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Helsen J, Reza H, Carvalho R, Sherlock G, Dey G. Spindle architecture constrains karyotype in budding yeast. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.25.563899. [PMID: 37961714 PMCID: PMC10634821 DOI: 10.1101/2023.10.25.563899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The eukaryotic cell division machinery must rapidly and reproducibly duplicate and partition the cell's chromosomes in a carefully coordinated process. However, chromosome number varies dramatically between genomes, even on short evolutionary timescales. We sought to understand how the mitotic machinery senses and responds to karyotypic changes by using a series of budding yeast strains in which the native chromosomes have been successively fused. Using a combination of cell biological profiling, genetic engineering, and experimental evolution, we show that chromosome fusions are well tolerated up until a critical point. Cells with fewer than five centromeres lack the necessary number of kinetochore-microtubule attachments needed to counter outward forces in the metaphase spindle, triggering the spindle assembly checkpoint and prolonging metaphase. Our findings demonstrate that spindle architecture is a constraining factor for karyotype evolution.
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Affiliation(s)
- Jana Helsen
- Cell Biology and Biophysics, European Molecular Biology Laboratory; Heidelberg, 69117, Germany
- Department of Genetics, Stanford University School of Medicine; Stanford, 94305, USA
| | - Hashim Reza
- Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research; Bengaluru, 560064, India
| | - Ricardo Carvalho
- Cell Biology and Biophysics, European Molecular Biology Laboratory; Heidelberg, 69117, Germany
| | - Gavin Sherlock
- Department of Genetics, Stanford University School of Medicine; Stanford, 94305, USA
| | - Gautam Dey
- Cell Biology and Biophysics, European Molecular Biology Laboratory; Heidelberg, 69117, Germany
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2
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Li S, Kasciukovic T, Tanaka TU. Kinetochore-microtubule error correction for biorientation: lessons from yeast. Biochem Soc Trans 2024; 52:29-39. [PMID: 38305688 PMCID: PMC10903472 DOI: 10.1042/bst20221261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/11/2024] [Accepted: 01/15/2024] [Indexed: 02/03/2024]
Abstract
Accurate chromosome segregation in mitosis relies on sister kinetochores forming stable attachments to microtubules (MTs) extending from opposite spindle poles and establishing biorientation. To achieve this, erroneous kinetochore-MT interactions must be resolved through a process called error correction, which dissolves improper kinetochore-MT attachment and allows new interactions until biorientation is achieved. The Aurora B kinase plays key roles in driving error correction by phosphorylating Dam1 and Ndc80 complexes, while Mps1 kinase, Stu2 MT polymerase and phosphatases also regulate this process. Once biorientation is formed, tension is applied to kinetochore-MT interaction, stabilizing it. In this review article, we discuss the mechanisms of kinetochore-MT interaction, error correction and biorientation. We focus mainly on recent insights from budding yeast, where the attachment of a single MT to a single kinetochore during biorientation simplifies the analysis of error correction mechanisms.
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Affiliation(s)
- Shuyu Li
- Division of Molecular, Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, U.K
| | - Taciana Kasciukovic
- Division of Molecular, Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, U.K
| | - Tomoyuki U. Tanaka
- Division of Molecular, Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, U.K
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3
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Garbacki N, Willems J, Neutelings T, Lambert C, Deroanne C, Adrian A, Franz M, Maurer M, De Gieter P, Nusgens B, Colige A. Microgravity triggers ferroptosis and accelerates senescence in the MG-63 cell model of osteoblastic cells. NPJ Microgravity 2023; 9:91. [PMID: 38104197 PMCID: PMC10725437 DOI: 10.1038/s41526-023-00339-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 12/01/2023] [Indexed: 12/19/2023] Open
Abstract
In space, cells sustain strong modifications of their mechanical environment. Mechanosensitive molecules at the cell membrane regulate mechanotransduction pathways that induce adaptive responses through the regulation of gene expression, post-translational modifications, protein interactions or intracellular trafficking, among others. In the current study, human osteoblastic cells were cultured on the ISS in microgravity and at 1 g in a centrifuge, as onboard controls. RNAseq analyses showed that microgravity inhibits cell proliferation and DNA repair, stimulates inflammatory pathways and induces ferroptosis and senescence, two pathways related to ageing. Morphological hallmarks of senescence, such as reduced nuclear size and changes in chromatin architecture, proliferation marker distribution, tubulin acetylation and lysosomal transport were identified by immunofluorescence microscopy, reinforcing the hypothesis of induction of cell senescence in microgravity during space flight. These processes could be attributed, at least in part, to the regulation of YAP1 and its downstream effectors NUPR1 and CKAP2L.
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Affiliation(s)
- Nancy Garbacki
- Laboratory of Connective Tissues Biology, GIGA-Cancer, University of Liège, 4000, Liège, Belgium
| | - Jérôme Willems
- Laboratory of Connective Tissues Biology, GIGA-Cancer, University of Liège, 4000, Liège, Belgium
| | - Thibaut Neutelings
- Laboratory of Connective Tissues Biology, GIGA-Cancer, University of Liège, 4000, Liège, Belgium
| | - Charles Lambert
- Laboratory of Connective Tissues Biology, GIGA-Cancer, University of Liège, 4000, Liège, Belgium
| | - Christophe Deroanne
- Laboratory of Connective Tissues Biology, GIGA-Cancer, University of Liège, 4000, Liège, Belgium
| | - Astrid Adrian
- Airbus Defence and Space, GmbH, 88090, Immenstaad, Germany
| | - Markus Franz
- Airbus Defence and Space, GmbH, 88090, Immenstaad, Germany
| | - Matthias Maurer
- European Space Agency (ESA), European Astronaut Centre (EAC), 51147, Cologne, Germany
| | | | - Betty Nusgens
- Laboratory of Connective Tissues Biology, GIGA-Cancer, University of Liège, 4000, Liège, Belgium
| | - Alain Colige
- Laboratory of Connective Tissues Biology, GIGA-Cancer, University of Liège, 4000, Liège, Belgium.
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4
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Muir KW, Batters C, Dendooven T, Yang J, Zhang Z, Burt A, Barford D. Structural mechanism of outer kinetochore Dam1-Ndc80 complex assembly on microtubules. Science 2023; 382:1184-1190. [PMID: 38060647 PMCID: PMC7615550 DOI: 10.1126/science.adj8736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 10/25/2023] [Indexed: 12/18/2023]
Abstract
Kinetochores couple chromosomes to the mitotic spindle to segregate the genome during cell division. An error correction mechanism drives the turnover of kinetochore-microtubule attachments until biorientation is achieved. The structural basis for how kinetochore-mediated chromosome segregation is accomplished and regulated remains an outstanding question. In this work, we describe the cryo-electron microscopy structure of the budding yeast outer kinetochore Ndc80 and Dam1 ring complexes assembled onto microtubules. Complex assembly occurs through multiple interfaces, and a staple within Dam1 aids ring assembly. Perturbation of key interfaces suppresses yeast viability. Force-rupture assays indicated that this is a consequence of impaired kinetochore-microtubule attachment. The presence of error correction phosphorylation sites at Ndc80-Dam1 ring complex interfaces and the Dam1 staple explains how kinetochore-microtubule attachments are destabilized and reset.
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Affiliation(s)
- Kyle W. Muir
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Christopher Batters
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Tom Dendooven
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Jing Yang
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Ziguo Zhang
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Alister Burt
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
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5
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Edgerton HD, Mukherjee S, Johansson M, Bachant J, Gardner MK, Clarke DJ. Low tension recruits the yeast Aurora B protein Ipl1 to centromeres in metaphase. J Cell Sci 2023; 136:jcs261416. [PMID: 37519149 PMCID: PMC10445749 DOI: 10.1242/jcs.261416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 07/26/2023] [Indexed: 08/01/2023] Open
Abstract
Accurate genome segregation in mitosis requires that all chromosomes are bioriented on the spindle. Cells monitor biorientation by sensing tension across sister centromeres. Chromosomes that are not bioriented have low centromere tension, which allows Aurora B (yeast Ipl1) to perform error correction that locally loosens kinetochore-microtubule attachments to allow detachment of microtubules and fresh attempts at achieving biorientation. However, it is not known whether low tension recruits Aurora B to centromeres or, alternatively, whether low tension directly activates Aurora B already localized at centromeres. In this work, we experimentally induced low tension in metaphase Saccharomyces cerevisiae yeast cells, then monitored Ipl1 localization. We find low tension recruits Ipl1 to centromeres. Furthermore, low tension-induced Ipl1 recruitment depended on Bub1, which is known to provide a binding site for Ipl1. In contrast, Top2, which can also recruit Ipl1 to centromeres, was not required. Our results demonstrate cells are sensitive to low tension at centromeres and respond by actively recruiting Ip1l for error correction.
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Affiliation(s)
- Heather D. Edgerton
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Soumya Mukherjee
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Marnie Johansson
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jeff Bachant
- Department of Molecular Cell Systems Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Melissa K. Gardner
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Duncan J. Clarke
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
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6
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Parmar S, Gonzalez SJ, Heckel JM, Mukherjee S, McClellan M, Clarke DJ, Johansson M, Tank D, Geisness A, Wood DK, Gardner MK. Robust microtubule dynamics facilitate low-tension kinetochore detachment in metaphase. J Cell Biol 2023; 222:e202202085. [PMID: 37166419 PMCID: PMC10182774 DOI: 10.1083/jcb.202202085] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 02/07/2023] [Accepted: 04/24/2023] [Indexed: 05/12/2023] Open
Abstract
During mitosis, sister chromatids are stretched apart at their centromeres via their attachment to oppositely oriented kinetochore microtubules. This stretching generates inwardly directed tension across the separated sister centromeres. The cell leverages this tension signal to detect and then correct potential errors in chromosome segregation, via a mechanical tension signaling pathway that detaches improperly attached kinetochores from their microtubules. However, the sequence of events leading up to these detachment events remains unknown. In this study, we used microfluidics to sustain and observe low-tension budding yeast metaphase spindles over multiple hours, allowing us to elucidate the tension history prior to a detachment event. We found that, under conditions in which kinetochore phosphorylation weakens low-tension kinetochore-microtubule connections, the mechanical forces produced via the dynamic growth and shortening of microtubules is required to efficiently facilitate detachment events. Our findings underscore the critical role of robust kinetochore microtubule dynamics in ensuring the fidelity of chromosome segregation during mitosis.
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Affiliation(s)
- Sneha Parmar
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA
| | - Samuel J. Gonzalez
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA
| | - Julia M. Heckel
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA
| | - Soumya Mukherjee
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA
| | - Mark McClellan
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA
| | - Duncan J. Clarke
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA
| | - Marnie Johansson
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA
| | - Damien Tank
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA
| | - Athena Geisness
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - David K. Wood
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Melissa K. Gardner
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA
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7
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Bunning AR, Gupta Jr. ML. The importance of microtubule-dependent tension in accurate chromosome segregation. Front Cell Dev Biol 2023; 11:1096333. [PMID: 36755973 PMCID: PMC9899852 DOI: 10.3389/fcell.2023.1096333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 01/11/2023] [Indexed: 01/24/2023] Open
Abstract
Accurate chromosome segregation is vital for cell and organismal viability. The mitotic spindle, a bipolar macromolecular machine composed largely of dynamic microtubules, is responsible for chromosome segregation during each cell replication cycle. Prior to anaphase, a bipolar metaphase spindle must be formed in which each pair of chromatids is attached to microtubules from opposite spindle poles. In this bipolar configuration pulling forces from the dynamic microtubules can generate tension across the sister kinetochores. The tension status acts as a signal that can destabilize aberrant kinetochore-microtubule attachments and reinforces correct, bipolar connections. Historically it has been challenging to isolate the specific role of tension in mitotic processes due to the interdependency of attachment and tension status at kinetochores. Recent technical and experimental advances have revealed new insights into how tension functions during mitosis. Here we summarize the evidence that tension serves as a biophysical signal that unifies multiple aspects of kinetochore and centromere function to ensure accurate chromosome segregation.
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8
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Yeast Kinesin-5 Motor Protein CIN8 Promotes Accurate Chromosome Segregation. Cells 2022; 11:cells11142144. [PMID: 35883587 PMCID: PMC9316075 DOI: 10.3390/cells11142144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 06/15/2022] [Accepted: 07/04/2022] [Indexed: 11/17/2022] Open
Abstract
Accurate chromosome segregation depends on bipolar chromosome–microtubule attachment and tension generation on chromosomes. Incorrect chromosome attachment results in chromosome missegregation, which contributes to genome instability. The kinetochore is a protein complex that localizes at the centromere region of a chromosome and mediates chromosome–microtubule interaction. Incorrect chromosome attachment leads to checkpoint activation to prevent anaphase onset. Kinetochore detachment activates the spindle assembly checkpoint (SAC), while tensionless kinetochore attachment relies on both the SAC and tension checkpoint. In budding yeast Saccharomyces cerevisiae, kinesin-5 motor proteins Cin8 and Kip1 are needed to separate spindle pole bodies for spindle assembly, and deletion of CIN8 causes lethality in the absence of SAC. To study the function of Cin8 and Kip1 in chromosome segregation, we constructed an auxin-inducible degron (AID) mutant, cin8-AID. With this conditional mutant, we first confirmed that cin8-AID kip1∆ double mutants were lethal when Cin8 is depleted in the presence of auxin. These cells arrested in metaphase with unseparated spindle pole bodies and kinetochores. We further showed that the absence of either the SAC or tension checkpoint was sufficient to abolish the cell-cycle delay in cin8-AID mutants, causing chromosome missegregation and viability loss. The tension checkpoint-dependent phenotype in cells with depleted Cin8 suggests the presence of tensionless chromosome attachment. We speculate that the failed spindle pole body separation in cin8 mutants could increase the chance of tensionless syntelic chromosome attachments, which depends on functional tension checkpoint for survival.
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9
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Vukušić K, Tolić IM. Polar Chromosomes—Challenges of a Risky Path. Cells 2022; 11:cells11091531. [PMID: 35563837 PMCID: PMC9101661 DOI: 10.3390/cells11091531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/28/2022] [Accepted: 04/30/2022] [Indexed: 12/29/2022] Open
Abstract
The process of chromosome congression and alignment is at the core of mitotic fidelity. In this review, we discuss distinct spatial routes that the chromosomes take to align during prometaphase, which are characterized by distinct biomolecular requirements. Peripheral polar chromosomes are an intriguing case as their alignment depends on the activity of kinetochore motors, polar ejection forces, and a transition from lateral to end-on attachments to microtubules, all of which can result in the delayed alignment of these chromosomes. Due to their undesirable position close to and often behind the spindle pole, these chromosomes may be particularly prone to the formation of erroneous kinetochore-microtubule interactions, such as merotelic attachments. To prevent such errors, the cell employs intricate mechanisms to preposition the spindle poles with respect to chromosomes, ensure the formation of end-on attachments in restricted spindle regions, repair faulty attachments by error correction mechanisms, and delay segregation by the spindle assembly checkpoint. Despite this protective machinery, there are several ways in which polar chromosomes can fail in alignment, mis-segregate, and lead to aneuploidy. In agreement with this, polar chromosomes are present in certain tumors and may even be involved in the process of tumorigenesis.
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10
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de Regt AK, Clark CJ, Asbury CL, Biggins S. Tension can directly suppress Aurora B kinase-triggered release of kinetochore-microtubule attachments. Nat Commun 2022; 13:2152. [PMID: 35443757 PMCID: PMC9021268 DOI: 10.1038/s41467-022-29542-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 03/03/2022] [Indexed: 11/09/2022] Open
Abstract
Chromosome segregation requires sister kinetochores to attach microtubules emanating from opposite spindle poles. Proper attachments come under tension and are stabilized, but defective attachments lacking tension are released, giving another chance for correct attachments to form. This error correction process depends on Aurora B kinase, which phosphorylates kinetochores to destabilize their microtubule attachments. However, the mechanism by which Aurora B distinguishes tense versus relaxed kinetochores remains unclear because it is difficult to detect kinase-triggered detachment and to manipulate kinetochore tension in vivo. To address these challenges, we apply an optical trapping-based assay using soluble Aurora B and reconstituted kinetochore-microtubule attachments. Strikingly, the tension on these attachments suppresses their Aurora B-triggered release, suggesting that tension-dependent changes in the conformation of kinetochores can regulate Aurora B activity or its outcome. Our work uncovers the basis for a key mechano-regulatory event that ensures accurate segregation and may inform studies of other mechanically regulated enzymes.
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Affiliation(s)
- Anna K de Regt
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Cordell J Clark
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Charles L Asbury
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA.
| | - Sue Biggins
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
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11
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Abstract
The centromere serves as the binding site for the kinetochore and is essential for the faithful segregation of chromosomes throughout cell division. The point centromere in yeast is encoded by a ∼115 bp specific DNA sequence, whereas regional centromeres range from 6-10 kbp in fission yeast to 5-10 Mbp in humans. Understanding the physical structure of centromere chromatin (pericentromere in yeast), defined as the chromatin between sister kinetochores, will provide fundamental insights into how centromere DNA is woven into a stiff spring that is able to resist microtubule pulling forces during mitosis. One hallmark of the pericentromere is the enrichment of the structural maintenance of chromosome (SMC) proteins cohesin and condensin. Based on studies from population approaches (ChIP-seq and Hi-C) and experimentally obtained images of fluorescent probes of pericentromeric structure, as well as quantitative comparisons between simulations and experimental results, we suggest a mechanism for building tension between sister kinetochores. We propose that the centromere is a chromatin bottlebrush that is organized by the loop-extruding proteins condensin and cohesin. The bottlebrush arrangement provides a biophysical means to transform pericentromeric chromatin into a spring due to the steric repulsion between radial loops. We argue that the bottlebrush is an organizing principle for chromosome organization that has emerged from multiple approaches in the field.
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12
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Aurora B Tension Sensing Mechanisms in the Kinetochore Ensure Accurate Chromosome Segregation. Int J Mol Sci 2021; 22:ijms22168818. [PMID: 34445523 PMCID: PMC8396173 DOI: 10.3390/ijms22168818] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/11/2021] [Accepted: 08/13/2021] [Indexed: 11/29/2022] Open
Abstract
The accurate segregation of chromosomes is essential for the survival of organisms and cells. Mistakes can lead to aneuploidy, tumorigenesis and congenital birth defects. The spindle assembly checkpoint ensures that chromosomes properly align on the spindle, with sister chromatids attached to microtubules from opposite poles. Here, we review how tension is used to identify and selectively destabilize incorrect attachments, and thus serves as a trigger of the spindle assembly checkpoint to ensure fidelity in chromosome segregation. Tension is generated on properly attached chromosomes as sister chromatids are pulled in opposing directions but resisted by centromeric cohesin. We discuss the role of the Aurora B kinase in tension-sensing and explore the current models for translating mechanical force into Aurora B-mediated biochemical signals that regulate correction of chromosome attachments to the spindle.
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13
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Barisic M, Rajendraprasad G. Mitotic poleward flux: Finding balance between microtubule dynamics and sliding. Bioessays 2021; 43:e2100079. [PMID: 34085708 DOI: 10.1002/bies.202100079] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 05/13/2021] [Accepted: 05/21/2021] [Indexed: 12/13/2022]
Abstract
Continuous poleward motion of microtubules in metazoan mitotic spindles has been fascinating generations of cell biologists over the last several decades. In human cells, this so-called poleward flux was recently shown to be driven by the coordinated action of four mitotic kinesins. The sliding activities of kinesin-5/EG5 and kinesin-12/KIF15 are sequentially supported by kinesin-7/CENP-E at kinetochores and kinesin-4/KIF4A on chromosome arms, with the individual contributions peaking during prometaphase and metaphase, respectively. Although recent data elucidate the molecular mechanism underlying this cellular phenomenon, the functional roles of microtubule poleward flux during cell division remain largely elusive. Here, we discuss potential contribution of microtubule flux engine to various essential processes at different stages of mitosis.
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Affiliation(s)
- Marin Barisic
- Cell Division and Cytoskeleton, Danish Cancer Society Research Center (DCRC), Copenhagen, Denmark.,Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Girish Rajendraprasad
- Cell Division and Cytoskeleton, Danish Cancer Society Research Center (DCRC), Copenhagen, Denmark
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14
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Bokros M, Sherwin D, Kabbaj MH, Wang Y. Yeast Fin1-PP1 dephosphorylates an Ipl1 substrate, Ndc80, to remove Bub1-Bub3 checkpoint proteins from the kinetochore during anaphase. PLoS Genet 2021; 17:e1009592. [PMID: 34033659 PMCID: PMC8184001 DOI: 10.1371/journal.pgen.1009592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 06/07/2021] [Accepted: 05/10/2021] [Indexed: 11/25/2022] Open
Abstract
The spindle assembly checkpoint (SAC) prevents anaphase onset in response to chromosome attachment defects, and SAC silencing is essential for anaphase onset. Following anaphase onset, activated Cdc14 phosphatase dephosphorylates the substrates of cyclin-dependent kinase to facilitate anaphase progression and mitotic exit. In budding yeast, Cdc14 dephosphorylates Fin1, a regulatory subunit of protein phosphatase 1 (PP1), to enable kinetochore localization of Fin1-PP1. We previously showed that kinetochore-localized Fin1-PP1 promotes the removal of the SAC protein Bub1 from the kinetochore during anaphase. We report here that Fin1-PP1 also promotes kinetochore removal of Bub3, the Bub1 partner, but has no effect on another SAC protein Mad1. Moreover, the kinetochore localization of Bub1-Bub3 during anaphase requires Aurora B/Ipl1 kinase activity. We further showed that Fin1-PP1 facilitates the dephosphorylation of kinetochore protein Ndc80, a known Ipl1 substrate. This dephosphorylation reduces kinetochore association of Bub1-Bub3 during anaphase. In addition, we found that untimely Ndc80 dephosphorylation causes viability loss in response to tensionless chromosome attachments. These results suggest that timely localization of Fin1-PP1 to the kinetochore controls the functional window of SAC and is therefore critical for faithful chromosome segregation.
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Affiliation(s)
- Michael Bokros
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America
- Sylvester Comprehensive Cancer Center, University of Miami, Miami, Florida, United States of America
| | - Delaney Sherwin
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America
| | - Marie-Helene Kabbaj
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America
| | - Yanchang Wang
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America
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15
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Chen GY, Renda F, Zhang H, Gokden A, Wu DZ, Chenoweth DM, Khodjakov A, Lampson MA. Tension promotes kinetochore-microtubule release by Aurora B kinase. J Cell Biol 2021; 220:212027. [PMID: 33904910 PMCID: PMC8082439 DOI: 10.1083/jcb.202007030] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 02/06/2021] [Accepted: 03/24/2021] [Indexed: 12/19/2022] Open
Abstract
To ensure accurate chromosome segregation, interactions between kinetochores and microtubules are regulated by a combination of mechanics and biochemistry. Tension provides a signal to discriminate attachment errors from bi-oriented kinetochores with sisters correctly attached to opposite spindle poles. Biochemically, Aurora B kinase phosphorylates kinetochores to destabilize interactions with microtubules. To link mechanics and biochemistry, current models regard tension as an input signal to locally regulate Aurora B activity. Here, we show that the outcome of kinetochore phosphorylation depends on tension. Using optogenetics to manipulate Aurora B at individual kinetochores, we find that kinase activity promotes microtubule release when tension is high. Conversely, when tension is low, Aurora B activity promotes depolymerization of kinetochore–microtubules while maintaining attachment. Thus, phosphorylation converts a catch-bond, in which tension stabilizes attachments, to a slip-bond, which releases microtubules under tension. We propose that tension is a signal inducing distinct error-correction pathways, with release or depolymerization being advantageous for typical errors characterized by high or low tension, respectively.
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Affiliation(s)
- Geng-Yuan Chen
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA
| | - Fioranna Renda
- Wadsworth Center, New York State Department of Health, Albany, NY
| | - Huaiying Zhang
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA
| | - Alper Gokden
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA
| | - Daniel Z Wu
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA
| | - David M Chenoweth
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA
| | - Alexey Khodjakov
- Wadsworth Center, New York State Department of Health, Albany, NY
| | - Michael A Lampson
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA
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16
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Shake It Off: The Elimination of Erroneous Kinetochore-Microtubule Attachments and Chromosome Oscillation. Int J Mol Sci 2021; 22:ijms22063174. [PMID: 33804687 PMCID: PMC8003821 DOI: 10.3390/ijms22063174] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 03/18/2021] [Indexed: 01/17/2023] Open
Abstract
Cell proliferation and sexual reproduction require the faithful segregation of chromosomes. Chromosome segregation is driven by the interaction of chromosomes with the spindle, and the attachment of chromosomes to the proper spindle poles is essential. Initial attachments are frequently erroneous due to the random nature of the attachment process; however, erroneous attachments are selectively eliminated. Proper attachment generates greater tension at the kinetochore than erroneous attachments, and it is thought that attachment selection is dependent on this tension. However, studies of meiotic chromosome segregation suggest that attachment elimination cannot be solely attributed to tension, and the precise mechanism of selective elimination of erroneous attachments remains unclear. During attachment elimination, chromosomes oscillate between the spindle poles. A recent study on meiotic chromosome segregation in fission yeast has suggested that attachment elimination is coupled to chromosome oscillation. In this review, the possible contribution of chromosome oscillation in the elimination of erroneous attachment is discussed in light of the recent finding.
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17
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Liu X, Liu X, Wang H, Dou Z, Ruan K, Hill DL, Li L, Shi Y, Yao X. Phase separation drives decision making in cell division. J Biol Chem 2020; 295:13419-13431. [PMID: 32699013 DOI: 10.1074/jbc.rev120.011746] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 07/22/2020] [Indexed: 12/11/2022] Open
Abstract
Liquid-liquid phase separation (LLPS) of biomolecules drives the formation of subcellular compartments with distinct physicochemical properties. These compartments, free of lipid bilayers and therefore called membraneless organelles, include nucleoli, centrosomes, heterochromatin, and centromeres. These have emerged as a new paradigm to account for subcellular organization and cell fate decisions. Here we summarize recent studies linking LLPS to mitotic spindle, heterochromatin, and centromere assembly and their plasticity controls in the context of the cell division cycle, highlighting a functional role for phase behavior and material properties of proteins assembled onto heterochromatin, centromeres, and central spindles via LLPS. The techniques and tools for visualizing and harnessing membraneless organelle dynamics and plasticity in mitosis are also discussed, as is the potential for these discoveries to promote new research directions for investigating chromosome dynamics, plasticity, and interchromosome interactions in the decision-making process during mitosis.
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Affiliation(s)
- Xing Liu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics and CAS Center for Excellence in Molecular Cell Science, University of Science and Technology of China School of Life Science, Hefei, China; Anhui Key Laboratory for Cellular Dynamics & Chemical Biology, Hefei National Center for Physical Sciences at Nanoscale, Hefei, China; Keck Center for Cellular Dynamics and Organoids Plasticity, Morehouse School of Medicine, Atlanta, Georgia, USA
| | - Xu Liu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics and CAS Center for Excellence in Molecular Cell Science, University of Science and Technology of China School of Life Science, Hefei, China; Anhui Key Laboratory for Cellular Dynamics & Chemical Biology, Hefei National Center for Physical Sciences at Nanoscale, Hefei, China; Keck Center for Cellular Dynamics and Organoids Plasticity, Morehouse School of Medicine, Atlanta, Georgia, USA
| | - Haowei Wang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics and CAS Center for Excellence in Molecular Cell Science, University of Science and Technology of China School of Life Science, Hefei, China; Anhui Key Laboratory for Cellular Dynamics & Chemical Biology, Hefei National Center for Physical Sciences at Nanoscale, Hefei, China
| | - Zhen Dou
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics and CAS Center for Excellence in Molecular Cell Science, University of Science and Technology of China School of Life Science, Hefei, China; Anhui Key Laboratory for Cellular Dynamics & Chemical Biology, Hefei National Center for Physical Sciences at Nanoscale, Hefei, China
| | - Ke Ruan
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics and CAS Center for Excellence in Molecular Cell Science, University of Science and Technology of China School of Life Science, Hefei, China; Anhui Key Laboratory for Cellular Dynamics & Chemical Biology, Hefei National Center for Physical Sciences at Nanoscale, Hefei, China
| | - Donald L Hill
- Comprehensive Cancer Center, University of Alabama, Birmingham, Alabama, USA
| | - Lin Li
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Shanghai, China
| | - Yunyu Shi
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics and CAS Center for Excellence in Molecular Cell Science, University of Science and Technology of China School of Life Science, Hefei, China; Anhui Key Laboratory for Cellular Dynamics & Chemical Biology, Hefei National Center for Physical Sciences at Nanoscale, Hefei, China
| | - Xuebiao Yao
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics and CAS Center for Excellence in Molecular Cell Science, University of Science and Technology of China School of Life Science, Hefei, China; Anhui Key Laboratory for Cellular Dynamics & Chemical Biology, Hefei National Center for Physical Sciences at Nanoscale, Hefei, China; Keck Center for Cellular Dynamics and Organoids Plasticity, Morehouse School of Medicine, Atlanta, Georgia, USA; Comprehensive Cancer Center, University of Alabama, Birmingham, Alabama, USA; CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Shanghai, China.
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18
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Relax, Kinetochores Are Exquisitely Sensitive to Tension. Dev Cell 2019; 49:5-7. [PMID: 30965035 DOI: 10.1016/j.devcel.2019.03.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
By estimating the absolute levels of tension at kinetochores in dividing yeast cells and relating these measurements to kinetochore detachment probability, Mukherjee et al. (2019) quantify in this issue of Developmental Cell the force sensitivity of the mitotic error correction system.
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19
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Lawrimore J, Bloom K. The regulation of chromosome segregation via centromere loops. Crit Rev Biochem Mol Biol 2019; 54:352-370. [PMID: 31573359 PMCID: PMC6856439 DOI: 10.1080/10409238.2019.1670130] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/02/2019] [Accepted: 09/17/2019] [Indexed: 12/14/2022]
Abstract
Biophysical studies of the yeast centromere have shown that the organization of the centromeric chromatin plays a crucial role in maintaining proper tension between sister kinetochores during mitosis. While centromeric chromatin has traditionally been considered a simple spring, recent work reveals the centromere as a multifaceted, tunable shock absorber. Centromeres can differ from other regions of the genome in their heterochromatin state, supercoiling state, and enrichment of structural maintenance of chromosomes (SMC) protein complexes. Each of these differences can be utilized to alter the effective stiffness of centromeric chromatin. In budding yeast, the SMC protein complexes condensin and cohesin stiffen chromatin by forming and cross-linking chromatin loops, respectively, into a fibrous structure resembling a bottlebrush. The high density of the loops compacts chromatin while spatially isolating the tension from spindle pulling forces to a subset of the chromatin. Paradoxically, the molecular crowding of chromatin via cohesin and condensin also causes an outward/poleward force. The structure allows the centromere to act as a shock absorber that buffers the variable forces generated by dynamic spindle microtubules. Based on the distribution of SMCs from bacteria to human and the conserved distance between sister kinetochores in a wide variety of organisms (0.4 to 1 micron), we propose that the bottlebrush mechanism is the foundational principle for centromere function in eukaryotes.
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Affiliation(s)
- Josh Lawrimore
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kerry Bloom
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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