromatid cohesion by a novel pathway regulated by the phosphorylation status of the cohesin kleisin subunit.
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Affiliation(s)
- Adrien Birot
- Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS - Université de Bordeaux, Bordeaux, France
| | - Karen Eguienta
- Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS - Université de Bordeaux, Bordeaux, France
| | - Stéphanie Vazquez
- Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS - Université de Bordeaux, Bordeaux, France
| | - Stéphane Claverol
- Centre Génomique Fonctionnelle de Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Marc Bonneu
- Centre Génomique Fonctionnelle de Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Karl Ekwall
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Jean-Paul Javerzat
- Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS - Université de Bordeaux, Bordeaux, France
| | - Sabine Vaur
- Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS - Université de Bordeaux, Bordeaux, France
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24
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Folco HD, Chalamcharla VR, Sugiyama T, Thillainadesan G, Zofall M, Balachandran V, Dhakshnamoorthy J, Mizuguchi T, Grewal SIS. Untimely expression of gametogenic genes in vegetative cells causes uniparental disomy. Nature 2017; 543:126-130. [PMID: 28199302 PMCID: PMC5567995 DOI: 10.1038/nature21372] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 12/28/2016] [Indexed: 01/03/2023]
Affiliation(s)
- H Diego Folco
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Venkata R Chalamcharla
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Tomoyasu Sugiyama
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Gobi Thillainadesan
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Martin Zofall
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Vanivilasini Balachandran
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Jothy Dhakshnamoorthy
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Takeshi Mizuguchi
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Shiv I S Grewal
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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25
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Abstract
The kollerin complex, consisting of Scc2/Scc4 in yeast and Nipbl/Mau2 in vertebrates, is crucial for the chromatin-association of the cohesin complex and therefore for the critical functions of cohesin in cell division, transcriptional regulation and chromatin organisation. Despite the recent efforts to determine the genomic localization of the kollerin complex in different cell lines, major questions still remain unresolved, for instance where cohesin is actually loaded onto chromatin. Further, Nipbl seems to have also additional roles, for instance as transcription factor.This chapter summarizes our current knowledge on kollerin function and the recent studies on the genomic localization of Scc2, highlighting and critically discussing controversial data.
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Affiliation(s)
- Kerstin S Wendt
- Department of Cell Biology, Erasmus MC, Faculty Building, Room Ee1020, Wytemaweg 80, 3015 CN, Rotterdam, The Netherlands.
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26
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Bolaños-Villegas P, De K, Pradillo M, Liu D, Makaroff CA. In Favor of Establishment: Regulation of Chromatid Cohesion in Plants. FRONTIERS IN PLANT SCIENCE 2017; 8:846. [PMID: 28588601 PMCID: PMC5440745 DOI: 10.3389/fpls.2017.00846] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 05/05/2017] [Indexed: 05/07/2023]
Abstract
In eukaryotic organisms, the correct regulation of sister chromatid cohesion, whereby sister chromatids are paired and held together, is essential for accurate segregation of the sister chromatids and homologous chromosomes into daughter cells during mitosis and meiosis, respectively. Sister chromatid cohesion requires a cohesin complex comprised of structural maintenance of chromosome adenosine triphosphatases and accessory proteins that regulate the association of the complex with chromosomes or that are involved in the establishment or release of cohesion. The cohesin complex also plays important roles in the repair of DNA double-strand breaks, regulation of gene expression and chromosome condensation. In this review, we summarize progress in understanding cohesion dynamics in plants, with the aim of uncovering differences at specific stages. We also highlight dissimilarities between plants and other eukaryotes with respect to the key players involved in the achievement of cohesion, pointing out areas that require further study.
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Affiliation(s)
- Pablo Bolaños-Villegas
- Laboratory of Molecular and Cell Biology, Fabio Baudrit Agricultural Research Station, University of Costa RicaAlajuela, Costa Rica
- *Correspondence: Christopher A. Makaroff, Pablo Bolaños-Villegas,
| | - Kuntal De
- Department of Radiation Oncology, James Cancer Hospital and Comprehensive Cancer Center, The Ohio State University Wexner School of Medicine, ColumbusOH, United States
| | - Mónica Pradillo
- Departamento de Genética, Facultad de Biología, Universidad Complutense de MadridMadrid, Spain
| | - Desheng Liu
- Hughes Laboratories, Department of Chemistry and Biochemistry, Miami University, OxfordOH, United States
| | - Christopher A. Makaroff
- Hughes Laboratories, Department of Chemistry and Biochemistry, Miami University, OxfordOH, United States
- *Correspondence: Christopher A. Makaroff, Pablo Bolaños-Villegas,
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27
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Davidson IF, Goetz D, Zaczek MP, Molodtsov MI, Huis In 't Veld PJ, Weissmann F, Litos G, Cisneros DA, Ocampo-Hafalla M, Ladurner R, Uhlmann F, Vaziri A, Peters JM. Rapid movement and transcriptional re-localization of human cohesin on DNA. EMBO J 2016; 35:2671-2685. [PMID: 27799150 PMCID: PMC5167347 DOI: 10.15252/embj.201695402] [Citation(s) in RCA: 154] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 09/08/2016] [Accepted: 10/03/2016] [Indexed: 01/17/2023] Open
Abstract
The spatial organization, correct expression, repair, and segregation of eukaryotic genomes depend on cohesin, ring-shaped protein complexes that are thought to function by entrapping DNA It has been proposed that cohesin is recruited to specific genomic locations from distal loading sites by an unknown mechanism, which depends on transcription, and it has been speculated that cohesin movements along DNA could create three-dimensional genomic organization by loop extrusion. However, whether cohesin can translocate along DNA is unknown. Here, we used single-molecule imaging to show that cohesin can diffuse rapidly on DNA in a manner consistent with topological entrapment and can pass over some DNA-bound proteins and nucleosomes but is constrained in its movement by transcription and DNA-bound CCCTC-binding factor (CTCF). These results indicate that cohesin can be positioned in the genome by moving along DNA, that transcription can provide directionality to these movements, that CTCF functions as a boundary element for moving cohesin, and they are consistent with the hypothesis that cohesin spatially organizes the genome via loop extrusion.
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Affiliation(s)
- Iain F Davidson
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | - Daniela Goetz
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | - Maciej P Zaczek
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | - Maxim I Molodtsov
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
- Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
| | | | | | - Gabriele Litos
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | - David A Cisneros
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | | | - Rene Ladurner
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | | | - Alipasha Vaziri
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
- Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
- The Rockefeller University, New York, NY, USA
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28
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The loading of condensin in the context of chromatin. Curr Genet 2016; 63:577-589. [PMID: 27909798 DOI: 10.1007/s00294-016-0669-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 11/24/2016] [Accepted: 11/25/2016] [Indexed: 12/23/2022]
Abstract
The packaging of DNA into chromosomes is a ubiquitous process that enables living organisms to structure and transmit their genome accurately through cell divisions. In the three kingdoms of life, the architecture and dynamics of chromosomes rely upon ring-shaped SMC (Structural Maintenance of Chromosomes) condensin complexes. To understand how condensin rings organize chromosomes, it is essential to decipher how they associate with chromatin filaments. Here, we use recent evidence to discuss the role played by nucleosomes and transcription factors in the loading of condensin at transcribed genes. We propose a model whereby cis-acting features nestled in the promoters of active genes synergistically attract condensin rings and promote their association with DNA.
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29
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Kim KD, Tanizawa H, Iwasaki O, Noma KI. Transcription factors mediate condensin recruitment and global chromosomal organization in fission yeast. Nat Genet 2016; 48:1242-52. [PMID: 27548313 PMCID: PMC5042855 DOI: 10.1038/ng.3647] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 07/22/2016] [Indexed: 12/13/2022]
Abstract
It is becoming clear that structural-maintenance-of-chromosomes (SMC) complexes such as condensin and cohesin are involved in three-dimensional genome organization, yet their exact roles in functional organization remain unclear. We used chromatin interaction analysis by paired-end tag sequencing (ChIA-PET) to comprehensively identify genome-wide associations mediated by condensin and cohesin in fission yeast. We found that although cohesin and condensin often bind to the same loci, they direct different association networks and generate small and larger chromatin domains, respectively. Cohesin mediates associations between loci positioned within 100 kb of each other; condensin can drive longer-range associations. Moreover, condensin, but not cohesin, connects cell cycle-regulated genes bound by mitotic transcription factors. This study describes the different functions of condensin and cohesin in genome organization and how specific transcription factors function in condensin loading, cell cycle-dependent genome organization and mitotic chromosome organization to support faithful chromosome segregation.
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30
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Bhardwaj S, Schlackow M, Rabajdova M, Gullerova M. Transcription facilitates sister chromatid cohesion on chromosomal arms. Nucleic Acids Res 2016; 44:6676-92. [PMID: 27084937 PMCID: PMC5001582 DOI: 10.1093/nar/gkw252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cohesin is a multi-subunit protein complex essential for sister chromatid cohesion, gene expression and DNA damage repair. Although structurally well studied, the underlying determinant of cohesion establishment on chromosomal arms remains enigmatic. Here, we show two populations of functionally distinct cohesin on chromosomal arms using a combination of genomics and single-locus specific DNA-FISH analysis. Chromatin bound cohesin at the loading sites co-localizes with Pds5 and Eso1 resulting in stable cohesion. In contrast, cohesin independent of its loader is unable to maintain cohesion and associates with chromatin in a dynamic manner. Cohesive sites coincide with highly expressed genes and transcription inhibition leads to destabilization of cohesin on chromatin. Furthermore, induction of transcription results in de novo recruitment of cohesive cohesin. Our data suggest that transcription facilitates cohesin loading onto chromosomal arms and is a key determinant of cohesive sites in fission yeast.
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Affiliation(s)
- Shweta Bhardwaj
- Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
| | | | | | - Monika Gullerova
- Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
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31
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Toselli-Mollereau E, Robellet X, Fauque L, Lemaire S, Schiklenk C, Klein C, Hocquet C, Legros P, N'Guyen L, Mouillard L, Chautard E, Auboeuf D, Haering CH, Bernard P. Nucleosome eviction in mitosis assists condensin loading and chromosome condensation. EMBO J 2016; 35:1565-81. [PMID: 27266525 DOI: 10.15252/embj.201592849] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 05/05/2016] [Indexed: 12/15/2022] Open
Abstract
Condensins associate with DNA and shape mitotic chromosomes. Condensins are enriched nearby highly expressed genes during mitosis, but how this binding is achieved and what features associated with transcription attract condensins remain unclear. Here, we report that condensin accumulates at or in the immediate vicinity of nucleosome-depleted regions during fission yeast mitosis. Two transcriptional coactivators, the Gcn5 histone acetyltransferase and the RSC chromatin-remodelling complex, bind to promoters adjoining condensin-binding sites and locally evict nucleosomes to facilitate condensin binding and allow efficient mitotic chromosome condensation. The function of Gcn5 is closely linked to condensin positioning, since neither the localization of topoisomerase II nor that of the cohesin loader Mis4 is altered in gcn5 mutant cells. We propose that nucleosomes act as a barrier for the initial binding of condensin and that nucleosome-depleted regions formed at highly expressed genes by transcriptional coactivators constitute access points into chromosomes where condensin binds free genomic DNA.
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Affiliation(s)
- Esther Toselli-Mollereau
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Xavier Robellet
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Lydia Fauque
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Sébastien Lemaire
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | | | - Carlo Klein
- Cell Biology and Biophysics Unit, EMBL, Heidelberg, Germany
| | - Clémence Hocquet
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Pénélope Legros
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Lia N'Guyen
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Léo Mouillard
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Emilie Chautard
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Didier Auboeuf
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | | | - Pascal Bernard
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
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Ocampo-Hafalla M, Muñoz S, Samora CP, Uhlmann F. Evidence for cohesin sliding along budding yeast chromosomes. Open Biol 2016; 6:150178. [PMID: 27278645 PMCID: PMC4929932 DOI: 10.1098/rsob.150178] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 05/13/2016] [Indexed: 11/12/2022] Open
Abstract
The ring-shaped cohesin complex is thought to topologically hold sister chromatids together from their synthesis in S phase until chromosome segregation in mitosis. How cohesin stably binds to chromosomes for extended periods, without impeding other chromosomal processes that also require access to the DNA, is poorly understood. Budding yeast cohesin is loaded onto DNA by the Scc2-Scc4 cohesin loader at centromeres and promoters of active genes, from where cohesin translocates to more permanent places of residence at transcription termination sites. Here we show that, at the GAL2 and MET17 loci, pre-existing cohesin is pushed downstream along the DNA in response to transcriptional gene activation, apparently without need for intermittent dissociation or reloading. We observe translocation intermediates and find that the distribution of most chromosomal cohesin is shaped by transcription. Our observations support a model in which cohesin is able to slide laterally along chromosomes while maintaining topological contact with DNA. In this way, stable cohesin binding to DNA and enduring sister chromatid cohesion become compatible with simultaneous underlying chromosomal activities, including but maybe not limited to transcription.
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Affiliation(s)
- Maria Ocampo-Hafalla
- The Francis Crick Institute, Lincoln's Inn Fields Laboratory, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Sofía Muñoz
- The Francis Crick Institute, Lincoln's Inn Fields Laboratory, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Catarina P Samora
- The Francis Crick Institute, Lincoln's Inn Fields Laboratory, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Frank Uhlmann
- The Francis Crick Institute, Lincoln's Inn Fields Laboratory, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
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33
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Abstract
SMC (structural maintenance of chromosomes) complexes - which include condensin, cohesin and the SMC5-SMC6 complex - are major components of chromosomes in all living organisms, from bacteria to humans. These ring-shaped protein machines, which are powered by ATP hydrolysis, topologically encircle DNA. With their ability to hold more than one strand of DNA together, SMC complexes control a plethora of chromosomal activities. Notable among these are chromosome condensation and sister chromatid cohesion. Moreover, SMC complexes have an important role in DNA repair. Recent mechanistic insight into the function and regulation of these universal chromosomal machines enables us to propose molecular models of chromosome structure, dynamics and function, illuminating one of the fundamental entities in biology.
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34
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Mizuguchi T, Barrowman J, Grewal SIS. Chromosome domain architecture and dynamic organization of the fission yeast genome. FEBS Lett 2015; 589:2975-86. [PMID: 26096785 PMCID: PMC4598268 DOI: 10.1016/j.febslet.2015.06.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 06/08/2015] [Accepted: 06/09/2015] [Indexed: 12/20/2022]
Abstract
Advanced techniques including the chromosome conformation capture (3C) methodology and its derivatives are complementing microscopy approaches to study genome organization, and are revealing new details of three-dimensional (3D) genome architecture at increasing resolution. The fission yeast Schizosaccharomyces pombe (S. pombe) comprises a small genome featuring organizational elements of more complex eukaryotic systems, including conserved heterochromatin assembly machinery. Here we review key insights into genome organization revealed in this model system through a variety of techniques. We discuss the predominant role of Rabl-like configuration for interphase chromosome organization and the dynamic changes that occur during mitosis and meiosis. High resolution Hi-C studies have also revealed the presence of locally crumpled chromatin regions called "globules" along chromosome arms, and implicated a critical role for pericentromeric heterochromatin in imposing fundamental constraints on the genome to maintain chromosome territoriality and stability. These findings have shed new light on the connections between genome organization and function. It is likely that insights gained from the S. pombe system will also broadly apply to higher eukaryotes.
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Affiliation(s)
- Takeshi Mizuguchi
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Jemima Barrowman
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shiv I S Grewal
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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35
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Rankin S. Complex elaboration: making sense of meiotic cohesin dynamics. FEBS J 2015; 282:2426-43. [PMID: 25895170 PMCID: PMC4490075 DOI: 10.1111/febs.13301] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 04/02/2015] [Accepted: 04/15/2015] [Indexed: 11/30/2022]
Abstract
In mitotically dividing cells, the cohesin complex tethers sister chromatids, the products of DNA replication, together from the time they are generated during S phase until anaphase. Cohesion between sister chromatids ensures accurate chromosome segregation, and promotes normal gene regulation and certain kinds of DNA repair. In somatic cells, the core cohesin complex is composed of four subunits: Smc1, Smc3, Rad21 and an SA subunit. During meiotic cell divisions meiosis-specific isoforms of several of the cohesin subunits are also expressed and incorporated into distinct meiotic cohesin complexes. The relative contributions of these meiosis-specific forms of cohesin to chromosome dynamics during meiotic progression have not been fully worked out. However, the localization of these proteins during chromosome pairing and synapsis, and their unique loss-of-function phenotypes, suggest non-overlapping roles in controlling meiotic chromosome behavior. Many of the proteins that regulate cohesin function during mitosis also appear to regulate cohesin during meiosis. Here we review how cohesin contributes to meiotic chromosome dynamics, and explore similarities and differences between cohesin regulation during the mitotic cell cycle and meiotic progression. A deeper understanding of the regulation and function of cohesin in meiosis will provide important new insights into how the cohesin complex is able to promote distinct kinds of chromosome interactions under diverse conditions.
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Affiliation(s)
- Susannah Rankin
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, OK, USA
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36
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Nakazawa N, Sajiki K, Xu X, Villar-Briones A, Arakawa O, Yanagida M. RNA pol II transcript abundance controls condensin accumulation at mitotically up-regulated and heat-shock-inducible genes in fission yeast. Genes Cells 2015; 20:481-99. [PMID: 25847133 PMCID: PMC4471619 DOI: 10.1111/gtc.12239] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 02/24/2015] [Indexed: 12/31/2022]
Abstract
Condensin plays fundamental roles in chromosome dynamics. In this study, we determined the binding sites of condensin on fission yeast (Schizosaccharomyces pombe) chromosomes at the level of nucleotide sequences using chromatin immunoprecipitation (ChIP) and ChIP sequencing (ChIP-seq). We found that condensin binds to RNA polymerase I-, II- and III-transcribed genes during both mitosis and interphase, and we focused on pol II constitutive and inducible genes. Accumulation sites for condensin are distinct from those of cohesin and DNA topoisomerase II. Using cell cycle stage and heat-shock-inducible genes, we show that pol II-mediated transcripts cause condensin accumulation. First, condensin's enrichment on mitotically activated genes was abolished by deleting the sep1(+) gene that encodes an M-phase-specific forkhead transcription factor. Second, by raising the temperature, condensin accumulation was rapidly induced at heat-shock protein genes in interphase and even during mid-mitosis. In interphase, condensin accumulates preferentially during the postreplicative phase. Pol II-mediated transcription was neither repressed nor activated by condensin, as levels of transcripts per se did not change when mutant condensin failed to associate with chromosomal DNA. However, massive chromosome missegregation occurred, suggesting that abundant pol II transcription may require active condensin before proper chromosome segregation.
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Affiliation(s)
- Norihiko Nakazawa
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, 904-0495, Japan
| | - Kenichi Sajiki
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, 904-0495, Japan
| | - Xingya Xu
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, 904-0495, Japan
| | - Alejandro Villar-Briones
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, 904-0495, Japan
| | - Orie Arakawa
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, 904-0495, Japan
| | - Mitsuhiro Yanagida
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, 904-0495, Japan
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Mizuguchi T, Fudenberg G, Mehta S, Belton JM, Taneja N, Folco HD, FitzGerald P, Dekker J, Mirny L, Barrowman J, Grewal SIS. Cohesin-dependent globules and heterochromatin shape 3D genome architecture in S. pombe. Nature 2014; 516:432-435. [PMID: 25307058 PMCID: PMC4465753 DOI: 10.1038/nature13833] [Citation(s) in RCA: 187] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 09/05/2014] [Indexed: 12/20/2022]
Abstract
Eukaryotic genomes are folded into three-dimensional structures, such as self-associating topological domains, the borders of which are enriched in cohesin and CCCTC-binding factor (CTCF) required for long-range interactions. How local chromatin interactions govern higher-order folding of chromatin fibres and the function of cohesin in this process remain poorly understood. Here we perform genome-wide chromatin conformation capture (Hi-C) analysis to explore the high-resolution organization of the Schizosaccharomyces pombe genome, which despite its small size exhibits fundamental features found in other eukaryotes. Our analyses of wild-type and mutant strains reveal key elements of chromosome architecture and genome organization. On chromosome arms, small regions of chromatin locally interact to form 'globules'. This feature requires a function of cohesin distinct from its role in sister chromatid cohesion. Cohesin is enriched at globule boundaries and its loss causes disruption of local globule structures and global chromosome territories. By contrast, heterochromatin, which loads cohesin at specific sites including pericentromeric and subtelomeric domains, is dispensable for globule formation but nevertheless affects genome organization. We show that heterochromatin mediates chromatin fibre compaction at centromeres and promotes prominent inter-arm interactions within centromere-proximal regions, providing structural constraints crucial for proper genome organization. Loss of heterochromatin relaxes constraints on chromosomes, causing an increase in intra- and inter-chromosomal interactions. Together, our analyses uncover fundamental genome folding principles that drive higher-order chromosome organization crucial for coordinating nuclear functions.
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Affiliation(s)
- Takeshi Mizuguchi
- Laboratory of Biochemistry and Molecular Biology National Cancer Institute, National Institutes of Health Bethesda, MD, 20892, USA
| | - Geoffrey Fudenberg
- Graduate Program in Biophysics, Harvard University, Cambridge, MA, 02139, USA
- Institute for Medical Engineering and Sciences, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Sameet Mehta
- Laboratory of Biochemistry and Molecular Biology National Cancer Institute, National Institutes of Health Bethesda, MD, 20892, USA
| | - Jon-Matthew Belton
- Program in Systems Biology University of Massachusetts Medical School Worcester, MA, 01605, USA
| | - Nitika Taneja
- Laboratory of Biochemistry and Molecular Biology National Cancer Institute, National Institutes of Health Bethesda, MD, 20892, USA
| | - Hernan Diego Folco
- Laboratory of Biochemistry and Molecular Biology National Cancer Institute, National Institutes of Health Bethesda, MD, 20892, USA
| | - Peter FitzGerald
- Genome Analysis Unit National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Job Dekker
- Program in Systems Biology University of Massachusetts Medical School Worcester, MA, 01605, USA
| | - Leonid Mirny
- Graduate Program in Biophysics, Harvard University, Cambridge, MA, 02139, USA
- Institute for Medical Engineering and Sciences, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Jemima Barrowman
- Laboratory of Biochemistry and Molecular Biology National Cancer Institute, National Institutes of Health Bethesda, MD, 20892, USA
| | - Shiv I S Grewal
- Laboratory of Biochemistry and Molecular Biology National Cancer Institute, National Institutes of Health Bethesda, MD, 20892, USA
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Abstract
The shugoshin/Mei-S332 family are proteins that associate with the chromosomal region surrounding the centromere (the pericentromere) and that play multiple and distinct roles in ensuring the accuracy of chromosome segregation during both mitosis and meiosis. The underlying role of shugoshins appears to be to serve as pericentromeric adaptor proteins that recruit several different effectors to this region of the chromosome to regulate processes critical for chromosome segregation. Crucially, shugoshins undergo changes in their localization in response to the tension that is exerted on sister chromosomes by the forces of the spindle that will pull them apart. This has led to the idea that shugoshins provide a platform for activities required at the pericentromere only when sister chromosomes lack tension. Conversely, disassembly of the shugoshin pericentromeric platform may provide a signal that sister chromosomes are under tension. Here the functions and regulation of these important tension-sensitive pericentromeric proteins are discussed.
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39
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The maintenance of chromosome structure: positioning and functioning of SMC complexes. Nat Rev Mol Cell Biol 2014; 15:601-14. [PMID: 25145851 DOI: 10.1038/nrm3857] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Structural maintenance of chromosomes (SMC) complexes, which in eukaryotic cells include cohesin, condensin and the Smc5/6 complex, are central regulators of chromosome dynamics and control sister chromatid cohesion, chromosome condensation, DNA replication, DNA repair and transcription. Even though the molecular mechanisms that lead to this large range of functions are still unclear, it has been established that the complexes execute their functions through their association with chromosomal DNA. A large set of data also indicates that SMC complexes work as intermolecular and intramolecular linkers of DNA. When combining these insights with results from ongoing analyses of their chromosomal binding, and how this interaction influences the structure and dynamics of chromosomes, a picture of how SMC complexes carry out their many functions starts to emerge.
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40
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Jeppsson K, Carlborg KK, Nakato R, Berta DG, Lilienthal I, Kanno T, Lindqvist A, Brink MC, Dantuma NP, Katou Y, Shirahige K, Sjögren C. The chromosomal association of the Smc5/6 complex depends on cohesion and predicts the level of sister chromatid entanglement. PLoS Genet 2014; 10:e1004680. [PMID: 25329383 PMCID: PMC4199498 DOI: 10.1371/journal.pgen.1004680] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 08/18/2014] [Indexed: 11/24/2022] Open
Abstract
The cohesin complex, which is essential for sister chromatid cohesion and chromosome segregation, also inhibits resolution of sister chromatid intertwinings (SCIs) by the topoisomerase Top2. The cohesin-related Smc5/6 complex (Smc5/6) instead accumulates on chromosomes after Top2 inactivation, known to lead to a buildup of unresolved SCIs. This suggests that cohesin can influence the chromosomal association of Smc5/6 via its role in SCI protection. Using high-resolution ChIP-sequencing, we show that the localization of budding yeast Smc5/6 to duplicated chromosomes indeed depends on sister chromatid cohesion in wild-type and top2-4 cells. Smc5/6 is found to be enriched at cohesin binding sites in the centromere-proximal regions in both cell types, but also along chromosome arms when replication has occurred under Top2-inhibiting conditions. Reactivation of Top2 after replication causes Smc5/6 to dissociate from chromosome arms, supporting the assumption that Smc5/6 associates with a Top2 substrate. It is also demonstrated that the amount of Smc5/6 on chromosomes positively correlates with the level of missegregation in top2-4, and that Smc5/6 promotes segregation of short chromosomes in the mutant. Altogether, this shows that the chromosomal localization of Smc5/6 predicts the presence of the chromatid segregation-inhibiting entities which accumulate in top2-4 mutated cells. These are most likely SCIs, and our results thus indicate that, at least when Top2 is inhibited, Smc5/6 facilitates their resolution.
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Affiliation(s)
- Kristian Jeppsson
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
| | - Kristian K. Carlborg
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
| | - Ryuichiro Nakato
- University of Tokyo, Institute of Molecular and Cellular Biosciences, Laboratory of Genome Structure and Function Center for Epigenetic Disease, Bunkyo-ku, Tokyo, Japan
| | - Davide G. Berta
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
| | - Ingrid Lilienthal
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
| | - Takaharu Kanno
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
| | - Arne Lindqvist
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
| | - Maartje C. Brink
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
| | - Nico P. Dantuma
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
| | - Yuki Katou
- University of Tokyo, Institute of Molecular and Cellular Biosciences, Laboratory of Genome Structure and Function Center for Epigenetic Disease, Bunkyo-ku, Tokyo, Japan
| | - Katsuhiko Shirahige
- University of Tokyo, Institute of Molecular and Cellular Biosciences, Laboratory of Genome Structure and Function Center for Epigenetic Disease, Bunkyo-ku, Tokyo, Japan
| | - Camilla Sjögren
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden
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41
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Lopez-Serra L, Kelly G, Patel H, Stewart A, Uhlmann F. The Scc2-Scc4 complex acts in sister chromatid cohesion and transcriptional regulation by maintaining nucleosome-free regions. Nat Genet 2014; 46:1147-51. [PMID: 25173104 PMCID: PMC4177232 DOI: 10.1038/ng.3080] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 08/06/2014] [Indexed: 12/14/2022]
Abstract
The cohesin complex is at the heart of many chromosomal activities, including sister chromatid cohesion and transcriptional regulation. Cohesin loading onto chromosomes depends on the Scc2-Scc4 cohesin loader complex, but the chromatin features that form cohesin loading sites remain poorly understood. Here we show that the RSC chromatin remodeling complex recruits budding yeast Scc2-Scc4 to broad nucleosome-free regions, which the cohesin loader helps to maintain. Consequently, inactivation of either the cohesin loader or the RSC complex has similar effects on nucleosome positioning, gene expression and sister chromatid cohesion. These results show an intimate link between local chromatin structure and higher-order chromosome architecture. Our findings pertain to the similarities between two severe human disorders, Cornelia de Lange syndrome, which is caused by alterations in the human cohesin loader, and Coffin-Siris syndrome, which results from alterations in human RSC complex components. Both syndromes can arise from gene misregulation due to related changes in the nucleosome landscape.
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MESH Headings
- Abnormalities, Multiple/genetics
- Abnormalities, Multiple/metabolism
- Binding Sites/genetics
- Chromatids/genetics
- Chromatids/metabolism
- Chromatin/genetics
- Chromatin/metabolism
- Chromosomal Proteins, Non-Histone/genetics
- Chromosomal Proteins, Non-Histone/metabolism
- Chromosomes, Fungal/genetics
- Chromosomes, Fungal/metabolism
- De Lange Syndrome/genetics
- De Lange Syndrome/metabolism
- Face/abnormalities
- Gene Expression Profiling
- Gene Expression Regulation, Fungal
- Hand Deformities, Congenital/genetics
- Hand Deformities, Congenital/metabolism
- Humans
- Intellectual Disability/genetics
- Intellectual Disability/metabolism
- Micrognathism/genetics
- Micrognathism/metabolism
- Neck/abnormalities
- Nucleosomes/genetics
- Nucleosomes/metabolism
- Oligonucleotide Array Sequence Analysis
- Promoter Regions, Genetic/genetics
- Protein Binding
- Saccharomyces cerevisiae Proteins/genetics
- Saccharomyces cerevisiae Proteins/metabolism
- Transcription Initiation Site
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Affiliation(s)
- Lidia Lopez-Serra
- Chromosome Segregation Laboratory, Cancer Research UK London Research Institute, London, UK
| | - Gavin Kelly
- Bioinformatics and Biostatistics Service, Cancer Research UK London Research Institute, London, UK
| | - Harshil Patel
- Bioinformatics and Biostatistics Service, Cancer Research UK London Research Institute, London, UK
| | - Aengus Stewart
- Bioinformatics and Biostatistics Service, Cancer Research UK London Research Institute, London, UK
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, Cancer Research UK London Research Institute, London, UK
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42
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Abstract
Enhancers are selectively utilized to orchestrate gene expression programs that first govern pluripotency and then proceed to highly specialized programs required for the process of cellular differentiation. Whereas gene-proximal promoters are typically active across numerous cell types, distal enhancer activation is cell-type-specific and central to cell fate determination, thereby accounting for cell identity. Recent studies have highlighted the diversity of enhancer usage, cataloguing millions of such elements in the human genome. The disruption of enhancer activity, through genetic or epigenetic alterations, can impact cell-type-specific functions, resulting in a wide range of pathologies. In cancer, these alterations can promote a 'cell identity crisis', in which enhancers associated with oncogenes and multipotentiality are activated, while those promoting cell fate commitment are inactivated. Overall, these alterations favor an undifferentiated cellular phenotype. Here, we review the current knowledge regarding the role of enhancers in normal cell function, and discuss how genetic and epigenetic changes in enhancer elements potentiate oncogenesis. In addition, we discuss how understanding the mechanisms regulating enhancer activity can inform therapeutic opportunities in cancer cells and highlight key challenges that remain in understanding enhancer biology as it relates to oncology.
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Affiliation(s)
- Ken J Kron
- The Princess Margaret Cancer Centre - University Health Network, Toronto, ON M5G 1 L7 Canada ; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1 L7 Canada
| | - Swneke D Bailey
- The Princess Margaret Cancer Centre - University Health Network, Toronto, ON M5G 1 L7 Canada ; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1 L7 Canada
| | - Mathieu Lupien
- The Princess Margaret Cancer Centre - University Health Network, Toronto, ON M5G 1 L7 Canada ; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1 L7 Canada ; Ontario Institute for Cancer Research, Toronto, ON M5G 0A3 Canada
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43
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Kim JH, Zhang T, Wong NC, Davidson N, Maksimovic J, Oshlack A, Earnshaw WC, Kalitsis P, Hudson DF. Condensin I associates with structural and gene regulatory regions in vertebrate chromosomes. Nat Commun 2014; 4:2537. [PMID: 24088984 DOI: 10.1038/ncomms3537] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 09/03/2013] [Indexed: 11/09/2022] Open
Abstract
The condensin complex is essential for correct packaging and segregation of chromosomes during mitosis and meiosis in all eukaryotes. To date, the genome-wide location and the nature of condensin-binding sites have remained elusive in vertebrates. Here we report the genome-wide map of condensin I in chicken DT40 cells. Unexpectedly, we find that condensin I binds predominantly to promoter sequences in mitotic cells. We also find a striking enrichment at both centromeres and telomeres, highlighting the importance of the complex in chromosome segregation. Taken together, the results show that condensin I is largely absent from heterochromatic regions. This map of the condensin I binding sites on the chicken genome reveals that patterns of condensin distribution on chromosomes are conserved from prokaryotes, through yeasts to vertebrates. Thus in three kingdoms of life, condensin is enriched on promoters of actively transcribed genes and at loci important for chromosome segregation.
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Affiliation(s)
- Ji Hun Kim
- 1] Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Melbourne, Victoria 3052, Australia [2] Department of Paediatrics, University of Melbourne, Parkville, Melbourne, Victoria 3052, Australia
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44
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Kinetochore assembly and heterochromatin formation occur autonomously in Schizosaccharomyces pombe. Proc Natl Acad Sci U S A 2014; 111:1903-8. [PMID: 24449889 DOI: 10.1073/pnas.1216934111] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Kinetochores in multicellular eukaryotes are usually associated with heterochromatin. Whether this heterochromatin simply promotes the cohesion necessary for accurate chromosome segregation at cell division or whether it also has a role in kinetochore assembly is unclear. Schizosaccharomyces pombe is an important experimental system for investigating centromere function, but all of the previous work with this species has exploited a single strain or its derivatives. The laboratory strain and most other S. pombe strains contain three chromosomes, but one recently discovered strain, CBS 2777, contains four. We show that the genome of CBS 2777 is related to that of the laboratory strain by a complex chromosome rearrangement. As a result, two of the kinetochores in CBS 2777 contain the central core sequences present in the laboratory strain centromeres, but lack adjacent heterochromatin. The closest block of heterochromatin to these rearranged kinetochores is ∼100 kb away at new telomeres. Despite lacking large amounts of adjacent heterochromatin, the rearranged kinetochores bind CENP-A(Cnp1) and CENP-C(Cnp3) in similar quantities and with similar specificities as those of the laboratory strain. The simplest interpretation of this result is that constitutive kinetochore assembly and heterochromatin formation occur autonomously.
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45
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Murayama Y, Uhlmann F. Biochemical reconstitution of topological DNA binding by the cohesin ring. Nature 2014; 505:367-71. [PMID: 24291789 PMCID: PMC3907785 DOI: 10.1038/nature12867] [Citation(s) in RCA: 212] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 11/13/2013] [Indexed: 01/06/2023]
Abstract
Cohesion between sister chromatids, mediated by the chromosomal cohesin complex, is a prerequisite for faithful chromosome segregation in mitosis. Cohesin also has vital roles in DNA repair and transcriptional regulation. The ring-shaped cohesin complex is thought to encircle sister DNA strands, but its molecular mechanism of action is poorly understood and the biochemical reconstitution of cohesin activity in vitro has remained an unattained goal. Here we reconstitute cohesin loading onto DNA using purified fission yeast cohesin and its loader complex, Mis4(Scc2)-Ssl3(Scc4) (Schizosaccharomyces pombe gene names appear throughout with their more commonly known Saccharomyces cerevisiae counterparts added in superscript). Incubation of cohesin with DNA leads to spontaneous topological loading, but this remains inefficient. The loader contacts cohesin at multiple sites around the ring circumference, including the hitherto enigmatic Psc3(Scc3) subunit, and stimulates cohesin's ATPase, resulting in efficient topological loading. The in vitro reconstitution of cohesin loading onto DNA provides mechanistic insight into the initial steps of the establishment of sister chromatid cohesion and other chromosomal processes mediated by cohesin.
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Affiliation(s)
- Yasuto Murayama
- Chromosome Segregation Laboratory, Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
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46
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Abstract
DNA replication during S phase generates two identical copies of each chromosome. Each chromosome is destined for a daughter cell, but each daughter must receive one and only one copy of each chromosome. To ensure accurate chromosome segregation, eukaryotic cells are equipped with a mechanism to pair the chromosomes during chromosome duplication and hold the pairs until a bi-oriented mitotic spindle is formed and the pairs are pulled apart. This mechanism is known as sister chromatid cohesion, and its actions span the entire cell cycle. During G1, before DNA is copied during S phase, proteins termed cohesins are loaded onto DNA. Paired chromosomes are held together through G2 phase, and finally the cohesins are dismantled during mitosis. The processes governing sister chromatid cohesion ensure that newly replicated sisters are held together from the moment they are generated to the metaphase-anaphase transition, when sisters separate.
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Affiliation(s)
- Adam R Leman
- Department of Biology, Duke University, Durham, NC, USA
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47
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Schlackow M, Marguerat S, Proudfoot NJ, Bähler J, Erban R, Gullerova M. Genome-wide analysis of poly(A) site selection in Schizosaccharomyces pombe. RNA (NEW YORK, N.Y.) 2013; 19:1617-1631. [PMID: 24152550 PMCID: PMC3884648 DOI: 10.1261/rna.040675.113] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 09/17/2013] [Indexed: 05/31/2023]
Abstract
Polyadenylation of pre-mRNAs, a critical step in eukaryotic gene expression, is mediated by cis elements collectively called the polyadenylation signal. Genome-wide analysis of such polyadenylation signals was missing in fission yeast, even though it is an important model organism. We demonstrate that the canonical AATAAA motif is the most frequent and functional polyadenylation signal in Schizosaccharomyces pombe. Using analysis of RNA-Seq data sets from cells grown under various physiological conditions, we identify 3' UTRs for nearly 90% of the yeast genes. Heterogeneity of cleavage sites is common, as is alternative polyadenylation within and between conditions. We validated the computationally identified sequence elements likely to promote polyadenylation by functional assays, including qRT-PCR and 3'RACE analysis. The biological importance of the AATAAA motif is underlined by functional analysis of the genes containing it. Furthermore, it has been shown that convergent genes require trans elements, like cohesin for efficient transcription termination. Here we show that convergent genes lacking cohesin (on chromosome 2) are generally associated with longer overlapping mRNA transcripts. Our bioinformatic and experimental genome-wide results are summarized and can be accessed and customized in a user-friendly database Pomb(A).
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MESH Headings
- 3' Untranslated Regions
- Base Sequence
- Chromosome Mapping
- Chromosomes, Fungal/genetics
- Gene Expression Regulation, Fungal
- Genes, Fungal
- Genome, Fungal
- Molecular Sequence Annotation
- Molecular Sequence Data
- Polyadenylation
- RNA Cleavage
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Schizosaccharomyces/genetics
- Schizosaccharomyces/metabolism
- Sequence Analysis, RNA
- Transcription Termination, Genetic
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Affiliation(s)
- Margarita Schlackow
- Mathematical Institute, University of Oxford, Oxford, Oxfordshire OX1 3LB, United Kingdom
| | - Samuel Marguerat
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
| | - Nicholas J. Proudfoot
- Sir William Dunn School of Pathology, University of Oxford, Oxford, Oxfordshire OX1 3RE, United Kingdom
| | - Jürg Bähler
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
| | - Radek Erban
- Mathematical Institute, University of Oxford, Oxford, Oxfordshire OX1 3LB, United Kingdom
| | - Monika Gullerova
- Sir William Dunn School of Pathology, University of Oxford, Oxford, Oxfordshire OX1 3RE, United Kingdom
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48
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Fernius J, Nerusheva O, Galander S, Alves F, Rappsilber J, Marston A. Cohesin-dependent association of scc2/4 with the centromere initiates pericentromeric cohesion establishment. Curr Biol 2013; 23:599-606. [PMID: 23499533 PMCID: PMC3627958 DOI: 10.1016/j.cub.2013.02.022] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 01/14/2013] [Accepted: 02/08/2013] [Indexed: 12/29/2022]
Abstract
Cohesin is a conserved ring-shaped multiprotein complex that participates in chromosome segregation, DNA repair, and transcriptional regulation [1, 2]. Cohesin loading onto chromosomes universally requires the Scc2/4 "loader" complex (also called NippedBL/Mau2), mutations in which cause the developmental disorder Cornelia de Lange syndrome in humans [1-9]. Cohesin is most concentrated in the pericentromere, the region surrounding the centromere [10-15]. Enriched pericentromeric cohesin requires the Ctf19 kinetochore subcomplex in budding yeast [16-18]. Here, we uncover the spatial and temporal determinants for Scc2/4 centromere association. We demonstrate that the critical role of the Ctf19 complex is to enable Scc2/4 association with centromeres, through which cohesin loads and spreads onto the adjacent pericentromere. We show that, unexpectedly, Scc2 association with centromeres depends on cohesin itself. The absence of the Scc1/Mcd1/Rad21 cohesin subunit precludes Scc2 association with centromeres from anaphase until late G1. Expression of SCC1 is both necessary and sufficient for the binding of cohesin to its loader, the association of Scc2 with centromeres, and cohesin loading. We propose that cohesin triggers its own loading by enabling Scc2/4 to connect with chromosomal landmarks, which at centromeres are specified by the Ctf19 complex. Overall, our findings provide a paradigm for the spatial and temporal control of cohesin loading.
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Affiliation(s)
- Josefin Fernius
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, Michael Swann Building, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Olga O. Nerusheva
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, Michael Swann Building, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Stefan Galander
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, Michael Swann Building, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Flavia de Lima Alves
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, Michael Swann Building, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Juri Rappsilber
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, Michael Swann Building, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Adele L. Marston
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, Michael Swann Building, Mayfield Road, Edinburgh EH9 3JR, UK
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49
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Abstract
The processes underlying the large-scale reorganisation of chromatin in mitosis that form compact mitotic chromosomes and ensure the fidelity of chromosome segregation during cell division still remain obscure. The chromosomal condensin complex is a major molecular effector of chromosome condensation and segregation in diverse organisms ranging from bacteria to humans. Condensin is a large, evolutionarily conserved, multisubunit protein assembly composed of dimers of the structural maintenance of chromosomes (SMC) family of ATPases, clasped into topologically closed rings by accessory subunits. Condensin binds to DNA dynamically, in a poorly understood cycle of ATP-modulated conformational changes, and exhibits the ability to positively supercoil DNA. During mitosis, condensin is phosphorylated by the cyclin-dependent kinase (CDK), Polo and Aurora B kinases in a manner that correlates with changes in its localisation, dynamics and supercoiling activity. Here we review the reported architecture, biochemical activities and regulators of condensin. We compare models of bacterial and eukaryotic condensins in order to uncover conserved mechanistic principles of condensin action and to propose a model for mitotic chromosome condensation.
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Affiliation(s)
- Rahul Thadani
- Chromosome Segregation Laboratory, Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
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50
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Abstract
During S phase, not only does DNA have to be replicated, but also newly synthesized DNA molecules have to be connected with each other. This sister chromatid cohesion is essential for the biorientation of chromosomes on the mitotic or meiotic spindle, and is thus an essential prerequisite for chromosome segregation. Cohesion is mediated by cohesin complexes that are thought to embrace sister chromatids as large rings. Cohesin binds to DNA dynamically before DNA replication and is converted into a stably DNA-bound form during replication. This conversion requires acetylation of cohesin, which in vertebrates leads to recruitment of sororin. Sororin antagonizes Wapl, a protein that is able to release cohesin from DNA, presumably by opening the cohesin ring. Inhibition of Wapl by sororin therefore "locks" cohesin rings on DNA and allows them to maintain cohesion for long periods of time in mammalian oocytes, possibly for months or even years.
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