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de Lima MF, Lisboa MDO, Terceiro LEL, Rangel-Pozzo A, Mai S. Chromosome Territories in Hematological Malignancies. Cells 2022; 11:cells11081368. [PMID: 35456046 PMCID: PMC9028803 DOI: 10.3390/cells11081368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/12/2022] [Accepted: 04/15/2022] [Indexed: 11/21/2022] Open
Abstract
Chromosomes are organized in distinct nuclear areas designated as chromosome territories (CT). The structural formation of CT is a consequence of chromatin packaging and organization that ultimately affects cell function. Chromosome positioning can identify structural signatures of genomic organization, especially for diseases where changes in gene expression contribute to a given phenotype. The study of CT in hematological diseases revealed chromosome position as an important factor for specific chromosome translocations. In this review, we highlight the history of CT theory, current knowledge on possible clinical applications of CT analysis, and the impact of CT in the development of hematological neoplasia such as multiple myeloma, leukemia, and lymphomas. Accumulating data on nuclear architecture in cancer allow one to propose the three-dimensional nuclear genomic landscape as a novel cancer biomarker for the future.
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Affiliation(s)
- Matheus Fabiao de Lima
- Department of Physiology and Pathophysiology, CancerCare Manitoba Research Institute, University of Manitoba, Winnipeg, MB R3E 0V9, Canada;
| | - Mateus de Oliveira Lisboa
- Core for Cell Technology, School of Medicine, Pontifícia Universidade Católica do Paraná—PUCPR, Curitiba 80215-901, Brazil;
| | - Lucas E. L. Terceiro
- Department of Pathology, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB R3E 3P5, Canada;
| | - Aline Rangel-Pozzo
- Department of Physiology and Pathophysiology, CancerCare Manitoba Research Institute, University of Manitoba, Winnipeg, MB R3E 0V9, Canada;
- Correspondence: (A.R.-P.); (S.M.); Tel.: +1-204-787-2135 (S.M.)
| | - Sabine Mai
- Department of Physiology and Pathophysiology, CancerCare Manitoba Research Institute, University of Manitoba, Winnipeg, MB R3E 0V9, Canada;
- Correspondence: (A.R.-P.); (S.M.); Tel.: +1-204-787-2135 (S.M.)
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2
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Samejima I, Spanos C, Samejima K, Rappsilber J, Kustatscher G, Earnshaw WC. Mapping the invisible chromatin transactions of prophase chromosome remodeling. Mol Cell 2022; 82:696-708.e4. [PMID: 35090599 PMCID: PMC8823707 DOI: 10.1016/j.molcel.2021.12.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 11/03/2021] [Accepted: 12/28/2021] [Indexed: 02/07/2023]
Abstract
We have used a combination of chemical genetics, chromatin proteomics, and imaging to map the earliest chromatin transactions during vertebrate cell entry into mitosis. Chicken DT40 CDK1as cells undergo synchronous mitotic entry within 15 min following release from a 1NM-PP1-induced arrest in late G2. In addition to changes in chromatin association with nuclear pores and the nuclear envelope, earliest prophase is dominated by changes in the association of ribonucleoproteins with chromatin, particularly in the nucleolus, where pre-rRNA processing factors leave chromatin significantly before RNA polymerase I. Nuclear envelope barrier function is lost early in prophase, and cytoplasmic proteins begin to accumulate on the chromatin. As a result, outer kinetochore assembly appears complete by nuclear envelope breakdown (NEBD). Most interphase chromatin proteins remain associated with chromatin until NEBD, after which their levels drop sharply. An interactive proteomic map of chromatin transactions during mitotic entry is available as a resource at https://mitoChEP.bio.ed.ac.uk.
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Affiliation(s)
- Itaru Samejima
- Wellcome Centre for Cell Biology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK
| | - Christos Spanos
- Wellcome Centre for Cell Biology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK
| | - Kumiko Samejima
- Wellcome Centre for Cell Biology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK
| | - Juri Rappsilber
- Wellcome Centre for Cell Biology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK; Technische Universität Berlin, Chair of Bioanalytics, 10623 Berlin, Germany
| | - Georg Kustatscher
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK.
| | - William C Earnshaw
- Wellcome Centre for Cell Biology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK.
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3
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Stochastic chromatin packing of 3D mitotic chromosomes revealed by coherent X-rays. Proc Natl Acad Sci U S A 2021; 118:2109921118. [PMID: 34750262 DOI: 10.1073/pnas.2109921118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2021] [Indexed: 11/18/2022] Open
Abstract
DNA molecules are atomic-scale information storage molecules that promote reliable information transfer via fault-free repetitions of replications and transcriptions. Remarkable accuracy of compacting a few-meters-long DNA into a micrometer-scale object, and the reverse, makes the chromosome one of the most intriguing structures from both physical and biological viewpoints. However, its three-dimensional (3D) structure remains elusive with challenges in observing native structures of specimens at tens-of-nanometers resolution. Here, using cryogenic coherent X-ray diffraction imaging, we succeeded in obtaining nanoscale 3D structures of metaphase chromosomes that exhibited a random distribution of electron density without characteristics of high-order folding structures. Scaling analysis of the chromosomes, compared with a model structure having the same density profile as the experimental results, has discovered the fractal nature of density distributions. Quantitative 3D density maps, corroborated by molecular dynamics simulations, reveal that internal structures of chromosomes conform to diffusion-limited aggregation behavior, which indicates that 3D chromatin packing occurs via stochastic processes.
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4
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Arimura Y, Shih RM, Froom R, Funabiki H. Structural features of nucleosomes in interphase and metaphase chromosomes. Mol Cell 2021; 81:4377-4397.e12. [PMID: 34478647 PMCID: PMC8571072 DOI: 10.1016/j.molcel.2021.08.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 08/05/2021] [Accepted: 08/06/2021] [Indexed: 12/17/2022]
Abstract
Structural heterogeneity of nucleosomes in functional chromosomes is unknown. Here, we devise the template-, reference- and selection-free (TRSF) cryo-EM pipeline to simultaneously reconstruct cryo-EM structures of protein complexes from interphase or metaphase chromosomes. The reconstructed interphase and metaphase nucleosome structures are on average indistinguishable from canonical nucleosome structures, despite DNA sequence heterogeneity, cell-cycle-specific posttranslational modifications, and interacting proteins. Nucleosome structures determined by a decoy-classifying method and structure variability analyses reveal the nucleosome structural variations in linker DNA, histone tails, and nucleosome core particle configurations, suggesting that the opening of linker DNA, which is correlated with H2A C-terminal tail positioning, is suppressed in chromosomes. High-resolution (3.4-3.5 Å) nucleosome structures indicate DNA-sequence-independent stabilization of superhelical locations ±0-1 and ±3.5-4.5. The linker histone H1.8 preferentially binds to metaphase chromatin, from which chromatosome cryo-EM structures with H1.8 at the on-dyad position are reconstituted. This study presents the structural characteristics of nucleosomes in chromosomes.
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Affiliation(s)
- Yasuhiro Arimura
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, New York, NY 10065, USA.
| | - Rochelle M Shih
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, New York, NY 10065, USA
| | - Ruby Froom
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Hironori Funabiki
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, New York, NY 10065, USA.
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5
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Abstract
Condensation and faithful separation of the genome are crucial for the cellular life cycle. During chromosome segregation, mechanical forces generated by the mitotic spindle pull apart the sister chromatids. The mechanical nature of this process has motivated a lot of research interest into the mechanical properties of mitotic chromosomes. Although their fundamental mechanical characteristics are known, it still remains unclear how these characteristics emerge from the structure of the mitotic chromosome. Recent advances in genomics, computational and super-resolution microscopy techniques have greatly promoted our understanding of the chromosomal structure and have motivated us to review the mechanical characteristics of chromosomes in light of the current structural insights. In this review, we will first introduce the current understanding of the chromosomal structure, before reviewing characteristic mechanical properties such as the Young's modulus and the bending modulus of mitotic chromosomes. Then we will address the approaches used to relate mechanical properties to the structure of chromosomes and we will also discuss how mechanical characterization can aid in elucidating their structure. Finally, future challenges, recent developments and emergent questions in this research field will be discussed.
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6
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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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7
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Banigan EJ, Mirny LA. The interplay between asymmetric and symmetric DNA loop extrusion. eLife 2020; 9:e63528. [PMID: 33295869 PMCID: PMC7793625 DOI: 10.7554/elife.63528] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/30/2020] [Indexed: 12/30/2022] Open
Abstract
Chromosome compaction is essential for reliable transmission of genetic information. Experiments suggest that ∼1000-fold compaction is driven by condensin complexes that extrude chromatin loops, by progressively collecting chromatin fiber from one or both sides of the complex to form a growing loop. Theory indicates that symmetric two-sided loop extrusion can achieve such compaction, but recent single-molecule studies (Golfier et al., 2020) observed diverse dynamics of condensins that perform one-sided, symmetric two-sided, and asymmetric two-sided extrusion. We use simulations and theory to determine how these molecular properties lead to chromosome compaction. High compaction can be achieved if even a small fraction of condensins have two essential properties: a long residence time and the ability to perform two-sided (not necessarily symmetric) extrusion. In mixtures of condensins I and II, coupling two-sided extrusion and stable chromatin binding by condensin II promotes compaction. These results provide missing connections between single-molecule observations and chromosome-scale organization.
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Affiliation(s)
- Edward J Banigan
- Department of Physics and Institute for Medical Engineering and Science, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Leonid A Mirny
- Department of Physics and Institute for Medical Engineering and Science, Massachusetts Institute of TechnologyCambridgeUnited States
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8
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Finardi A, Massari LF, Visintin R. Anaphase Bridges: Not All Natural Fibers Are Healthy. Genes (Basel) 2020; 11:genes11080902. [PMID: 32784550 PMCID: PMC7464157 DOI: 10.3390/genes11080902] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 02/07/2023] Open
Abstract
At each round of cell division, the DNA must be correctly duplicated and distributed between the two daughter cells to maintain genome identity. In order to achieve proper chromosome replication and segregation, sister chromatids must be recognized as such and kept together until their separation. This process of cohesion is mainly achieved through proteinaceous linkages of cohesin complexes, which are loaded on the sister chromatids as they are generated during S phase. Cohesion between sister chromatids must be fully removed at anaphase to allow chromosome segregation. Other (non-proteinaceous) sources of cohesion between sister chromatids consist of DNA linkages or sister chromatid intertwines. DNA linkages are a natural consequence of DNA replication, but must be timely resolved before chromosome segregation to avoid the arising of DNA lesions and genome instability, a hallmark of cancer development. As complete resolution of sister chromatid intertwines only occurs during chromosome segregation, it is not clear whether DNA linkages that persist in mitosis are simply an unwanted leftover or whether they have a functional role. In this review, we provide an overview of DNA linkages between sister chromatids, from their origin to their resolution, and we discuss the consequences of a failure in their detection and processing and speculate on their potential role.
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Affiliation(s)
- Alice Finardi
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, 20139 Milan, Italy;
| | - Lucia F. Massari
- The Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK;
| | - Rosella Visintin
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, 20139 Milan, Italy;
- Correspondence: ; Tel.: +39-02-5748-9859; Fax: +39-02-9437-5991
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9
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Kong M, Cutts EE, Pan D, Beuron F, Kaliyappan T, Xue C, Morris EP, Musacchio A, Vannini A, Greene EC. Human Condensin I and II Drive Extensive ATP-Dependent Compaction of Nucleosome-Bound DNA. Mol Cell 2020; 79:99-114.e9. [PMID: 32445620 PMCID: PMC7335352 DOI: 10.1016/j.molcel.2020.04.026] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 02/08/2020] [Accepted: 04/22/2020] [Indexed: 12/15/2022]
Abstract
Structural maintenance of chromosomes (SMC) complexes are essential for genome organization from bacteria to humans, but their mechanisms of action remain poorly understood. Here, we characterize human SMC complexes condensin I and II and unveil the architecture of the human condensin II complex, revealing two putative DNA-entrapment sites. Using single-molecule imaging, we demonstrate that both condensin I and II exhibit ATP-dependent motor activity and promote extensive and reversible compaction of double-stranded DNA. Nucleosomes are incorporated into DNA loops during compaction without being displaced from the DNA, indicating that condensin complexes can readily act upon nucleosome-bound DNA molecules. These observations shed light on critical processes involved in genome organization in human cells.
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Affiliation(s)
- Muwen Kong
- Department of Biochemistry and Molecular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Erin E Cutts
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK
| | - Dongqing Pan
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Fabienne Beuron
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK
| | - Thangavelu Kaliyappan
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK
| | - Chaoyou Xue
- Department of Biochemistry and Molecular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Edward P Morris
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Alessandro Vannini
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK; Fondazione Human Technopole, Structural Biology Research Centre, 20157 Milan, Italy.
| | - Eric C Greene
- Department of Biochemistry and Molecular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA.
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10
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Kleinschnitz K, Vießmann N, Jordan M, Heidmann SK. Condensin I is required for faithful meiosis in Drosophila males. Chromosoma 2020; 129:141-160. [PMID: 32314039 PMCID: PMC7260282 DOI: 10.1007/s00412-020-00733-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 02/17/2020] [Accepted: 02/20/2020] [Indexed: 01/03/2023]
Abstract
The heteropentameric condensin complexes play vital roles in the formation and faithful segregation of mitotic chromosomes in eukaryotes. While the different contributions of the two common condensin complexes, condensin I and condensin II, to chromosome morphology and behavior in mitosis have been thoroughly investigated, much less is known about the specific roles of the two complexes during meiotic divisions. In Drosophila melanogaster, faithful mitotic divisions depend on functional condensin I, but not on condensin II. However, meiotic divisions in Drosophila males require functional condensin II subunits. The role of condensin I during male meiosis in Drosophila has been unresolved. Here, we show that condensin I-specific subunits localize to meiotic chromatin in both meiosis I and II during Drosophila spermatogenesis. Live cell imaging reveals defects during meiotic divisions after RNAi-mediated knockdown of condensin I-specific mRNAs. This phenotype correlates with reduced male fertility and an increase in nondisjunction events both in meiosis I and meiosis II. Consistently, a reduction in male fertility was also observed after proteasome-mediated degradation of the condensin I subunit Barren. Taken together, our results demonstrate an essential role of condensin I during male meiosis in Drosophila melanogaster.
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Affiliation(s)
| | - Nina Vießmann
- Lehrstuhl für Genetik, University of Bayreuth, Bayreuth, Germany
| | - Mareike Jordan
- Lehrstuhl für Genetik, University of Bayreuth, Bayreuth, Germany
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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11
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Zhou CY, Heald R. Emergent properties of mitotic chromosomes. Curr Opin Cell Biol 2020; 64:43-49. [PMID: 32151949 DOI: 10.1016/j.ceb.2020.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/21/2020] [Accepted: 02/01/2020] [Indexed: 12/27/2022]
Abstract
As a cell prepares to divide, its genetic material changes dramatically in both form and function. During interphase, a dynamic interplay between DNA compartmentalization and transcription functions to program cell identity. During mitosis, this purpose is put on hold and instead chromosomes function to facilitate their accurate segregation to daughter cells. Chromatin loops are rearranged, stacked, and compressed to form X-shaped chromosomes that are neatly aligned at the center of the mitotic spindle and ready to withstand the forces of anaphase. Many factors that contribute to mitotic chromosome assembly have now been identified, but how the plethora of molecular mechanisms operate in concert to give rise to the distinct form and physical properties of mitotic chromosomes at the cellular scale remains under active investigation. In this review, we discuss recent work that addresses a major challenge for the field: How to connect the molecular-level activities to large-scale changes in whole-chromosome architecture that determine mitotic chromosome size, shape, and function.
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Affiliation(s)
- Coral Y Zhou
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720 USA.
| | - Rebecca Heald
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720 USA.
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12
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Beseda T, Cápal P, Kubalová I, Schubert V, Doležel J, Šimková H. Mitotic chromosome organization: General rules meet species-specific variability. Comput Struct Biotechnol J 2020; 18:1311-1319. [PMID: 32612754 PMCID: PMC7305364 DOI: 10.1016/j.csbj.2020.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/13/2020] [Accepted: 01/16/2020] [Indexed: 10/31/2022] Open
Abstract
Research on the formation of mitotic chromosomes from interphase chromatin domains, ongoing for several decades, made significant progress in recent years. It was stimulated by the development of advanced microscopic techniques and implementation of chromatin conformation capture methods that provide new insights into chromosome ultrastructure. This review aims to summarize and compare several models of chromatin fiber folding to form mitotic chromosomes and discusses them in the light of the novel findings. Functional genomics studies in several organisms confirmed condensins and cohesins as the major players in chromosome condensation. Here we compare available data on the role of these proteins across lower and higher eukaryotes and point to differences indicating evolutionary different pathways to shape mitotic chromosomes. Moreover, we discuss a controversial phenomenon of the mitotic chromosome ultrastructure - chromosome cavities - and using our super-resolution microscopy data, we contribute to its elucidation.
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Affiliation(s)
- Tomáš Beseda
- Institute of Experimental Botany, Czech Acad. Sci., Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, CZ-77900 Olomouc, Czech Republic
| | - Petr Cápal
- Institute of Experimental Botany, Czech Acad. Sci., Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, CZ-77900 Olomouc, Czech Republic
| | - Ivona Kubalová
- The Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Corrensstrasse 3, D-06466 Seeland, Germany
| | - Veit Schubert
- The Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Corrensstrasse 3, D-06466 Seeland, Germany
| | - Jaroslav Doležel
- Institute of Experimental Botany, Czech Acad. Sci., Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, CZ-77900 Olomouc, Czech Republic
| | - Hana Šimková
- Institute of Experimental Botany, Czech Acad. Sci., Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, CZ-77900 Olomouc, Czech Republic
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13
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Brackley CA, Marenduzzo D. Bridging-induced microphase separation: photobleaching experiments, chromatin domains and the need for active reactions. Brief Funct Genomics 2020; 19:111-118. [DOI: 10.1093/bfgp/elz032] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/09/2019] [Accepted: 10/15/2019] [Indexed: 01/11/2023] Open
Abstract
Abstract
We review the mechanism and consequences of the ‘bridging-induced attraction’, a generic biophysical principle that underpins some existing models for chromosome organization in 3D. This attraction, which was revealed in polymer physics-inspired computer simulations, is a generic clustering tendency arising in multivalent chromatin-binding proteins, and it provides an explanation for the biogenesis of nuclear bodies and transcription factories via microphase separation. Including post-translational modification reactions involving these multivalent proteins can account for the fast dynamics of the ensuing clusters, as is observed via microscopy and photobleaching experiments. The clusters found in simulations also give rise to chromatin domains that conform well with the observation of A/B compartments in HiC experiments.
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