1
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Sethi S, Ghetti S, Cmentowski V, Guerriere TB, Stege P, Piano V, Musacchio A. Interplay of kinetochores and catalysts drives rapid assembly of the mitotic checkpoint complex. Nat Commun 2025; 16:4823. [PMID: 40410156 PMCID: PMC12102207 DOI: 10.1038/s41467-025-59970-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2024] [Accepted: 05/09/2025] [Indexed: 05/25/2025] Open
Abstract
The spindle assembly checkpoint (SAC) ensures mitotic exit occurs only after sister chromatid biorientation, but how this coordination is mechanistically achieved remains unclear. Kinetochores, the megadalton complexes linking chromosomes to spindle microtubules, contribute to SAC signaling. However, whether they act solely as docking platforms or actively promote the co-orientation of SAC catalysts such as MAD1:MAD2 and BUB1:BUB3 remains unresolved. Here, we reconstitute kinetochores and SAC signaling in vitro to address this question. We engineer recombinant kinetochore particles that recruit core SAC components and trigger checkpoint signaling upon Rapamycin induction, and test their function using a panel of targeted mutants. At approximately physiological concentrations of SAC proteins, kinetochores are essential for efficient mitotic checkpoint complex (MCC) assembly, the key effector of SAC signaling. Our results suggest that kinetochores serve not only as structural hubs but also as catalytic platforms that concentrate and spatially organize SAC components to accelerate MCC formation and ensure timely checkpoint activation.
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Affiliation(s)
- Suruchi Sethi
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227, Dortmund, Germany
- Eradigm Consulting, 6-7 St Cross St, London, EC1N 8UB, UK
| | - Sabrina Ghetti
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227, Dortmund, Germany
| | - Verena Cmentowski
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227, Dortmund, Germany
| | - Teresa Benedetta Guerriere
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227, Dortmund, Germany
| | - Patricia Stege
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227, Dortmund, Germany
| | - Valentina Piano
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227, Dortmund, Germany
- Institute of Human Genetics, Center of Molecular Medicine Cologne (CMMC), University of Cologne, Robert-Koch Str. 21 50931, Cologne, Germany
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227, Dortmund, Germany.
- Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen, Germany.
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2
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Lima I, Borges F, Pombinho A, Chavarria D. The spindle assembly checkpoint: Molecular mechanisms and kinase-targeted drug discovery. Drug Discov Today 2025; 30:104355. [PMID: 40216293 DOI: 10.1016/j.drudis.2025.104355] [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: 01/17/2025] [Revised: 03/27/2025] [Accepted: 04/04/2025] [Indexed: 04/20/2025]
Abstract
The spindle assembly checkpoint (SAC) is a surveillance mechanism required for the fidelity of chromosome segregation, ensuring that anaphase is not initiated until all chromosomes are properly attached to the mitotic spindle. In cancer cells, SAC inactivation leads to aneuploidy beyond the cell's adaptation, culminating in cell death. This review provides a concise overview of the SAC signaling process and properties. Recent drug discovery strategies to selectively target kinases, particularly Aurora B and monopolar spindle kinase (MPS1), aimed at developing innovative anticancer agents able to override SAC are also presented.
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Affiliation(s)
- Inês Lima
- CIQUP-IMS - Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, R. Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Fernanda Borges
- CIQUP-IMS - Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, R. Campo Alegre s/n, 4169-007 Porto, Portugal
| | - António Pombinho
- i3S, Institute for Research and Innovation in Health, University of Porto 4200-135 Porto, Portugal; IBMC, Institute for Molecular and Cell Biology, University of Porto 4200-135 Porto, Portugal
| | - Daniel Chavarria
- CIQUP-IMS - Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, R. Campo Alegre s/n, 4169-007 Porto, Portugal.
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3
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Yu CWH, Fischer ES, Greener JG, Yang J, Zhang Z, Freund SMV, Barford D. Molecular mechanism of Mad2 conformational conversion promoted by the Mad2-interaction motif of Cdc20. Protein Sci 2025; 34:e70099. [PMID: 40143766 PMCID: PMC11947619 DOI: 10.1002/pro.70099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 02/25/2025] [Accepted: 02/28/2025] [Indexed: 03/28/2025]
Abstract
During mitosis, unattached kinetochores trigger the spindle assembly checkpoint by promoting the assembly of the mitotic checkpoint complex, a heterotetramer comprising Mad2, Cdc20, BubR1, and Bub3. Critical to this process is the kinetochore-mediated catalysis of an intrinsically slow conformational conversion of Mad2 from an open (O-Mad2) inactive state to a closed (C-Mad2) active state bound to Cdc20. These Mad2 conformational changes involve substantial remodeling of the N-terminal β1 strand and C-terminal β7/β8 hairpin. In vitro, the Mad2-interaction motif (MIM) of Cdc20 (Cdc20MIM) triggers the rapid conversion of O-Mad2 to C-Mad2, effectively removing the kinetic barrier for MCC assembly. How Cdc20MIM directly induces Mad2 conversion remains unclear. In this study, we demonstrate that the Cdc20MIM-binding site is inaccessible in O-Mad2. Time-resolved NMR and molecular dynamics simulations show how Mad2 conversion involves sequential conformational changes of flexible structural elements in O-Mad2, orchestrated by Cdc20MIM. Conversion is initiated by the β7/β8 hairpin of O-Mad2 transiently unfolding to expose a nascent Cdc20MIM-binding site. Engagement of Cdc20MIM to this site promotes the release of the β1 strand. We propose that initial conformational changes of the β7/β8 hairpin allow binding of Cdc20MIM to a transient intermediate state of Mad2, thereby lowering the kinetic barrier to Mad2 conversion.
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Affiliation(s)
- Conny W. H. Yu
- MRC Laboratory of Molecular BiologyCambridgeUK
- Present address:
EMBL European Bioinformatics InstituteWellcome Genome CampusHinxtonCB10 1SDUK
| | | | - Joe G. Greener
- MRC Laboratory of Molecular BiologyCambridgeUK
- Present address:
Monod BioSeattleWashingtonUS
| | - Jing Yang
- MRC Laboratory of Molecular BiologyCambridgeUK
| | - Ziguo Zhang
- MRC Laboratory of Molecular BiologyCambridgeUK
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4
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Kixmoeller K, Tarasovetc EV, Mer E, Chang YW, Black BE. Centromeric chromatin clearings demarcate the site of kinetochore formation. Cell 2025; 188:1280-1296.e19. [PMID: 39855195 PMCID: PMC11890969 DOI: 10.1016/j.cell.2024.12.025] [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: 05/06/2024] [Revised: 11/24/2024] [Accepted: 12/18/2024] [Indexed: 01/27/2025]
Abstract
The centromere is the chromosomal locus that recruits the kinetochore, directing faithful propagation of the genome during cell division. Using cryo-ET on human mitotic chromosomes, we reveal a distinctive architecture at the centromere: clustered 20- to 25-nm nucleosome-associated complexes within chromatin clearings that delineate them from surrounding chromatin. Centromere components CENP-C and CENP-N are each required for the integrity of the complexes, while CENP-C is also required to maintain the chromatin clearing. We find that CENP-C is required in mitosis, not just for kinetochore assembly, likely reflecting its role in organizing the inner kinetochore during chromosome segregation. We further visualize the scaffold of the fibrous corona, a structure amplified at unattached kinetochores, revealing crescent-shaped parallel arrays of fibrils extending >1 μm. Thus, we reveal how the organization of centromeric chromatin creates a clearing at the site of kinetochore formation as well as the nature of kinetochore amplification mediated by corona fibrils.
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Affiliation(s)
- Kathryn Kixmoeller
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Biochemistry, Biophysics, Chemical Biology Graduate Group, University of Pennsylvania, Philadelphia, PA, USA; Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ekaterina V Tarasovetc
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Elie Mer
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Biochemistry, Biophysics, Chemical Biology Graduate Group, University of Pennsylvania, Philadelphia, PA, USA; Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Yi-Wei Chang
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Biochemistry, Biophysics, Chemical Biology Graduate Group, University of Pennsylvania, Philadelphia, PA, USA; Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Ben E Black
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Biochemistry, Biophysics, Chemical Biology Graduate Group, University of Pennsylvania, Philadelphia, PA, USA; Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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5
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Pun R, North BJ. Role of spindle assembly checkpoint proteins in gametogenesis and embryogenesis. Front Cell Dev Biol 2025; 12:1491394. [PMID: 39911185 PMCID: PMC11794522 DOI: 10.3389/fcell.2024.1491394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2024] [Accepted: 12/17/2024] [Indexed: 02/07/2025] Open
Abstract
The spindle assembly checkpoint (SAC) is a surveillance mechanism that prevents uneven segregation of sister chromatids between daughter cells during anaphase. This essential regulatory checkpoint prevents aneuploidy which can lead to various congenital defects observed in newborns. Many studies have been carried out to elucidate the role of proteins involved in the SAC as well as the function of the checkpoint during gametogenesis and embryogenesis. In this review, we discuss the role of SAC proteins in regulating both meiotic and mitotic cell division along with several factors that influence the SAC strength in various species. Finally, we outline the role of SAC proteins and the consequences of their absence or insufficiency on proper gametogenesis and embryogenesis in vivo.
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Affiliation(s)
| | - Brian J. North
- Biomedical Sciences Department, School of Medicine, Creighton University, Omaha, NE, United States
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6
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Ibrahim B. Dynamics of spindle assembly and position checkpoints: Integrating molecular mechanisms with computational models. Comput Struct Biotechnol J 2025; 27:321-332. [PMID: 39897055 PMCID: PMC11782880 DOI: 10.1016/j.csbj.2024.12.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2024] [Revised: 12/18/2024] [Accepted: 12/20/2024] [Indexed: 02/04/2025] Open
Abstract
Mitotic checkpoints orchestrate cell division through intricate molecular networks that ensure genomic stability. While experimental research has uncovered key aspects of checkpoint function, the complexity of protein interactions and spatial dynamics necessitates computational modeling for a deeper, system-level understanding. This review explores mathematical frameworks-from ordinary differential equations to stochastic simulations, which reveal checkpoint dynamics across multiple scales, encompassing models ranging from simple protein interactions to whole-system simulations with thousands of parameters. These approaches have elucidated fundamental properties, including bistable switches driving spindle assembly checkpoint (SAC) activation, spatial organization principles underlying spindle position checkpoint (SPOC) signaling, and critical system-level features ensuring checkpoint robustness. This study evaluates diverse modeling approaches, from rule-based models to chemical organization theory, highlighting their successful application in predicting protein localization patterns and checkpoint response dynamics validated through live-cell imaging. Contemporary challenges persist in integrating spatial and temporal scales, refining parameter estimation, and enhancing spatial modeling fidelity. However, recent advances in single-molecule imaging, data-driven algorithms, and machine learning techniques, particularly deep learning for parameter optimization, present transformative opportunities for improving model accuracy and predictive power. By bridging molecular mechanisms with system-level behaviors through validated computational frameworks, this review offers a comprehensive perspective on the mathematical modeling of cell cycle control, with practical implications for cancer research and therapeutic development.
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Affiliation(s)
- Bashar Ibrahim
- Department of Mathematics & Natural Sciences and Centre for Applied Mathematics & Bioinformatics, Gulf University for Science and Technology, Hawally, 32093, Kuwait
- Department of Mathematics and Computer Science, Friedrich Schiller University Jena, Ernst-Abbe-Platz 2, Jena, 07743, Germany
- European Virus Bioinformatics Center, Leutragraben 1, Jena, 07743, Germany
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7
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Chen C, Li P, Fan G, Yang E, Jing S, Shi Y, Gong Y, Zhang L, Wang Z. Role of TRIP13 in human cancer development. Mol Biol Rep 2024; 51:1088. [PMID: 39436503 DOI: 10.1007/s11033-024-10012-x] [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: 08/21/2024] [Accepted: 10/11/2024] [Indexed: 10/23/2024]
Abstract
As an AAA + ATPase, thyroid hormone receptor interacting protein 13 (TRIP13) primarily functions in DNA double-strand break repair, chromosome recombination, and cell cycle checkpoint regulation; aberrant expression of TRIP13 can result in chromosomal instability (CIN). According to recent research, TRIP13 is aberrantly expressed in a variety of cancers, and a patient's poor prognosis and tumor stage are strongly correlated with high expression of TRIP13. Tumor cell and subcutaneous xenograft growth can be markedly inhibited by TRIP13 knockdown or TRIP13 inhibitor administration. In the initiation and advancement of human malignancies, TRIP13 seems to function as an oncogene. Based on available data, TRIP13 may function as a biological target and biomarker for cancer. The creation of inhibitors that specifically target TRIP13 may present novel approaches to treating cancer.
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Affiliation(s)
- Chaohu Chen
- Institute of Urology, Lanzhou University Second Hospital, NO.82 Linxia Road, Chengguan District Lanzhou, Lanzhou, Gansu Province, 730030, PR China
- Gansu Province Clinical Research Center for urinary system disease, Lanzhou, Gansu Province, 730030, PR China
| | - Pan Li
- Institute of Urology, Lanzhou University Second Hospital, NO.82 Linxia Road, Chengguan District Lanzhou, Lanzhou, Gansu Province, 730030, PR China
- Gansu Province Clinical Research Center for urinary system disease, Lanzhou, Gansu Province, 730030, PR China
| | - Guangrui Fan
- Institute of Urology, Lanzhou University Second Hospital, NO.82 Linxia Road, Chengguan District Lanzhou, Lanzhou, Gansu Province, 730030, PR China
- Gansu Province Clinical Research Center for urinary system disease, Lanzhou, Gansu Province, 730030, PR China
| | - Enguang Yang
- Institute of Urology, Lanzhou University Second Hospital, NO.82 Linxia Road, Chengguan District Lanzhou, Lanzhou, Gansu Province, 730030, PR China
- Gansu Province Clinical Research Center for urinary system disease, Lanzhou, Gansu Province, 730030, PR China
| | - Suoshi Jing
- Institute of Urology, Lanzhou University Second Hospital, NO.82 Linxia Road, Chengguan District Lanzhou, Lanzhou, Gansu Province, 730030, PR China
- Gansu Province Clinical Research Center for urinary system disease, Lanzhou, Gansu Province, 730030, PR China
| | - Yibo Shi
- Institute of Urology, Lanzhou University Second Hospital, NO.82 Linxia Road, Chengguan District Lanzhou, Lanzhou, Gansu Province, 730030, PR China
- Gansu Province Clinical Research Center for urinary system disease, Lanzhou, Gansu Province, 730030, PR China
| | - Yuwen Gong
- Institute of Urology, Lanzhou University Second Hospital, NO.82 Linxia Road, Chengguan District Lanzhou, Lanzhou, Gansu Province, 730030, PR China
- Gansu Province Clinical Research Center for urinary system disease, Lanzhou, Gansu Province, 730030, PR China
| | - Luyang Zhang
- Institute of Urology, Lanzhou University Second Hospital, NO.82 Linxia Road, Chengguan District Lanzhou, Lanzhou, Gansu Province, 730030, PR China
- Gansu Province Clinical Research Center for urinary system disease, Lanzhou, Gansu Province, 730030, PR China
| | - Zhiping Wang
- Institute of Urology, Lanzhou University Second Hospital, NO.82 Linxia Road, Chengguan District Lanzhou, Lanzhou, Gansu Province, 730030, PR China.
- Gansu Province Clinical Research Center for urinary system disease, Lanzhou, Gansu Province, 730030, PR China.
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8
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Zhang G, Yang R, Wang B, Yan Q, Zhao P, Zhang J, Su W, Yang L, Cui H. TRIP13 regulates progression of gastric cancer through stabilising the expression of DDX21. Cell Death Dis 2024; 15:622. [PMID: 39187490 PMCID: PMC11347623 DOI: 10.1038/s41419-024-07012-x] [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: 02/17/2024] [Revised: 08/13/2024] [Accepted: 08/16/2024] [Indexed: 08/28/2024]
Abstract
GC (Gastric cancer) is one of the most common malignant tumours, with over 95% of gastric cancer patients being adenocarcinoma and most gastric cancer patients having no apparent symptoms in the early stages. Finding biomarkers for early screening of gastric cancer and exploring new targets for gastric cancer treatment are urgent problems to be solved in the treatment of gastric cancer, with significant clinical outcomes for the survival rate of gastric cancer patients. The AAA+ family ATPase thyroid hormone receptor-interacting protein 13 (TRIP13) has been reported to play an essential role in developing various tumours. However, the biological function and molecular mechanism of TRIP13 in gastric cancer remain unclear. This study confirms that TRIP13 is highly expressed in gastric cancer tissue samples and that TRIP13 participates in the proliferation, migration, invasion in vitro, and tumourigenesis and metastasis in vivo of gastric cancer cells. Mechanistically, this study confirms that TRIP13 directly interacts with DDX21 and stabilises its expression by restraining its ubiquitination degradation, thereby promoting gastric cancer progression. Additionally, histone deacetylase 1 (HDAC1) is an upstream factor of TRIP13, which could target the TRIP13 promoter region to promote the proliferation, migration, and invasion of gastric cancer cells. These results indicate that TRIP13 serve is a promising biomarker for the treating of gastric cancer patients, and the HDAC1-TRIP13/DDX21 axis might provide a solid theoretical basis for clinical treatment of gastric cancer patients.
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Affiliation(s)
- Guanghui Zhang
- Medical College, Henan University of Chinese Medicine, Zhengzhou, China.
| | - Rui Yang
- Biomedical Laboratory, School of Medicine, Liaocheng University, Liaocheng, China
| | - Baiyan Wang
- Medical College, Henan University of Chinese Medicine, Zhengzhou, China
| | - Qiujin Yan
- Medical College, Henan University of Chinese Medicine, Zhengzhou, China
| | - Peiyuan Zhao
- Medical College, Henan University of Chinese Medicine, Zhengzhou, China
| | - Jiaming Zhang
- Medical College, Henan University of Chinese Medicine, Zhengzhou, China
| | - Weiyu Su
- Medical College, Henan University of Chinese Medicine, Zhengzhou, China
| | - Lianhe Yang
- Medical College, Henan University of Chinese Medicine, Zhengzhou, China
| | - Hongjuan Cui
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China.
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9
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Karbon G, Schuler F, Braun VZ, Eichin F, Haschka M, Drach M, Sotillo R, Geley S, Spierings DC, Tijhuis AE, Foijer F, Villunger A. Chronic spindle assembly checkpoint activation causes myelosuppression and gastrointestinal atrophy. EMBO Rep 2024; 25:2743-2772. [PMID: 38806674 PMCID: PMC11169569 DOI: 10.1038/s44319-024-00160-3] [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: 09/07/2023] [Revised: 04/30/2024] [Accepted: 05/06/2024] [Indexed: 05/30/2024] Open
Abstract
Interference with microtubule dynamics in mitosis activates the spindle assembly checkpoint (SAC) to prevent chromosome segregation errors. The SAC induces mitotic arrest by inhibiting the anaphase-promoting complex (APC) via the mitotic checkpoint complex (MCC). The MCC component MAD2 neutralizes the critical APC cofactor, CDC20, preventing exit from mitosis. Extended mitotic arrest can promote mitochondrial apoptosis and caspase activation. However, the impact of mitotic cell death on tissue homeostasis in vivo is ill-defined. By conditional MAD2 overexpression, we observe that chronic SAC activation triggers bone marrow aplasia and intestinal atrophy in mice. While myelosuppression can be compensated for, gastrointestinal atrophy is detrimental. Remarkably, deletion of pro-apoptotic Bim/Bcl2l11 prevents gastrointestinal syndrome, while neither loss of Noxa/Pmaip or co-deletion of Bid and Puma/Bbc3 has such a protective effect, identifying BIM as rate-limiting apoptosis effector in mitotic cell death of the gastrointestinal epithelium. In contrast, only overexpression of anti-apoptotic BCL2, but none of the BH3-only protein deficiencies mentioned above, can mitigate myelosuppression. Our findings highlight tissue and cell-type-specific survival dependencies in response to SAC perturbation in vivo.
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Affiliation(s)
- Gerlinde Karbon
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Fabian Schuler
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Vincent Z Braun
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Felix Eichin
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Manuel Haschka
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Mathias Drach
- Dermatology, General Hospital, University Hospital Vienna, Vienna, Austria
| | - Rocio Sotillo
- German Cancer Research Center (DKFZ), Division of Molecular Thoracic Oncology, Heidelberg, Germany
| | - Stephan Geley
- Institute for Pathophysiology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Diana Cj Spierings
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, 9713 AV, Groningen, The Netherlands
| | - Andrea E Tijhuis
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, 9713 AV, Groningen, The Netherlands
| | - Floris Foijer
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, 9713 AV, Groningen, The Netherlands
| | - Andreas Villunger
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria.
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090, Vienna, Austria.
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10
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Kixmoeller K, Chang YW, Black BE. Centromeric chromatin clearings demarcate the site of kinetochore formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.26.591177. [PMID: 38712116 PMCID: PMC11071481 DOI: 10.1101/2024.04.26.591177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
The centromere is the chromosomal locus that recruits the kinetochore, directing faithful propagation of the genome during cell division. The kinetochore has been interrogated by electron microscopy since the middle of the last century, but with methodologies that compromised fine structure. Using cryo-ET on human mitotic chromosomes, we reveal a distinctive architecture at the centromere: clustered 20-25 nm nucleosome-associated complexes within chromatin clearings that delineate them from surrounding chromatin. Centromere components CENP-C and CENP-N are each required for the integrity of the complexes, while CENP-C is also required to maintain the chromatin clearing. We further visualize the scaffold of the fibrous corona, a structure amplified at unattached kinetochores, revealing crescent-shaped parallel arrays of fibrils that extend >1 μm. Thus, we reveal how the organization of centromeric chromatin creates a clearing at the site of kinetochore formation as well as the nature of kinetochore amplification mediated by corona fibrils.
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Affiliation(s)
- Kathryn Kixmoeller
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, PA, USA
- Biochemistry Biophysics Chemical Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, PA, USA
- Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, PA, USA
- Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, PA, USA
- Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, PA, USA
| | - Yi-Wei Chang
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, PA, USA
- Biochemistry Biophysics Chemical Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, PA, USA
- Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, PA, USA
| | - Ben E. Black
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, PA, USA
- Biochemistry Biophysics Chemical Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, PA, USA
- Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, PA, USA
- Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, PA, USA
- Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, PA, USA
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11
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Iglesias-Romero AB, Soto T, Flor-Parra I, Salas-Pino S, Ruiz-Romero G, Gould KL, Cansado J, Daga RR. MAPK-dependent control of mitotic progression in S. pombe. BMC Biol 2024; 22:71. [PMID: 38523261 PMCID: PMC10962199 DOI: 10.1186/s12915-024-01865-6] [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: 02/25/2023] [Accepted: 03/08/2024] [Indexed: 03/26/2024] Open
Abstract
BACKGROUND Mitogen-activated protein kinases (MAPKs) preserve cell homeostasis by transducing physicochemical fluctuations of the environment into multiple adaptive responses. These responses involve transcriptional rewiring and the regulation of cell cycle transitions, among others. However, how stress conditions impinge mitotic progression is largely unknown. The mitotic checkpoint is a surveillance mechanism that inhibits mitotic exit in situations of defective chromosome capture, thus preventing the generation of aneuploidies. In this study, we investigate the role of MAPK Pmk1 in the regulation of mitotic exit upon stress. RESULTS We show that Schizosaccharomyces pombe cells lacking Pmk1, the MAP kinase effector of the cell integrity pathway (CIP), are hypersensitive to microtubule damage and defective in maintaining a metaphase arrest. Epistasis analysis suggests that Pmk1 is involved in maintaining spindle assembly checkpoint (SAC) signaling, and its deletion is additive to the lack of core SAC components such as Mad2 and Mad3. Strikingly, pmk1Δ cells show up to twofold increased levels of the anaphase-promoting complex (APC/C) activator Cdc20Slp1 during unperturbed growth. We demonstrate that Pmk1 physically interacts with Cdc20Slp1 N-terminus through a canonical MAPK docking site. Most important, the Cdc20Slp1 pool is rapidly degraded in stressed cells undergoing mitosis through a mechanism that requires MAPK activity, Mad3, and the proteasome, thus resulting in a delayed mitotic exit. CONCLUSIONS Our data reveal a novel function of MAPK in preventing mitotic exit and activation of cytokinesis in response to stress. The regulation of Cdc20Slp1 turnover by MAPK Pmk1 provides a key mechanism by which the timing of mitotic exit can be adjusted relative to environmental conditions.
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Affiliation(s)
| | - Terersa Soto
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, Murcia, 30071, Spain
| | - Ignacio Flor-Parra
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide, Seville, 41013, Spain
| | - Silvia Salas-Pino
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide, Seville, 41013, Spain
| | - Gabriel Ruiz-Romero
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide, Seville, 41013, Spain
| | - Kathleen L Gould
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, 37240, USA
| | - José Cansado
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, Murcia, 30071, Spain.
| | - Rafael R Daga
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide, Seville, 41013, Spain.
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12
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Nguyen A, Faesen AC. The role of the HORMA domain proteins ATG13 and ATG101 in initiating autophagosome biogenesis. FEBS Lett 2024; 598:114-126. [PMID: 37567770 DOI: 10.1002/1873-3468.14717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 08/13/2023]
Abstract
Autophagy is a process of regulated degradation. It eliminates damaged and unnecessary cellular components by engulfing them with a de novo-generated organelle: the double-membrane autophagosome. The past three decades have provided us with a detailed parts list of the autophagy initiation machinery, have developed important insights into how these processes function and have identified regulatory proteins. It is now clear that autophagosome biogenesis requires the timely assembly of a complex machinery. However, it is unclear how a putative stable machine is assembled and disassembled and how the different parts cooperate to perform its overall function. Although they have long been somewhat enigmatic in their precise role, HORMA domain proteins (first identified in Hop1p, Rev7p and MAD2 proteins) autophagy-related protein 13 (ATG13) and ATG101 of the ULK-kinase complex have emerged as important coordinators of the autophagy-initiating subcomplexes. Here, we will particularly focus on ATG13 and ATG101 and the role of their unusual metamorphosis in initiating autophagosome biogenesis. We will also explore how this metamorphosis could potentially be purposefully rate-limiting and speculate on how it could regulate the spontaneous self-assembly of the autophagy-initiating machinery.
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Affiliation(s)
- Anh Nguyen
- Laboratory of Biochemistry of Signal Dynamics, Max-Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Alex C Faesen
- Laboratory of Biochemistry of Signal Dynamics, Max-Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
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13
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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: 102] [Impact Index Per Article: 51.0] [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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14
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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: 13] [Impact Index Per Article: 4.3] [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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15
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CENP-F-dependent DRP1 function regulates APC/C activity during oocyte meiosis I. Nat Commun 2022; 13:7732. [PMID: 36513638 PMCID: PMC9747930 DOI: 10.1038/s41467-022-35461-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 12/05/2022] [Indexed: 12/15/2022] Open
Abstract
Chromosome segregation is initiated by cohesin degradation, which is driven by anaphase-promoting complex/cyclosome (APC/C). Chromosome cohesin is removed by activated separase, with the degradation of securin and cyclinB1. Dynamin-related protein 1 (DRP1), a component of the mitochondrial fission machinery, is related to cyclin dynamics in mitosis progression. Here, we show that DRP1 is recruited to the kinetochore by centromeric Centromere protein F (CENP-F) after nuclear envelope breakdown in mouse oocytes. Loss of DRP1 during prometaphase leads to premature cohesin degradation and chromosome segregation. Importantly, acute DRP1 depletion activates separase by initiating cyclinB1 and securin degradation during the metaphase-to-anaphase transition. Finally, we demonstrate that DRP1 is bound to APC2 to restrain the E3 ligase activity of APC/C. In conclusion, DRP1 is a CENP-F-dependent atypical spindle assembly checkpoint (SAC) protein that modulates metaphase-to-anaphase transition by controlling APC/C activity during meiosis I in oocytes.
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16
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Fischer ES, Yu CWH, Hevler JF, McLaughlin SH, Maslen SL, Heck AJR, Freund SMV, Barford D. Juxtaposition of Bub1 and Cdc20 on phosphorylated Mad1 during catalytic mitotic checkpoint complex assembly. Nat Commun 2022; 13:6381. [PMID: 36289199 PMCID: PMC9605988 DOI: 10.1038/s41467-022-34058-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 10/11/2022] [Indexed: 12/25/2022] Open
Abstract
In response to improper kinetochore-microtubule attachments in mitosis, the spindle assembly checkpoint (SAC) assembles the mitotic checkpoint complex (MCC) to inhibit the anaphase-promoting complex/cyclosome, thereby delaying entry into anaphase. The MCC comprises Mad2:Cdc20:BubR1:Bub3. Its assembly is catalysed by unattached kinetochores on a Mad1:Mad2 platform. Mad1-bound closed-Mad2 (C-Mad2) recruits open-Mad2 (O-Mad2) through self-dimerization. This interaction, combined with Mps1 kinase-mediated phosphorylation of Bub1 and Mad1, accelerates MCC assembly, in a process that requires O-Mad2 to C-Mad2 conversion and concomitant binding of Cdc20. How Mad1 phosphorylation catalyses MCC assembly is poorly understood. Here, we characterized Mps1 phosphorylation of Mad1 and obtained structural insights into a phosphorylation-specific Mad1:Cdc20 interaction. This interaction, together with the Mps1-phosphorylation dependent association of Bub1 and Mad1, generates a tripartite assembly of Bub1 and Cdc20 onto the C-terminal domain of Mad1 (Mad1CTD). We additionally identify flexibility of Mad1:Mad2 that suggests how the Cdc20:Mad1CTD interaction brings the Mad2-interacting motif (MIM) of Cdc20 near O-Mad2. Thus, Mps1-dependent formation of the MCC-assembly scaffold functions to position and orient Cdc20 MIM near O-Mad2, thereby catalysing formation of C-Mad2:Cdc20.
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Affiliation(s)
- Elyse S Fischer
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 0QH, UK.
| | - Conny W H Yu
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Johannes F Hevler
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, 3584 CH, Utrecht, The Netherlands
- Netherlands Proteomics Center, University of Utrecht, 3584 CH, Utrecht, The Netherlands
| | - Stephen H McLaughlin
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Sarah L Maslen
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, 3584 CH, Utrecht, The Netherlands
- Netherlands Proteomics Center, University of Utrecht, 3584 CH, Utrecht, The Netherlands
| | - Stefan M V Freund
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 0QH, UK.
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17
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Esposito E, Weidemann DE, Rogers JM, Morton CM, Baybay EK, Chen J, Hauf S. Mitotic checkpoint gene expression is tuned by codon usage bias. EMBO J 2022; 41:e107896. [PMID: 35811551 PMCID: PMC9340482 DOI: 10.15252/embj.2021107896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 05/30/2022] [Accepted: 06/06/2022] [Indexed: 11/09/2022] Open
Abstract
The mitotic checkpoint (also called spindle assembly checkpoint, SAC) is a signaling pathway that safeguards proper chromosome segregation. Correct functioning of the SAC depends on adequate protein concentrations and appropriate stoichiometries between SAC proteins. Yet very little is known about the regulation of SAC gene expression. Here, we show in the fission yeast Schizosaccharomyces pombe that a combination of short mRNA half-lives and long protein half-lives supports stable SAC protein levels. For the SAC genes mad2+ and mad3+ , their short mRNA half-lives are caused, in part, by a high frequency of nonoptimal codons. In contrast, mad1+ mRNA has a short half-life despite a higher frequency of optimal codons, and despite the lack of known RNA-destabilizing motifs. Hence, different SAC genes employ different strategies of expression. We further show that Mad1 homodimers form co-translationally, which may necessitate a certain codon usage pattern. Taken together, we propose that the codon usage of SAC genes is fine-tuned to ensure proper SAC function. Our work shines light on gene expression features that promote spindle assembly checkpoint function and suggests that synonymous mutations may weaken the checkpoint.
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Affiliation(s)
- Eric Esposito
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
| | - Douglas E Weidemann
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
| | - Jessie M Rogers
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
| | - Claire M Morton
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
| | - Erod Keaton Baybay
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
| | - Jing Chen
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
| | - Silke Hauf
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
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18
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Raina VB, Schoot Uiterkamp M, Vader G. Checkpoint control in meiotic prophase: Idiosyncratic demands require unique characteristics. Curr Top Dev Biol 2022; 151:281-315. [PMID: 36681474 DOI: 10.1016/bs.ctdb.2022.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Chromosomal transactions such as replication, recombination and segregation are monitored by cell cycle checkpoint cascades. These checkpoints ensure the proper execution of processes that are needed for faithful genome inheritance from one cell to the next, and across generations. In meiotic prophase, a specialized checkpoint monitors defining events of meiosis: programmed DNA break formation, followed by dedicated repair through recombination based on interhomolog (IH) crossovers. This checkpoint shares molecular characteristics with canonical DNA damage checkpoints active during somatic cell cycles. However, idiosyncratic requirements of meiotic prophase have introduced unique features in this signaling cascade. In this review, we discuss the unique features of the meiotic prophase checkpoint. While being related to canonical DNA damage checkpoint cascades, the meiotic prophase checkpoint also shows similarities with the spindle assembly checkpoint (SAC) that guards chromosome segregation. We highlight these emerging similarities in the signaling logic of the checkpoints that govern meiotic prophase and chromosome segregation, and how thinking of these similarities can help us better understand meiotic prophase control. We also discuss work showing that, when aberrantly expressed, components of the meiotic prophase checkpoint might alter DNA repair fidelity and chromosome segregation in cancer cells. Considering checkpoint function in light of demands imposed by the special characteristics of meiotic prophase helps us understand checkpoint integration into the meiotic cell cycle machinery.
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Affiliation(s)
- Vivek B Raina
- Department of Biochemistry and Molecular Biophysics, Columbia University Medical Center, New York City, NY, United States
| | - Maud Schoot Uiterkamp
- Center for Reproductive Medicine, Reproductive Biology Laboratory, Amsterdam Reproduction and Development Research Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands; Cancer Center Amsterdam, Cancer Biology and Immunology, Amsterdam, The Netherlands; Section of Oncogenetics, Department of Human Genetics, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands
| | - Gerben Vader
- Center for Reproductive Medicine, Reproductive Biology Laboratory, Amsterdam Reproduction and Development Research Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands; Cancer Center Amsterdam, Cancer Biology and Immunology, Amsterdam, The Netherlands; Section of Oncogenetics, Department of Human Genetics, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands.
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19
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Zhang Y, Song C, Wang L, Jiang H, Zhai Y, Wang Y, Fang J, Zhang G. Zombies Never Die: The Double Life Bub1 Lives in Mitosis. Front Cell Dev Biol 2022; 10:870745. [PMID: 35646932 PMCID: PMC9136299 DOI: 10.3389/fcell.2022.870745] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/06/2022] [Indexed: 11/17/2022] Open
Abstract
When eukaryotic cells enter mitosis, dispersed chromosomes move to the cell center along microtubules to form a metaphase plate which facilitates the accurate chromosome segregation. Meanwhile, kinetochores not stably attached by microtubules activate the spindle assembly checkpoint and generate a wait signal to delay the initiation of anaphase. These events are highly coordinated. Disruption of the coordination will cause severe problems like chromosome gain or loss. Bub1, a conserved serine/threonine kinase, plays important roles in mitosis. After extensive studies in the last three decades, the role of Bub1 on checkpoint has achieved a comprehensive understanding; its role on chromosome alignment also starts to emerge. In this review, we summarize the latest development of Bub1 on supporting the two mitotic events. The essentiality of Bub1 in higher eukaryotic cells is also discussed. At the end, some undissolved questions are raised for future study.
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Affiliation(s)
- Yuqing Zhang
- The Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Chunlin Song
- The Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Lei Wang
- The Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Hongfei Jiang
- The Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yujing Zhai
- School of Public Health, Qingdao University, Qingdao, China
| | - Ying Wang
- School of Public Health, Qingdao University, Qingdao, China
| | - Jing Fang
- The Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao, China
- *Correspondence: Jing Fang, ; Gang Zhang,
| | - Gang Zhang
- The Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao, China
- *Correspondence: Jing Fang, ; Gang Zhang,
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20
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Yamada C, Morooka A, Miyazaki S, Nagai M, Mase S, Iemura K, Tasnin MN, Takuma T, Nakamura S, Morshed S, Koike N, Mostofa MG, Rahman MA, Sharmin T, Katsuta H, Ohara K, Tanaka K, Ushimaru T. TORC1 inactivation promotes APC/C-dependent mitotic slippage in yeast and human cells. iScience 2022; 25:103675. [PMID: 35141499 PMCID: PMC8814761 DOI: 10.1016/j.isci.2021.103675] [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: 12/28/2020] [Revised: 10/20/2021] [Accepted: 12/20/2021] [Indexed: 12/31/2022] Open
Abstract
Unsatisfied kinetochore-microtubule attachment activates the spindle assembly checkpoint to inhibit the metaphase-anaphase transition. However, some cells eventually override mitotic arrest by mitotic slippage. Here, we show that inactivation of TORC1 kinase elicits mitotic slippage in budding yeast and human cells. Yeast mitotic slippage was accompanied with aberrant aspects, such as degradation of the nucleolar protein Net1, release of phosphatase Cdc14, and anaphase-promoting complex/cyclosome (APC/C)-Cdh1-dependent degradation of securin and cyclin B in metaphase. This mitotic slippage caused chromosome instability. In human cells, mammalian TORC1 (mTORC1) inactivation also invoked mitotic slippage, indicating that TORC1 inactivation-induced mitotic slippage is conserved from yeast to mammalian cells. However, the invoked mitotic slippage in human cells was not dependent on APC/C-Cdh1. This study revealed an unexpected involvement of TORC1 in mitosis and provides information on undesirable side effects of the use of TORC1 inhibitors as immunosuppressants and anti-tumor drugs. Yeast TORC1 inhibition promotes Net1 degradation and Cdc14 release Yeast TORC1 inhibition invokes mitotic slippage in an APC/C-Cdh1-dependent manner Human mTORC1 inhibition also elicits mitotic slippage
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Affiliation(s)
- Chihiro Yamada
- Department of Science, Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka 422-8021, Japan
| | - Aya Morooka
- Department of Biological Science, Faculty of Science, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Seira Miyazaki
- Department of Biological Science, Faculty of Science, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Masayoshi Nagai
- Department of Science, Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka 422-8021, Japan.,Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan
| | - Satoru Mase
- Department of Science, Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka 422-8021, Japan
| | - Kenji Iemura
- Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan
| | - Most Naoshia Tasnin
- Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka 422-8021, Japan
| | - Tsuneyuki Takuma
- Department of Science, Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka 422-8021, Japan
| | - Shotaro Nakamura
- Department of Science, Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka 422-8021, Japan
| | - Shamsul Morshed
- Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka 422-8021, Japan
| | - Naoki Koike
- Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka 422-8021, Japan
| | - Md Golam Mostofa
- Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka 422-8021, Japan
| | - Muhammad Arifur Rahman
- Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka 422-8021, Japan
| | - Tasnuva Sharmin
- Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka 422-8021, Japan
| | - Haruko Katsuta
- Department of Science, Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka 422-8021, Japan
| | - Kotaro Ohara
- Department of Biological Science, Faculty of Science, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Kozo Tanaka
- Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan
| | - Takashi Ushimaru
- Department of Science, Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka 422-8021, Japan.,Department of Biological Science, Faculty of Science, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan.,Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka 422-8021, Japan
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21
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Gu Y, Desai A, Corbett KD. Evolutionary Dynamics and Molecular Mechanisms of HORMA Domain Protein Signaling. Annu Rev Biochem 2022; 91:541-569. [PMID: 35041460 DOI: 10.1146/annurev-biochem-090920-103246] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Controlled assembly and disassembly of multi-protein complexes is central to cellular signaling. Proteins of the widespread and functionally diverse HORMA family nucleate assembly of signaling complexes by binding short peptide motifs through a distinctive safety-belt mechanism. HORMA proteins are now understood as key signaling proteins across kingdoms, serving as infection sensors in a bacterial immune system and playing central roles in eukaryotic cell cycle, genome stability, sexual reproduction, and cellular homeostasis pathways. Here, we describe how HORMA proteins' unique ability to adopt multiple conformational states underlies their functions in these diverse contexts. We also outline how a dedicated AAA+ ATPase regulator, Pch2/TRIP13, manipulates HORMA proteins' conformational states to activate or inactivate signaling in different cellular contexts. The emergence of Pch2/TRIP13 as a lynchpin for HORMA protein action in multiple genome-maintenance pathways accounts for its frequent misregulation in human cancers and highlights TRIP13 as a novel therapeutic target. Expected final online publication date for the Annual Review of Biochemistry, Volume 91 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Yajie Gu
- Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, California, USA;
| | - Arshad Desai
- Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, California, USA; .,Section of Cell & Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, California, USA.,Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, California, USA
| | - Kevin D Corbett
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, USA
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22
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MAD2L2 dimerization and TRIP13 control shieldin activity in DNA repair. Nat Commun 2021; 12:5421. [PMID: 34521823 PMCID: PMC8440562 DOI: 10.1038/s41467-021-25724-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 08/28/2021] [Indexed: 12/13/2022] Open
Abstract
MAD2L2 (REV7) plays an important role in DNA double-strand break repair. As a member of the shieldin complex, consisting of MAD2L2, SHLD1, SHLD2 and SHLD3, it controls DNA repair pathway choice by counteracting DNA end-resection. Here we investigated the requirements for shieldin complex assembly and activity. Besides a dimerization-surface, HORMA-domain protein MAD2L2 has the extraordinary ability to wrap its C-terminus around SHLD3, likely creating a very stable complex. We show that appropriate function of MAD2L2 within shieldin requires its dimerization, mediated by SHLD2 and accelerating MAD2L2-SHLD3 interaction. Dimerization-defective MAD2L2 impairs shieldin assembly and fails to promote NHEJ. Moreover, MAD2L2 dimerization, along with the presence of SHLD3, allows shieldin to interact with the TRIP13 ATPase, known to drive topological switches in HORMA-domain proteins. We find that appropriate levels of TRIP13 are important for proper shieldin (dis)assembly and activity in DNA repair. Together our data provide important insights in the dependencies for shieldin activity.
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23
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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: 140] [Impact Index Per Article: 35.0] [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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24
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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: 42] [Impact Index Per Article: 10.5] [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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25
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Fischer ES, Yu CWH, Bellini D, McLaughlin SH, Orr CM, Wagner A, Freund SMV, Barford D. Molecular mechanism of Mad1 kinetochore targeting by phosphorylated Bub1. EMBO Rep 2021; 22:e52242. [PMID: 34013668 PMCID: PMC8391104 DOI: 10.15252/embr.202052242] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 04/02/2021] [Accepted: 04/13/2021] [Indexed: 01/10/2023] Open
Abstract
During metaphase, in response to improper kinetochore-microtubule attachments, the spindle assembly checkpoint (SAC) activates the mitotic checkpoint complex (MCC), an inhibitor of the anaphase-promoting complex/cyclosome (APC/C). This process is orchestrated by the kinase Mps1, which initiates the assembly of the MCC onto kinetochores through a sequential phosphorylation-dependent signalling cascade. The Mad1-Mad2 complex, which is required to catalyse MCC formation, is targeted to kinetochores through a direct interaction with the phosphorylated conserved domain 1 (CD1) of Bub1. Here, we present the crystal structure of the C-terminal domain of Mad1 (Mad1CTD ) bound to two phosphorylated Bub1CD1 peptides at 1.75 Å resolution. This interaction is mediated by phosphorylated Bub1 Thr461, which not only directly interacts with Arg617 of the Mad1 RLK (Arg-Leu-Lys) motif, but also directly acts as an N-terminal cap to the CD1 α-helix dipole. Surprisingly, only one Bub1CD1 peptide binds to the Mad1 homodimer in solution. We suggest that this stoichiometry is due to inherent asymmetry in the coiled-coil of Mad1CTD and has implications for how the Mad1-Bub1 complex at kinetochores promotes efficient MCC assembly.
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Affiliation(s)
| | | | - Dom Bellini
- MRC Laboratory of Molecular BiologyCambridgeUK
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26
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Garcia YA, Velasquez EF, Gao LW, Gholkar AA, Clutario KM, Cheung K, Williams-Hamilton T, Whitelegge JP, Torres JZ. Mapping Proximity Associations of Core Spindle Assembly Checkpoint Proteins. J Proteome Res 2021; 20:3414-3427. [PMID: 34087075 PMCID: PMC8256817 DOI: 10.1021/acs.jproteome.0c00941] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Indexed: 12/25/2022]
Abstract
The spindle assembly checkpoint (SAC) is critical for sensing defective microtubule-kinetochore attachments and tension across the kinetochore and functions to arrest cells in prometaphase to allow time to repair any errors before proceeding into anaphase. Dysregulation of the SAC leads to chromosome segregation errors that have been linked to human diseases like cancer. Although much has been learned about the composition of the SAC and the factors that regulate its activity, the proximity associations of core SAC components have not been explored in a systematic manner. Here, we have taken a BioID2-proximity-labeling proteomic approach to define the proximity protein environment for each of the five core SAC proteins BUB1, BUB3, BUBR1, MAD1L1, and MAD2L1 in mitotic-enriched populations of cells where the SAC is active. These five protein association maps were integrated to generate a SAC proximity protein network that contains multiple layers of information related to core SAC protein complexes, protein-protein interactions, and proximity associations. Our analysis validated many known SAC complexes and protein-protein interactions. Additionally, it uncovered new protein associations, including the ELYS-MAD1L1 interaction that we have validated, which lend insight into the functioning of core SAC proteins and highlight future areas of investigation to better understand the SAC.
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Affiliation(s)
- Yenni A. Garcia
- Department of Chemistry and Biochemistry,
University of California, Los Angeles, California 90095,
United States
| | - Erick F. Velasquez
- Department of Chemistry and Biochemistry,
University of California, Los Angeles, California 90095,
United States
| | - Lucy W. Gao
- Pasarow Mass Spectrometry Laboratory, The Jane and
Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of
Medicine, University of California, Los Angeles, California
90095, United States
| | - Ankur A. Gholkar
- Department of Chemistry and Biochemistry,
University of California, Los Angeles, California 90095,
United States
| | - Kevin M. Clutario
- Department of Chemistry and Biochemistry,
University of California, Los Angeles, California 90095,
United States
| | - Keith Cheung
- Department of Chemistry and Biochemistry,
University of California, Los Angeles, California 90095,
United States
| | - Taylor Williams-Hamilton
- Department of Chemistry and Biochemistry,
University of California, Los Angeles, California 90095,
United States
| | - Julian P. Whitelegge
- Pasarow Mass Spectrometry Laboratory, The Jane and
Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of
Medicine, University of California, Los Angeles, California
90095, United States
- Molecular Biology Institute, University of
California, Los Angeles, California 90095, United
States
- Jonsson Comprehensive Cancer Center,
University of California, Los Angeles, California 90095,
United States
| | - Jorge Z. Torres
- Department of Chemistry and Biochemistry,
University of California, Los Angeles, California 90095,
United States
- Molecular Biology Institute, University of
California, Los Angeles, California 90095, United
States
- Jonsson Comprehensive Cancer Center,
University of California, Los Angeles, California 90095,
United States
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27
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Abstract
Accurate chromosome segregation is required for cell survival and organismal development. During mitosis, the spindle assembly checkpoint acts as a safeguard to maintain the high fidelity of mitotic chromosome segregation by monitoring the attachment of kinetochores to the mitotic spindle. Bub1 is a conserved kinase critical for the spindle assembly checkpoint. Bub1 also facilitates chromosome alignment and contributes to the regulation of mitotic duration. Here, focusing on the spindle assembly checkpoint and on chromosome alignment, we summarize the primary literature on Bub1, discussing its structure and functional domains, as well its regulation and roles in mitosis. In addition, we discuss recent evidence for roles of Bub1 beyond mitosis regulation in TGFβ signaling and telomere replication. Finally, we discuss the involvement of Bub1 in human diseases, especially in cancer, and the potential of using Bub1 as a drug target for therapeutic applications.
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Affiliation(s)
- Taekyung Kim
- Department of Biology Education, Pusan National University, Busan, Korea
| | - Anton Gartner
- IBS Center for Genomic Integrity, Ulsan, Korea.,School of Life Sciences, Ulsan National Institute of Science and Technology
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28
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Piano V, Alex A, Stege P, Maffini S, Stoppiello GA, Huis In 't Veld PJ, Vetter IR, Musacchio A. CDC20 assists its catalytic incorporation in the mitotic checkpoint complex. Science 2021; 371:67-71. [PMID: 33384373 DOI: 10.1126/science.abc1152] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 11/18/2020] [Indexed: 12/16/2022]
Abstract
Open (O) and closed (C) topologies of HORMA-domain proteins are respectively associated with inactive and active states of fundamental cellular pathways. The HORMA protein O-MAD2 converts to C-MAD2 upon binding CDC20. This is rate limiting for assembly of the mitotic checkpoint complex (MCC), the effector of a checkpoint required for mitotic fidelity. A catalyst assembled at kinetochores accelerates MAD2:CDC20 association through a poorly understood mechanism. Using a reconstituted SAC system, we discovered that CDC20 is an impervious substrate for which access to MAD2 requires simultaneous docking on several sites of the catalytic complex. Our analysis indicates that the checkpoint catalyst is substrate assisted and promotes MCC assembly through spatially and temporally coordinated conformational changes in both MAD2 and CDC20. This may define a paradigm for other HORMA-controlled systems.
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Affiliation(s)
- Valentina Piano
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany.
| | - Amal Alex
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Patricia Stege
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Stefano Maffini
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Gerardo A Stoppiello
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Pim J Huis In 't Veld
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Ingrid R Vetter
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany. .,Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, 45141 Essen, Germany
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29
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Raina VB, Vader G. Homeostatic Control of Meiotic Prophase Checkpoint Function by Pch2 and Hop1. Curr Biol 2020; 30:4413-4424.e5. [PMID: 32916108 DOI: 10.1016/j.cub.2020.08.064] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/31/2020] [Accepted: 08/18/2020] [Indexed: 01/15/2023]
Abstract
Checkpoint cascades link cell cycle progression with essential chromosomal processes. During meiotic prophase, recombination and chromosome synapsis are monitored by what are considered distinct checkpoints. In budding yeast, cells that lack the AAA+ ATPase Pch2 show an impaired cell cycle arrest in response to synapsis defects. However, unperturbed pch2Δ cells are delayed in meiotic prophase, suggesting paradoxical roles for Pch2 in cell cycle progression. Here, we provide insight into the checkpoint roles of Pch2 and its connection to Hop1, a HORMA domain-containing client protein. Contrary to current understanding, we find that Pch2 (together with Hop1) is crucial for checkpoint function in response to both recombination and synapsis defects, thus revealing a shared meiotic checkpoint cascade. Meiotic checkpoint responses are transduced by DNA break-dependent phosphorylation of Hop1. Based on our data and on the described effect of Pch2 on HORMA topology, we propose that Pch2 promotes checkpoint proficiency by catalyzing the availability of signaling-competent Hop1. Conversely, we demonstrate that Pch2 can act as a checkpoint silencer, also in the face of persistent DNA repair defects. We establish a framework in which Pch2 and Hop1 form a homeostatic module that governs general meiotic checkpoint function. We show that this module can-depending on the cellular context-fuel or extinguish meiotic checkpoint function, which explains the contradictory roles of Pch2 in cell cycle control. Within the meiotic prophase checkpoint, the Pch2-Hop1 module thus operates analogous to the Pch2/TRIP13-Mad2 module in the spindle assembly checkpoint that monitors chromosome segregation.
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Affiliation(s)
- Vivek B Raina
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, Dortmund 44227, Germany; International Max Planck Research School (IMPRS) in Chemical and Molecular Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, Dortmund 44227, Germany
| | - Gerben Vader
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, Dortmund 44227, Germany; International Max Planck Research School (IMPRS) in Chemical and Molecular Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, Dortmund 44227, Germany.
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30
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Cunha-Silva S, Conde C. From the Nuclear Pore to the Fibrous Corona: A MAD Journey to Preserve Genome Stability. Bioessays 2020; 42:e2000132. [PMID: 32885448 DOI: 10.1002/bies.202000132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/22/2020] [Indexed: 11/09/2022]
Abstract
The relationship between kinetochores and nuclear pore complexes (NPCs) is intimate but poorly understood. Several NPC components and associated proteins are relocated to mitotic kinetochores to assist in different activities that ensure faithful chromosome segregation. Such is the case of the Mad1-c-Mad2 complex, the catalytic core of the spindle assembly checkpoint (SAC), a surveillance pathway that delays anaphase until all kinetochores are attached to spindle microtubules. Mad1-c-Mad2 is recruited to discrete domains of unattached kinetochores from where it promotes the rate-limiting step in the assembly of anaphase-inhibitory complexes. SAC proficiency further requires Mad1-c-Mad2 to be anchored at NPCs during interphase. However, the mechanistic relevance of this arrangement for SAC function remains ill-defined. Recent studies uncover the molecular underpinnings that coordinate the release of Mad1-c-Mad2 from NPCs with its prompt recruitment to kinetochores. Here, current knowledge on Mad1-c-Mad2 function and spatiotemporal regulation is reviewed and the critical questions that remain unanswered are highlighted.
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Affiliation(s)
- Sofia Cunha-Silva
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, 4200-135, Portugal.,IBMC, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, 4200-135, Portugal.,Programa Doutoral em Biologia Molecular e Celular (MCbiology), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, 4050-313, Portugal
| | - Carlos Conde
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, 4200-135, Portugal.,IBMC, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, 4200-135, Portugal
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31
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Saez-Atienzar S, Masliah E. Cellular senescence and Alzheimer disease: the egg and the chicken scenario. Nat Rev Neurosci 2020; 21:433-444. [PMID: 32601397 DOI: 10.1038/s41583-020-0325-z] [Citation(s) in RCA: 161] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2020] [Indexed: 12/21/2022]
Abstract
Globally, 50 million people live with dementia, with Alzheimer disease (AD) being responsible for two-thirds of the total cases. As ageing is the main risk factor for dementia-related neurodegeneration, changes in the timing or nature of the cellular hallmarks of normal ageing might be key to understanding the events that convert normal ageing into neurodegeneration. Cellular senescence is a candidate mechanism that might be important for this conversion. Under persistent stress, as occurs in ageing, both postmitotic cells - including neurons - and proliferative cells - such as astrocytes and microglia, among others - can engender a state of chronic cellular senescence that is characterized by the secretion of pro-inflammatory molecules that promote the functional decline of tissues and organs. Ablation of senescent cells has been postulated as a promising therapeutic venue to target the ageing phenotype and, thus, prevent or mitigate ageing-related diseases. However, owing to a lack of evidence, it is not possible to label cellular senescence as a cause or a consequence of neurodegeneration. This Review examines cellular senescence in the context of ageing and AD, and discusses which of the processes - cellular senescence or AD - might come first.
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Affiliation(s)
- Sara Saez-Atienzar
- Neuromuscular Disease Research Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
| | - Eliezer Masliah
- Molecular Neuropathology Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA. .,Division of Neuroscience, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA.
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32
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Matellán L, Monje-Casas F. Regulation of Mitotic Exit by Cell Cycle Checkpoints: Lessons From Saccharomyces cerevisiae. Genes (Basel) 2020; 11:E195. [PMID: 32059558 PMCID: PMC7074328 DOI: 10.3390/genes11020195] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/07/2020] [Accepted: 02/11/2020] [Indexed: 02/06/2023] Open
Abstract
In order to preserve genome integrity and their ploidy, cells must ensure that the duplicated genome has been faithfully replicated and evenly distributed before they complete their division by mitosis. To this end, cells have developed highly elaborated checkpoints that halt mitotic progression when problems in DNA integrity or chromosome segregation arise, providing them with time to fix these issues before advancing further into the cell cycle. Remarkably, exit from mitosis constitutes a key cell cycle transition that is targeted by the main mitotic checkpoints, despite these surveillance mechanisms being activated by specific intracellular signals and acting at different stages of cell division. Focusing primarily on research carried out using Saccharomyces cerevisiae as a model organism, the aim of this review is to provide a general overview of the molecular mechanisms by which the major cell cycle checkpoints control mitotic exit and to highlight the importance of the proper regulation of this process for the maintenance of genome stability during the distribution of the duplicated chromosomes between the dividing cells.
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Affiliation(s)
| | - Fernando Monje-Casas
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Spanish National Research Council (CSIC)—University of Seville—University Pablo de Olavide, Avda, Américo Vespucio, 24, 41092 Sevilla, Spain;
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33
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Ruggiero A, Katou Y, Shirahige K, Séveno M, Piatti S. The Phosphatase PP1 Promotes Mitotic Slippage through Mad3 Dephosphorylation. Curr Biol 2020; 30:335-343.e5. [PMID: 31928870 DOI: 10.1016/j.cub.2019.11.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 10/04/2019] [Accepted: 11/18/2019] [Indexed: 11/17/2022]
Abstract
Accurate chromosome segregation requires bipolar attachment of kinetochores to spindle microtubules. A conserved surveillance mechanism, the spindle assembly checkpoint (SAC), responds to lack of kinetochore-microtubule connections and delays anaphase onset until all chromosomes are bipolarly attached [1]. SAC signaling fires at kinetochores and involves a soluble mitotic checkpoint complex (MCC) that inhibits the anaphase-promoting complex (APC) [2, 3]. The mitotic delay imposed by SAC, however, is not everlasting. If kinetochores fail to establish bipolar connections, cells can escape from the SAC-induced mitotic arrest through a process called mitotic slippage [4]. Mitotic slippage occurs in the presence of SAC signaling at kinetochores [5, 6], but whether and how MCC stability and APC inhibition are actively controlled during slippage is unknown. The PP1 phosphatase has emerged as a key factor in SAC silencing once all kinetochores are bipolarly attached [7, 8]. PP1 turns off SAC signaling through dephosphorylation of the SAC scaffold Knl1/Blinkin at kinetochores [9-11]. Here, we show that, in budding yeast, PP1 is also required for mitotic slippage. However, its involvement in this process is not linked to kinetochores but rather to MCC stability. We identify S268 of Mad3 as a critical target of PP1 in this process. Mad3 S268 dephosphorylation destabilizes the MCC without affecting the initial SAC-induced mitotic arrest. Conversely, it accelerates mitotic slippage and overcomes the slippage defect of PP1 mutants. Thus, slippage is not the mere consequence of incomplete APC inactivation that brings about mitotic exit, as originally proposed, but involves the exertive antagonism between kinases and phosphatases.
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Affiliation(s)
- Antonella Ruggiero
- CRBM, University of Montpellier, CNRS, 1919 Route de Mende, 34293 Montpellier, France
| | - Yuki Katou
- Research Center for Epigenetic Disease, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, 113-0032 Tokyo, Japan
| | - Katsuhiko Shirahige
- Research Center for Epigenetic Disease, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, 113-0032 Tokyo, Japan
| | - Martial Séveno
- BioCampus Montpellier, CNRS, INSERM, University of Montpellier, 34000 Montpellier, France
| | - Simonetta Piatti
- CRBM, University of Montpellier, CNRS, 1919 Route de Mende, 34293 Montpellier, France.
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34
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Deubiquitinating Enzymes: A Critical Regulator of Mitosis. Int J Mol Sci 2019; 20:ijms20235997. [PMID: 31795161 PMCID: PMC6929034 DOI: 10.3390/ijms20235997] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 11/25/2019] [Accepted: 11/25/2019] [Indexed: 12/20/2022] Open
Abstract
Mitosis is a complex and dynamic process that is tightly regulated by a large number of mitotic proteins. Dysregulation of these proteins can generate daughter cells that exhibit genomic instability and aneuploidy, and such cells can transform into tumorigenic cells. Thus, it is important for faithful mitotic progression to regulate mitotic proteins at specific locations in the cells at a given time in each phase of mitosis. Ubiquitin-dependent modifications play critical roles in this process by regulating the degradation, translocation, or signal transduction of mitotic proteins. Here, we review how ubiquitination and deubiquitination regulate the progression of mitosis. In addition, we summarize the substrates and roles of some deubiquitinating enzymes (DUBs) crucial for mitosis and describe how they contribute error correction during mitosis and control the transition between the mitotic phases.
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35
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Lara-Gonzalez P, Moyle MW, Budrewicz J, Mendoza-Lopez J, Oegema K, Desai A. The G2-to-M Transition Is Ensured by a Dual Mechanism that Protects Cyclin B from Degradation by Cdc20-Activated APC/C. Dev Cell 2019; 51:313-325.e10. [PMID: 31588029 DOI: 10.1016/j.devcel.2019.09.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 06/26/2019] [Accepted: 09/05/2019] [Indexed: 12/23/2022]
Abstract
In the eukaryotic cell cycle, a threshold level of cyclin B accumulation triggers the G2-to-M transition, and subsequent cyclin B destruction triggers mitotic exit. The anaphase-promoting complex/cyclosome (APC/C) is the E3 ubiquitin ligase that, together with its co-activator Cdc20, targets cyclin B for destruction during mitotic exit. Here, we show that two pathways act in concert to protect cyclin B from Cdc20-activated APC/C in G2, in order to enable cyclin B accumulation and the G2-to-M transition. The first pathway involves the Mad1-Mad2 spindle checkpoint complex, acting in a distinct manner from checkpoint signaling after mitotic entry but employing a common molecular mechanism-the promotion of Mad2-Cdc20 complex formation. The second pathway involves cyclin-dependent kinase phosphorylation of Cdc20, which is known to reduce Cdc20's affinity for the APC/C. Cooperation of these two mechanisms, which target distinct APC/C binding interfaces of Cdc20, enables cyclin B accumulation and the G2-to-M transition.
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Affiliation(s)
- Pablo Lara-Gonzalez
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, USA; Department of Cellular & Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Mark W Moyle
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, USA; Department of Cellular & Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jacqueline Budrewicz
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, USA; Department of Cellular & Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jose Mendoza-Lopez
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, USA; Department of Cellular & Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Karen Oegema
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, USA; Department of Cellular & Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Arshad Desai
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, USA; Department of Cellular & Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
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36
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Choi HJ, Zhu BT. Upregulated cyclin B1/CDK1 mediates apoptosis following 2-methoxyestradiol-induced mitotic catastrophe: Role of Bcl-X L phosphorylation. Steroids 2019; 150:108381. [PMID: 30797877 DOI: 10.1016/j.steroids.2019.02.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 01/15/2019] [Accepted: 02/18/2019] [Indexed: 12/13/2022]
Abstract
2-Methoxyestradiol is an endogenous nonpolar metabolite of 17β-estradiol with a strong antitubulin activity. Earlier we showed that 2-methoxyestradiol increases the level and activity of cyclin B1/CDK1, which subsequently induces mitotic prometaphase arrest. In the present study, we demonstrate that upregulation of cyclin B1/CDK1 is responsible for the increased phosphorylation of the anti-apoptotic proteins Bcl-2 and Bcl-XL in 2-methoxyestradiol-induced, mitotically-arrested cancer cells. Additional analysis shows that only the increase in phosphorylation of Bcl-XL, but not Bcl-2, is associated with activation of the mitochondrial cell death pathway. We find that MAD2 is an important upstream mediator of the antitubulin function of 2-methoxyestradiol, resulting in activation of the MKK4-JNK1 pathway. JNK1 activation then leads to cyclin B1/CDK1 upregulation, which further increases Bcl-2 and Bcl-XL phosphorylation. Together, these results indicate that cyclin B1/CDK1 upregulation in cancer cells undergoing 2-methoxyestradiol-induced mitotic catastrophe causes apoptosis via Bcl-XL phosphorylation.
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Affiliation(s)
- Hye Joung Choi
- School of Life and Health Sciences and School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Bao Ting Zhu
- School of Life and Health Sciences and School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China.
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37
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Hayward D, Alfonso-Pérez T, Gruneberg U. Orchestration of the spindle assembly checkpoint by CDK1-cyclin B1. FEBS Lett 2019; 593:2889-2907. [PMID: 31469407 DOI: 10.1002/1873-3468.13591] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/01/2019] [Accepted: 08/19/2019] [Indexed: 12/11/2022]
Abstract
In mitosis, the spindle assembly checkpoint (SAC) monitors the formation of microtubule-kinetochore attachments during capture of chromosomes by the mitotic spindle. Spindle assembly is complete once there are no longer any unattached kinetochores. Here, we will discuss the mechanism and key components of spindle checkpoint signalling. Unattached kinetochores bind the principal spindle checkpoint kinase monopolar spindle 1 (MPS1). MPS1 triggers the recruitment of other spindle checkpoint proteins and the formation of a soluble inhibitor of anaphase, thus preventing exit from mitosis. On microtubule attachment, kinetochores become checkpoint silent due to the actions of PP2A-B56 and PP1. This SAC responsive period has to be coordinated with mitotic spindle formation to ensure timely mitotic exit and accurate chromosome segregation. We focus on the molecular mechanisms by which the SAC permissive state is created, describing a central role for CDK1-cyclin B1 and its counteracting phosphatase PP2A-B55. Furthermore, we discuss how CDK1-cyclin B1, through its interaction with MAD1, acts as an integral component of the SAC, and actively orchestrates checkpoint signalling and thus contributes to the faithful execution of mitosis.
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Affiliation(s)
- Daniel Hayward
- Sir William Dunn School of Pathology, University of Oxford, UK
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38
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Lu S, Qian J, Guo M, Gu C, Yang Y. Insights into a Crucial Role of TRIP13 in Human Cancer. Comput Struct Biotechnol J 2019; 17:854-861. [PMID: 31321001 PMCID: PMC6612527 DOI: 10.1016/j.csbj.2019.06.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 06/05/2019] [Accepted: 06/08/2019] [Indexed: 01/06/2023] Open
Abstract
Thyroid Hormone Receptor Interacting Protein 13 (TRIP13) plays a key role in regulating mitotic processes, including spindle assembly checkpoint and DNA repair pathways, which may account for Chromosome instability (CIN). As CIN is a predominant hallmark of cancer, TRIP13 may act as a tumor susceptibility locus. Amplification of TRIP13 has been observed in various human cancers and implicated in several aspects of malignant transformation, including cancer cell proliferation, drug resistance and tumor progression. Here, we discussed the functional significance of TRIP13 in cell progression, highlighted the recent findings on the aberrant expression in human cancers and emphasized its significance for the therapeutic potential.
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Affiliation(s)
- S Lu
- The Third Affiliated Hospital, Nanjing University of Chinese Medicine, Nanjing 210023, China.,School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - J Qian
- School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - M Guo
- School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - C Gu
- The Third Affiliated Hospital, Nanjing University of Chinese Medicine, Nanjing 210023, China.,School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Y Yang
- School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing 210023, China.,School of Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023 0Nanjing, China
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39
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Etemad B, Vertesy A, Kuijt TEF, Sacristan C, van Oudenaarden A, Kops GJPL. Spindle checkpoint silencing at kinetochores with submaximal microtubule occupancy. J Cell Sci 2019; 132:jcs.231589. [PMID: 31138679 DOI: 10.1242/jcs.231589] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 05/17/2019] [Indexed: 11/20/2022] Open
Abstract
The spindle assembly checkpoint (SAC) ensures proper chromosome segregation by monitoring kinetochore-microtubule interactions. SAC proteins are shed from kinetochores once stable attachments are achieved. Human kinetochores consist of hundreds of SAC protein recruitment modules and bind up to 20 microtubules, raising the question of how the SAC responds to intermediate attachment states. We show that one protein module ('RZZS-MAD1-MAD2') of the SAC is removed from kinetochores at low microtubule occupancy and remains absent at higher occupancies, while another module ('BUB1-BUBR1') is retained at substantial levels irrespective of attachment states. These behaviours reflect different silencing mechanisms: while BUB1 displacement is almost fully dependent on MPS1 inactivation, MAD1 (also known as MAD1L1) displacement is not. Artificially tuning the affinity of kinetochores for microtubules further shows that ∼50% occupancy is sufficient to shed MAD2 and silence the SAC. Kinetochores thus respond as a single unit to shut down SAC signalling at submaximal occupancy states, but retain one SAC module. This may ensure continued SAC silencing on kinetochores with fluctuating occupancy states while maintaining the ability for fast SAC re-activation.
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Affiliation(s)
- Banafsheh Etemad
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, 3584 CT, The Netherlands
| | - Abel Vertesy
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, 3584 CT, The Netherlands
| | - Timo E F Kuijt
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, 3584 CT, The Netherlands
| | - Carlos Sacristan
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, 3584 CT, The Netherlands
| | - Alexander van Oudenaarden
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, 3584 CT, The Netherlands
| | - Geert J P L Kops
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, 3584 CT, The Netherlands
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40
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Ma HT, Poon RYC. TRIP13 Functions in the Establishment of the Spindle Assembly Checkpoint by Replenishing O-MAD2. Cell Rep 2019; 22:1439-1450. [PMID: 29425500 DOI: 10.1016/j.celrep.2018.01.027] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Revised: 12/10/2017] [Accepted: 01/10/2018] [Indexed: 12/14/2022] Open
Abstract
The spindle assembly checkpoint (SAC) prevents premature segregation of chromosomes during mitosis. This process requires structural remodeling of MAD2 from O-MAD2 to C-MAD2 conformation. After the checkpoint is satisfied, C-MAD2 is reverted to O-MAD2 to allow anaphase-promoting complex/cyclosome (APC/C) to trigger anaphase. Recently, the AAA+-ATPase TRIP13 was shown to act in concert with p31comet to catalyze C- to O-MAD2. Paradoxically, although C-MAD2 is present in TRIP13-deficient cells, the SAC cannot be activated. Using a degron-mediated system to uncouple TRIP13 from O- and C-MAD2 equilibrium, we demonstrated that the loss of TRIP13 did not immediately abolish the SAC, but the resulting C-MAD2-only environment was insufficient to enable the SAC. These results favor a model in which MAD2-CDC20 interaction is coupled directly to the conversion of O- to C-MAD2 instead of one that involves unliganded C-MAD2. TRIP13 replenishes the O-MAD2 pool for activation by unattached kinetochores.
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Affiliation(s)
- Hoi Tang Ma
- Division of Life Science, Center for Cancer Research, and State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Randy Y C Poon
- Division of Life Science, Center for Cancer Research, and State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
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41
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Recent Progress on the Localization of the Spindle Assembly Checkpoint Machinery to Kinetochores. Cells 2019; 8:cells8030278. [PMID: 30909555 PMCID: PMC6468716 DOI: 10.3390/cells8030278] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/13/2019] [Accepted: 03/16/2019] [Indexed: 12/14/2022] Open
Abstract
Faithful chromosome segregation during mitosis is crucial for maintaining genome stability. The spindle assembly checkpoint (SAC) is a surveillance mechanism that ensures accurate mitotic progression. Defective SAC signaling leads to premature sister chromatid separation and aneuploid daughter cells. Mechanistically, the SAC couples the kinetochore microtubule attachment status to the cell cycle progression machinery. In the presence of abnormal kinetochore microtubule attachments, the SAC prevents the metaphase-to-anaphase transition through a complex kinase-phosphatase signaling cascade which results in the correct balance of SAC components recruited to the kinetochore. The correct kinetochore localization of SAC proteins is a prerequisite for robust SAC signaling and, hence, accurate chromosome segregation. Here, we review recent progresses on the kinetochore recruitment of core SAC factors.
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42
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Choi E, Yu H. Spindle Checkpoint Regulators in Insulin Signaling. Front Cell Dev Biol 2018; 6:161. [PMID: 30555826 PMCID: PMC6281718 DOI: 10.3389/fcell.2018.00161] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 11/08/2018] [Indexed: 12/17/2022] Open
Abstract
The spindle checkpoint ensures accurate chromosome segregation during mitosis and guards against aneuploidy. Insulin signaling governs metabolic homeostasis and cell growth, and its dysregulation leads to metabolic disorders, such as diabetes. These critical pathways have been extensively investigated, but a link between the two has not been established until recently. Our recent study reveals a critical role of spindle checkpoint regulators in insulin signaling and metabolic homeostasis through regulating endocytosis of the insulin receptor (IR). These findings have linked spindle checkpoint proteins to metabolic regulation, expanding the connection between cell division and metabolism. Here, we briefly review the unexpected roles of spindle checkpoint regulators in vesicle trafficking and insulin signaling.
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Affiliation(s)
- Eunhee Choi
- Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Hongtao Yu
- Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, United States
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43
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Kim DH, Han JS, Ly P, Ye Q, McMahon MA, Myung K, Corbett KD, Cleveland DW. TRIP13 and APC15 drive mitotic exit by turnover of interphase- and unattached kinetochore-produced MCC. Nat Commun 2018; 9:4354. [PMID: 30341343 PMCID: PMC6195577 DOI: 10.1038/s41467-018-06774-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 09/13/2018] [Indexed: 12/18/2022] Open
Abstract
The mitotic checkpoint ensures accurate chromosome segregation through assembly of the mitotic checkpoint complex (MCC), a soluble inhibitor of the anaphase-promoting complex/cyclosome (APC/C) produced by unattached kinetochores. MCC is also assembled during interphase by Mad1/Mad2 bound at nuclear pores, thereby preventing premature mitotic exit prior to kinetochore maturation and checkpoint activation. Using degron tagging to rapidly deplete the AAA+ ATPase TRIP13, we show that its catalytic activity is required to maintain a pool of open-state Mad2 for MCC assembly, thereby supporting mitotic checkpoint activation, but is also required for timely mitotic exit through catalytic disassembly of MCC. Strikingly, combining TRIP13 depletion with elimination of APC15-dependent Cdc20 ubiquitination/degradation results in a complete inability to exit mitosis, even when MCC assembly at unattached kinetochores is prevented. Thus, mitotic exit requires MCC produced either in interphase or mitosis to be disassembled by TRIP13-catalyzed removal of Mad2 or APC15-driven ubiquitination/degradation of its Cdc20 subunit.
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Affiliation(s)
- Dong Hyun Kim
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, 92093, USA.,Department of Cellular and Molecular Medicine, University of California-San Diego, La Jolla, CA, 92093, USA
| | - Joo Seok Han
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
| | - Peter Ly
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, 92093, USA.,Department of Cellular and Molecular Medicine, University of California-San Diego, La Jolla, CA, 92093, USA
| | - Qiaozhen Ye
- Department of Cellular and Molecular Medicine, University of California-San Diego, La Jolla, CA, 92093, USA
| | - Moira A McMahon
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, 92093, USA.,Department of Cellular and Molecular Medicine, University of California-San Diego, La Jolla, CA, 92093, USA.,Ionis Pharmaceuticals, 2855 Gazelle Ct, Carlsbad, CA, 92010, USA
| | - Kyungjae Myung
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea.,School of Life Sciences, Ulsan National Institute for Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Kevin D Corbett
- Department of Cellular and Molecular Medicine, University of California-San Diego, La Jolla, CA, 92093, USA. .,Department of Chemistry, University of California-San Diego, La Jolla, CA, 92093, USA.
| | - Don W Cleveland
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, 92093, USA. .,Department of Cellular and Molecular Medicine, University of California-San Diego, La Jolla, CA, 92093, USA.
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44
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Amin P, Soper Ní Chafraidh S, Leontiou I, Hardwick KG. Regulated reconstitution of spindle checkpoint arrest and silencing through chemically induced dimerisation in vivo. J Cell Sci 2018; 132:jcs.219766. [PMID: 30237224 PMCID: PMC6398473 DOI: 10.1242/jcs.219766] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 09/04/2018] [Indexed: 12/19/2022] Open
Abstract
Chemically induced dimerisation (CID) uses small molecules to control specific protein-protein interactions. We employed CID dependent on the plant hormone abscisic acid (ABA) to reconstitute spindle checkpoint signalling in fission yeast. The spindle checkpoint signal usually originates at unattached or inappropriately attached kinetochores. These are complex, multiprotein structures with several important functions. To bypass kinetochore complexity, we took a reductionist approach to studying checkpoint signalling. We generated a synthetic checkpoint arrest ectopically by inducing heterodimerisation of the checkpoint proteins Mph1 (the fission yeast homologue of Mps1) and Spc7 (the fission yeast homologue of KNL1). These proteins were engineered such that they cannot localise to kinetochores, and only form a complex in the presence of ABA. Using this novel assay we were able to checkpoint arrest a synchronous population of cells within 30 min of ABA addition. This assay allows detailed genetic dissection of checkpoint activation and, importantly, also provides a valuable tool for studying checkpoint silencing. To analyse silencing of the checkpoint and the ensuing mitotic exit, we simply washed out the ABA from arrested fission yeast cells. We show here that silencing is critically dependent on protein phosphatase 1 (PP1) recruitment to Mph1-Spc7 signalling platforms.
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Affiliation(s)
- Priya Amin
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK
| | - Sadhbh Soper Ní Chafraidh
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK
| | - Ioanna Leontiou
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK
| | - Kevin G Hardwick
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK
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45
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Abstract
The mitotic checkpoint ensures proper chromosome segregation; defects in this checkpoint can lead to aneuploidy, a hallmark of cancer. The mitotic checkpoint blocks progression through mitosis as long as chromosomes remain unattached to spindle microtubules. Unattached kinetochores induce the formation of a mitotic checkpoint complex (MCC) composed of Mad2, BubR1, Bub1 and Bub3 which inhibits anaphase onset. Spindle toxins induce prolonged mitotic arrest by creating persistently unattached kinetochores which trigger MCC formation. We find that the multifunctional ser/thr kinase, glycogen synthase kinase 3 (GSK3) is required for a strong mitotic checkpoint. Spindle toxin-induced mitotic arrest is relieved by GSK3 inhibitors SB 415286 (SB), RO 318220 (RO) and lithium chloride. Similarly, targeting GSK3β with knockout or RNAi reduced mitotic arrest in the presence of Taxol. GSK3 was required for optimal localization of Mad2, BubR1, and Bub1 at kinetochores and for optimal assembly of the MCC in spindle toxin-arrested cells. The WNT- and PI3K/Akt signaling pathways negatively regulate GSK3β activity. Inhibition of WNT and PI3K/Akt signaling, in the presence of Taxol, induced a longer mitotic arrest compared to Taxol alone. Our observations provide novel insight into the regulation of the mitotic checkpoint and its connection to growth-signaling pathways.
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46
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Gross F, Bonaiuti P, Hauf S, Ciliberto A. Implications of alternative routes to APC/C inhibition by the mitotic checkpoint complex. PLoS Comput Biol 2018; 14:e1006449. [PMID: 30199529 PMCID: PMC6157902 DOI: 10.1371/journal.pcbi.1006449] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 09/26/2018] [Accepted: 08/20/2018] [Indexed: 01/19/2023] Open
Abstract
The mitotic checkpoint (also called spindle assembly checkpoint) is a signaling pathway that ensures faithful chromosome segregation. Mitotic checkpoint proteins inhibit the anaphase-promoting complex (APC/C) and its activator Cdc20 to prevent precocious anaphase. Checkpoint signaling leads to a complex of APC/C, Cdc20, and checkpoint proteins, in which the APC/C is inactive. In principle, this final product of the mitotic checkpoint can be obtained via different pathways, whose relevance still needs to be fully ascertained experimentally. Here, we use mathematical models to compare the implications on checkpoint response of the possible pathways leading to APC/C inhibition. We identify a previously unrecognized funneling effect for Cdc20, which favors Cdc20 incorporation into the inhibitory complex and therefore promotes checkpoint activity. Furthermore, we find that the presence or absence of one specific assembly reaction determines whether the checkpoint remains functional at elevated levels of Cdc20, which can occur in cancer cells. Our results reveal the inhibitory logics behind checkpoint activity, predict checkpoint efficiency in perturbed situations, and could inform molecular strategies to treat malignancies that exhibit Cdc20 overexpression. Cell division is a fundamental event in the life of cells. It requires that a mother cell gives rise to two daughters which carry the same genetic material of their mother. Thus, during each cell cycle the genetic material needs to be replicated, compacted into chromosomes and redistributed to the two daughter cells. Any mistake in chromosome segregation would attribute the wrong number of chromosomes to the progeny. Hence, the process of chromosome segregation is closely watched by a surveillance mechanism known as the mitotic checkpoint. The molecular players of the checkpoint pathway are well known: we know both the input (ie, the species to be inhibited and their inhibitors), and the output (ie, the inhibited species). However, we do not exactly know the path that leads from the former to the latter. In this manuscript, we use a mathematical approach to explore the properties of plausible mitotic checkpoint networks. We find that seemingly similar circuits show very different behaviors for high levels of the protein targeted by the mitotic checkpoint, Cdc20. Interestingly, this protein is often overexpressed in cancer cells. For physiological levels of Cdc20, instead, all the models we have analyzed are capable to mount an efficient response. We find that this is due to a series of consecutive protein-protein binding reactions that funnel Cdc20 towards its inhibited state. We call this the funneling effect. Our analysis helps understanding the inhibitory logics underlying the checkpoint, and proposes new concepts that could be applied to other inhibitory pathways.
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Affiliation(s)
- Fridolin Gross
- Istituto Firc di Oncologia Molecolare, IFOM, Milano, Italy
| | - Paolo Bonaiuti
- Istituto Firc di Oncologia Molecolare, IFOM, Milano, Italy
| | - Silke Hauf
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States of America
- Biocomplexity Institute, Virginia Tech, Blacksburg, VA, United States of America
- Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA, United States of America
- * E-mail: (SH); (AC)
| | - Andrea Ciliberto
- Istituto Firc di Oncologia Molecolare, IFOM, Milano, Italy
- Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche (IGM-CNR), Pavia, Italy
- * E-mail: (SH); (AC)
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47
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Loss of Kif18A Results in Spindle Assembly Checkpoint Activation at Microtubule-Attached Kinetochores. Curr Biol 2018; 28:2685-2696.e4. [DOI: 10.1016/j.cub.2018.06.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/21/2018] [Accepted: 06/13/2018] [Indexed: 11/18/2022]
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48
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Alfieri C, Chang L, Barford D. Mechanism for remodelling of the cell cycle checkpoint protein MAD2 by the ATPase TRIP13. Nature 2018; 559:274-278. [PMID: 29973720 PMCID: PMC6057611 DOI: 10.1038/s41586-018-0281-1] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 05/16/2018] [Indexed: 11/09/2022]
Abstract
The maintenance of genome stability during mitosis is coordinated by the spindle assembly checkpoint (SAC) through its effector the mitotic checkpoint complex (MCC), an inhibitor of the anaphase-promoting complex (APC/C, also known as the cyclosome)1,2. Unattached kinetochores control MCC assembly by catalysing a change in the topology of the β-sheet of MAD2 (an MCC subunit), thereby generating the active closed MAD2 (C-MAD2) conformer3-5. Disassembly of free MCC, which is required for SAC inactivation and chromosome segregation, is an ATP-dependent process driven by the AAA+ ATPase TRIP13. In combination with p31comet, an SAC antagonist6, TRIP13 remodels C-MAD2 into inactive open MAD2 (O-MAD2)7-10. Here, we present a mechanism that explains how TRIP13-p31comet disassembles the MCC. Cryo-electron microscopy structures of the TRIP13-p31comet-C-MAD2-CDC20 complex reveal that p31comet recruits C-MAD2 to a defined site on the TRIP13 hexameric ring, positioning the N terminus of C-MAD2 (MAD2NT) to insert into the axial pore of TRIP13 and distorting the TRIP13 ring to initiate remodelling. Molecular modelling suggests that by gripping MAD2NT within its axial pore, TRIP13 couples sequential ATP-driven translocation of its hexameric ring along MAD2NT to push upwards on, and simultaneously rotate, the globular domains of the p31comet-C-MAD2 complex. This unwinds a region of the αA helix of C-MAD2 that is required to stabilize the C-MAD2 β-sheet, thus destabilizing C-MAD2 in favour of O-MAD2 and dissociating MAD2 from p31comet. Our study provides insights into how specific substrates are recruited to AAA+ ATPases through adaptor proteins and suggests a model of how translocation through the axial pore of AAA+ ATPases is coupled to protein remodelling.
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Affiliation(s)
| | - Leifu Chang
- MRC Laboratory of Molecular Biology, Cambridge, UK
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
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49
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Schuyler SC, Wu YFO, Chen HY, Ding YS, Lin CJ, Chu YT, Chen TC, Liao L, Tsai WW, Huang A, Wang LI, Liao TW, Jhuo JH, Cheng V. Peptide inhibitors of the anaphase promoting-complex that cause sensitivity to microtubule poison. PLoS One 2018; 13:e0198930. [PMID: 29883473 PMCID: PMC5993284 DOI: 10.1371/journal.pone.0198930] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 05/29/2018] [Indexed: 02/01/2023] Open
Abstract
There is an interest in identifying Anaphase Promoting-Complex/Cyclosome (APC/C) inhibitors that lead to sensitivity to microtubule poisons as a strategy for targeting cancer cells. Using budding yeast Saccharomyces cerevisiae, peptides derived from the Mitotic Arrest Deficient 2 (Mad2)-binding motif of Cell Division Cycle 20 (Cdc20) were observed to inhibit both Cdc20- and CDC20 Homology 1 (Cdh1)-dependent APC/C activity. Over expression of peptides in vivo led to sensitivity to a microtubule poison and, in a recovery from a microtubule poison arrest, delayed degradation of yeast Securin protein Precocious Dissociation of Sisters 1 (Pds1). Peptides with mutations in the Cdc20 activating KILR-motif still bound APC/C, but lost the ability to inhibit APC/C in vitro and lost the ability to induce sensitivity to a microtubule poison in vivo. Thus, an APC/C binding and activation motif that promotes mitotic progression, namely the Cdc20 KILR-motif, can also function as an APC/C inhibitor when present in excess. Another activator for mitotic progression after recovery from microtubule poison is p31comet, where a yeast predicted open-reading frame YBR296C-A encoding a 39 amino acid predicted protein was identified by homology to p31comet, and named Tiny Yeast Comet 1 (TYC1). Tyc1 over expression resulted in sensitivity to microtubule poison. Tyc1 inhibited both APC/CCdc20 and APC/CCdh1 activities in vitro and bound to APC/C. A homologous peptide derived from human p31comet bound to and inhibited yeast APC/C demonstrating evolutionary retention of these biochemical activities. Cdc20 Mad2-binding motif peptides and Tyc1 disrupted the ability of the co-factors Cdc20 and Cdh1 to bind to APC/C, and co-over expression of both together in vivo resulted in an increased sensitivity to microtubule poison. We hypothesize that Cdc20 Mad2-binding motif peptides, Tyc1 and human hp31 peptide can serve as novel molecular tools for investigating APC/C inhibition that leads to sensitivity to microtubule poison in vivo.
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Affiliation(s)
- Scott C. Schuyler
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
- Division of Colorectal Surgery, Department of Surgery, Chang Gung Memorial Hospital, Kwei-Shan, Tao-Yuan, Taiwan
- * E-mail:
| | - Yueh-Fu Olivia Wu
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
| | - Hsin-Yu Chen
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
| | - Yi-Shan Ding
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
| | - Chia-Jung Lin
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
| | - Yu-Ting Chu
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
| | - Ting-Chun Chen
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
| | - Louis Liao
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
| | - Wei-Wei Tsai
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
| | - Anna Huang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
| | - Lin-Ing Wang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
| | - Ting-Wei Liao
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
| | - Jia-Hua Jhuo
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
| | - Vivien Cheng
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
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Mechanistic insight into TRIP13-catalyzed Mad2 structural transition and spindle checkpoint silencing. Nat Commun 2017; 8:1956. [PMID: 29208896 PMCID: PMC5717197 DOI: 10.1038/s41467-017-02012-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 11/01/2017] [Indexed: 01/20/2023] Open
Abstract
The spindle checkpoint maintains genomic stability and prevents aneuploidy. Unattached kinetochores convert the latent open conformer of the checkpoint protein Mad2 (O-Mad2) to the active closed conformer (C-Mad2), bound to Cdc20. C-Mad2–Cdc20 is incorporated into the mitotic checkpoint complex (MCC), which inhibits the anaphase-promoting complex/cyclosome (APC/C). The C-Mad2-binding protein p31comet and the ATPase TRIP13 promote MCC disassembly and checkpoint silencing. Here, using nuclear magnetic resonance (NMR) spectroscopy, we show that TRIP13 and p31comet catalyze the conversion of C-Mad2 to O-Mad2, without disrupting its stably folded core. We determine the crystal structure of human TRIP13, and identify functional TRIP13 residues that mediate p31comet–Mad2 binding and couple ATP hydrolysis to local unfolding of Mad2. TRIP13 and p31comet prevent APC/C inhibition by MCC components, but cannot reactivate APC/C already bound to MCC. Therefore, TRIP13–p31comet intercepts and disassembles free MCC not bound to APC/C through mediating the local unfolding of the Mad2 C-terminal region. The spindle checkpoint ensures the fidelity of chromosome segregation during mitosis and meiosis. Here the authors use a combination of biochemical and structural biology approaches to show how the TRIP13 ATPase and its adaptor, p31comet, catalyze the conversion of the checkpoint protein Mad2 between latent and active forms
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