1
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Zahm JA, Harrison SC. A communication hub for phosphoregulation of kinetochore-microtubule attachment. Curr Biol 2024; 34:2308-2318.e6. [PMID: 38776904 DOI: 10.1016/j.cub.2024.04.067] [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: 11/22/2023] [Revised: 04/06/2024] [Accepted: 04/29/2024] [Indexed: 05/25/2024]
Abstract
The Mps1 and Aurora B kinases regulate and monitor kinetochore attachment to spindle microtubules during cell division, ultimately ensuring accurate chromosome segregation. In yeast, the critical spindle attachment components are the Ndc80 and Dam1 complexes (Ndc80c and DASH/Dam1c, respectively). Ndc80c is a 600-Å-long heterotetramer that binds microtubules through a globular "head" at one end and centromere-proximal kinetochore components through a globular knob at the other end. Dam1c is a heterodecamer that forms a ring of 16-17 protomers around the shaft of the single kinetochore microtubule in point-centromere yeast. The ring coordinates the approximately eight Ndc80c rods per kinetochore. In published work, we showed that a site on the globular "head" of Ndc80c, including residues from both Ndc80 and Nuf2, binds a bipartite segment in the long C-terminal extension of Dam1. Results reported here show, both by in vitro binding experiments and by crystal structure determination, that the same site binds a conserved segment in the long N-terminal extension of Mps1. It also binds, less tightly, a conserved segment in the N-terminal extension of Ipl1 (yeast Aurora B). Together with results from experiments in yeast cells and from biochemical assays reported in two accompanying papers, the structures and graded affinities identify a communication hub for ensuring uniform bipolar attachment and for signaling anaphase onset.
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Affiliation(s)
- Jacob A Zahm
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Stephen C Harrison
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Howard Hughes Medical Institute, Boston, MA 02115, USA.
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2
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Parnell EJ, Jenson EE, Miller MP. A conserved site on Ndc80 complex facilitates dynamic recruitment of Mps1 to yeast kinetochores to promote accurate chromosome segregation. Curr Biol 2024; 34:2294-2307.e4. [PMID: 38776906 PMCID: PMC11178286 DOI: 10.1016/j.cub.2024.04.054] [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: 11/09/2023] [Revised: 03/27/2024] [Accepted: 04/24/2024] [Indexed: 05/25/2024]
Abstract
Accurate chromosome segregation relies on kinetochores carrying out multiple functions, including establishing and maintaining microtubule attachments, forming precise bi-oriented attachments between sister chromatids, and activating the spindle assembly checkpoint. Central to these processes is the highly conserved Ndc80 complex. This kinetochore subcomplex interacts directly with microtubules but also serves as a critical platform for recruiting kinetochore-associated factors and as a key substrate for error correction kinases. The precise manner in which these kinetochore factors interact and regulate each other's function remains unknown, considerably hindering our understanding of how Ndc80 complex-dependent processes function together to orchestrate accurate chromosome segregation. Here, we aimed to uncover the role of Nuf2's CH domain, a component of the Ndc80 complex, in ensuring these processes. Through extensive mutational analysis, we identified a conserved interaction domain composed of two segments in Nuf2's CH domain that form the binding site for Mps1 within the yeast Ndc80 complex. Interestingly, this site also associates with the Dam1 complex, suggesting Mps1 recruitment may be subject to regulation by competitive binding with other factors. Mutants disrupting this "interaction hub" exhibit defects in spindle assembly checkpoint function and severe chromosome segregation errors. Significantly, specifically restoring Mps1-Ndc80 complex association rescues these defects. Our findings shed light on the intricate regulation of Ndc80 complex-dependent functions and highlight the essential role of Mps1 in kinetochore bi-orientation and accurate chromosome segregation.
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Affiliation(s)
- Emily J Parnell
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Erin E Jenson
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Matthew P Miller
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
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3
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Pleuger R, Cozma C, Hohoff S, Denkhaus C, Dudziak A, Kaschani F, Kaiser M, Musacchio A, Vetter IR, Westermann S. Microtubule end-on attachment maturation regulates Mps1 association with its kinetochore receptor. Curr Biol 2024; 34:2279-2293.e6. [PMID: 38776902 DOI: 10.1016/j.cub.2024.03.062] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 02/23/2024] [Accepted: 03/27/2024] [Indexed: 05/25/2024]
Abstract
Faithful chromosome segregation requires that sister chromatids establish bi-oriented kinetochore-microtubule attachments. The spindle assembly checkpoint (SAC) prevents premature anaphase onset with incomplete attachments. However, how microtubule attachment and checkpoint signaling are coordinated remains unclear. The conserved kinase Mps1 initiates SAC signaling by localizing transiently to kinetochores in prometaphase and is released upon bi-orientation. Using biochemistry, structure predictions, and cellular assays, we shed light on this dynamic behavior in Saccharomyces cerevisiae. A conserved N-terminal segment of Mps1 binds the neck region of Ndc80:Nuf2, the main microtubule receptor of kinetochores. Mutational disruption of this interface, located at the backside of the paired CH domains and opposite the microtubule-binding site, prevents Mps1 localization, eliminates SAC signaling, and impairs growth. The same interface of Ndc80:Nuf2 binds the microtubule-associated Dam1 complex. We demonstrate that the error correction kinase Ipl1/Aurora B controls the competition between Dam1 and Mps1 for the same binding site. Thus, binding of the Dam1 complex to Ndc80:Nuf2 may release Mps1 from the kinetochore to promote anaphase onset.
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Affiliation(s)
- Richard Pleuger
- Department of Molecular Genetics, Faculty of Biology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany; Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany
| | - Christian Cozma
- Department of Molecular Genetics, Faculty of Biology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany; Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany
| | - Simone Hohoff
- Department of Molecular Genetics, Faculty of Biology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany; Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany
| | - Christian Denkhaus
- Department of Molecular Genetics, Faculty of Biology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany; Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany
| | - Alexander Dudziak
- Department of Molecular Genetics, Faculty of Biology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany; Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany
| | - Farnusch Kaschani
- Department of Chemical Biology and ACE Analytical Core Facility Essen, Faculty of Biology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany; Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany
| | - Markus Kaiser
- Department of Chemical Biology and ACE Analytical Core Facility Essen, Faculty of Biology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany; Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max-Planck-Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany; Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany
| | - Ingrid R Vetter
- Department of Mechanistic Cell Biology, Max-Planck-Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Stefan Westermann
- Department of Molecular Genetics, Faculty of Biology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany; Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstrasse 5, 45117 Essen, Germany.
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4
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Kim S, Lau TT, Liao MK, Ma HT, Poon RY. Coregulation of NDC80 Complex Subunits Determines the Fidelity of the Spindle-Assembly Checkpoint and Mitosis. Mol Cancer Res 2024; 22:423-439. [PMID: 38324016 PMCID: PMC11063766 DOI: 10.1158/1541-7786.mcr-23-0828] [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: 10/10/2023] [Revised: 12/07/2023] [Accepted: 02/05/2024] [Indexed: 02/08/2024]
Abstract
NDC80 complex (NDC80C) is composed of four subunits (SPC24, SPC25, NDC80, and NUF2) and is vital for kinetochore-microtubule (KT-MT) attachment during mitosis. Paradoxically, NDC80C also functions in the activation of the spindle-assembly checkpoint (SAC). This raises an interesting question regarding how mitosis is regulated when NDC80C levels are compromised. Using a degron-mediated depletion system, we found that acute silencing of SPC24 triggered a transient mitotic arrest followed by mitotic slippage. SPC24-deficient cells were unable to sustain SAC activation despite the loss of KT-MT interaction. Intriguingly, our results revealed that other subunits of the NDC80C were co-downregulated with SPC24 at a posttranslational level. Silencing any individual subunit of NDC80C likewise reduced the expression of the entire complex. We found that the SPC24-SPC25 and NDC80-NUF2 subcomplexes could be individually stabilized using ectopically expressed subunits. The synergism of SPC24 downregulation with drugs that promote either mitotic arrest or mitotic slippage further underscored the dual roles of NDC80C in KT-MT interaction and SAC maintenance. The tight coordinated regulation of NDC80C subunits suggests that targeting individual subunits could disrupt mitotic progression and provide new avenues for therapeutic intervention. IMPLICATIONS These results highlight the tight coordinated regulation of NDC80C subunits and their potential as targets for antimitotic therapies.
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Affiliation(s)
- Sehong Kim
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Thomas T.Y. Lau
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Man Kit Liao
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Hoi Tang Ma
- Department of Pathology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong
| | - Randy Y.C. Poon
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
- State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
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5
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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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6
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Jian Y, Jiang Y, Nie L, Dou Z, Liu X, Fu C. Phosphorylation of Bub1 by Mph1 promotes Bub1 signaling at the kinetochore to ensure accurate chromosome segregation. J Biol Chem 2024; 300:105559. [PMID: 38097187 PMCID: PMC10805674 DOI: 10.1016/j.jbc.2023.105559] [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: 07/04/2023] [Revised: 11/30/2023] [Accepted: 12/02/2023] [Indexed: 01/02/2024] Open
Abstract
Bub1 is a conserved mitotic kinase involved in signaling of the spindle assembly checkpoint. Multiple phosphorylation sites on Bub1 have been characterized, yet it is challenging to understand the interplay between the multiple phosphorylation sites due to the limited availability of phosphospecific antibodies. In addition, phosphoregulation of Bub1 in Schizosaccharomyces pombe is poorly understood. Here we report the identification of a new Mph1/Mps1-mediated phosphorylation site, i.e., Ser532, of Bub1 in Schizosaccharomyces pombe. A phosphospecific antibody against phosphorylated Bub1-Ser532 was developed. Using the phosphospecific antibody, we demonstrated that phosphorylation of Bub1-Ser352 was mediated specifically by Mph1/Mps1 and took place during early mitosis. Moreover, live-cell microscopy showed that inhibition of the phosphorylation of Bub1 at Ser532 impaired the localization of Bub1, Mad1, and Mad2 to the kinetochore. In addition, inhibition of the phosphorylation of Bub1 at Ser532 caused anaphase B lagging chromosomes. Hence, our study constitutes a model in which Mph1/Mps1-mediated phosphorylation of fission yeast Bub1 promotes proper kinetochore localization of Bub1 and faithful chromosome segregation.
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Affiliation(s)
- Yanze Jian
- MOE Key Laboratory for Cellular Dynamics & Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China; Anhui Key Laboratory of Cellular Dynamics and Chemical Biology & Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Yueyue Jiang
- MOE Key Laboratory for Cellular Dynamics & Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China; Anhui Key Laboratory of Cellular Dynamics and Chemical Biology & Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Lingyun Nie
- MOE Key Laboratory for Cellular Dynamics & Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China; Anhui Key Laboratory of Cellular Dynamics and Chemical Biology & Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Zhen Dou
- MOE Key Laboratory for Cellular Dynamics & Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China; Anhui Key Laboratory of Cellular Dynamics and Chemical Biology & Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Xing Liu
- MOE Key Laboratory for Cellular Dynamics & Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China; Anhui Key Laboratory of Cellular Dynamics and Chemical Biology & Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Chuanhai Fu
- MOE Key Laboratory for Cellular Dynamics & Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China; Anhui Key Laboratory of Cellular Dynamics and Chemical Biology & Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China.
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7
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Parnell EJ, Jenson E, Miller MP. An interaction hub on Ndc80 complex facilitates dynamic recruitment of Mps1 to yeast kinetochores to promote accurate chromosome segregation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.07.566082. [PMID: 37986816 PMCID: PMC10659343 DOI: 10.1101/2023.11.07.566082] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Accurate chromosome segregation relies on kinetochores carrying out multiple functions, including establishing and maintaining microtubule attachments, forming precise bioriented attachments between sister chromatids, and activating the spindle assembly checkpoint. Central to these processes is the highly conserved Ndc80 complex. This kinetochore subcomplex interacts directly with microtubules, but also serves as a critical platform for recruiting kinetochore-associated factors and as a key substrate for error correction kinases. The precise manner in which these kinetochore factors interact, and regulate each other's function, remains unknown - considerably hindering our understanding of how Ndc80 complex-dependent processes function together to orchestrate accurate chromosome segregation. Here, we aimed to uncover the role of Nuf2's CH domain, a component of the Ndc80 complex, in ensuring accurate chromosome segregation. Through extensive mutational analysis, we identified a conserved "interaction hub" comprising two segments in Nuf2's CH domain, forming the binding site for Mps1 within the yeast Ndc80 complex. Intriguingly, the interaction between Mps1 and the Ndc80 complex seems to be subject to regulation by competitive binding with other factors. Mutants disrupting this interaction hub exhibit defects in spindle assembly checkpoint function and severe chromosome segregation errors. Significantly, specifically restoring Mps1-Ndc80 complex association rescues these defects. Our findings shed light on the intricate regulation of Ndc80 complex-dependent functions and highlight the essential role of Mps1 in kinetochore biorientation and accurate chromosome segregation.
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Affiliation(s)
- Emily J. Parnell
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Erin Jenson
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Matthew P. Miller
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
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8
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Liu L, Liu F, Yan Z, Zhou H, Song W. Transcriptome analysis of damage mechanism of Candida utilis under U(VI) stress. MARINE POLLUTION BULLETIN 2023; 196:115650. [PMID: 37839133 DOI: 10.1016/j.marpolbul.2023.115650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 10/05/2023] [Accepted: 10/07/2023] [Indexed: 10/17/2023]
Abstract
Marine radioactive pollution has a great impact on Marine microorganisms, but the damage mechanism by hexavalent uranium (U(VI)) exposure has been rarely known. In this study, Candida utilis (C. utilis) were exposed to U(VI) for 50, 100 and 150 mg/L, and then morphologic change and RNA-Seq in C. utilis were determined. U(VI) exposure significantly induced the changes of morphological characteristics of C. utilis. There were 39 DEGs in the 50 mg/L treated group, including 30 up-regulated genes and 9 down-regulated genes. There were 196 DEGs, 31 up-regulated and 165 down-regulated in the 100 mg/L treated group. The 150 mg/L treated group had 272 DEGs, 74 up-regulated and 198 down-regulated, compared with the control group. The results showed that the number of DEGs increased dose-dependently with U(VI) treatment. The results of this study provide a theoretical basis for the mechanism of radioactive wastewater damage to Marine microorganisms.
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Affiliation(s)
- Lei Liu
- Anhui Province Key Laboratory of Medical Physics and Technology, Institute of Health & Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, PR China; School of Environment and Chemical Engineering, Anhui Vocational and Technical College, Hefei 230011, PR China
| | - Fang Liu
- Anhui Province Key Laboratory of Medical Physics and Technology, Institute of Health & Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, PR China
| | - Zhuna Yan
- Anhui Province Key Laboratory of Medical Physics and Technology, Institute of Health & Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, PR China
| | - Han Zhou
- Anhui Province Key Laboratory of Medical Physics and Technology, Institute of Health & Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, PR China
| | - Wencheng Song
- Anhui Province Key Laboratory of Medical Physics and Technology, Institute of Health & Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, PR China; Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei 230031, PR China; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions and School for Radiological and Interdisciplinary Sciences, Soochow University, 215123 Suzhou, PR China.
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9
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McAinsh AD, Kops GJPL. Principles and dynamics of spindle assembly checkpoint signalling. Nat Rev Mol Cell Biol 2023:10.1038/s41580-023-00593-z. [PMID: 36964313 DOI: 10.1038/s41580-023-00593-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2023] [Indexed: 03/26/2023]
Abstract
The transmission of a complete set of chromosomes to daughter cells during cell division is vital for development and tissue homeostasis. The spindle assembly checkpoint (SAC) ensures correct segregation by informing the cell cycle machinery of potential errors in the interactions of chromosomes with spindle microtubules prior to anaphase. To do so, the SAC monitors microtubule engagement by specialized structures known as kinetochores and integrates local mechanical and chemical cues such that it can signal in a sensitive, responsive and robust manner. In this Review, we discuss how SAC proteins interact to allow production of the mitotic checkpoint complex (MCC) that halts anaphase progression by inhibiting the anaphase-promoting complex/cyclosome (APC/C). We highlight recent advances aimed at understanding the dynamic signalling properties of the SAC and how it interprets various naturally occurring intermediate attachment states. Further, we discuss SAC signalling in the context of the mammalian multisite kinetochore and address the impact of the fibrous corona. We also identify current challenges in understanding how the SAC ensures high-fidelity chromosome segregation.
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Affiliation(s)
- Andrew D McAinsh
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK.
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK.
| | - Geert J P L Kops
- Hubrecht Institute - KNAW (Royal Netherlands Academy of Arts and Sciences) and University Medical Centre Utrecht, Utrecht, The Netherlands.
- Oncode Institute, Utrecht, The Netherlands.
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10
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Fischer ES. Kinetochore‐catalyzed MCC
formation: A structural perspective. IUBMB Life 2022; 75:289-310. [PMID: 36518060 DOI: 10.1002/iub.2697] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/08/2022] [Indexed: 12/23/2022]
Abstract
The spindle assembly checkpoint (SAC) is a cellular surveillance mechanism that functions to ensure accurate chromosome segregation during mitosis. Macromolecular complexes known as kinetochores, act as the interface of sister chromatid attachment to spindle microtubules. In response to unattached kinetochores, the SAC activates its effector, the mitotic checkpoint complex (MCC), which delays mitotic exit until all sister chromatid pairs have achieved successful attachment to the bipolar mitotic spindle. Formation of the MCC (composed of Mad2, BubR1, Bub3 and Cdc20) is regulated by an Mps1 kinase-dependent phosphorylation signaling cascade which assembles and repositions components of the MCC onto a catalytic scaffold. This scaffold functions to catalyze the conversion of the HORMA-domain protein Mad2 from an "inactive" open-state (O-Mad2) into an "active" closed-Mad2 (C-Mad2), and simultaneous Cdc20 binding. Here, our current understanding of the molecular mechanisms underlying the kinetic barrier to C-Mad2:Cdc20 formation will be reviewed. Recent progress in elucidating the precise molecular choreography orchestrated by the catalytic scaffold to rapidly assemble the MCC will be examined, and unresolved questions will be highlighted. Ultimately, understanding how the SAC rapidly activates the checkpoint not only provides insights into how cells maintain genomic integrity during mitosis, but also provides a paradigm for how cells can utilize molecular switches, including other HORMA domain-containing proteins, to make rapid changes to a cell's physiological state.
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Affiliation(s)
- Elyse S. Fischer
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus Cambridge UK
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11
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SWAP, SWITCH, and STABILIZE: Mechanisms of Kinetochore–Microtubule Error Correction. Cells 2022; 11:cells11091462. [PMID: 35563768 PMCID: PMC9104000 DOI: 10.3390/cells11091462] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/20/2022] [Accepted: 04/21/2022] [Indexed: 11/17/2022] Open
Abstract
For correct chromosome segregation in mitosis, eukaryotic cells must establish chromosome biorientation where sister kinetochores attach to microtubules extending from opposite spindle poles. To establish biorientation, any aberrant kinetochore–microtubule interactions must be resolved in the process called error correction. For resolution of the aberrant interactions in error correction, kinetochore–microtubule interactions must be exchanged until biorientation is formed (the SWAP process). At initiation of biorientation, the state of weak kinetochore–microtubule interactions should be converted to the state of stable interactions (the SWITCH process)—the conundrum of this conversion is called the initiation problem of biorientation. Once biorientation is established, tension is applied on kinetochore–microtubule interactions, which stabilizes the interactions (the STABILIZE process). Aurora B kinase plays central roles in promoting error correction, and Mps1 kinase and Stu2 microtubule polymerase also play important roles. In this article, we review mechanisms of error correction by considering the SWAP, SWITCH, and STABILIZE processes. We mainly focus on mechanisms found in budding yeast, where only one microtubule attaches to a single kinetochore at biorientation, making the error correction mechanisms relatively simpler.
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12
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Doodhi H, Tanaka TU. Swap and stop - Kinetochores play error correction with microtubules: Mechanisms of kinetochore-microtubule error correction: Mechanisms of kinetochore-microtubule error correction. Bioessays 2022; 44:e2100246. [PMID: 35261042 PMCID: PMC9344824 DOI: 10.1002/bies.202100246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 12/30/2022]
Abstract
Correct chromosome segregation in mitosis relies on chromosome biorientation, in which sister kinetochores attach to microtubules from opposite spindle poles prior to segregation. To establish biorientation, aberrant kinetochore–microtubule interactions must be resolved through the error correction process. During error correction, kinetochore–microtubule interactions are exchanged (swapped) if aberrant, but the exchange must stop when biorientation is established. In this article, we discuss recent findings in budding yeast, which have revealed fundamental molecular mechanisms promoting this “swap and stop” process for error correction. Where relevant, we also compare the findings in budding yeast with mechanisms in higher eukaryotes. Evidence suggests that Aurora B kinase differentially regulates kinetochore attachments to the microtubule end and its lateral side and switches relative strength of the two kinetochore–microtubule attachment modes, which drives the exchange of kinetochore–microtubule interactions to resolve aberrant interactions. However, Aurora B kinase, recruited to centromeres and inner kinetochores, cannot reach its targets at kinetochore–microtubule interface when tension causes kinetochore stretching, which stops the kinetochore–microtubule exchange once biorientation is established.
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Affiliation(s)
- Harinath Doodhi
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, UK
| | - Tomoyuki U Tanaka
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, UK
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13
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Roy B, Han SJY, Fontan AN, Jema S, Joglekar AP. Aurora B phosphorylates Bub1 to promote spindle assembly checkpoint signaling. Curr Biol 2022; 32:237-247.e6. [PMID: 34861183 PMCID: PMC8752509 DOI: 10.1016/j.cub.2021.10.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 08/24/2021] [Accepted: 10/22/2021] [Indexed: 01/12/2023]
Abstract
Accurate chromosome segregation during cell division requires amphitelic chromosome attachment to the spindle apparatus. It is ensured by the combined activity of the spindle assembly checkpoint (SAC),1 a signaling mechanism that delays anaphase onset in response to unattached chromosomes, and an error correction mechanism that eliminates syntelic attachments.2 The SAC becomes active when Mps1 kinase sequentially phosphorylates the kinetochore protein Spc105/KNL1 and the signaling proteins that Spc105/KNL1 recruits to facilitate the production of the mitotic checkpoint complex (MCC).3-8 The error correction mechanism is regulated by the Aurora B kinase, but Aurora B also promotes SAC signaling via indirect mechanisms.9-12 Here we present evidence that Aurora B kinase activity directly promotes MCC production by working downstream of Mps1 in budding yeast and human cells. Using the ectopic SAC activation (eSAC) system, we find that the conditional dimerization of Aurora B in budding yeast and an Aurora B recruitment domain in HeLa cells with either Bub1 or Mad1, but not the phosphodomain of Spc105/KNL1, leads to ectopic MCC production and mitotic arrest.13-16 Importantly, Bub1 must recruit both Mad1 and Cdc20 for this ectopic signaling activity. These and other data show that Aurora B cooperates with Bub1 to promote MCC production, but only after Mps1 licenses Bub1 recruitment to the kinetochore. This direct involvement of Aurora B in SAC signaling may maintain SAC signaling even after Mps1 activity in the kinetochore is lowered.
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Affiliation(s)
- Babhrubahan Roy
- Cell & Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl., Ann Arbor, MI-48109, USA
| | - Simon J. Y. Han
- Cell & Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl., Ann Arbor, MI-48109, USA,present address: Medical Scientist Training Program, University of Cincinnati College of Medicine, 3230 Eden Ave, Cincinnati, OH 45267, USA
| | - Adrienne N. Fontan
- Cell & Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl., Ann Arbor, MI-48109, USA,present address: Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, 455 Main St, Cambridge, MA 02142
| | - Soubhagyalaxmi Jema
- Cell & Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl., Ann Arbor, MI-48109, USA
| | - Ajit P. Joglekar
- Cell & Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl., Ann Arbor, MI-48109, USA,corresponding author, lead contact: , Twitter handle: @AjitJoglekar1
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14
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Laine LJ, Mäki-Jouppila JHE, Kutvonen E, Tiikkainen P, Nyholm TKM, Tien JF, Umbreit NT, Härmä V, Kallio L, Davis TN, Asbury CL, Poso A, Gorbsky GJ, Kallio MJ. VTT-006, an anti-mitotic compound, binds to the Ndc80 complex and suppresses cancer cell growth in vitro. Oncoscience 2021; 8:134-153. [PMID: 34926718 PMCID: PMC8667816 DOI: 10.18632/oncoscience.549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 12/01/2021] [Indexed: 11/25/2022] Open
Abstract
Hec1 (Highly expressed in cancer 1) resides in the outer kinetochore where it works to facilitate proper kinetochore-microtubule interactions during mitosis. Hec1 is overexpressed in various cancers and its expression shows correlation with high tumour grade and poor patient prognosis. Chemical perturbation of Hec1 is anticipated to impair kinetochore-microtubule binding, activate the spindle assembly checkpoint (spindle checkpoint) and thereby suppress cell proliferation. In this study, we performed high-throughput screen to identify novel small molecules that target the Hec1 calponin homology domain (CHD), which is needed for normal microtubule attachments. 4 million compounds were first virtually fitted against the CHD, and the best hit molecules were evaluated in vitro. These approaches led to the identification of VTT-006, a 1,2-disubstituted-tetrahydro-beta-carboline derivative, which showed binding to recombinant Ndc80 complex and modulated Hec1 association with microtubules in vitro. VTT-006 treatment resulted in chromosome congression defects, reduced chromosome oscillations and induced loss of inter-kinetochore tension. Cells remained arrested in mitosis with an active spindle checkpoint for several hours before undergoing cell death. VTT-006 suppressed the growth of several cancer cell lines and enhanced the sensitivity of HeLa cells to Taxol. Our findings propose that VTT-006 is a potential anti-mitotic compound that disrupts M phase, impairs kinetochore-microtubule interactions, and activates the spindle checkpoint.
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Affiliation(s)
- Leena J Laine
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland.,Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku 20520, Finland.,These authors contributed equally to this work
| | - Jenni H E Mäki-Jouppila
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland.,Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku 20520, Finland.,Drug Research Doctoral Programme, University of Turku, Finland.,Department of Pharmacology, Drug Development and Therapeutics, University of Turku, Turku, Finland.,These authors contributed equally to this work
| | - Emma Kutvonen
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland.,Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku 20520, Finland
| | - Pekka Tiikkainen
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland
| | | | - Jerry F Tien
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Neil T Umbreit
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Ville Härmä
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland
| | - Lila Kallio
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland
| | - Trisha N Davis
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Charles L Asbury
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Antti Poso
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Gary J Gorbsky
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Marko J Kallio
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland.,Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku 20520, Finland
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15
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Sarangapani KK, Koch LB, Nelson CR, Asbury CL, Biggins S. Kinetochore-bound Mps1 regulates kinetochore-microtubule attachments via Ndc80 phosphorylation. J Cell Biol 2021; 220:e202106130. [PMID: 34647959 PMCID: PMC8641409 DOI: 10.1083/jcb.202106130] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/03/2021] [Accepted: 09/09/2021] [Indexed: 12/22/2022] Open
Abstract
Dividing cells detect and correct erroneous kinetochore-microtubule attachments during mitosis, thereby avoiding chromosome missegregation. The Aurora B kinase phosphorylates microtubule-binding elements specifically at incorrectly attached kinetochores, promoting their release and providing another chance for proper attachments to form. However, growing evidence suggests that the Mps1 kinase is also required for error correction. Here we directly examine how Mps1 activity affects kinetochore-microtubule attachments using a reconstitution-based approach that allows us to separate its effects from Aurora B activity. When endogenous Mps1 that copurifies with kinetochores is activated in vitro, it weakens their attachments to microtubules via phosphorylation of Ndc80, a major microtubule-binding protein. This phosphorylation contributes to error correction because phospho-deficient Ndc80 mutants exhibit genetic interactions and segregation defects when combined with mutants in other error correction pathways. In addition, Mps1 phosphorylation of Ndc80 is stimulated on kinetochores lacking tension. These data suggest that Mps1 provides an additional mechanism for correcting erroneous kinetochore-microtubule attachments, complementing the well-known activity of Aurora B.
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Affiliation(s)
| | - Lori B. Koch
- Howard Hughes Medical Institute, Chevy Chase, MD
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA
| | - Christian R. Nelson
- Howard Hughes Medical Institute, Chevy Chase, MD
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
| | - Charles L. Asbury
- Department of Physiology & Biophysics, University of Washington, Seattle, WA
| | - Sue Biggins
- Howard Hughes Medical Institute, Chevy Chase, MD
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
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16
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Lara-Gonzalez P, Pines J, Desai A. Spindle assembly checkpoint activation and silencing at kinetochores. Semin Cell Dev Biol 2021; 117:86-98. [PMID: 34210579 PMCID: PMC8406419 DOI: 10.1016/j.semcdb.2021.06.009] [Citation(s) in RCA: 99] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/17/2021] [Accepted: 06/17/2021] [Indexed: 01/01/2023]
Abstract
The spindle assembly checkpoint (SAC) is a surveillance mechanism that promotes accurate chromosome segregation in mitosis. The checkpoint senses the attachment state of kinetochores, the proteinaceous structures that assemble onto chromosomes in mitosis in order to mediate their interaction with spindle microtubules. When unattached, kinetochores generate a diffusible inhibitor that blocks the activity of the anaphase-promoting complex/cyclosome (APC/C), an E3 ubiquitin ligase required for sister chromatid separation and exit from mitosis. Work from the past decade has greatly illuminated our understanding of the mechanisms by which the diffusible inhibitor is assembled and how it inhibits the APC/C. However, less is understood about how SAC proteins are recruited to kinetochores in the absence of microtubule attachment, how the kinetochore catalyzes formation of the diffusible inhibitor, and how attachments silence the SAC at the kinetochore. Here, we summarize current understanding of the mechanisms that activate and silence the SAC at kinetochores and highlight open questions for future investigation.
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Affiliation(s)
- Pablo Lara-Gonzalez
- Ludwig Institute for Cancer Research, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA.
| | | | - Arshad Desai
- Ludwig Institute for Cancer Research, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA.
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17
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Kops GJPL, Snel B, Tromer EC. Evolutionary Dynamics of the Spindle Assembly Checkpoint in Eukaryotes. Curr Biol 2021; 30:R589-R602. [PMID: 32428500 DOI: 10.1016/j.cub.2020.02.021] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The tremendous diversity in eukaryotic life forms can ultimately be traced back to evolutionary modifications at the level of molecular networks. Deep understanding of these modifications will not only explain cellular diversity, but will also uncover different ways to execute similar processes and expose the evolutionary 'rules' that shape the molecular networks. Here, we review the evolutionary dynamics of the spindle assembly checkpoint (SAC), a signaling network that guards fidelity of chromosome segregation. We illustrate how the interpretation of divergent SAC systems in eukaryotic species is facilitated by combining detailed molecular knowledge of the SAC and extensive comparative genome analyses. Ultimately, expanding this to other core cellular systems and experimentally interrogating such systems in organisms from all major lineages may start outlining the routes to and eventual manifestation of the cellular diversity of eukaryotic life.
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Affiliation(s)
- Geert J P L Kops
- Oncode Institute, Hubrecht Institute - KNAW (Royal Netherlands Academy of Arts and Sciences) and University Medical Centre Utrecht, Utrecht, The Netherlands.
| | - Berend Snel
- Theoretical Biology and Bioinformatics, Department of Biology, Science Faculty, Utrecht University, Utrecht, The Netherlands.
| | - Eelco C Tromer
- Department of Biochemistry, University of Cambridge, Cambridge, UK.
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18
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Dudziak A, Engelhard L, Bourque C, Klink BU, Rombaut P, Kornakov N, Jänen K, Herzog F, Gatsogiannis C, Westermann S. Phospho-regulated Bim1/EB1 interactions trigger Dam1c ring assembly at the budding yeast outer kinetochore. EMBO J 2021; 40:e108004. [PMID: 34313341 PMCID: PMC8441410 DOI: 10.15252/embj.2021108004] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/01/2021] [Accepted: 07/07/2021] [Indexed: 11/16/2022] Open
Abstract
Kinetochores form the link between chromosomes and microtubules of the mitotic spindle. The heterodecameric Dam1 complex (Dam1c) is a major component of the Saccharomyces cerevisiae outer kinetochore, assembling into 3 MDa‐sized microtubule‐embracing rings, but how ring assembly is specifically initiated in vivo remains to be understood. Here, we describe a molecular pathway that provides local control of ring assembly during the establishment of sister kinetochore bi‐orientation. We show that Dam1c and the general microtubule plus end‐associated protein (+TIP) Bim1/EB1 form a stable complex depending on a conserved motif in the Duo1 subunit of Dam1c. EM analyses reveal that Bim1 crosslinks protrusion domains of adjacent Dam1c heterodecamers and promotes the formation of oligomers with defined curvature. Disruption of the Dam1c‐Bim1 interaction impairs kinetochore localization of Dam1c in metaphase and delays mitosis. Phosphorylation promotes Dam1c‐Bim1 binding by relieving an intramolecular inhibition of the Dam1 C‐terminus. In addition, Bim1 recruits Bik1/CLIP‐170 to Dam1c and induces formation of full rings even in the absence of microtubules. Our data help to explain how new kinetochore end‐on attachments are formed during the process of attachment error correction.
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Affiliation(s)
- Alexander Dudziak
- Department of Molecular Genetics I, Center of Molecular Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Lena Engelhard
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Cole Bourque
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.,Institute for Medical Physics and Biophysics and Center for Soft Nanoscience, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Björn Udo Klink
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.,Institute for Medical Physics and Biophysics and Center for Soft Nanoscience, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Pascaline Rombaut
- Gene Center Munich, Ludwig Maximilian University Munich, Munich, Germany
| | - Nikolay Kornakov
- Department of Molecular Genetics I, Center of Molecular Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Karolin Jänen
- Department of Molecular Genetics I, Center of Molecular Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Franz Herzog
- Gene Center Munich, Ludwig Maximilian University Munich, Munich, Germany
| | - Christos Gatsogiannis
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.,Institute for Medical Physics and Biophysics and Center for Soft Nanoscience, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Stefan Westermann
- Department of Molecular Genetics I, Center of Molecular Biotechnology, University of Duisburg-Essen, Essen, Germany
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19
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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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20
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Chen J, Ünal E. Meiotic regulation of the Ndc80 complex composition and function. Curr Genet 2021; 67:511-518. [PMID: 33745061 PMCID: PMC8254699 DOI: 10.1007/s00294-021-01174-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 03/01/2021] [Accepted: 03/03/2021] [Indexed: 11/30/2022]
Abstract
This review describes the current models for how the subunit abundance of the Ndc80 complex, a key kinetochore component, is regulated in budding yeast and metazoan meiosis. The past decades of kinetochore research have established the Ndc80 complex to be a key microtubule interactor and a central hub for regulating chromosome segregation. Recent studies further demonstrate that Ndc80 is the limiting kinetochore subunit that dictates the timing of kinetochore activation in budding yeast meiosis. Here, we discuss the molecular circuits that regulate Ndc80 protein synthesis and degradation in budding yeast meiosis and compare the findings with those from metazoans. We envision the regulatory principles discovered in budding yeast to be conserved in metazoans, thereby providing guidance into future investigations on kinetochore regulation in human health and disease.
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Affiliation(s)
- Jingxun Chen
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA
| | - Elçin Ünal
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA.
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21
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Sarkar S, Sahoo PK, Mahata S, Pal R, Ghosh D, Mistry T, Ghosh S, Bera T, Nasare VD. Mitotic checkpoint defects: en route to cancer and drug resistance. Chromosome Res 2021; 29:131-144. [PMID: 33409811 DOI: 10.1007/s10577-020-09646-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/24/2020] [Accepted: 12/01/2020] [Indexed: 12/11/2022]
Abstract
Loss of mitosis regulation is a common feature of malignant cells that leads to aberrant cell division with inaccurate chromosome segregation. The mitotic checkpoint is responsible for faithful transmission of genetic material to the progeny. Defects in this checkpoint, such as mutations and changes in gene expression, lead to abnormal chromosome content or aneuploidy that may facilitate cancer development. Furthermore, a defective checkpoint response is indicated in the development of drug resistance to microtubule poisons that are used in treatment of various blood and solid cancers for several decades. Mitotic slippage and senescence are important cell fates that occur even with an active mitotic checkpoint and are held responsible for the resistance. However, contradictory findings in both the scenarios of carcinogenesis and drug resistance have aroused questions on whether mitotic checkpoint defects are truly responsible for these dismal outcomes. Here, we discuss the possible contribution of the faulty checkpoint signaling in cancer development and drug resistance, followed by the latest research on this pathway for better outcomes in cancer treatment.
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Affiliation(s)
- Sinjini Sarkar
- Department of Pathology and Cancer Screening, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata, West Bengal, 700026, India.,Department of Pharmaceutical Technology, Jadavpur University, Kolkata, West Bengal, 700032, India
| | - Pranab Kumar Sahoo
- Department of Pathology and Cancer Screening, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata, West Bengal, 700026, India
| | - Sutapa Mahata
- Department of Pathology and Cancer Screening, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata, West Bengal, 700026, India
| | - Ranita Pal
- Department of Pathology and Cancer Screening, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata, West Bengal, 700026, India
| | - Dipanwita Ghosh
- Department of Pathology and Cancer Screening, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata, West Bengal, 700026, India
| | - Tanuma Mistry
- Department of Pathology and Cancer Screening, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata, West Bengal, 700026, India
| | - Sushmita Ghosh
- Department of Pathology and Cancer Screening, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata, West Bengal, 700026, India
| | - Tanmoy Bera
- Department of Pharmaceutical Technology, Jadavpur University, Kolkata, West Bengal, 700032, India
| | - Vilas D Nasare
- Department of Pathology and Cancer Screening, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata, West Bengal, 700026, India.
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22
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Kuijt TEF, Lambers MLA, Weterings S, Ponsioen B, Bolhaqueiro ACF, Staijen DHM, Kops GJPL. A Biosensor for the Mitotic Kinase MPS1 Reveals Spatiotemporal Activity Dynamics and Regulation. Curr Biol 2020; 30:3862-3870.e6. [PMID: 32888483 DOI: 10.1016/j.cub.2020.07.062] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 06/18/2020] [Accepted: 07/14/2020] [Indexed: 01/10/2023]
Abstract
Accurate chromosome segregation during cell division critically depends on error correction of chromosome-spindle interactions and the spindle assembly checkpoint (SAC) [1-3]. The kinase MPS1 is an essential regulator of both processes, ensuring full chromosome biorientation before anaphase onset [3, 4]. To understand when and where MPS1 activation occurs and how MPS1 signaling is modulated during mitosis, we developed MPS1sen, a sensitive and specific FRET-based biosensor for MPS1 activity. By placing MPS1sen at different subcellular locations, we show that MPS1 activity initiates in the nucleus ∼9-12 min prior to nuclear envelope breakdown (NEB) in a kinetochore-dependent manner and reaches the cytoplasm at the start of NEB. Soon after initiation, MPS1 activity increases with switch-like kinetics, peaking at completion of NEB. We further show that timing and extent of pre-NEB MPS1 activity is regulated by Aurora B and PP2A-B56. MPS1sen phosphorylation declines in prometaphase as a result of formation of kinetochore-microtubule attachments, reaching low but still detectable levels at metaphase. Finally, leveraging the sensitivity and dynamic range of MPS1sen, we show deregulated MPS1 signaling dynamics in colorectal cancer cell lines and tumor organoids with diverse genomic instability phenotypes.
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Affiliation(s)
- Timo E F Kuijt
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Centre Utrecht, 3584CT Utrecht, the Netherlands
| | - Maaike L A Lambers
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Centre Utrecht, 3584CT Utrecht, the Netherlands
| | - Sonja Weterings
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Centre Utrecht, 3584CT Utrecht, the Netherlands
| | - Bas Ponsioen
- Cancer Genomics Netherlands, UMC Utrecht, 3584CG Utrecht, the Netherlands; Molecular Cancer Research, Centre for Molecular Medicine, UMC Utrecht, 3584CG Utrecht, the Netherlands
| | - Ana C F Bolhaqueiro
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Centre Utrecht, 3584CT Utrecht, the Netherlands
| | - Debbie H M Staijen
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Centre Utrecht, 3584CT Utrecht, the Netherlands
| | - Geert J P L Kops
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Centre Utrecht, 3584CT Utrecht, the Netherlands.
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23
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Benzi G, Piatti S. Killing two birds with one stone: how budding yeast Mps1 controls chromosome segregation and spindle assembly checkpoint through phosphorylation of a single kinetochore protein. Curr Genet 2020; 66:1037-1044. [PMID: 32632756 DOI: 10.1007/s00294-020-01091-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/23/2020] [Accepted: 06/25/2020] [Indexed: 12/11/2022]
Abstract
During mitosis, the identical sister chromatids of each chromosome must attach through their kinetochores to microtubules emanating from opposite spindle poles. This process, referred to as chromosome biorientation, is essential for equal partitioning of the genetic information to the two daughter cells. Defects in chromosome biorientation can give rise to aneuploidy, a hallmark of cancer and genetic diseases. A conserved surveillance mechanism called spindle assembly checkpoint (SAC) prevents the onset of anaphase until biorientation is attained. Key to chromosome biorientation is an error correction mechanism that allows kinetochores to establish proper bipolar attachments by disengaging faulty kinetochore-microtubule connections. Error correction relies on the Aurora B and Mps1 kinases that also promote SAC signaling, raising the possibility that they are part of a single sensory device responding to improper attachments and concomitantly controlling both their disengagement and a temporary mitotic arrest. In budding yeast, Aurora B and Mps1 promote error correction independently from one another, but while the substrates of Aurora B in this process are at least partially known, the mechanism underlying the involvement of Mps1 in the error correction pathway is unknown. Through the characterization of a novel mps1 mutant and an unbiased genetic screen for extragenic suppressors, we recently gained evidence that a common mechanism based on Mps1-dependent phosphorylation of the Knl1/Spc105 kinetochore scaffold and subsequent recruitment of the Bub1 kinase is critical for the function of Mps1 in chromosome biorientation as well as for SAC activation (Benzi et al. EMBO Rep, 2020).
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Affiliation(s)
- Giorgia Benzi
- CRBM, University of Montpellier, CNRS, 1919 Route de Mende, 34293, Montpellier, France
| | - Simonetta Piatti
- CRBM, University of Montpellier, CNRS, 1919 Route de Mende, 34293, Montpellier, France.
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24
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Roy B, Han SJ, Fontan AN, Joglekar AP. The copy-number and varied strengths of MELT motifs in Spc105 balance the strength and responsiveness of the spindle assembly checkpoint. eLife 2020; 9:55096. [PMID: 32479259 PMCID: PMC7292645 DOI: 10.7554/elife.55096] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 05/29/2020] [Indexed: 12/15/2022] Open
Abstract
During mitosis, the Spindle Assembly Checkpoint (SAC) maintains genome stability while also ensuring timely anaphase onset. To maintain genome stability, the SAC must be strong to delay anaphase even if just one chromosome is unattached, but for timely anaphase onset, it must promptly respond to silencing mechanisms. How the SAC meets these potentially antagonistic requirements is unclear. Here we show that the balance between SAC strength and responsiveness is determined by the number of ‘MELT’ motifs in the kinetochore protein Spc105/KNL1 and their Bub3-Bub1 binding affinities. Many strong MELT motifs per Spc105/KNL1 minimize chromosome missegregation, but too many delay anaphase onset. We demonstrate this by constructing a Spc105 variant that trades SAC responsiveness for much more accurate chromosome segregation. We propose that the necessity of balancing SAC strength and responsiveness drives the dual evolutionary trend of the amplification of MELT motif number, but degeneration of their functionally optimal amino acid sequence.
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Affiliation(s)
- Babhrubahan Roy
- Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, United States
| | - Simon Jy Han
- Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, United States
| | - Adrienne Nicole Fontan
- Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, United States
| | - Ajit P Joglekar
- Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, United States
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25
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Wimbish RT, DeLuca KF, Mick JE, Himes J, Jiménez-Sánchez I, Jeyaprakash AA, DeLuca JG. The Hec1/Ndc80 tail domain is required for force generation at kinetochores, but is dispensable for kinetochore-microtubule attachment formation and Ska complex recruitment. Mol Biol Cell 2020; 31:1453-1473. [PMID: 32401635 PMCID: PMC7359571 DOI: 10.1091/mbc.e20-05-0286] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The conserved kinetochore-associated NDC80 complex (composed of Hec1/Ndc80, Nuf2, Spc24, and Spc25) has well-documented roles in mitosis including 1) connecting mitotic chromosomes to spindle microtubules to establish force-transducing kinetochore–microtubule attachments and 2) regulating the binding strength between kinetochores and microtubules such that correct attachments are stabilized and erroneous attachments are released. Although the NDC80 complex plays a central role in forming and regulating attachments to microtubules, additional factors support these processes as well, including the spindle and kinetochore-associated (Ska) complex. Multiple lines of evidence suggest that Ska complexes strengthen attachments by increasing the ability of NDC80 complexes to bind microtubules, especially to depolymerizing microtubule plus ends, but how this is accomplished remains unclear. Using cell-based and in vitro assays, we demonstrate that the Hec1 tail domain is dispensable for Ska complex recruitment to kinetochores and for generation of kinetochore–microtubule attachments in human cells. We further demonstrate that Hec1 tail phosphorylation regulates kinetochore–microtubule attachment stability independently of the Ska complex. Finally, we map the location of the Ska complex in cells to a region near the coiled-coil domain of the NDC80 complex and demonstrate that this region is required for Ska complex recruitment to the NDC80 complex-–microtubule interface.
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Affiliation(s)
- Robert T Wimbish
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523
| | - Keith F DeLuca
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523
| | - Jeanne E Mick
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523
| | - Jack Himes
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523
| | | | - A Arockia Jeyaprakash
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, EH9 3BF Edinburgh, UK
| | - Jennifer G DeLuca
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523
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26
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Pachis ST, Hiruma Y, Tromer EC, Perrakis A, Kops GJPL. Interactions between N-terminal Modules in MPS1 Enable Spindle Checkpoint Silencing. Cell Rep 2020; 26:2101-2112.e6. [PMID: 30784592 DOI: 10.1016/j.celrep.2019.01.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/13/2018] [Accepted: 01/04/2019] [Indexed: 10/27/2022] Open
Abstract
Faithful chromosome segregation relies on the ability of the spindle assembly checkpoint (SAC) to delay anaphase onset until chromosomes are attached to the mitotic spindle via their kinetochores. MPS1 kinase is recruited to kinetochores to initiate SAC signaling and is removed from kinetochores once stable microtubule attachments have been formed to allow normal mitotic progression. Here, we show that a helical fragment within the kinetochore-targeting N-terminal extension (NTE) module of MPS1 is required for interactions with kinetochores and forms intramolecular interactions with its adjacent tetratricopeptide repeat (TPR) domain. Bypassing this NTE-TPR interaction results in high MPS1 levels at kinetochores due to loss of regulatory input into MPS1 localization, inefficient MPS1 delocalization upon microtubule attachment, and SAC silencing defects. These results show that SAC responsiveness to attachments relies on regulated intramolecular interactions in MPS1 and highlight the sensitivity of mitosis to perturbations in the dynamics of the MPS1-NDC80-C interactions.
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Affiliation(s)
- Spyridon T Pachis
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, 3584 CT, the Netherlands
| | - Yoshitaka Hiruma
- Department of Biochemistry, the Netherlands Cancer Institute, Amsterdam, 1066 CX, the Netherlands
| | - Eelco C Tromer
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK
| | - Anastassis Perrakis
- Department of Biochemistry, the Netherlands Cancer Institute, Amsterdam, 1066 CX, the Netherlands
| | - Geert J P L Kops
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, 3584 CT, the Netherlands.
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27
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Wimbish RT, DeLuca JG. Hec1/Ndc80 Tail Domain Function at the Kinetochore-Microtubule Interface. Front Cell Dev Biol 2020; 8:43. [PMID: 32161753 PMCID: PMC7054225 DOI: 10.3389/fcell.2020.00043] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/17/2020] [Indexed: 12/28/2022] Open
Abstract
Successful mitotic cell division is critically dependent on the formation of correct attachments between chromosomes and spindle microtubules. Microtubule attachments are mediated by kinetochores, which are large proteinaceous structures assembled on centromeric chromatin of mitotic chromosomes. These attachments must be sufficiently stable to transduce force; however, the strength of these attachments are also tightly regulated to ensure timely, error-free progression through mitosis. The highly conserved, kinetochore-associated NDC80 complex is a core component of the kinetochore-microtubule attachment machinery in eukaryotic cells. A small, disordered region within the Hec1 subunit of the NDC80 complex – the N-terminal “tail” domain – has been actively investigated during the last decade due to its roles in generating and regulating kinetochore-microtubule attachments. In this review, we discuss the role of the NDC80 complex, and specifically the Hec1 tail domain, at the kinetochore-microtubule interface, and how recent studies provide a more unified view of Hec1 tail domain function.
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Affiliation(s)
- Robert T Wimbish
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Jennifer G DeLuca
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States
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28
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Abstract
The coordinated activities of many protein kinases, acting on multiple protein substrates, ensures the error-free progression through mitosis of eukaryotic cells. Enormous research effort has thus been devoted to studying the roles and regulation of these mitotic kinases, and to the identification of their physiological substrates. Central for the timely deployment of specific protein kinases to their appropriate substrates during the cell division cycle are the many anchoring proteins, which serve critical regulatory roles. Through direct association, anchoring proteins are capable of modulating the catalytic activity and/or sub-cellular distribution of the mitotic kinases they associate with. The key roles of some anchoring proteins in cell division are well-established, whilst others are still being unearthed. Here, we review the current knowledge on anchoring proteins for some mitotic kinases, and highlight how targeting anchoring proteins for inhibition, instead of the mitotic kinases themselves, could be advantageous for disrupting the cell division cycle.
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Affiliation(s)
- Luke J Fulcher
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, Scotland, UK
| | - Gopal P Sapkota
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, Scotland, UK
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29
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Sherwin D, Wang Y. The Opposing Functions of Protein Kinases and Phosphatases in Chromosome Bipolar Attachment. Int J Mol Sci 2019; 20:ijms20246182. [PMID: 31817904 PMCID: PMC6940769 DOI: 10.3390/ijms20246182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 11/22/2019] [Accepted: 12/06/2019] [Indexed: 01/17/2023] Open
Abstract
Accurate chromosome segregation during cell division is essential to maintain genome integrity in all eukaryotic cells, and chromosome missegregation leads to aneuploidy and therefore represents a hallmark of many cancers. Accurate segregation requires sister kinetochores to attach to microtubules emanating from opposite spindle poles, known as bipolar attachment or biorientation. Recent studies have uncovered several mechanisms critical to chromosome bipolar attachment. First, a mechanism exists to ensure that the conformation of sister centromeres is biased toward bipolar attachment. Second, the phosphorylation of some kinetochore proteins destabilizes kinetochore attachment to facilitate error correction, but a protein phosphatase reverses this phosphorylation. Moreover, the activity of the spindle assembly checkpoint is regulated by kinases and phosphatases at the kinetochore, and this checkpoint prevents anaphase entry in response to faulty kinetochore attachment. The fine-tuned kinase/phosphatase balance at kinetochores is crucial for faithful chromosome segregation during both mitosis and meiosis. Here, we discuss the function and regulation of protein phosphatases in the establishment of chromosome bipolar attachment with a focus on the model organism budding yeast.
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Affiliation(s)
| | - Yanchang Wang
- Correspondence: ; Tel.: +1-850-644-0402; Fax: +1-850-644-5781
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30
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Autophosphorylation is sufficient to release Mps1 kinase from native kinetochores. Proc Natl Acad Sci U S A 2019; 116:17355-17360. [PMID: 31405987 DOI: 10.1073/pnas.1901653116] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Accurate mitosis depends on a surveillance system called the spindle assembly checkpoint. This checkpoint acts at kinetochores, which attach chromosomes to the dynamic tips of spindle microtubules. When a kinetochore is unattached or improperly attached, the protein kinase Mps1 phosphorylates kinetochore components, catalyzing the generation of a diffusible "wait" signal that delays anaphase and gives the cell time to correct the error. When a kinetochore becomes properly attached, its checkpoint signal is silenced to allow progression into anaphase. Recently, microtubules were found to compete directly against recombinant human Mps1 fragments for binding to the major microtubule-binding kinetochore element Ndc80c, suggesting a direct competition model for silencing the checkpoint signal at properly attached kinetochores. Here, by developing single-particle fluorescence-based assays, we tested whether such direct competition occurs in the context of native kinetochores isolated from yeast. Mps1 levels were not reduced on kinetochore particles bound laterally to the sides of microtubules or on particles tracking processively with disassembling tips. Instead, we found that Mps1 kinase activity was sufficient to promote its release from the isolated kinetochores. Mps1 autophosphorylation, rather than phosphorylation of other kinetochore components, was responsible for this dissociation. Our findings suggest that checkpoint silencing in yeast does not arise from a direct competition between Mps1 and microtubules, and that phosphoregulation of Mps1 may be a critical aspect of the silencing mechanism.
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31
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Mishra PK, Basrai MA. Protein kinases in mitotic phosphorylation of budding yeast CENP-A. Curr Genet 2019; 65:1325-1332. [PMID: 31119371 DOI: 10.1007/s00294-019-00997-5] [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: 05/03/2019] [Revised: 05/16/2019] [Accepted: 05/18/2019] [Indexed: 01/24/2023]
Abstract
Centromere identity is specified epigenetically by specialized nucleosomes containing the evolutionarily conserved centromeric histone H3 variant (Cse4 in budding yeast, CENP-A in humans) which is essential for faithful chromosome segregation. However, the mechanisms of epigenetic regulation of Cse4 have not been clearly defined. We have identified two kinases, Cdc5 (Plk1 in humans) and Ipl1 (Aurora B kinase in humans) that phosphorylate Cse4 to prevent chromosomal instability (CIN). Cdc5 associates with Cse4 in mitosis and Cdc5-mediated phosphorylation of Cse4 is coincident with the centromeric enrichment of Cdc5 during metaphase. Defects in Cdc5-mediated Cse4 phosphorylation causes CIN, whereas constitutive association of Cdc5 with Cse4 results in lethality. Cse4 is also a substrate for Ipl1 and phospho-mimetic cse4 mutants suppress growth defects of ipl1 and Ipl1 kinetochore substrate mutants, namely dam1 spc34 and ndc80. Ipl1-mediated phosphorylation of Cse4 regulates kinetochore-microtubule interactions and chromosome biorientation. We propose that collaboration of Cdc5- and Ipl1-mediated phosphorylation of Cse4 modulates kinetochore structure and function, and chromosome biorientation. These findings demonstrate how phosphorylation of Cse4 regulates the integrity of the kinetochore, and acts as an epigenetic marker for mitotic control.
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Affiliation(s)
- Prashant K Mishra
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Munira A Basrai
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
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32
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Pachis ST, Kops GJPL. Leader of the SAC: molecular mechanisms of Mps1/TTK regulation in mitosis. Open Biol 2019; 8:rsob.180109. [PMID: 30111590 PMCID: PMC6119859 DOI: 10.1098/rsob.180109] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 07/19/2018] [Indexed: 12/14/2022] Open
Abstract
Discovered in 1991 in a screen for genes involved in spindle pole body duplication, the monopolar spindle 1 (Mps1) kinase has since claimed a central role in processes that ensure error-free chromosome segregation. As a result, Mps1 kinase activity has become an attractive candidate for pharmaceutical companies in the search for compounds that target essential cellular processes to eliminate, for example, tumour cells or pathogens. Research in recent decades has offered many insights into the molecular function of Mps1 and its regulation. In this review, we integrate the latest knowledge regarding the regulation of Mps1 activity and its spatio-temporal distribution, highlight gaps in our understanding of these processes and propose future research avenues to address them.
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Affiliation(s)
- Spyridon T Pachis
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Geert J P L Kops
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, The Netherlands
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33
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Agarwal S, Smith KP, Zhou Y, Suzuki A, McKenney RJ, Varma D. Cdt1 stabilizes kinetochore-microtubule attachments via an Aurora B kinase-dependent mechanism. J Cell Biol 2018; 217:3446-3463. [PMID: 30154187 PMCID: PMC6168275 DOI: 10.1083/jcb.201705127] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 02/06/2018] [Accepted: 07/17/2018] [Indexed: 12/03/2022] Open
Abstract
Cdt1 is a novel kinetochore–microtubule binding protein. The middle and the C-terminal winged-helix domains of Cdt1 are involved in microtubule binding. Aurora B kinase phosphorylation of Cdt1 influences its microtubule binding in vitro and is necessary for kinetochore–microtubule stability and mitotic progression in cells. Robust kinetochore–microtubule (kMT) attachment is critical for accurate chromosome segregation. G2/M-specific depletion of human Cdt1 that localizes to kinetochores in an Ndc80 complex–dependent manner leads to abnormal kMT attachments and mitotic arrest. This indicates an independent mitotic role for Cdt1 in addition to its prototypic function in DNA replication origin licensing. Here, we show that Cdt1 directly binds to microtubules (MTs). Endogenous or transiently expressed Cdt1 localizes to both mitotic spindle MTs and kinetochores. Deletion mapping of Cdt1 revealed that the regions comprising the middle and C-terminal winged-helix domains but lacking the N-terminal unstructured region were required for efficient MT binding. Mitotic kinase Aurora B interacts with and phosphorylates Cdt1. Aurora B–phosphomimetic Cdt1 exhibited attenuated MT binding, and its cellular expression induced defective kMT attachments with a concomitant delay in mitotic progression. Thus we provide mechanistic insight into how Cdt1 affects overall kMT stability in an Aurora B kinase phosphorylation-dependent manner; which is envisioned to augment the MT-binding of the Ndc80 complex.
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Affiliation(s)
- Shivangi Agarwal
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Kyle Paul Smith
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Yizhuo Zhou
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Aussie Suzuki
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Richard J McKenney
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA
| | - Dileep Varma
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
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34
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Joglekar AP, Kukreja AA. How Kinetochore Architecture Shapes the Mechanisms of Its Function. Curr Biol 2018; 27:R816-R824. [PMID: 28829971 DOI: 10.1016/j.cub.2017.06.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The eukaryotic kinetochore is a sophisticated multi-protein machine that segregates chromosomes during cell division. To ensure accurate chromosome segregation, it performs three major functions using disparate molecular mechanisms. It operates a mechanosensitive signaling cascade known as the spindle assembly checkpoint (SAC) to detect and signal the lack of attachment to spindle microtubules, and delay anaphase onset in response. In addition, after attaching to spindle microtubules, the kinetochore generates the force necessary to move chromosomes. Finally, if the two sister kinetochores on a chromosome are both attached to microtubules emanating from the same spindle pole, they activate another mechanosensitive mechanism to correct the monopolar attachments. All three of these functions maintain genome stability during cell division. The outlines of the biochemical activities responsible for these functions are now available. How the kinetochore integrates the underlying molecular mechanisms is still being elucidated. In this Review, we discuss how the nanoscale protein organization in the kinetochore, which we refer to as kinetochore 'architecture', organizes its biochemical activities to facilitate the realization and integration of emergent mechanisms underlying its three major functions. For this discussion, we will use the relatively simple budding yeast kinetochore as a model, and extrapolate insights gained from this model to elucidate functional roles of the architecture of the much more complex human kinetochore.
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Affiliation(s)
- Ajit P Joglekar
- Department of Cell & Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Biophysics, University of Michigan, Ann Arbor, MI, USA.
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35
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Schleicher K, Porter M, Ten Have S, Sundaramoorthy R, Porter IM, Swedlow JR. The Ndc80 complex targets Bod1 to human mitotic kinetochores. Open Biol 2018; 7:rsob.170099. [PMID: 29142109 PMCID: PMC5717335 DOI: 10.1098/rsob.170099] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 10/16/2017] [Indexed: 12/26/2022] Open
Abstract
Regulation of protein phosphatase activity by endogenous protein inhibitors is an important mechanism to control protein phosphorylation in cells. We recently identified Biorientation defective 1 (Bod1) as a small protein inhibitor of protein phosphatase 2A containing the B56 regulatory subunit (PP2A-B56). This phosphatase controls the amount of phosphorylation of several kinetochore proteins and thus the establishment of load-bearing chromosome-spindle attachments in time for accurate separation of sister chromatids in mitosis. Like PP2A-B56, Bod1 directly localizes to mitotic kinetochores and is required for correct segregation of mitotic chromosomes. In this report, we have probed the spatio-temporal regulation of Bod1 during mitotic progression. Kinetochore localization of Bod1 increases from nuclear envelope breakdown until metaphase. Phosphorylation of Bod1 at threonine 95 (T95), which increases Bod1's binding to and inhibition of PP2A-B56, peaks in prometaphase when PP2A-B56 localization to kinetochores is highest. We demonstrate here that kinetochore targeting of Bod1 depends on the outer kinetochore protein Ndc80 and not PP2A-B56. Crucially, Bod1 depletion functionally affects Ndc80 phosphorylation at the N-terminal serine 55 (S55), as well as a number of other phosphorylation sites within the outer kinetochore, including Knl1 at serine 24 and 60 (S24, S60), and threonine T943 and T1155 (T943, T1155). Therefore, Ndc80 recruits a phosphatase inhibitor to kinetochores which directly feeds forward to regulate Ndc80, and Knl1 phosphorylation, including sites that mediate the attachment of microtubules to kinetochores.
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Affiliation(s)
- Katharina Schleicher
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, UK
| | - Michael Porter
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, UK
| | - Sara Ten Have
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, UK
| | | | - Iain M Porter
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, UK
| | - Jason R Swedlow
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, UK
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36
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Dhatchinamoorthy K, Mattingly M, Gerton JL. Regulation of kinetochore configuration during mitosis. Curr Genet 2018; 64:1197-1203. [DOI: 10.1007/s00294-018-0841-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 04/19/2018] [Accepted: 04/20/2018] [Indexed: 12/15/2022]
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37
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Kolenda C, Ortiz J, Pelzl M, Norell S, Schmeiser V, Lechner J. Unattached kinetochores drive their own capturing by sequestering a CLASP. Nat Commun 2018; 9:886. [PMID: 29491436 PMCID: PMC5830412 DOI: 10.1038/s41467-018-03108-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 01/17/2018] [Indexed: 12/24/2022] Open
Abstract
Kinetochores that are not attached to microtubules prevent chromosome missegregation via the spindle assembly checkpoint. We show that they also promote their own capturing. Similar to what governs the localization of spindle assembly checkpoint proteins, the phosphorylation of Spc105 by Mps1 allows unattached kinetochores to sequester Stu1 in cooperation with Slk19. The withdrawal of Stu1, a CLASP essential for spindle integrity, from microtubules and attached kinetochores disrupts the organization of the spindle and thus allows the enhanced formation of dynamic random microtubules that span the nucleus and are ideal to capture unattached kinetochores. The enhanced formation of nuclear random microtubules does not occur if Stu1 sequestering to unattached kinetochores fails and the spindle remains uncompromised. Consequently, these cells exhibit a severely decreased capturing efficiency. After the capturing event, Stu1 is relocated to the capturing microtubule and prevents precocious microtubule depolymerization as long as kinetochores are laterally or incompletely end-on attached. Kinetochores (KT) that are not attached to microtubules prevent chromosome missegregation via the spindle assembly checkpoint. Here the authors show that Mps1 localizes Stu1 at unattached KTs together with Slk19, causing a reorganization of the nuclear MT network that favors the capturing of unattached KT.
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Affiliation(s)
- Caroline Kolenda
- Biochemie-Zentrum der Universität Heidelberg, INF 328, 69120, Heidelberg, Germany
| | - Jennifer Ortiz
- Biochemie-Zentrum der Universität Heidelberg, INF 328, 69120, Heidelberg, Germany
| | - Marina Pelzl
- Biochemie-Zentrum der Universität Heidelberg, INF 328, 69120, Heidelberg, Germany
| | - Sarina Norell
- Biochemie-Zentrum der Universität Heidelberg, INF 328, 69120, Heidelberg, Germany
| | - Verena Schmeiser
- Biochemie-Zentrum der Universität Heidelberg, INF 328, 69120, Heidelberg, Germany
| | - Johannes Lechner
- Biochemie-Zentrum der Universität Heidelberg, INF 328, 69120, Heidelberg, Germany.
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38
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Meyer RE, Brown J, Beck L, Dawson DS. Mps1 promotes chromosome meiotic chromosome biorientation through Dam1. Mol Biol Cell 2017; 29:479-489. [PMID: 29237818 PMCID: PMC6014172 DOI: 10.1091/mbc.e17-08-0503] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 12/01/2017] [Accepted: 12/07/2017] [Indexed: 11/11/2022] Open
Abstract
During meiosis, chromosomes attach to microtubules at their kinetochores and are moved by microtubule depolymerization. The Mps1 kinase is essential for this process. Phosphorylation of Dam1 by Mps1 allows kinetochores to move processively poleward along microtubules during the biorientation process. In budding yeast meiosis, homologous chromosomes become linked by chiasmata and then move back and forth on the spindle until they are bioriented, with the kinetochores of the partners attached to microtubules from opposite spindle poles. Certain mutations in the conserved kinase, Mps1, result in catastrophic meiotic segregation errors but mild mitotic defects. We tested whether Dam1, a known substrate of Mps1, was necessary for its critical meiotic role. We found that kinetochore–microtubule attachments are established even when Dam1 is not phosphorylated by Mps1, but that Mps1 phosphorylation of Dam1 sustains those connections. But the meiotic defects when Dam1 is not phosphorylated are not nearly as catastrophic as when Mps1 is inactivated. The results demonstrate that one meiotic role of Mps1 is to stabilize connections that have been established between kinetochores and microtubles by phosphorylating Dam1.
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Affiliation(s)
- Régis E Meyer
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Jamin Brown
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Lindsay Beck
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Dean S Dawson
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104 .,Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
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39
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Komaki S, Schnittger A. The Spindle Assembly Checkpoint in Arabidopsis Is Rapidly Shut Off during Severe Stress. Dev Cell 2017; 43:172-185.e5. [PMID: 29065308 DOI: 10.1016/j.devcel.2017.09.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 07/18/2017] [Accepted: 09/21/2017] [Indexed: 12/24/2022]
Abstract
The spindle assembly checkpoint (SAC) in animals and yeast assures equal segregation of chromosomes during cell division. The prevalent occurrence of polyploidy in flowering plants together with the observation that many plants can be readily forced to double their genomes by application of microtubule drugs raises the question of whether plants have a proper SAC. Here, we provide a functional framework of the core SAC proteins in Arabidopsis. We reveal that Arabidopsis will delay mitosis in a SAC-dependent manner if the spindle is perturbed. However, we also show that the molecular architecture of the SAC is unique in plants. Moreover, the SAC is short-lived and cannot stay active for more than 2 hr, after which the cell cycle is reset. This resetting opens the possibility for genome duplications and raises the hypothesis that a rapid termination of a SAC-induced mitotic arrest provides an adaptive advantage for plants impacting plant genome evolution.
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Affiliation(s)
- Shinichiro Komaki
- University of Hamburg, Biozentrum Klein Flottbek, Department of Developmental Biology, Ohnhorststrasse 18, D-22609 Hamburg, Germany
| | - Arp Schnittger
- University of Hamburg, Biozentrum Klein Flottbek, Department of Developmental Biology, Ohnhorststrasse 18, D-22609 Hamburg, Germany.
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40
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Rad52 phosphorylation by Ipl1 and Mps1 contributes to Mps1 kinetochore localization and spindle assembly checkpoint regulation. Proc Natl Acad Sci U S A 2017; 114:E9261-E9270. [PMID: 29078282 DOI: 10.1073/pnas.1705261114] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rad52 is well known as a key factor in homologous recombination. Here, we report that Rad52 has functions unrelated to homologous recombination in Saccharomyces cerevisiae; it plays a role in the recruitment of Mps1 to the kinetochores and the maintenance of spindle assembly checkpoint (SAC) activity. Deletion of RAD52 causes various phenotypes related to the dysregulation of chromosome biorientation. Rad52 directly affects efficient operation of the SAC and accurate chromosome segregation. Remarkably, by using an in vitro kinase assay, we found that Rad52 is a substrate of Ipl1/Aurora and Mps1 in yeast and humans. Ipl1-dependent phosphorylation of Rad52 facilitates the kinetochore accumulation of Mps1, and Mps1-dependent phosphorylation of Rad52 is important for the accurate regulation of the SAC under spindle damage conditions. Taken together, our data provide detailed insights into the regulatory mechanism of chromosome biorientation by mitotic kinases.
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41
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Cheerambathur DK, Prevo B, Hattersley N, Lewellyn L, Corbett KD, Oegema K, Desai A. Dephosphorylation of the Ndc80 Tail Stabilizes Kinetochore-Microtubule Attachments via the Ska Complex. Dev Cell 2017; 41:424-437.e4. [PMID: 28535376 PMCID: PMC5572820 DOI: 10.1016/j.devcel.2017.04.013] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 03/16/2017] [Accepted: 04/19/2017] [Indexed: 12/24/2022]
Abstract
During cell division, genome inheritance is orchestrated by microtubule attachments formed at kinetochores of mitotic chromosomes. The primary microtubule coupler at the kinetochore, the Ndc80 complex, is regulated by Aurora kinase phosphorylation of its N-terminal tail. Dephosphorylation is proposed to stabilize kinetochore-microtubule attachments by strengthening electrostatic interactions of the tail with the microtubule lattice. Here, we show that removal of the Ndc80 tail, which compromises in vitro microtubule binding, has no effect on kinetochore-microtubule attachments in the Caenorhabditis elegans embryo. Despite this, preventing Aurora phosphorylation of the tail results in prematurely stable attachments that restrain spindle elongation. This premature stabilization requires the conserved microtubule-binding Ska complex, which enriches at attachment sites prior to anaphase onset to dampen chromosome motion. We propose that Ndc80-tail dephosphorylation promotes stabilization of kinetochore-microtubule attachments via the Ska complex and that this mechanism ensures accurate segregation by constraining chromosome motion following biorientation on the spindle.
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Affiliation(s)
- Dhanya K Cheerambathur
- Ludwig Institute for Cancer Research, CMM-E Room 3052, 9500 Gilman Drive, La Jolla, CA 92093-0653, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA.
| | - Bram Prevo
- Ludwig Institute for Cancer Research, CMM-E Room 3052, 9500 Gilman Drive, La Jolla, CA 92093-0653, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Neil Hattersley
- Ludwig Institute for Cancer Research, CMM-E Room 3052, 9500 Gilman Drive, La Jolla, CA 92093-0653, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Lindsay Lewellyn
- Department of Biological Sciences, Butler University, 4600 Sunset Boulevard, Indianapolis, IN 46208, USA
| | - Kevin D Corbett
- Ludwig Institute for Cancer Research, CMM-E Room 3052, 9500 Gilman Drive, La Jolla, CA 92093-0653, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Karen Oegema
- Ludwig Institute for Cancer Research, CMM-E Room 3052, 9500 Gilman Drive, La Jolla, CA 92093-0653, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Arshad Desai
- Ludwig Institute for Cancer Research, CMM-E Room 3052, 9500 Gilman Drive, La Jolla, CA 92093-0653, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA.
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42
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Matsuo Y, Maurer SP, Surrey T, Toda T. Purification and characterisation of the fission yeast Ndc80 complex. Protein Expr Purif 2017; 135:61-69. [PMID: 28502666 PMCID: PMC5489075 DOI: 10.1016/j.pep.2017.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 05/07/2017] [Accepted: 05/08/2017] [Indexed: 12/02/2022]
Abstract
The Ndc80 complex is a conserved outer kinetochore protein complex consisting of Ndc80 (Hec1), Nuf2, Spc24 and Spc25. This complex comprises a major, if not the sole, platform with which the plus ends of the spindle microtubules directly interact. In fission yeast, several studies indicate that multiple microtubule-associated proteins including the Dis1/chTOG microtubule polymerase and the Mal3/EB1 microtubule plus-end tracking protein directly or indirectly bind Ndc80, thereby ensuring stable kinetochore-microtubule attachment. However, the purification of the Ndc80 complex from this yeast has not been achieved, which hampers the in-depth investigation as to how the outer kinetochore attaches to the plus end of the spindle microtubule. Here we report the two-step purification of the fission yeast Ndc80 holo complex from bacteria. First, we purified separately two sub-complexes consisting of Ndc80-Nuf2 and Spc24-Spc25. Then, these two sub-complexes were mixed and applied to size-exclusion chromatography. The reconstituted Ndc80 holo complex is composed of four subunits with equal stoichiometry. The complex possesses microtubule-binding activity, and Total Internal Reflection Fluorescence (TIRF)-microscopy assays show that the complex binds the microtubule lattice. Interestingly, unlike the human complex, the fission yeast complex does not track depolymerising microtubule ends. Further analysis shows that under physiological ionic conditions, the Ndc80 holo complex does not detectably bind Dis1, but instead it interacts with Mal3/EB1, by which the Ndc80 complex tracks the growing microtubule plus end. This result substantiates the notion that the Ndc80 complex plays a crucial role in establishment of the dynamic kinetochore-microtubule interface by cooperating with chTOG and EB1. The Ndc80 complex is a conserved outer kinetochore complex. The fission yeast Ndc80 complex is purified from bacteria through a two-step purification scheme. The Ndc80 complex possesses microtubule-binding activity similar to those from other species. TIRF-microscopy assays show that the complex binds the microtubule lattice. The Ndc80 complex tracks the microtubule plus end when mixed with Mal3/EB1.
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Affiliation(s)
- Yuzy Matsuo
- Cell Regulation Laboratory, The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK; Synthetic and Systems Biochemistry of the Microtubule Cytoskeleton Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Sebastian P Maurer
- Synthetic and Systems Biochemistry of the Microtubule Cytoskeleton Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK; Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Thomas Surrey
- Synthetic and Systems Biochemistry of the Microtubule Cytoskeleton Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
| | - Takashi Toda
- Cell Regulation Laboratory, The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK; Hiroshima Research Center for Healthy Aging (HiHA), Department of Molecular Biotechnology, Graduate School of Advanced Science of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530, Japan.
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43
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Moura M, Osswald M, Leça N, Barbosa J, Pereira AJ, Maiato H, Sunkel CE, Conde C. Protein Phosphatase 1 inactivates Mps1 to ensure efficient Spindle Assembly Checkpoint silencing. eLife 2017; 6. [PMID: 28463114 PMCID: PMC5433843 DOI: 10.7554/elife.25366] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 04/29/2017] [Indexed: 12/13/2022] Open
Abstract
Faithfull genome partitioning during cell division relies on the Spindle Assembly Checkpoint (SAC), a conserved signaling pathway that delays anaphase onset until all chromosomes are attached to spindle microtubules. Mps1 kinase is an upstream SAC regulator that promotes the assembly of an anaphase inhibitor through a sequential multi-target phosphorylation cascade. Thus, the SAC is highly responsive to Mps1, whose activity peaks in early mitosis as a result of its T-loop autophosphorylation. However, the mechanism controlling Mps1 inactivation once kinetochores attach to microtubules and the SAC is satisfied remains unknown. Here we show in vitro and in Drosophila that Protein Phosphatase 1 (PP1) inactivates Mps1 by dephosphorylating its T-loop. PP1-mediated dephosphorylation of Mps1 occurs at kinetochores and in the cytosol, and inactivation of both pools of Mps1 during metaphase is essential to ensure prompt and efficient SAC silencing. Overall, our findings uncover a mechanism of SAC inactivation required for timely mitotic exit. DOI:http://dx.doi.org/10.7554/eLife.25366.001
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Affiliation(s)
- Margarida Moura
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Mariana Osswald
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Nelson Leça
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - João Barbosa
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - António J Pereira
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Helder Maiato
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,Departamento de Biomedicina, Unidade de Biologia Experimental, FMUP - Faculdade de Medicina da Universidade do Porto, Porto, Portugal
| | - Claudio E Sunkel
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,Departamento de Biologia Molecular, ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Porto, Portugal
| | - Carlos Conde
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
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44
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Choi M, Min YH, Pyo J, Lee CW, Jang CY, Kim JE. TC Mps1 12, a novel Mps1 inhibitor, suppresses the growth of hepatocellular carcinoma cells via the accumulation of chromosomal instability. Br J Pharmacol 2017; 174:1810-1825. [PMID: 28299790 DOI: 10.1111/bph.13782] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 03/01/2017] [Accepted: 03/05/2017] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Chromosomal instability is not only a hallmark of cancer but also an attractive therapeutic target. A diverse set of mitotic kinases maintains chromosomal stability. One of these is monopolar spindle 1 (Mps1, also known as TTK), which is essential for chromosome alignment and for the spindle assembly checkpoint (SAC). Pharmacological inhibition of Mps1 has been suggested as a cancer therapeutic; however, despite the existence of a novel Mps1 inhibitor, TC Mps1 12, no such studies have been performed. EXPERIMENTAL APPROACH The effects of TC Mps1 12 on cell viability, chromosome alignment, centrosome number, mitotic duration, apoptosis and SAC were determined in hepatocellular carcinoma (HCC) cells. In addition, the association of Mps1 expression with the overall survival of HCC patients was analysed. KEY RESULTS Treatment of human HCC cells with TC Mps1 12 led to chromosome misalignment and missegregation, and disorganization of centrosomes. Even in the presence of these errors, TC Mps1 12-treated cells overrode the SAC, resulting in a shortened mitotic duration and mitotic slippage. This mitotic catastrophe triggered apoptosis and, finally, inhibited the growth of HCC cells. In addition, the expression of the Mps1-encoding TTK gene was associated with poor overall survival of HCC patients. CONCLUSION AND IMPLICATIONS TC Mps1 12 results in the accumulation of chromosomal instabilities and mitotic catastrophe in HCC cells. Overall, these data demonstrate that the inhibition of Mps1 kinase using TC Mps1 12 is a promising therapeutic approach for liver cancer.
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Affiliation(s)
- Minji Choi
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Yoo Hong Min
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Jaehyuk Pyo
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Chang-Woo Lee
- Department of Molecular Cell Biology, School of Medicine, Sungkyunkwan University, Suwon, Republic of Korea
| | - Chang-Young Jang
- College of Pharmacy, Sookmyung Women's University, Seoul, Republic of Korea
| | - Ja-Eun Kim
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea.,East-West Medical Research Institute, Kyung Hee University, Seoul, Republic of Korea.,Department of Pharmacology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
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45
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Zheng H, Wu H, Pan X, Jin W, Li X. Aberrant Meiotic Modulation Partially Contributes to the Lower Germination Rate of Pollen Grains in Maize (Zea mays L.) Under Low Nitrogen Supply. PLANT & CELL PHYSIOLOGY 2017; 58:342-353. [PMID: 28007967 DOI: 10.1093/pcp/pcw195] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 11/08/2016] [Indexed: 06/06/2023]
Abstract
Pollen germination is an essential step towards successful pollination during maize reproduction. How low niutrogen (N) affects pollen germination remains an interesting biological question to be addressed. We found that only low N resulted in a significantly lower germination rate of pollen grains after 4 weeks of low N, phosphorus or potassium treatment in maize production. Importantly, cytological analysis showed 7-fold more micronuclei in male meiocytes under the low N treatment than in the control, indicating that the lower germination rate of pollen grains was partially due to numerous chromosome loss events resulting from preceding meiosis. The appearance of 10 bivalents in the control and low N cells at diakinesis suggested that chromosome pairing and recombination in meiosis I was not affected by low N. Further gene expression analysis revealed dramatic down-regulation of Nuclear Division Cycle 80 (Ndc80) and Regulator of Chromosome Condensation 1 (Rcc1-1) expression and up-regulation of Cell Division Cycle 20 (Cdc20-1) expression, although no significant difference in the expression level of kinetochore foundation proteins Centromeric Histone H3 (Cenh3) and Centromere Protein C (Cenpc) and cohesion regulators Recombination 8 (Rec8) and Shugoshin (Sgo1) was observed. Aberrant modulation of three key meiotic regulators presumably resulted in a high likelihood of erroneous chromosome segregation, as testified by pronounced lagging chromosomes at anaphase I or cell cycle disruption at meiosis II. Thus, we proposed a cytogenetic mechanism whereby low N affects male meiosis and causes a higher chromosome loss frequency and eventually a lower germination rate of pollen grains in a staple crop plant.
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Affiliation(s)
- Hongyan Zheng
- Key Laboratory of Plant-Soil Interactions of the Ministry of Education, and Department of Plant Nutrition, China Agricultural University, Beijing, China
| | - Huamao Wu
- Key Laboratory of Plant-Soil Interactions of the Ministry of Education, and Department of Plant Nutrition, China Agricultural University, Beijing, China
| | - Xiaoying Pan
- Key Laboratory of Plant-Soil Interactions of the Ministry of Education, and Department of Plant Nutrition, China Agricultural University, Beijing, China
| | - Weiwei Jin
- The National Maize Center, and Department of Plant Genetics and Breeding, China Agricultural University, Beijing, China
| | - Xuexian Li
- Key Laboratory of Plant-Soil Interactions of the Ministry of Education, and Department of Plant Nutrition, China Agricultural University, Beijing, China
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46
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Musacchio A, Desai A. A Molecular View of Kinetochore Assembly and Function. BIOLOGY 2017; 6:E5. [PMID: 28125021 PMCID: PMC5371998 DOI: 10.3390/biology6010005] [Citation(s) in RCA: 310] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 01/16/2017] [Accepted: 01/17/2017] [Indexed: 12/15/2022]
Abstract
Kinetochores are large protein assemblies that connect chromosomes to microtubules of the mitotic and meiotic spindles in order to distribute the replicated genome from a mother cell to its daughters. Kinetochores also control feedback mechanisms responsible for the correction of incorrect microtubule attachments, and for the coordination of chromosome attachment with cell cycle progression. Finally, kinetochores contribute to their own preservation, across generations, at the specific chromosomal loci devoted to host them, the centromeres. They achieve this in most species by exploiting an epigenetic, DNA-sequence-independent mechanism; notable exceptions are budding yeasts where a specific sequence is associated with centromere function. In the last 15 years, extensive progress in the elucidation of the composition of the kinetochore and the identification of various physical and functional modules within its substructure has led to a much deeper molecular understanding of kinetochore organization and the origins of its functional output. Here, we provide a broad summary of this progress, focusing primarily on kinetochores of humans and budding yeast, while highlighting work from other models, and present important unresolved questions for future studies.
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Affiliation(s)
- Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn Straße 11, Dortmund 44227, Germany.
- Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen 45117, Germany.
| | - Arshad Desai
- Ludwig Institute for Cancer Research, La Jolla, CA 92093, USA.
- Department of Cellular & Molecular Medicine, 9500 Gilman Dr., La Jolla, CA 92093, USA.
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47
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Affiliation(s)
- Jakob Nilsson
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej, Copenhagen, Denmark
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48
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Chmielewska AE, Tang NH, Toda T. The hairpin region of Ndc80 is important for the kinetochore recruitment of Mph1/MPS1 in fission yeast. Cell Cycle 2016; 15:740-7. [PMID: 26900649 PMCID: PMC4845937 DOI: 10.1080/15384101.2016.1148842] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The establishment of proper kinetochore-microtubule attachments facilitates faithful chromosome segregation. Incorrect attachments activate the spindle assembly checkpoint (SAC), which blocks anaphase onset via recruitment of a cohort of SAC components (Mph1/MPS1, Mad1, Mad2, Mad3/BubR1, Bub1 and Bub3) to kinetochores. KNL1, a component of the outer kinetochore KMN network (KNL1/Mis12 complex/Ndc80 complex), acts as a platform for Bub1 and Bub3 localization upon its phosphorylation by Mph1/MPS1. The Ndc80 protein, a major microtubule-binding site, is critical for MPS1 localization to the kinetochores in mammalian cells. Here we characterized the newly isolated mutant ndc80-AK01 in fission yeast, which contains a single point mutation within the hairpin region. This hairpin connects the preceding calponin-homology domain with the coiled-coil region. ndc80-AK01 was hypersensitive to microtubule depolymerizing reagents with no apparent growth defects without drugs. Subsequent analyses indicated that ndc80-AK01 is defective in SAC signaling, as mutant cells proceeded into lethal cell division in the absence of microtubules. Under mitotic arrest conditions, all SAC components (Ark1/Aurora B, Mph1, Bub1, Bub3, Mad3, Mad2 and Mad1) did not localize to the kinetochore. Further genetic analyses indicated that the Ndc80 hairpin region might act as a platform for the kinetochore recruitment of Mph1, which is one of the most upstream SAC components in the hierarchy. Intriguingly, artificial tethering of Mph1 to the kinetochore fully restored checkpoint signaling in ndc80-AK01 cells, further substantiating the notion that Ndc80 is a kinetochore platform for Mph1. The hairpin region of Ndc80, therefore, plays a critical role in kinetochore recruitment of Mph1.
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Affiliation(s)
| | - Ngang Heok Tang
- a The Francis Crick Institute, Lincoln's Inn Fields , London , United Kingdom
| | - Takashi Toda
- a The Francis Crick Institute, Lincoln's Inn Fields , London , United Kingdom.,b Hiroshima Research Center for Healthy Aging (HiHA), Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University , Higashi-Hiroshima , Japan
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49
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Joglekar AP. A Cell Biological Perspective on Past, Present and Future Investigations of the Spindle Assembly Checkpoint. BIOLOGY 2016; 5:biology5040044. [PMID: 27869759 PMCID: PMC5192424 DOI: 10.3390/biology5040044] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/10/2016] [Accepted: 11/14/2016] [Indexed: 12/04/2022]
Abstract
The spindle assembly checkpoint (SAC) is a quality control mechanism that ensures accurate chromosome segregation during cell division. It consists of a mechanochemical signal transduction mechanism that senses the attachment of chromosomes to the spindle, and a signaling cascade that inhibits cell division if one or more chromosomes are not attached. Extensive investigations of both these component systems of the SAC have synthesized a comprehensive understanding of the underlying molecular mechanisms. This review recounts the milestone results that elucidated the SAC, compiles a simple model of the complex molecular machinery underlying the SAC, and highlights poorly understood facets of the biochemical design and cell biological operation of the SAC that will drive research forward in the near future.
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Affiliation(s)
- Ajit P Joglekar
- Cell & Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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50
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Manic G, Corradi F, Sistigu A, Siteni S, Vitale I. Molecular Regulation of the Spindle Assembly Checkpoint by Kinases and Phosphatases. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 328:105-161. [PMID: 28069132 DOI: 10.1016/bs.ircmb.2016.08.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The spindle assembly checkpoint (SAC) is a surveillance mechanism contributing to the preservation of genomic stability by monitoring the microtubule attachment to, and/or the tension status of, each kinetochore during mitosis. The SAC halts metaphase to anaphase transition in the presence of unattached and/or untensed kinetochore(s) by releasing the mitotic checkpoint complex (MCC) from these improperly-oriented kinetochores to inhibit the anaphase-promoting complex/cyclosome (APC/C). The reversible phosphorylation of a variety of substrates at the kinetochore by antagonistic kinases and phosphatases is one major signaling mechanism for promptly turning on or turning off the SAC. In such a complex network, some kinases act at the apex of the SAC cascade by either generating (monopolar spindle 1, MPS1/TTK and likely polo-like kinase 1, PLK1), or contributing to generate (Aurora kinase B) kinetochore phospho-docking sites for the hierarchical recruitment of the SAC proteins. Aurora kinase B, MPS1 and budding uninhibited by benzimidazoles 1 (BUB1) also promote sister chromatid biorientation by modulating kinetochore microtubule stability. Moreover, MPS1, BUB1, and PLK1 seem to play key roles in APC/C inhibition by mechanisms dependent and/or independent on MCC assembly. The protein phosphatase 1 and 2A (PP1 and PP2A) are recruited to kinetochores to oppose kinase activity. These phosphatases reverse the phosphorylation of kinetochore targets promoting the microtubule attachment stabilization, sister kinetochore biorientation and SAC silencing. The kinase-phosphatase network is crucial as it renders the SAC a dynamic, graded-signaling, high responsive, and robust process thereby ensuring timely anaphase onset and preventing the generation of proneoplastic aneuploidy.
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Affiliation(s)
- G Manic
- Regina Elena National Cancer Institute, Rome, Italy.
| | - F Corradi
- Department of Biology, University of Rome "Tor Vergata", Rome, Italy
| | - A Sistigu
- Regina Elena National Cancer Institute, Rome, Italy
| | - S Siteni
- Regina Elena National Cancer Institute, Rome, Italy; Department of Biology, University of Rome "Roma Tre", Rome, Italy
| | - I Vitale
- Regina Elena National Cancer Institute, Rome, Italy; Department of Biology, University of Rome "Tor Vergata", Rome, Italy.
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