1
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Liang C, Zhou Y, Xin L, Kang K, Tian L, Zhang D, Li H, Zhao Q, Gao H, Shi Z. Hijacking monopolar spindle 1 (MPS1) for various cancer types by small molecular inhibitors: Deep insights from a decade of research and patents. Eur J Med Chem 2024; 273:116504. [PMID: 38795520 DOI: 10.1016/j.ejmech.2024.116504] [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: 02/29/2024] [Revised: 05/03/2024] [Accepted: 05/13/2024] [Indexed: 05/28/2024]
Abstract
Monopolar spindle 1 (MPS1) has garnered significant attention due to its pivotal role in regulating the cell cycle. Anomalous expression and hyperactivation of MPS1 have been associated with the onset and advancement of diverse cancers, positioning it as a promising target for therapeutic interventions. This review focuses on MPS1 small molecule inhibitors from the past decade, exploring design strategies, structure-activity relationships (SAR), safety considerations, and clinical performance. Notably, we propose prospects for MPS1 degraders based on proteolysis targeting chimeras (PROTACs), as well as reversible covalent bonding as innovative MPS1 inhibitor design strategies. The objective is to provide valuable information for future development and novel perspectives on potential MPS1 inhibitors.
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Affiliation(s)
- Chengyuan Liang
- School of Biological and Pharmaceutical Sciences, Shaanxi University of Science & Technology, Xi'an, 710021, China; Key Laboratory for Antiviral and Antimicrobial-Resistant Bacteria Research of Xi'an, Xi'an, 710021, China.
| | - Ying Zhou
- School of Biological and Pharmaceutical Sciences, Shaanxi University of Science & Technology, Xi'an, 710021, China; Key Laboratory for Antiviral and Antimicrobial-Resistant Bacteria Research of Xi'an, Xi'an, 710021, China
| | - Liang Xin
- School of Biological and Pharmaceutical Sciences, Shaanxi University of Science & Technology, Xi'an, 710021, China; Key Laboratory for Antiviral and Antimicrobial-Resistant Bacteria Research of Xi'an, Xi'an, 710021, China
| | - Kairui Kang
- School of Biological and Pharmaceutical Sciences, Shaanxi University of Science & Technology, Xi'an, 710021, China; Key Laboratory for Antiviral and Antimicrobial-Resistant Bacteria Research of Xi'an, Xi'an, 710021, China
| | - Lei Tian
- Key Laboratory for Antiviral and Antimicrobial-Resistant Bacteria Research of Xi'an, Xi'an, 710021, China; College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science& Technology, Xi'an, 710021, China
| | - Dezhu Zhang
- Key Laboratory for Antiviral and Antimicrobial-Resistant Bacteria Research of Xi'an, Xi'an, 710021, China; Shaanxi Panlong Pharmaceutical Group Co., Ltd., Xi'an, 710025, China
| | - Han Li
- School of Biological and Pharmaceutical Sciences, Shaanxi University of Science & Technology, Xi'an, 710021, China; Shaanxi Pioneer Biotech Co., Ltd., Xi'an, 710082, China
| | - Qianqian Zhao
- School of Biological and Pharmaceutical Sciences, Shaanxi University of Science & Technology, Xi'an, 710021, China; Key Laboratory for Antiviral and Antimicrobial-Resistant Bacteria Research of Xi'an, Xi'an, 710021, China
| | - Hong Gao
- Key Laboratory for Antiviral and Antimicrobial-Resistant Bacteria Research of Xi'an, Xi'an, 710021, China; Shaanxi Pioneer Biotech Co., Ltd., Xi'an, 710082, China
| | - Zhenfeng Shi
- Department of Urology Surgery Center, The People's Hospital of Xinjiang Uyghur Autonomous Region, Urumqi, 830002, China
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2
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Kim S, Lau TT, Liao MK, Ma HT, Poon RY. Coregulation of NDC80 Complex Subunits Determines the Fidelity of the Spindle-Assembly Checkpoint and Mitosis. Mol Cancer Res 2024; 22:423-439. [PMID: 38324016 PMCID: PMC11063766 DOI: 10.1158/1541-7786.mcr-23-0828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/07/2023] [Accepted: 02/05/2024] [Indexed: 02/08/2024]
Abstract
NDC80 complex (NDC80C) is composed of four subunits (SPC24, SPC25, NDC80, and NUF2) and is vital for kinetochore-microtubule (KT-MT) attachment during mitosis. Paradoxically, NDC80C also functions in the activation of the spindle-assembly checkpoint (SAC). This raises an interesting question regarding how mitosis is regulated when NDC80C levels are compromised. Using a degron-mediated depletion system, we found that acute silencing of SPC24 triggered a transient mitotic arrest followed by mitotic slippage. SPC24-deficient cells were unable to sustain SAC activation despite the loss of KT-MT interaction. Intriguingly, our results revealed that other subunits of the NDC80C were co-downregulated with SPC24 at a posttranslational level. Silencing any individual subunit of NDC80C likewise reduced the expression of the entire complex. We found that the SPC24-SPC25 and NDC80-NUF2 subcomplexes could be individually stabilized using ectopically expressed subunits. The synergism of SPC24 downregulation with drugs that promote either mitotic arrest or mitotic slippage further underscored the dual roles of NDC80C in KT-MT interaction and SAC maintenance. The tight coordinated regulation of NDC80C subunits suggests that targeting individual subunits could disrupt mitotic progression and provide new avenues for therapeutic intervention. IMPLICATIONS These results highlight the tight coordinated regulation of NDC80C subunits and their potential as targets for antimitotic therapies.
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Affiliation(s)
- Sehong Kim
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Thomas T.Y. Lau
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Man Kit Liao
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Hoi Tang Ma
- Department of Pathology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong
| | - Randy Y.C. Poon
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
- State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
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3
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Chen Q, Li Y, Shen T, Wang R, Su M, Luo Q, Shi H, Lu G, Wang Z, Hardwick KG, Wang M. Phosphorylation of Mad1 at serine 18 by Mps1 is required for the full virulence of rice blast fungus, Magnaporthe oryzae. MOLECULAR PLANT PATHOLOGY 2024; 25:e13456. [PMID: 38619864 PMCID: PMC11018248 DOI: 10.1111/mpp.13456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 02/14/2024] [Accepted: 03/23/2024] [Indexed: 04/16/2024]
Abstract
The spindle assembly checkpoint (SAC) proteins are conserved among eukaryotes safeguarding chromosome segregation fidelity during mitosis. However, their biological functions in plant-pathogenic fungi remain largely unknown. In this study, we found that the SAC protein MoMad1 in rice blast fungus (Magnaporthe oryzae) localizes on the nuclear envelope and is dispensable for M. oryzae vegetative growth and tolerance to microtubule depolymerizing agent treatment. MoMad1 plays an important role in M. oryzae infection-related development and pathogenicity. The monopolar spindle 1 homologue in M. oryzae (MoMps1) interacts with MoMad1 through its N-terminal domain and phosphorylates MoMad1 at Ser-18, which is conserved within the extended N termini of Mad1s from fungal plant pathogens. This phosphorylation is required for maintaining MoMad1 protein abundance and M. oryzae full virulence. Similar to the deletion of MoMad1, treatment with Mps1-IN-1 (an Mps1 inhibitor) caused compromised appressorium formation and decreased M. oryzae virulence, and these defects were dependent on its attenuating MoMad1 Ser-18 phosphorylation. Therefore, our study indicates the function of Mad1 in rice blast fungal pathogenicity and sheds light on the potential of blocking Mad1 phosphorylation by Mps1 to control crop fungal diseases.
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Affiliation(s)
- Qiushi Chen
- Fujian University Key Laboratory for Plant–Microbe Interaction, College of Plant Protection, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross‐Strait CropsFujian Agriculture and Forestry UniversityFuzhouChina
- State Key Laboratory for Conservation and Utilization of Bio‐Resources in YunnanYunnan Agricultural UniversityKunmingChina
| | - Ya Li
- Fujian University Key Laboratory for Plant–Microbe Interaction, College of Plant Protection, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross‐Strait CropsFujian Agriculture and Forestry UniversityFuzhouChina
| | - Tianjiao Shen
- Fujian University Key Laboratory for Plant–Microbe Interaction, College of Plant Protection, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross‐Strait CropsFujian Agriculture and Forestry UniversityFuzhouChina
| | - Rong Wang
- Fujian University Key Laboratory for Plant–Microbe Interaction, College of Plant Protection, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross‐Strait CropsFujian Agriculture and Forestry UniversityFuzhouChina
| | - Meiling Su
- Fujian University Key Laboratory for Plant–Microbe Interaction, College of Plant Protection, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross‐Strait CropsFujian Agriculture and Forestry UniversityFuzhouChina
| | - Qiong Luo
- State Key Laboratory for Conservation and Utilization of Bio‐Resources in YunnanYunnan Agricultural UniversityKunmingChina
| | - Hua Shi
- State Key Laboratory for Conservation and Utilization of Bio‐Resources in YunnanYunnan Agricultural UniversityKunmingChina
| | - Guodong Lu
- Fujian University Key Laboratory for Plant–Microbe Interaction, College of Plant Protection, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross‐Strait CropsFujian Agriculture and Forestry UniversityFuzhouChina
| | - Zonghua Wang
- Institute of OceanographyMinjiang UniversityFuzhouChina
| | - Kevin G. Hardwick
- Institute of Cell Biology, School of Biological SciencesUniversity of EdinburghEdinburghUK
| | - Mo Wang
- State Key Laboratory for Conservation and Utilization of Bio‐Resources in YunnanYunnan Agricultural UniversityKunmingChina
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4
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Zhang Y, Young R, Garvanska DH, Song C, Zhai Y, Wang Y, Jiang H, Fang J, Nilsson J, Alfieri C, Zhang G. Functional analysis of Cdc20 reveals a critical role of CRY box in mitotic checkpoint signaling. Commun Biol 2024; 7:164. [PMID: 38337031 PMCID: PMC10858191 DOI: 10.1038/s42003-024-05859-6] [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: 09/01/2023] [Accepted: 01/26/2024] [Indexed: 02/12/2024] Open
Abstract
Accurate mitosis is coordinated by the spindle assembly checkpoint (SAC) through the mitotic checkpoint complex (MCC), which inhibits the anaphase-promoting complex or cyclosome (APC/C). As an essential regulator, Cdc20 promotes mitotic exit through activating APC/C and monitors kinetochore-microtubule attachment through activating SAC. Cdc20 requires multiple interactions with APC/C and MCC subunits to elicit these functions. Functionally assessing these interactions within cells requires efficient depletion of endogenous Cdc20, which is highly difficult to achieve by RNA interference (RNAi). Here we generated Cdc20 RNAi-sensitive cell lines which display a penetrant metaphase arrest by a single RNAi treatment. In this null background, we accurately measured the contribution of each known motif of Cdc20 on APC/C and SAC activation. The CRY box, a previously identified degron, was found critical for SAC by promoting MCC formation and its interaction with APC/C. These data reveal additional regulation within the SAC and establish a novel method to interrogate Cdc20.
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Affiliation(s)
- Yuqing Zhang
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Rose Young
- Chester Beatty Laboratories, Structural Biology Division, Institute of Cancer Research, London, UK
| | | | - Chunlin Song
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Yujing Zhai
- School of Public Health, Qingdao University, Qingdao, China
| | - Ying Wang
- School of Public Health, Qingdao University, Qingdao, China
| | - Hongfei Jiang
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Jing Fang
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Jakob Nilsson
- The NNF Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Claudio Alfieri
- Chester Beatty Laboratories, Structural Biology Division, Institute of Cancer Research, London, UK.
| | - Gang Zhang
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.
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5
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Jian Y, Jiang Y, Nie L, Dou Z, Liu X, Fu C. Phosphorylation of Bub1 by Mph1 promotes Bub1 signaling at the kinetochore to ensure accurate chromosome segregation. J Biol Chem 2024; 300:105559. [PMID: 38097187 PMCID: PMC10805674 DOI: 10.1016/j.jbc.2023.105559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 11/30/2023] [Accepted: 12/02/2023] [Indexed: 01/02/2024] Open
Abstract
Bub1 is a conserved mitotic kinase involved in signaling of the spindle assembly checkpoint. Multiple phosphorylation sites on Bub1 have been characterized, yet it is challenging to understand the interplay between the multiple phosphorylation sites due to the limited availability of phosphospecific antibodies. In addition, phosphoregulation of Bub1 in Schizosaccharomyces pombe is poorly understood. Here we report the identification of a new Mph1/Mps1-mediated phosphorylation site, i.e., Ser532, of Bub1 in Schizosaccharomyces pombe. A phosphospecific antibody against phosphorylated Bub1-Ser532 was developed. Using the phosphospecific antibody, we demonstrated that phosphorylation of Bub1-Ser352 was mediated specifically by Mph1/Mps1 and took place during early mitosis. Moreover, live-cell microscopy showed that inhibition of the phosphorylation of Bub1 at Ser532 impaired the localization of Bub1, Mad1, and Mad2 to the kinetochore. In addition, inhibition of the phosphorylation of Bub1 at Ser532 caused anaphase B lagging chromosomes. Hence, our study constitutes a model in which Mph1/Mps1-mediated phosphorylation of fission yeast Bub1 promotes proper kinetochore localization of Bub1 and faithful chromosome segregation.
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Affiliation(s)
- Yanze Jian
- MOE Key Laboratory for Cellular Dynamics & Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China; Anhui Key Laboratory of Cellular Dynamics and Chemical Biology & Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Yueyue Jiang
- MOE Key Laboratory for Cellular Dynamics & Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China; Anhui Key Laboratory of Cellular Dynamics and Chemical Biology & Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Lingyun Nie
- MOE Key Laboratory for Cellular Dynamics & Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China; Anhui Key Laboratory of Cellular Dynamics and Chemical Biology & Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Zhen Dou
- MOE Key Laboratory for Cellular Dynamics & Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China; Anhui Key Laboratory of Cellular Dynamics and Chemical Biology & Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Xing Liu
- MOE Key Laboratory for Cellular Dynamics & Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China; Anhui Key Laboratory of Cellular Dynamics and Chemical Biology & Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Chuanhai Fu
- MOE Key Laboratory for Cellular Dynamics & Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China; Anhui Key Laboratory of Cellular Dynamics and Chemical Biology & Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China.
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6
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Zeng Y, Ren X, Jin P, Zhang Y, Zhuo M, Wang J. Development of MPS1 Inhibitors: Recent Advances and Perspectives. J Med Chem 2023; 66:16484-16514. [PMID: 38095579 DOI: 10.1021/acs.jmedchem.3c00963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Monopolar spindle kinase 1 (MPS1) plays a pivotal role as a dual-specificity kinase governing spindle assembly checkpoint activation and sister chromatid separation in mitosis. Its overexpression has been observed in various human malignancies. MPS1 reduces spindle assembly checkpoint sensitivity, allowing tumor cells with a high degree of aneuploidy to complete mitosis and survive. Thus, MPS1 has emerged as a promising candidate for cancer therapy. Despite the identification of numerous MPS1 inhibitors, only five have advanced to clinical trials with none securing FDA approval for cancer treatment. In this perspective, we provide a concise overview of the structural and functional characteristics of MPS1 by highlighting its relevance to cancer. Additionally, we explore the structure-activity relationships, selectivity, and pharmacokinetics of MPS1 inhibitors featuring diverse scaffolds. Moreover, we review the reported work on enhancing MPS1 inhibitor selectivity, offering valuable insights into the discovery of novel, highly potent small-molecule MPS1 inhibitors.
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Affiliation(s)
- Yangjie Zeng
- Medical College, Guizhou University, Guiyang, Guizhou 550025, China
| | - Xiaodong Ren
- Medical College, Guizhou University, Guiyang, Guizhou 550025, China
| | - Pengyao Jin
- Medical College, Guizhou University, Guiyang, Guizhou 550025, China
| | - Yali Zhang
- Medical College, Guizhou University, Guiyang, Guizhou 550025, China
| | - Ming Zhuo
- Medical College, Guizhou University, Guiyang, Guizhou 550025, China
| | - Jubo Wang
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 210009, China
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Zhang XX, Yu X, Zhu L, Luo JH. Establishment of a 6-signature risk model associated with cellular senescence for predicting the prognosis of breast cancer. Medicine (Baltimore) 2023; 102:e35923. [PMID: 37986376 PMCID: PMC10659633 DOI: 10.1097/md.0000000000035923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/18/2023] [Accepted: 10/12/2023] [Indexed: 11/22/2023] Open
Abstract
This study focused on screening novel markers associated with cellular senescence for predicting the prognosis of breast cancer. The RNA-seq expression profile of BRCA and clinical data were obtained from TCGA. The pam algorithm was used to cluster patients based on senescence-related genes. The weighted gene co-expression network analysis was used to identify co-expressed genes, and LASSO-Cox analysis was performed to build a risk prognosis model. The performance of the model was also evaluated. We additionally explored the role of senescence in cancer development and possible regulatory mechanism. The patients were clustered into 2 subtypes. A total of 5259 genes significantly related to senescence were identified by weighted gene co-expression network analysis. LASSO-Cox finally established a 6-signature risk model (ADAMTS8, DCAF12L2, PCDHA10, PGK1, SLC16A2, and TMEM233) that exhibited favorable and stable performance in our training, validation, and whole BRCA datasets. Furthermore, the superiority of our model was also observed after comparing it to other published models. The 6-signature was proved to be an independent risk factor for prognosis. In addition, mechanism prediction implied the activation of glycometabolism processes such as glycolysis and TCA cycle under the condition of senescence. Glycometabolism pathways were further found to negatively correlate with the infiltration level of CD8 T-cells and natural killer cells but positively correlate with M2 macrophage infiltration and expressions of tissue degeneration biomarkers, which suggested the deficit immune surveillance and risk of tumor migration. The constructed 6-gene model based on cellular senescence could be an effective indicator for predicting the prognosis of BRCA.
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Affiliation(s)
- Xiu-Xia Zhang
- Department of Thyroid and Breast Surgery, Linping Campus, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xin Yu
- Department of Thyroid and Breast Surgery, Linping Campus, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Li Zhu
- Pathology Department, Linping Campus, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jun-Hua Luo
- Department of Thyroid and Breast Surgery, Linping Campus, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
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8
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Jema S, Chen C, Humphrey L, Karmarkar S, Ferrari F, Joglekar AP. Signaling protein abundance modulates the strength of the spindle assembly checkpoint. Curr Biol 2023; 33:4505-4515.e4. [PMID: 37738972 PMCID: PMC10615864 DOI: 10.1016/j.cub.2023.08.074] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 07/19/2023] [Accepted: 08/24/2023] [Indexed: 09/24/2023]
Abstract
During mitosis, unattached kinetochores in a dividing cell signal to the spindle assembly checkpoint (SAC) to delay anaphase onset and prevent chromosome missegregation.1,2,3,4 The signaling activity of these kinetochores and the likelihood of chromosome missegregation depend on the amount of SAC signaling proteins each kinetochore recruits.5,6,7,8 Therefore, factors that control SAC protein recruitment must be thoroughly understood. Phosphoregulation of kinetochore and SAC signaling proteins due to the concerted action of many kinases and phosphatases is a significant determinant of the SAC protein recruitment to signaling kinetochores.9 Whether the abundance of SAC proteins also influences the recruitment and signaling activity of human kinetochores has not been studied.8,10 Here, we reveal that the low cellular abundance of the SAC signaling protein Bub1 limits its own recruitment and that of BubR1 and restricts the SAC signaling activity of the kinetochore. Conversely, Bub1 overexpression results in higher recruitment of SAC proteins, producing longer delays in anaphase onset. We also find that the number of SAC proteins recruited by a signaling kinetochore is inversely correlated with the total number of signaling kinetochores in the cell. This correlation likely arises from the competition among the signaling kinetochores to recruit from a limited pool of signaling proteins, including Bub1. The inverse correlation may allow the dividing cell to prevent a large number of signaling kinetochores in early prophase from generating an overly large signal while enabling the last unaligned kinetochore in late prometaphase to signal at the maximum strength.
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Affiliation(s)
- Soubhagyalaxmi Jema
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Chu Chen
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lauren Humphrey
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Shriya Karmarkar
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Frank Ferrari
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Ajit P Joglekar
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA.
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9
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Corno A, Cordeiro MH, Allan LA, Lim Q, Harrington E, Smith RJ, Saurin AT. A bifunctional kinase-phosphatase module balances mitotic checkpoint strength and kinetochore-microtubule attachment stability. EMBO J 2023; 42:e112630. [PMID: 37712330 PMCID: PMC10577578 DOI: 10.15252/embj.2022112630] [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: 09/16/2022] [Revised: 08/23/2023] [Accepted: 08/28/2023] [Indexed: 09/16/2023] Open
Abstract
Two major mechanisms safeguard genome stability during mitosis: the mitotic checkpoint delays mitosis until all chromosomes have attached to microtubules, and the kinetochore-microtubule error-correction pathway keeps this attachment process free from errors. We demonstrate here that the optimal strength and dynamics of these processes are set by a kinase-phosphatase pair (PLK1-PP2A) that engage in negative feedback from adjacent phospho-binding motifs on the BUB complex. Uncoupling this feedback to skew the balance towards PLK1 produces a strong checkpoint, hypostable microtubule attachments and mitotic delays. Conversely, skewing the balance towards PP2A causes a weak checkpoint, hyperstable microtubule attachments and chromosome segregation errors. These phenotypes are associated with altered BUB complex recruitment to KNL1-MELT motifs, implicating PLK1-PP2A in controlling auto-amplification of MELT phosphorylation. In support, KNL1-BUB disassembly becomes contingent on PLK1 inhibition when KNL1 is engineered to contain excess MELT motifs. This elevates BUB-PLK1/PP2A complex levels on metaphase kinetochores, stabilises kinetochore-microtubule attachments, induces chromosome segregation defects and prevents KNL1-BUB disassembly at anaphase. Together, these data demonstrate how a bifunctional PLK1/PP2A module has evolved together with the MELT motifs to optimise BUB complex dynamics and ensure accurate chromosome segregation.
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Affiliation(s)
- Andrea Corno
- Cellular and Systems Medicine, School of MedicineUniversity of DundeeDundeeUK
| | - Marilia H Cordeiro
- Cellular and Systems Medicine, School of MedicineUniversity of DundeeDundeeUK
| | - Lindsey A Allan
- Cellular and Systems Medicine, School of MedicineUniversity of DundeeDundeeUK
| | - Qian‐Wei Lim
- Cellular and Systems Medicine, School of MedicineUniversity of DundeeDundeeUK
| | - Elena Harrington
- Cellular and Systems Medicine, School of MedicineUniversity of DundeeDundeeUK
| | - Richard J Smith
- Cellular and Systems Medicine, School of MedicineUniversity of DundeeDundeeUK
| | - Adrian T Saurin
- Cellular and Systems Medicine, School of MedicineUniversity of DundeeDundeeUK
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10
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Ma JJ, Xiang C, Wang JW. TTK is a potential regulator of tumor progression correlated with dedifferentiation and immune cell infiltration in papillary thyroid cancer. Aging (Albany NY) 2023; 15:10607-10626. [PMID: 37815894 PMCID: PMC10599754 DOI: 10.18632/aging.205100] [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: 05/12/2023] [Accepted: 09/09/2023] [Indexed: 10/12/2023]
Abstract
OBJECTIVE To investigate the role and clinical significance of threonine tyrosine kinase (TTK) in papillary thyroid cancer (PTC). METHODS TTK expression in PTC and normal groups were compared using TCGA data and in vitro experiments. The prognostic value of TTK and its possible role in PTC dedifferentiation was evaluated. Next, TTK involvement in PTC occurrence and progression was analyzed via in vitro experiments. Subsequently, analyses of enrichment and immune cell infiltration were conducted to reveal the possible mechanism. Finally, we predicted the target miRNAs followed by performing a luciferase reporter experiment. RESULTS TTK upregulation was observed in PTC, and its elevated level was significantly related to an unfavorable prognosis (P < 0.05). Interestingly, TTK negatively correlated with thyroid differentiation score (TDS), and patients with higher TDS showed longer survival (all P < 0.05). PTC cell growth, migration, and invasion were inhibited upon TTK knockdown. Besides, TTK was involved in metabolic processes and regulated cell adhesion molecules pathway. Its overexpression was positively associated with immune cell infiltrates (P < 0.05). Moreover, miR-582-5p was an upstream target of TTK. CONCLUSION TTK serves as a potential biomarker for tumorigenesis and prognosis in PTC, especially for those that may differentiate into more aggressive thyroid cancers.
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Affiliation(s)
- Jun-Jie Ma
- Department of Thyroid Surgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310009, Zhejiang, China
| | - Cheng Xiang
- Department of Thyroid Surgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310009, Zhejiang, China
| | - Jian-Wei Wang
- The Colorectal Surgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310009, Zhejiang, China
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Zhou KD, Zhang CX, Niu FR, Bai HC, Wu DD, Deng JC, Qian HY, Jiang YL, Ma W. Exploring Plant Meiosis: Insights from the Kinetochore Perspective. Curr Issues Mol Biol 2023; 45:7974-7995. [PMID: 37886947 PMCID: PMC10605258 DOI: 10.3390/cimb45100504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/12/2023] [Accepted: 09/20/2023] [Indexed: 10/28/2023] Open
Abstract
The central player for chromosome segregation in both mitosis and meiosis is the macromolecular kinetochore structure, which is assembled by >100 structural and regulatory proteins on centromere DNA. Kinetochores play a crucial role in cell division by connecting chromosomal DNA and microtubule polymers. This connection helps in the proper segregation and alignment of chromosomes. Additionally, kinetochores can act as a signaling hub, regulating the start of anaphase through the spindle assembly checkpoint, and controlling the movement of chromosomes during anaphase. However, the role of various kinetochore proteins in plant meiosis has only been recently elucidated, and these proteins differ in their functionality from those found in animals. In this review, our current knowledge of the functioning of plant kinetochore proteins in meiosis will be summarized. In addition, the functional similarities and differences of core kinetochore proteins in meiosis between plants and other species are discussed, and the potential applications of manipulating certain kinetochore genes in meiosis for breeding purposes are explored.
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Affiliation(s)
- Kang-Di Zhou
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (K.-D.Z.); (C.-X.Z.)
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (H.-C.B.); (J.-C.D.); (H.-Y.Q.); (Y.-L.J.)
| | - Cai-Xia Zhang
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (K.-D.Z.); (C.-X.Z.)
| | - Fu-Rong Niu
- College of Forestry, Gansu Agricultural University, Lanzhou 730070, China;
| | - Hao-Chen Bai
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (H.-C.B.); (J.-C.D.); (H.-Y.Q.); (Y.-L.J.)
| | - Dan-Dan Wu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China;
| | - Jia-Cheng Deng
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (H.-C.B.); (J.-C.D.); (H.-Y.Q.); (Y.-L.J.)
| | - Hong-Yuan Qian
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (H.-C.B.); (J.-C.D.); (H.-Y.Q.); (Y.-L.J.)
| | - Yun-Lei Jiang
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (H.-C.B.); (J.-C.D.); (H.-Y.Q.); (Y.-L.J.)
| | - Wei Ma
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (K.-D.Z.); (C.-X.Z.)
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12
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Ide AH, DeLuca KF, Wiggan O, Markus SM, DeLuca JG. The role of kinetochore dynein in checkpoint silencing is restricted to disassembly of the corona. Mol Biol Cell 2023; 34:ar76. [PMID: 37126397 PMCID: PMC10295480 DOI: 10.1091/mbc.e23-04-0130] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 04/20/2023] [Indexed: 05/02/2023] Open
Abstract
During mitosis, kinetochore-microtubule attachments are monitored by a molecular surveillance system known as the spindle assembly checkpoint. The prevailing model posits that dynein evicts checkpoint proteins (e.g., Mad1, Mad2) from stably attached kinetochores by transporting them away from kinetochores, thus contributing to checkpoint silencing. However, the mechanism by which dynein performs this function, and its precise role in checkpoint silencing remain unresolved. Here, we find that dynein's role in checkpoint silencing is restricted to evicting checkpoint effectors from the fibrous corona, and not the outer kinetochore. Dynein evicts these molecules from the corona in a manner that does not require stable, end-on microtubule attachments. Thus, by disassembling the corona through indiscriminate microtubule encounters, dynein primes the checkpoint signaling apparatus so it can respond to stable end-on microtubule attachments and permit cells to progress through mitosis. Accordingly, we find that dynein function in checkpoint silencing becomes largely dispensable in cells in which checkpoint effectors are excluded from the corona.
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Affiliation(s)
- Amy H. Ide
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523
| | - Keith F. DeLuca
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523
| | - O’Neil Wiggan
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523
| | - Steven M. Markus
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523
| | - Jennifer G. DeLuca
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523
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13
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Tsang MJ, Cheeseman IM. Alternative CDC20 translational isoforms tune mitotic arrest duration. Nature 2023; 617:154-161. [PMID: 37100900 PMCID: PMC10461078 DOI: 10.1038/s41586-023-05943-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 03/13/2023] [Indexed: 04/28/2023]
Abstract
Mitotic defects activate the spindle-assembly checkpoint, which inhibits the anaphase-promoting complex co-activator CDC20 to induce a prolonged cell cycle arrest1,2. Once errors are corrected, the spindle-assembly checkpoint is silenced, allowing anaphase onset to occur. However, in the presence of persistent unresolvable errors, cells can undergo 'mitotic slippage', exiting mitosis into a tetraploid G1 state and escaping the cell death that results from a prolonged arrest. The molecular logic that enables cells to balance these duelling mitotic arrest and slippage behaviours remains unclear. Here we demonstrate that human cells modulate the duration of their mitotic arrest through the presence of conserved, alternative CDC20 translational isoforms. Downstream translation initiation results in a truncated CDC20 isoform that is resistant to spindle-assembly-checkpoint-mediated inhibition and promotes mitotic exit even in the presence of mitotic perturbations. Our study supports a model in which the relative levels of CDC20 translational isoforms control the duration of mitotic arrest. During a prolonged mitotic arrest, new protein synthesis and differential CDC20 isoform turnover create a timer, with mitotic exit occurring once the truncated Met43 isoform achieves sufficient levels. Targeted molecular changes or naturally occurring cancer mutations that alter CDC20 isoform ratios or its translational control modulate mitotic arrest duration and anti-mitotic drug sensitivity, with potential implications for the diagnosis and treatment of human cancers.
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Affiliation(s)
- Mary-Jane Tsang
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Iain M Cheeseman
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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14
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MacKenzie A, Vicory V, Lacefield S. Meiotic cells escape prolonged spindle checkpoint activity through kinetochore silencing and slippage. PLoS Genet 2023; 19:e1010707. [PMID: 37018287 PMCID: PMC10109492 DOI: 10.1371/journal.pgen.1010707] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 04/17/2023] [Accepted: 03/20/2023] [Indexed: 04/06/2023] Open
Abstract
To prevent chromosome mis-segregation, a surveillance mechanism known as the spindle checkpoint delays the cell cycle if kinetochores are not attached to spindle microtubules, allowing the cell additional time to correct improper attachments. During spindle checkpoint activation, checkpoint proteins bind the unattached kinetochore and send a diffusible signal to inhibit the anaphase promoting complex/cyclosome (APC/C). Previous work has shown that mitotic cells with depolymerized microtubules can escape prolonged spindle checkpoint activation in a process called mitotic slippage. During slippage, spindle checkpoint proteins bind unattached kinetochores, but the cells cannot maintain the checkpoint arrest. We asked if meiotic cells had as robust of a spindle checkpoint response as mitotic cells and whether they also undergo slippage after prolonged spindle checkpoint activity. We performed a direct comparison between mitotic and meiotic budding yeast cells that signal the spindle checkpoint through two different assays. We find that the spindle checkpoint delay is shorter in meiosis I or meiosis II compared to mitosis, overcoming a checkpoint arrest approximately 150 minutes earlier in meiosis than in mitosis. In addition, cells in meiosis I escape spindle checkpoint signaling using two mechanisms, silencing the checkpoint at the kinetochore and through slippage. We propose that meiotic cells undertake developmentally-regulated mechanisms to prevent persistent spindle checkpoint activity to ensure the production of gametes.
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Affiliation(s)
- Anne MacKenzie
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Victoria Vicory
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Soni Lacefield
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
- Department of Biochemistry and Cell Biology, the Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
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15
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Jiao Y, Li S, Gong J, Zheng K, Xie Y. Comprehensive analysis of the expression and prognosis for RAI2: A promising biomarker in breast cancer. Front Oncol 2023; 13:1134149. [PMID: 37064084 PMCID: PMC10090471 DOI: 10.3389/fonc.2023.1134149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 03/20/2023] [Indexed: 03/31/2023] Open
Abstract
IntroductionRetinoic acid-induced 2 (RAI2) was initially related to cell differentiation and induced by retinoic acid. RAI2 has been identified as an emerging tumor suppressor in breast cancer and colorectal cancer.MethodsIn this study, we performed systematic analyses of RAI2 in breast cancer. Meta-analysis and Kaplan-Meier survival curves were applied to identify the survival prediction potential of RAI2. Moreover, the association between RAI2 expression and the abundance of six tumor-infiltrating immune cells was investigated by TIMER, including B cells, CD8+ T cells, CD4+ T cells, B cells, dendritic cells, neutrophils, and macrophages. The expression profiles of high and low RAI2 mRNA levels in GSE7390 were compared to identify differentially expressed genes (DEGs) and the biological function of these DEGs was analyzed by R software, which was further proved in GSE7390.ResultsOur results showed that the normal tissues had more RAI2 expression than breast cancer tissues. Patients with high RAI2 expression were related to a favorable prognosis and more immune infiltrates. A total of 209 DEGs and 182 DEGs were identified between the expression profiles of high and low RAI2 mRNA levels in the GSE7390 and GSE21653 databases, respectively. Furthermore, Gene Ontology (GO) enrichment indicated that these DEGs from two datasets were both mainly distributed in “biological processes” (BP), including “organelle fission” and “nuclear division”. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis demonstrated that these DEGs from two datasets were both significantly enriched in the “cell cycle”. Common hub genes between the DEGs in GSE7390 and GSE21653 were negatively associated with RAI2 expression, including CCNA2, MAD2L1, MELK, CDC20, and CCNB2.DiscussionsThese results above suggested that RAI2 might play a pivotal role in preventing the initiation and progression of breast cancer. The present study may contribute to understanding the molecular mechanisms of RAI2 and enriching biomarkers to predict patient prognosis in breast cancer.
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Affiliation(s)
- Ying Jiao
- Department of Oncology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Shiyu Li
- Department of Oncology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Juejun Gong
- Department of Oncology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kun Zheng
- Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Ya Xie
- Department of Gynecology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- *Correspondence: Ya Xie,
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16
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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: 55] [Impact Index Per Article: 55.0] [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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17
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Chen C, Piano V, Alex A, Han SJY, Huis In 't Veld PJ, Roy B, Fergle D, Musacchio A, Joglekar AP. The structural flexibility of MAD1 facilitates the assembly of the Mitotic Checkpoint Complex. Nat Commun 2023; 14:1529. [PMID: 36934097 PMCID: PMC10024682 DOI: 10.1038/s41467-023-37235-z] [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: 06/26/2022] [Accepted: 03/08/2023] [Indexed: 03/20/2023] Open
Abstract
The spindle assembly checkpoint (SAC) safeguards the genome during cell division by generating an effector molecule known as the Mitotic Checkpoint Complex (MCC). The MCC comprises two subcomplexes: BUBR1:BUB3 and CDC20:MAD2, and the formation of CDC20:MAD2 is the rate-limiting step during MCC assembly. Recent studies show that the rate of CDC20:MAD2 formation is significantly accelerated by the cooperative binding of CDC20 to the SAC proteins MAD1 and BUB1. However, the molecular basis for this acceleration is not fully understood. Here, we demonstrate that the structural flexibility of MAD1 at a conserved hinge near the C-terminus is essential for catalytic MCC assembly. This MAD1 hinge enables the MAD1:MAD2 complex to assume a folded conformation in vivo. Importantly, truncating the hinge reduces the rate of MCC assembly in vitro and SAC signaling in vivo. Conversely, mutations that preserve hinge flexibility retain SAC signaling, indicating that the structural flexibility of the hinge, rather than a specific amino acid sequence, is important for SAC signaling. We summarize these observations as the 'knitting model' that explains how the folded conformation of MAD1:MAD2 promotes CDC20:MAD2 assembly.
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Affiliation(s)
- Chu Chen
- Biophysics, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Molecular Genetics of Ageing, Max Planck Institute for Biology of Ageing, Cologne, 50931, Germany
| | - Valentina Piano
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, 44227, Germany
- Institute of Human Genetics, University Hospital Cologne, Cologne, 50931, Germany
| | - Amal Alex
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, 44227, Germany
| | - Simon J Y Han
- Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
- Medical Scientist Training Program, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Pim J Huis In 't Veld
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, 44227, Germany
| | - Babhrubahan Roy
- Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Daniel Fergle
- Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, 44227, Germany
- Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen, 45141, Germany
| | - Ajit P Joglekar
- Biophysics, University of Michigan, Ann Arbor, MI, 48109, USA.
- Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
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18
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MacKenzie A, Vicory V, Lacefield S. Meiotic Cells Escape Prolonged Spindle Checkpoint Activity Through Premature Silencing and Slippage. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.02.522494. [PMID: 36711621 PMCID: PMC9881877 DOI: 10.1101/2023.01.02.522494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
To prevent chromosome mis-segregation, a surveillance mechanism known as the spindle checkpoint delays the cell cycle if kinetochores are not attached to spindle microtubules, allowing the cell additional time to correct improper attachments. During spindle checkpoint activation, checkpoint proteins bind the unattached kinetochore and send a diffusible signal to inhibit the anaphase promoting complex/cyclosome (APC/C). Previous work has shown that mitotic cells with depolymerized microtubules can escape prolonged spindle checkpoint activation in a process called mitotic slippage. During slippage, spindle checkpoint proteins bind unattached kinetochores, but the cells cannot maintain the checkpoint arrest. We asked if meiotic cells had as robust of a spindle checkpoint response as mitotic cells and whether they also undergo slippage after prolonged spindle checkpoint activity. We performed a direct comparison between mitotic and meiotic budding yeast cells that signal the spindle checkpoint due to a lack of either kinetochore-microtubule attachments or due to a loss of tension-bearing attachments. We find that the spindle checkpoint is not as robust in meiosis I or meiosis II compared to mitosis, overcoming a checkpoint arrest approximately 150 minutes earlier in meiosis. In addition, cells in meiosis I escape spindle checkpoint signaling using two mechanisms, silencing the checkpoint at the kinetochore and through slippage. We propose that meiotic cells undertake developmentally-regulated mechanisms to prevent persistent spindle checkpoint activity to ensure the production of gametes. AUTHOR SUMMARY Mitosis and meiosis are the two major types of cell divisions. Mitosis gives rise to genetically identical daughter cells, while meiosis is a reductional division that gives rise to gametes. Cell cycle checkpoints are highly regulated surveillance mechanisms that prevent cell cycle progression when circumstances are unfavorable. The spindle checkpoint promotes faithful chromosome segregation to safeguard against aneuploidy, in which cells have too many or too few chromosomes. The spindle checkpoint is activated at the kinetochore and then diffuses to inhibit cell cycle progression. Although the checkpoint is active in both mitosis and meiosis, most studies involving checkpoint regulation have been performed in mitosis. By activating the spindle checkpoint in both mitosis and meiosis in budding yeast, we show that cells in meiosis elicit a less persistent checkpoint signal compared to cells in mitosis. Further, we show that cells use distinct mechanisms to escape the checkpoint in mitosis and meiosis I. While cells in mitosis and meiosis II undergo anaphase onset while retaining checkpoint proteins at the kinetochore, cells in meiosis I prematurely lose checkpoint protein localization at the kinetochore. If the mechanism to remove the checkpoint components from the kinetochore is disrupted, meiosis I cells can still escape checkpoint activity. Together, these results highlight that cell cycle checkpoints are differentially regulated during meiosis to avoid long delays and to allow gametogenesis.
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Affiliation(s)
- Anne MacKenzie
- Department of Biology, Indiana University, Bloomington, IN USA
| | - Victoria Vicory
- Department of Biology, Indiana University, Bloomington, IN USA
| | - Soni Lacefield
- Department of Biology, Indiana University, Bloomington, IN USA,Department of Biochemistry and Cell Biology, the Geisel School of Medicine at Dartmouth, Hanover, NH USA,To whom correspondence should be addressed to Soni Lacefield:
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19
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Fischer ES. Kinetochore‐catalyzed MCC
formation: A structural perspective. IUBMB Life 2022; 75:289-310. [PMID: 36518060 DOI: 10.1002/iub.2697] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/08/2022] [Indexed: 12/23/2022]
Abstract
The spindle assembly checkpoint (SAC) is a cellular surveillance mechanism that functions to ensure accurate chromosome segregation during mitosis. Macromolecular complexes known as kinetochores, act as the interface of sister chromatid attachment to spindle microtubules. In response to unattached kinetochores, the SAC activates its effector, the mitotic checkpoint complex (MCC), which delays mitotic exit until all sister chromatid pairs have achieved successful attachment to the bipolar mitotic spindle. Formation of the MCC (composed of Mad2, BubR1, Bub3 and Cdc20) is regulated by an Mps1 kinase-dependent phosphorylation signaling cascade which assembles and repositions components of the MCC onto a catalytic scaffold. This scaffold functions to catalyze the conversion of the HORMA-domain protein Mad2 from an "inactive" open-state (O-Mad2) into an "active" closed-Mad2 (C-Mad2), and simultaneous Cdc20 binding. Here, our current understanding of the molecular mechanisms underlying the kinetic barrier to C-Mad2:Cdc20 formation will be reviewed. Recent progress in elucidating the precise molecular choreography orchestrated by the catalytic scaffold to rapidly assemble the MCC will be examined, and unresolved questions will be highlighted. Ultimately, understanding how the SAC rapidly activates the checkpoint not only provides insights into how cells maintain genomic integrity during mitosis, but also provides a paradigm for how cells can utilize molecular switches, including other HORMA domain-containing proteins, to make rapid changes to a cell's physiological state.
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Affiliation(s)
- Elyse S. Fischer
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus Cambridge UK
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20
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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: 12] [Impact Index Per Article: 6.0] [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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21
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Francois L, Boskovic P, Knerr J, He W, Sigismondo G, Schwan C, More TH, Schlotter M, Conway ME, Krijgsveld J, Hiller K, Grosse R, Lichter P, Radlwimmer B. BCAT1 redox function maintains mitotic fidelity. Cell Rep 2022; 41:111524. [PMID: 36260995 DOI: 10.1016/j.celrep.2022.111524] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 08/15/2022] [Accepted: 09/26/2022] [Indexed: 11/16/2022] Open
Abstract
The metabolic enzyme branched-chain amino acid transaminase 1 (BCAT1) drives cell proliferation in aggressive cancers such as glioblastoma. Here, we show that BCAT1 localizes to mitotic structures and has a non-metabolic function as a mitotic regulator. Furthermore, BCAT1 is required for chromosome segregation in cancer and induced pluripotent stem cells and tumor growth in human cerebral organoid and mouse syngraft models. Applying gene knockout and rescue strategies, we show that the BCAT1 CXXC redox motif is crucial for controlling cysteine sulfenylation specifically in mitotic cells, promoting Aurora kinase B localization to centromeres, and securing accurate chromosome segregation. These findings offer an explanation for the well-established role of BCAT1 in promoting cancer cell proliferation. In summary, our data establish BCAT1 as a component of the mitotic apparatus that safeguards mitotic fidelity through a moonlighting redox functionality.
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Affiliation(s)
- Liliana Francois
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Pavle Boskovic
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; Faculty of Biosciences, Heidelberg University, 69120 Heidelberg, Germany
| | - Julian Knerr
- Institute of Pharmacology, University of Freiburg, 79102 Freiburg, Germany
| | - Wei He
- Integrated Center of Systems Biology (BRICS), Technische Universität Braunschweig, and Computational Biology of Infection Research, Helmholtz Centre for Infection Research, Braunschweig, 38092 Braunschweig, Germany
| | - Gianluca Sigismondo
- Division of Proteomics of Stem Cells and Cancer, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Carsten Schwan
- Institute of Pharmacology, University of Freiburg, 79102 Freiburg, Germany
| | - Tushar H More
- Integrated Center of Systems Biology (BRICS), Technische Universität Braunschweig, and Computational Biology of Infection Research, Helmholtz Centre for Infection Research, Braunschweig, 38092 Braunschweig, Germany
| | - Magdalena Schlotter
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Myra E Conway
- College of Science and Engineering, University of Derby, Derby DE22 1GB, UK
| | - Jeroen Krijgsveld
- Division of Proteomics of Stem Cells and Cancer, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Karsten Hiller
- Integrated Center of Systems Biology (BRICS), Technische Universität Braunschweig, and Computational Biology of Infection Research, Helmholtz Centre for Infection Research, Braunschweig, 38092 Braunschweig, Germany
| | - Robert Grosse
- Institute of Pharmacology, University of Freiburg, 79102 Freiburg, Germany
| | - Peter Lichter
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Bernhard Radlwimmer
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.
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22
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Inhibition of Mps1 kinase enhances taxanes efficacy in castration resistant prostate cancer. Cell Death Dis 2022; 13:868. [PMID: 36229449 PMCID: PMC9561175 DOI: 10.1038/s41419-022-05312-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 09/19/2022] [Accepted: 09/29/2022] [Indexed: 01/23/2023]
Abstract
Androgen ablation therapy is the standard of care for newly diagnosed prostate cancer (PC) patients. PC that relapsed after hormonal therapy, referred to as castration-resistant PC (CRPC), often presents with metastasis (mCRPC) and is the major cause of disease lethality. The few available therapies for mCRPC include the Taxanes Docetaxel (DTX) and Cabazitaxel (CBZ). Alas, clinical success of Taxanes in mCRPC is limited by high intrinsic and acquired resistance. Therefore, it remains essential to develop rationally designed treatments for managing therapy-resistant mCRPC disease. The major effect of Taxanes on microtubule hyper-polymerization is a prolonged mitotic block due to activation of the Spindle Assembly Checkpoint (SAC). Taxane-sensitive cells eventually inactivate SAC and exit mitosis by mitotic catastrophe, resulting in genome instability and blockade of proliferation. Resistant cells remain in mitotic block, and, upon drug decay, resume mitosis and proliferation, underlying one resistance mechanism. In our study we explored the possibility of forced mitotic exit to elevate Taxane efficacy. Inactivation of the SAC component, mitotic checkpoint kinase Mps1/TTK with a small molecule inhibitor (Msp1i), potentiated efficacy of Taxanes treatment in both 2D cell culture and 3D prostasphere settings. Mechanistically, Mps1 inhibition forced mitotic catastrophe in cells blocked in mitosis by Taxanes. Androgen receptor (AR), the main driver of PC, is often mutated or truncated in mCRPC. Remarkably, Mps1i significantly potentiated CBZ cytotoxicity regardless of AR status, in both AR-WT and in AR-truncated CRPC cells. Overall, our data demonstrate that forced mitotic exit by Mps1 inhibition potentiates Taxanes efficacy. Given that several Mps1i's are currently in different stages of clinical trials, our results point to Mps1 as a new therapeutic target to potentiate efficacy of Taxanes in mCRPC patients.
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23
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Banerjee A, Chen C, Humphrey L, Tyson JJ, Joglekar AP. BubR1 recruitment to the kinetochore via Bub1 enhances spindle assembly checkpoint signaling. Mol Biol Cell 2022; 33:br16. [PMID: 35767360 PMCID: PMC9582629 DOI: 10.1091/mbc.e22-03-0085] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 06/15/2022] [Accepted: 06/21/2022] [Indexed: 11/11/2022] Open
Abstract
During mitosis, unattached kinetochores in a dividing cell activate the spindle assembly checkpoint (SAC) and delay anaphase onset by generating the anaphase-inhibitory mitotic checkpoint complex (MCC). These kinetochores generate the MCC by recruiting its constituent proteins, including BubR1. In principle, BubR1 recruitment to signaling kinetochores should increase its local concentration and promote MCC formation. However, in human cells BubR1 is mainly thought to sensitize the SAC to silencing. Whether BubR1 localization to signaling kinetochores by itself enhances SAC signaling remains unknown. Therefore, we used ectopic SAC activation (eSAC) systems to isolate two molecules that recruit BubR1 to the kinetochore, the checkpoint protein Bub1 and the KI and MELT motifs in the kinetochore protein KNL1, and observed their contribution to eSAC signaling. Our quantitative analyses and mathematical modeling show that Bub1-mediated BubR1 recruitment to the human kinetochore promotes SAC signaling and highlight BubR1's dual role of strengthening the SAC directly and silencing it indirectly.
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Affiliation(s)
- Anand Banerjee
- Academy of Integrated Science, Virginia Polytechnic Institute & State University, Blacksburg, VA 24601
| | - Chu Chen
- Cell & Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Lauren Humphrey
- Cell & Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - John J. Tyson
- Department of Biological Sciences, Virginia Polytechnic Institute & State University, Blacksburg, VA 24601
| | - Ajit P. Joglekar
- Cell & Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109
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24
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Cosma MA, Curtis NL, Pain C, Kriechbaumer V, Bolanos-Garcia VM. Biochemical, biophysical, and functional characterisation of the E3 ubiquitin ligase APC/C regulator CDC20 from Arabidopsis thaliana. Front Physiol 2022; 13:938688. [PMID: 35957989 PMCID: PMC9357983 DOI: 10.3389/fphys.2022.938688] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 06/28/2022] [Indexed: 12/03/2022] Open
Abstract
The Anaphase Promoting Complex (APC/C), a large cullin-RING E3-type ubiquitin ligase, constitutes the ultimate target of the Spindle Assembly Checkpoint (SAC), an intricate regulatory circuit that ensures the high fidelity of chromosome segregation in eukaryotic organisms by delaying the onset of anaphase until each chromosome is properly bi-oriented on the mitotic spindle. Cell-division cycle protein 20 homologue (CDC20) is a key regulator of APC/C function in mitosis. The formation of the APC/CCDC20 complex is required for the ubiquitination and degradation of select substrates, which is necessary to maintain the mitotic state. In contrast to the roles of CDC20 in animal species, little is known about CDC20 roles in the regulation of chromosome segregation in plants. Here we address this gap in knowledge and report the expression in insect cells; the biochemical and biophysical characterisation of Arabidopsis thaliana (AtCDC20) WD40 domain; and the nuclear and cytoplasmic distribution of full-length AtCDC20 when transiently expressed in tobacco plants. We also show that most AtCDC20 degrons share a high sequence similarity to other eukaryotes, arguing in favour of conserved degron functions in AtCDC20. However, important exceptions were noted such as the lack of a canonical MAD1 binding motif; a fully conserved RRY-box in all six AtCDC20 isoforms instead of a CRY-box motif, and low conservation of key residues known to be phosphorylated by BUB1 and PLK1 in other species to ensure a robust SAC response. Taken together, our studies provide insights into AtCDC20 structure and function and the evolution of SAC signalling in plants.
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25
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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: 4] [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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26
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Kim T. Recent Progress on the Localization of PLK1 to the Kinetochore and Its Role in Mitosis. Int J Mol Sci 2022; 23:ijms23095252. [PMID: 35563642 PMCID: PMC9102930 DOI: 10.3390/ijms23095252] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/03/2022] [Accepted: 05/04/2022] [Indexed: 12/10/2022] Open
Abstract
The accurate distribution of the replicated genome during cell division is essential for cell survival and healthy organismal development. Errors in this process have catastrophic consequences, such as birth defects and aneuploidy, a hallmark of cancer cells. PLK1 is one of the master kinases in mitosis and has multiple functions, including mitotic entry, chromosome segregation, spindle assembly checkpoint, and cytokinesis. To dissect the role of PLK1 in mitosis, it is important to understand how PLK1 localizes in the specific region in cells. PLK1 localizes at the kinetochore and is essential in spindle assembly checkpoint and chromosome segregation. However, how PLK1 localizes at the kinetochore remains elusive. Here, we review the recent literature on the kinetochore recruitment mechanisms of PLK1 and its roles in spindle assembly checkpoint and attachment between kinetochores and spindle microtubules. Together, this review provides an overview of how the local distribution of PLK1 could regulate major pathways in mitosis.
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Affiliation(s)
- Taekyung Kim
- Department of Biology Education, Pusan National University, 2, Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan 46241, Korea
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27
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Elowe S, Bolanos-Garcia VM. The spindle checkpoint proteins BUB1 and BUBR1: (SLiM)ming down to the basics. Trends Biochem Sci 2022; 47:352-366. [DOI: 10.1016/j.tibs.2022.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 12/16/2022]
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28
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Roy B, Han SJY, Fontan AN, Jema S, Joglekar AP. Aurora B phosphorylates Bub1 to promote spindle assembly checkpoint signaling. Curr Biol 2022; 32:237-247.e6. [PMID: 34861183 PMCID: PMC8752509 DOI: 10.1016/j.cub.2021.10.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 08/24/2021] [Accepted: 10/22/2021] [Indexed: 01/12/2023]
Abstract
Accurate chromosome segregation during cell division requires amphitelic chromosome attachment to the spindle apparatus. It is ensured by the combined activity of the spindle assembly checkpoint (SAC),1 a signaling mechanism that delays anaphase onset in response to unattached chromosomes, and an error correction mechanism that eliminates syntelic attachments.2 The SAC becomes active when Mps1 kinase sequentially phosphorylates the kinetochore protein Spc105/KNL1 and the signaling proteins that Spc105/KNL1 recruits to facilitate the production of the mitotic checkpoint complex (MCC).3-8 The error correction mechanism is regulated by the Aurora B kinase, but Aurora B also promotes SAC signaling via indirect mechanisms.9-12 Here we present evidence that Aurora B kinase activity directly promotes MCC production by working downstream of Mps1 in budding yeast and human cells. Using the ectopic SAC activation (eSAC) system, we find that the conditional dimerization of Aurora B in budding yeast and an Aurora B recruitment domain in HeLa cells with either Bub1 or Mad1, but not the phosphodomain of Spc105/KNL1, leads to ectopic MCC production and mitotic arrest.13-16 Importantly, Bub1 must recruit both Mad1 and Cdc20 for this ectopic signaling activity. These and other data show that Aurora B cooperates with Bub1 to promote MCC production, but only after Mps1 licenses Bub1 recruitment to the kinetochore. This direct involvement of Aurora B in SAC signaling may maintain SAC signaling even after Mps1 activity in the kinetochore is lowered.
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Affiliation(s)
- Babhrubahan Roy
- Cell & Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl., Ann Arbor, MI-48109, USA
| | - Simon J. Y. Han
- Cell & Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl., Ann Arbor, MI-48109, USA,present address: Medical Scientist Training Program, University of Cincinnati College of Medicine, 3230 Eden Ave, Cincinnati, OH 45267, USA
| | - Adrienne N. Fontan
- Cell & Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl., Ann Arbor, MI-48109, USA,present address: Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, 455 Main St, Cambridge, MA 02142
| | - Soubhagyalaxmi Jema
- Cell & Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl., Ann Arbor, MI-48109, USA
| | - Ajit P. Joglekar
- Cell & Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl., Ann Arbor, MI-48109, USA,corresponding author, lead contact: , Twitter handle: @AjitJoglekar1
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29
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Bolanos-Garcia VM. On the Regulation of Mitosis by the Kinetochore, a Macromolecular Complex and Organising Hub of Eukaryotic Organisms. Subcell Biochem 2022; 99:235-267. [PMID: 36151378 DOI: 10.1007/978-3-031-00793-4_7] [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] [Indexed: 06/16/2023]
Abstract
The kinetochore is the multiprotein complex of eukaryotic organisms that is assembled on mitotic or meiotic centromeres to connect centromeric DNA with microtubules. Its function involves the coordinated action of more than 100 different proteins. The kinetochore acts as an organiser hub that establishes physical connections with microtubules and centromere-associated proteins and recruits central protein components of the spindle assembly checkpoint (SAC), an evolutionarily conserved surveillance mechanism of eukaryotic organisms that detects unattached kinetochores and destabilises incorrect kinetochore-microtubule attachments. The molecular communication between the kinetochore and the SAC is highly dynamic and tightly regulated to ensure that cells can progress towards anaphase until each chromosome is properly bi-oriented on the mitotic spindle. This is achieved through an interplay of highly cooperative interactions and concerted phosphorylation/dephosphorylation events that are organised in time and space.This contribution discusses our current understanding of the function, structure and regulation of the kinetochore, in particular, how its communication with the SAC results in the amplification of specific signals to exquisitely control the eukaryotic cell cycle. This contribution also addresses recent advances in machine learning approaches, cell imaging and proteomics techniques that have enhanced our understanding of the molecular mechanisms that ensure the high fidelity and timely segregation of the genetic material every time a cell divides as well as the current challenges in the study of this fascinating molecular machine.
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Affiliation(s)
- Victor M Bolanos-Garcia
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK.
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30
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Mitotic phosphorylation of tumor suppressor DAB2IP maintains spindle assembly checkpoint and chromosomal stability through activating PLK1-Mps1 signal pathway and stabilizing mitotic checkpoint complex. Oncogene 2022; 41:489-501. [PMID: 34775484 PMCID: PMC8782720 DOI: 10.1038/s41388-021-02106-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 10/19/2021] [Accepted: 10/27/2021] [Indexed: 11/09/2022]
Abstract
Chromosomal instability (CIN) is a driving force for cancer development. The most common causes of CIN include the dysregulation of the spindle assembly checkpoint (SAC), which is a surveillance mechanism that prevents premature chromosome separation during mitosis by targeting anaphase-promoting complex/cyclosome (APC/C). DAB2IP is frequently silenced in advanced prostate cancer (PCa) and is associated with aggressive phenotypes of PCa. Our previous study showed that DAB2IP activates PLK1 and functions in mitotic regulation. Here, we report the novel mitotic phosphorylation of DAB2IP by Cdks, which mediates DAB2IP's interaction with PLK1 and the activation of the PLK1-Mps1 pathway. DAB2IP interacts with Cdc20 in a phosphorylation-independent manner. However, the phosphorylation of DAB2IP inhibits the ubiquitylation of Cdc20 in response to SAC, and blocks the premature release of the APC/C-MCC. The PLK1-Mps1 pathway plays an important role in mitotic checkpoint complex (MCC) assembly. It is likely that DAB2IP acts as a scaffold to aid PLK1-Mps1 in targeting Cdc20. Depletion or loss of the Cdks-mediated phosphorylation of DAB2IP destabilizes the MCC, impairs the SAC, and increases chromosome missegregation and subsequent CIN, thus contributing to tumorigenesis. Collectively, these results demonstrate the mechanism of DAB2IP in SAC regulation and provide a rationale for targeting the SAC to cause lethal CIN against DAB2IP-deficient aggressive PCa, which exhibits a weak SAC.
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31
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The specialized mitotic behavior of human embryonic stem cells. Cell Tissue Res 2021; 387:85-93. [PMID: 34729647 DOI: 10.1007/s00441-021-03544-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 10/08/2021] [Indexed: 10/19/2022]
Abstract
Human embryonic stem cells (hESCs) are self-renewing and pluripotent cells that originate from the inner cell mass of the blastocyst. Mitosis is fundamental to organism survival and reproduction and is responsible for the equal distribution of duplicated chromosomes into daughter cells. Mitotic dysfunction is associated with a wide variety of human diseases, not least cancer. hESCs have a unique cell cycle distribution, but it is unclear exactly how the mitotic activity of hESCs is related to their proliferation and differentiation. Here, we established a cell line of hESCs stably expressing GFP-α-tubulin and mCherry-H2B by lentiviral infection to analyze and visualize mitosis in detail. During metaphase, the mitotic spindle was smaller and wider and contained a greater proportion of astral microtubules than normal cells. In addition, spindle microtubules were more stable, and chromosome alignment was faster in hESCs than in somatic cells. We also found that the spindle assembly checkpoint was functional in hESCs. These findings thus reveal a specialized mitotic behavior of hESCs.
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32
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Deng DJ, Xia QC, Jia GS, Suo F, Chen JL, Sun L, Wang JQ, Wang SM, Du LL, Wang Y, Jin QW. Perturbation of kinetochore function using GFP-binding protein in fission yeast. G3 GENES|GENOMES|GENETICS 2021; 11:6353032. [PMID: 34849791 PMCID: PMC8527488 DOI: 10.1093/g3journal/jkab290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/10/2021] [Indexed: 11/12/2022]
Abstract
Abstract
Using genetic mutations to study protein functions in vivo is a central paradigm of modern biology. Single-domain camelid antibodies generated against GFP have been engineered as nanobodies or GFP-binding proteins (GBPs) that can bind GFP as well as some GFP variants with high affinity and selectivity. In this study, we have used GBP-mCherry fusion protein as a tool to perturb the natural functions of a few kinetochore proteins in the fission yeast Schizosaccharomyces pombe. We found that cells simultaneously expressing GBP-mCherry and the GFP-tagged inner kinetochore protein Cnp1 are sensitive to high temperature and microtubule drug thiabendazole (TBZ). In addition, kinetochore-targeted GBP-mCherry by a few major kinetochore proteins with GFP tags causes defects in faithful chromosome segregation. Thus, this setting compromises the functions of kinetochores and renders cells to behave like conditional mutants. Our study highlights the potential of using GBP as a general tool to perturb the function of some GFP-tagged proteins in vivo with the objective of understanding their functional relevance to certain physiological processes, not only in yeasts, but also potentially in other model systems.
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Affiliation(s)
- Da-Jie Deng
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Qian-Cheng Xia
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Guo-Song Jia
- National Institute of Biological Sciences, Beijing 102206, China
| | - Fang Suo
- National Institute of Biological Sciences, Beijing 102206, China
| | - Jia-Li Chen
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Li Sun
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Jin-Qing Wang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Shuang-Min Wang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing 102206, China
| | - Yamei Wang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Quan-Wen Jin
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
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33
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Chen Q, Zhang M, Pan X, Yuan X, Zhou L, Yan L, Zeng LH, Xu J, Yang B, Zhang L, Huang J, Lu W, Fukagawa T, Wang F, Yan H. Bub1 and CENP-U redundantly recruit Plk1 to stabilize kinetochore-microtubule attachments and ensure accurate chromosome segregation. Cell Rep 2021; 36:109740. [PMID: 34551298 DOI: 10.1016/j.celrep.2021.109740] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/03/2021] [Accepted: 08/30/2021] [Indexed: 11/23/2022] Open
Abstract
Bub1 is required for the kinetochore/centromere localization of two essential mitotic kinases Plk1 and Aurora B. Surprisingly, stable depletion of Bub1 by ∼95% in human cells marginally affects whole chromosome segregation fidelity. We show that CENP-U, which is recruited to kinetochores by the CENP-P and CENP-Q subunits of the CENP-O complex, is required to prevent chromosome mis-segregation in Bub1-depleted cells. Mechanistically, Bub1 and CENP-U redundantly recruit Plk1 to kinetochores to stabilize kinetochore-microtubule attachments, thereby ensuring accurate chromosome segregation. Furthermore, unlike its budding yeast homolog, the CENP-O complex does not regulate centromeric localization of Aurora B. Consistently, depletion of Bub1 or CENP-U sensitizes cells to the inhibition of Plk1 but not Aurora B kinase activity. Taken together, our findings provide mechanistic insight into the regulation of kinetochore function, which may have implications for targeted treatment of cancer cells with mutations perturbing kinetochore recruitment of Plk1 by Bub1 or the CENP-O complex.
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Affiliation(s)
- Qinfu Chen
- Department of Pharmacology, Zhejiang University City College, Hangzhou 310015, China; The MOE Key Laboratory of Biosystems Homeostasis & Protection, The Key Laboratory of Cancer Molecular Cell Biology of Zhejiang Province, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Miao Zhang
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, The Key Laboratory of Cancer Molecular Cell Biology of Zhejiang Province, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Xuan Pan
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, The Key Laboratory of Cancer Molecular Cell Biology of Zhejiang Province, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Xueying Yuan
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, The Key Laboratory of Cancer Molecular Cell Biology of Zhejiang Province, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Linli Zhou
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, The Key Laboratory of Cancer Molecular Cell Biology of Zhejiang Province, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Lu Yan
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, The Key Laboratory of Cancer Molecular Cell Biology of Zhejiang Province, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Ling-Hui Zeng
- Department of Pharmacology, Zhejiang University City College, Hangzhou 310015, China
| | - Junfen Xu
- Department of Gynecological Oncology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, China
| | - Bing Yang
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, The Key Laboratory of Cancer Molecular Cell Biology of Zhejiang Province, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Long Zhang
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, The Key Laboratory of Cancer Molecular Cell Biology of Zhejiang Province, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Jun Huang
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, The Key Laboratory of Cancer Molecular Cell Biology of Zhejiang Province, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Weiguo Lu
- Department of Gynecological Oncology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, China; Cancer Center, Zhejiang University, Hangzhou 310058, China
| | - Tatsuo Fukagawa
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Fangwei Wang
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, The Key Laboratory of Cancer Molecular Cell Biology of Zhejiang Province, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China; Department of Gynecological Oncology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, China; Cancer Center, Zhejiang University, Hangzhou 310058, China.
| | - Haiyan Yan
- Department of Pharmacology, Zhejiang University City College, Hangzhou 310015, China.
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34
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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: 105] [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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35
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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: 41] [Impact Index Per Article: 13.7] [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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36
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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: 5.7] [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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37
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Novais P, Silva PMA, Amorim I, Bousbaa H. Second-Generation Antimitotics in Cancer Clinical Trials. Pharmaceutics 2021; 13:1011. [PMID: 34371703 PMCID: PMC8309102 DOI: 10.3390/pharmaceutics13071011] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/24/2021] [Accepted: 06/29/2021] [Indexed: 12/17/2022] Open
Abstract
Mitosis represents a promising target to block cancer cell proliferation. Classical antimitotics, mainly microtubule-targeting agents (MTAs), such as taxanes and vinca alkaloids, are amongst the most successful anticancer drugs. By disrupting microtubules, they activate the spindle assembly checkpoint (SAC), which induces a prolonged delay in mitosis, expected to induce cell death. However, resistance, toxicity, and slippage limit the MTA's effectiveness. With the desire to overcome some of the MTA's limitations, mitotic and SAC components have attracted great interest as promising microtubule-independent targets, leading to the so-called second-generation antimitotics (SGAs). The identification of inhibitors against most of these targets, and the promising outcomes achieved in preclinical assays, has sparked the interest of academia and industry. Many of these inhibitors have entered clinical trials; however, they exhibited limited efficacy as monotherapy, and failed to go beyond phase II trials. Combination therapies are emerging as promising strategies to give a second chance to these SGAs. Here, an updated view of the SGAs that reached clinical trials is here provided, together with future research directions, focusing on inhibitors that target the SAC components.
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Affiliation(s)
- Pedro Novais
- CESPU, Institute of Research and Advanced Training in Health Sciences and Technologies (IINFACTS), Rua Central de Gandra, 1317, 4585-116 Gandra, Portugal; (P.N.); (P.M.A.S.)
- Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar, University of Porto, 4050-313 Porto, Portugal
| | - Patrícia M. A. Silva
- CESPU, Institute of Research and Advanced Training in Health Sciences and Technologies (IINFACTS), Rua Central de Gandra, 1317, 4585-116 Gandra, Portugal; (P.N.); (P.M.A.S.)
| | - Isabel Amorim
- GreenUPorto (Sustainable Agrifood Production) Research Center, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal;
| | - Hassan Bousbaa
- CESPU, Institute of Research and Advanced Training in Health Sciences and Technologies (IINFACTS), Rua Central de Gandra, 1317, 4585-116 Gandra, Portugal; (P.N.); (P.M.A.S.)
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38
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Bokros M, Sherwin D, Kabbaj MH, Wang Y. Yeast Fin1-PP1 dephosphorylates an Ipl1 substrate, Ndc80, to remove Bub1-Bub3 checkpoint proteins from the kinetochore during anaphase. PLoS Genet 2021; 17:e1009592. [PMID: 34033659 PMCID: PMC8184001 DOI: 10.1371/journal.pgen.1009592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 06/07/2021] [Accepted: 05/10/2021] [Indexed: 11/25/2022] Open
Abstract
The spindle assembly checkpoint (SAC) prevents anaphase onset in response to chromosome attachment defects, and SAC silencing is essential for anaphase onset. Following anaphase onset, activated Cdc14 phosphatase dephosphorylates the substrates of cyclin-dependent kinase to facilitate anaphase progression and mitotic exit. In budding yeast, Cdc14 dephosphorylates Fin1, a regulatory subunit of protein phosphatase 1 (PP1), to enable kinetochore localization of Fin1-PP1. We previously showed that kinetochore-localized Fin1-PP1 promotes the removal of the SAC protein Bub1 from the kinetochore during anaphase. We report here that Fin1-PP1 also promotes kinetochore removal of Bub3, the Bub1 partner, but has no effect on another SAC protein Mad1. Moreover, the kinetochore localization of Bub1-Bub3 during anaphase requires Aurora B/Ipl1 kinase activity. We further showed that Fin1-PP1 facilitates the dephosphorylation of kinetochore protein Ndc80, a known Ipl1 substrate. This dephosphorylation reduces kinetochore association of Bub1-Bub3 during anaphase. In addition, we found that untimely Ndc80 dephosphorylation causes viability loss in response to tensionless chromosome attachments. These results suggest that timely localization of Fin1-PP1 to the kinetochore controls the functional window of SAC and is therefore critical for faithful chromosome segregation.
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Affiliation(s)
- Michael Bokros
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America
- Sylvester Comprehensive Cancer Center, University of Miami, Miami, Florida, United States of America
| | - Delaney Sherwin
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America
| | - Marie-Helene Kabbaj
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America
| | - Yanchang Wang
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America
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Sakalli-Tecim E, Uyar-Arpaci P, Guray NT. Identification of Potential Therapeutic Genes and Pathways in Phytoestrogen Emodin Treated Breast Cancer Cell Lines via Network Biology Approaches. Nutr Cancer 2021; 74:592-604. [PMID: 33645356 DOI: 10.1080/01635581.2021.1889622] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Phytoestrogens have been investigated for their potential anti-tumorigenic effects in various cancers including breast cancer. Emodin being a phytoestrogen shows anti-carcinogenic properties especially in estrogen receptor positive (ER+) breast cancers. The aim of this study is to identify the molecular mechanism and related biological pathways in both (ER+) MCF-7 and (ER-) MDA-MB-231 breast cancer cell lines upon Emodin treatment via microarray analysis in order to find out therapeutic biomarkers. In both cell lines, first differentially expressed genes were identified, then gene ontology and functional pathway enrichment analyses were performed. Genes regulated through multiple pathways were studied together with literature and a gene cluster was determined for each cell line. Further GeneMANIA and STRING databases were used to study the interactions within the related gene clusters. The results showed that, the genes which are related to cell cycle were significantly regulated in both cell lines. Also, Forkhead Box O1-related genes were found to be prominent in MCF-7 cells. In MDA-MB-231 cells, spindle attachment checkpoint mechanism-related genes were regulated, remarkably. As a result, novel gene regulations reported in this study in response to Emodin will give more information about its metabolism and antiproliferative effect, especially in ER + cells.
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Affiliation(s)
- Elif Sakalli-Tecim
- Department of Biotechnology, Middle East Technical University, Ankara, Turkey
| | | | - N Tulin Guray
- Department of Biotechnology, Middle East Technical University, Ankara, Turkey.,Department of Biological Sciences, Middle East Technical University, Ankara, Turkey
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40
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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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41
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Lara-Gonzalez P, Kim T, Oegema K, Corbett K, Desai A. A tripartite mechanism catalyzes Mad2-Cdc20 assembly at unattached kinetochores. Science 2021; 371:64-67. [PMID: 33384372 DOI: 10.1126/science.abc1424] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 11/17/2020] [Indexed: 12/22/2022]
Abstract
During cell division, kinetochores couple chromosomes to spindle microtubules. To protect against chromosome gain or loss, kinetochores lacking microtubule attachment locally catalyze association of the checkpoint proteins Cdc20 and Mad2, which is the key event in the formation of a diffusible checkpoint complex that prevents mitotic exit. We elucidated the mechanism of kinetochore-catalyzed Mad2-Cdc20 assembly with a probe that specifically monitors this assembly reaction at kinetochores in living cells. We found that catalysis occurs through a tripartite mechanism that includes localized delivery of Mad2 and Cdc20 substrates and two phosphorylation-dependent interactions that geometrically constrain their positions and prime Cdc20 for interaction with Mad2. These results reveal how unattached kinetochores create a signal that ensures genome integrity during cell division.
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Affiliation(s)
- Pablo Lara-Gonzalez
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA. .,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA.,Ludwig Institute for Cancer Research, San Diego Branch, 9500 Gilman Drive, La Jolla, CA, USA
| | - Taekyung Kim
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA.,Ludwig Institute for Cancer Research, San Diego Branch, 9500 Gilman Drive, La Jolla, CA, USA
| | - Karen Oegema
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA.,Ludwig Institute for Cancer Research, San Diego Branch, 9500 Gilman Drive, La Jolla, CA, USA
| | - Kevin Corbett
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA.,Ludwig Institute for Cancer Research, San Diego Branch, 9500 Gilman Drive, La Jolla, CA, USA
| | - Arshad Desai
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA. .,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA.,Ludwig Institute for Cancer Research, San Diego Branch, 9500 Gilman Drive, La Jolla, CA, USA
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42
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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: 45] [Impact Index Per Article: 15.0] [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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43
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Specificity determinants of phosphoprotein phosphatases controlling kinetochore functions. Essays Biochem 2021; 64:325-336. [PMID: 32501472 DOI: 10.1042/ebc20190065] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/11/2020] [Accepted: 05/14/2020] [Indexed: 12/12/2022]
Abstract
Kinetochores are instrumental for accurate chromosome segregation by binding to microtubules in order to move chromosomes and by delaying anaphase onset through the spindle assembly checkpoint (SAC). Dynamic phosphorylation of kinetochore components is key to control these activities and is tightly regulated by temporal and spatial recruitment of kinases and phosphoprotein phosphatases (PPPs). Here we focus on PP1, PP2A-B56 and PP2A-B55, three PPPs that are important regulators of mitosis. Despite the fact that these PPPs share a very similar active site, they target unique ser/thr phosphorylation sites to control kinetochore function. Specificity is in part achieved by PPPs binding to short linear motifs (SLiMs) that guide their substrate specificity. SLiMs bind to conserved pockets on PPPs and are degenerate in nature, giving rise to a range of binding affinities. These SLiMs control the assembly of numerous substrate specifying complexes and their position and binding strength allow PPPs to target specific phosphorylation sites. In addition, the activity of PPPs is regulated by mitotic kinases and inhibitors, either directly at the activity level or through affecting PPP-SLiM interactions. Here, we discuss recent progress in understanding the regulation of PPP specificity and activity and how this controls kinetochore biology.
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44
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Hong Z, Wang Q, Hong C, Liu M, Qiu P, Lin R, Lin X, Chen F, Li Q, Liu L, Wang C, Chen D. Identification of Seven Cell Cycle-Related Genes with Unfavorable Prognosis and Construction of their TF-miRNA-mRNA regulatory network in Breast Cancer. J Cancer 2021; 12:740-753. [PMID: 33403032 PMCID: PMC7778540 DOI: 10.7150/jca.48245] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 11/04/2020] [Indexed: 12/24/2022] Open
Abstract
Breast cancer (BC), with complex tumorigenesis and progression, remains the most common malignancy in women. We aimed to explore some novel and significant genes with unfavorable prognoses and potential pathways involved in BC initiation and progression via bioinformatics methods. BC tissue-specific microarray datasets of GSE42568, GSE45827 and GSE54002, which included a total of 651 BC tissues and 44 normal breast tissues, were obtained from the Gene Expression Omnibus (GEO) database, and 124 differentially expressed genes (DEGs) were identified between BC tissues and normal breast tissues via R software and an online Venn diagram tool. Database for Annotation, Visualization and Integration Discovery (DAVID) software showed that 65 upregulated DEGs were mainly enriched in the regulation of the cell cycle, and Search Tool for the Retrieval of Interacting Genes (STRING) software identified the 39 closest associated upregulated DEGs in protein-protein interactions (PPIs), which validated the high expression of genes in BC tissues by the Gene Expression Profiling Interactive Analysis (GEPIA) tool. In addition, 36 out of 39 BC patients showed significantly worse outcomes by Kaplan-Meier plotter (KM plotter), and an additional Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that seven genes (cyclin E2 (CCNE2), cyclin B1 (CCNB1), cyclin B2 (CCNB2), mitotic checkpoint serine/threonine kinase B (BUB1B), dual-specificity protein kinase (TTK), cell division cycle 20 (CDC20), and pituitary tumor transforming gene 1 (PTTG1)) were markedly enriched in the cell cycle pathway. Analysis of the clinicopathological characteristics of hub genes revealed that seven cell cycle-related genes (CCRGs) were significantly highly expressed in four BC subtypes (luminal A, luminal B, HER2-positive and triple-negative (TNBC)), and except for the CCNE2 gene, high expression levels were significantly associated with tumor pathological grade and stage and metastatic events of BC. Furthermore, genetic mutation analysis indicated that genetic alterations of CCRGs could also significantly affect BC patients' prognosis. A quantitative real-time polymerase chain reaction (qRT-PCR) assay found that the seven CCRGs were significantly differentially expressed in BC cell lines. Integration of published multilevel expression data and a bioinformatics computational approach were used to predict and construct a regulation mechanism: a transcription factor (TF)-microRNA (miRNA)-messenger RNA (mRNA) regulation network. The present work is the first to construct a regulatory network of TF-miRNA-mRNA in BC for CCRGs and provides new insights into the molecular mechanism of BC.
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Affiliation(s)
- Zhipeng Hong
- Department of Breast Surgery, Affiliated Quanzhou First Hospital of Fujian Medical University, Quanzhou, Fujian Province, 362000, P. R. China.,Department of Breast Surgery and General Surgery, The Affiliated Union Hospital of Fujian Medical University, Fuzhou, Fujian Province, 350001, P. R. China.,Breast Cancer Institute, Fujian Medical University, Fuzhou, Fujian Province, 350001, P.R. China
| | - Qinglan Wang
- Department of Breast Surgery, Affiliated Quanzhou First Hospital of Fujian Medical University, Quanzhou, Fujian Province, 362000, P. R. China
| | - Chengye Hong
- Department of Breast Surgery, Affiliated Quanzhou First Hospital of Fujian Medical University, Quanzhou, Fujian Province, 362000, P. R. China
| | - Meimei Liu
- Department of Breast Surgery, Affiliated Quanzhou First Hospital of Fujian Medical University, Quanzhou, Fujian Province, 362000, P. R. China
| | - Pengqin Qiu
- Department of Breast Surgery, Affiliated Quanzhou First Hospital of Fujian Medical University, Quanzhou, Fujian Province, 362000, P. R. China
| | - Rongrong Lin
- Department of Breast Surgery, Affiliated Quanzhou First Hospital of Fujian Medical University, Quanzhou, Fujian Province, 362000, P. R. China
| | - Xiaolan Lin
- Department of Breast Surgery, Affiliated Quanzhou First Hospital of Fujian Medical University, Quanzhou, Fujian Province, 362000, P. R. China
| | - Fangfang Chen
- Department of Breast Surgery, Affiliated Quanzhou First Hospital of Fujian Medical University, Quanzhou, Fujian Province, 362000, P. R. China
| | - Qiuhuang Li
- Department of Breast Surgery, Affiliated Quanzhou First Hospital of Fujian Medical University, Quanzhou, Fujian Province, 362000, P. R. China
| | - Lingling Liu
- Department of Breast Surgery, Affiliated Quanzhou First Hospital of Fujian Medical University, Quanzhou, Fujian Province, 362000, P. R. China
| | - Chuan Wang
- Department of Breast Surgery and General Surgery, The Affiliated Union Hospital of Fujian Medical University, Fuzhou, Fujian Province, 350001, P. R. China.,Breast Cancer Institute, Fujian Medical University, Fuzhou, Fujian Province, 350001, P.R. China
| | - Debo Chen
- Department of Breast Surgery, Affiliated Quanzhou First Hospital of Fujian Medical University, Quanzhou, Fujian Province, 362000, P. R. China
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45
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Cordeiro MH, Smith RJ, Saurin AT. Kinetochore phosphatases suppress autonomous Polo-like kinase 1 activity to control the mitotic checkpoint. J Cell Biol 2020; 219:e202002020. [PMID: 33125045 PMCID: PMC7608062 DOI: 10.1083/jcb.202002020] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 08/20/2020] [Accepted: 10/12/2020] [Indexed: 01/04/2023] Open
Abstract
Local phosphatase regulation is needed at kinetochores to silence the mitotic checkpoint (a.k.a. spindle assembly checkpoint [SAC]). A key event in this regard is the dephosphorylation of MELT repeats on KNL1, which removes SAC proteins from the kinetochore, including the BUB complex. We show here that PP1 and PP2A-B56 phosphatases are primarily required to remove Polo-like kinase 1 (PLK1) from the BUB complex, which can otherwise maintain MELT phosphorylation in an autocatalytic manner. This appears to be their principal role in the SAC because both phosphatases become redundant if PLK1 is inhibited or BUB-PLK1 interaction is prevented. Surprisingly, MELT dephosphorylation can occur normally under these conditions even when the levels or activities of PP1 and PP2A are strongly inhibited at kinetochores. Therefore, these data imply that kinetochore phosphatase regulation is critical for the SAC, but primarily to restrain and extinguish autonomous PLK1 activity. This is likely a conserved feature of the metazoan SAC, since the relevant PLK1 and PP2A-B56 binding motifs have coevolved in the same region on MADBUB homologues.
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Affiliation(s)
| | | | - Adrian T. Saurin
- Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, UK
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46
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Shirnekhi HK, Herman JA, Paddison PJ, DeLuca JG. BuGZ facilitates loading of spindle assembly checkpoint proteins to kinetochores in early mitosis. J Biol Chem 2020; 295:14666-14677. [PMID: 32820050 DOI: 10.1074/jbc.ra120.013598] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 08/07/2020] [Indexed: 11/06/2022] Open
Abstract
BuGZ is a kinetochore component that binds to and stabilizes Bub3, a key player in mitotic spindle assembly checkpoint signaling. Bub3 is required for kinetochore recruitment of Bub1 and BubR1, two proteins that have essential and distinct roles in the checkpoint. Both Bub1 and BubR1 localize to kinetochores through interactions with Bub3, which are mediated through conserved GLEBS domains in both Bub1 and BubR1. BuGZ also has a GLEBS domain, which is required for its kinetochore localization as well, presumably mediated through Bub3 binding. Although much is understood about the requirements for Bub1 and BubR1 interaction with Bub3 and kinetochores, much less is known regarding BuGZ's requirements. Here, we used a series of mutants to demonstrate that BuGZ kinetochore localization requires only its core GLEBS domain, which is distinct from the requirements for both Bub1 and BubR1. Furthermore, we found that the kinetics of Bub1, BubR1, and BuGZ loading to kinetochores differ, with BuGZ localizing prior to BubR1 and Bub1. To better understand how complexes containing Bub3 and its binding partners are loaded to kinetochores, we carried out size-exclusion chromatography and analyzed Bub3-containing complexes from cells under different spindle assembly checkpoint signaling conditions. We found that prior to kinetochore formation, Bub3 is complexed with BuGZ but not Bub1 or BubR1. Our results point to a model in which BuGZ stabilizes Bub3 and promotes Bub3 loading onto kinetochores in early mitosis, which, in turn, facilitates Bub1 and BubR1 kinetochore recruitment and spindle assembly checkpoint signaling.
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Affiliation(s)
- Hazheen K Shirnekhi
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Jacob A Herman
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Patrick J Paddison
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Jennifer G DeLuca
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA.
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Cunha-Silva S, Osswald M, Goemann J, Barbosa J, Santos LM, Resende P, Bange T, Ferrás C, Sunkel CE, Conde C. Mps1-mediated release of Mad1 from nuclear pores ensures the fidelity of chromosome segregation. J Cell Biol 2020; 219:133569. [PMID: 31913420 PMCID: PMC7054998 DOI: 10.1083/jcb.201906039] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 10/20/2019] [Accepted: 11/28/2019] [Indexed: 12/26/2022] Open
Abstract
The spindle assembly checkpoint (SAC) relies on the recruitment of Mad1-C-Mad2 to unattached kinetochores but also on its binding to Megator/Tpr at nuclear pore complexes (NPCs) during interphase. However, the molecular underpinnings controlling the spatiotemporal redistribution of Mad1-C-Mad2 as cells progress into mitosis remain elusive. Here, we show that activation of Mps1 during prophase triggers Mad1 release from NPCs and that this is required for kinetochore localization of Mad1-C-Mad2 and robust SAC signaling. We find that Mps1 phosphorylates Megator/Tpr to reduce its interaction with Mad1 in vitro and in Drosophila cells. Importantly, preventing Mad1 from binding to Megator/Tpr restores Mad1 accumulation at kinetochores, the fidelity of chromosome segregation, and genome stability in larval neuroblasts of mps1-null mutants. Our findings demonstrate that the subcellular localization of Mad1 is tightly coordinated with cell cycle progression by kinetochore-extrinsic activity of Mps1. This ensures that both NPCs in interphase and kinetochores in mitosis can generate anaphase inhibitors to efficiently preserve genomic stability.
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Affiliation(s)
- Sofia Cunha-Silva
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,Programa Doutoral em Biologia Molecular e Celular (MCbiology), Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Mariana Osswald
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Jana Goemann
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - João Barbosa
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Luis M Santos
- Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Pedro Resende
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Tanja Bange
- Max-Planck-Institut für Molekulare Physiologie, Dortmund, Germany
| | - Cristina Ferrás
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Claudio E Sunkel
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,Departamento de Biologia Molecular, Instituto de Ciências Biomédicas Abel Salazar, Porto, Portugal
| | - Carlos Conde
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
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48
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Bancroft J, Holder J, Geraghty Z, Alfonso-Pérez T, Murphy D, Barr FA, Gruneberg U. PP1 promotes cyclin B destruction and the metaphase-anaphase transition by dephosphorylating CDC20. Mol Biol Cell 2020; 31:2315-2330. [PMID: 32755477 PMCID: PMC7851957 DOI: 10.1091/mbc.e20-04-0252] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/22/2020] [Accepted: 07/29/2020] [Indexed: 12/30/2022] Open
Abstract
Ubiquitin-dependent proteolysis of cyclin B and securin initiates sister chromatid segregation and anaphase. The anaphase-promoting complex/cyclosome and its coactivator CDC20 (APC/CCDC20) form the main ubiquitin E3 ligase for these two proteins. APC/CCDC20 is regulated by CDK1-cyclin B and counteracting PP1 and PP2A family phosphatases through modulation of both activating and inhibitory phosphorylation. Here, we report that PP1 promotes cyclin B destruction at the onset of anaphase by removing specific inhibitory phosphorylation in the N-terminus of CDC20. Depletion or chemical inhibition of PP1 stabilizes cyclin B and results in a pronounced delay at the metaphase-to-anaphase transition after chromosome alignment. This requirement for PP1 is lost in cells expressing CDK1 phosphorylation-defective CDC206A mutants. These CDC206A cells show a normal spindle checkpoint response and rapidly destroy cyclin B once all chromosomes have aligned and enter into anaphase in the absence of PP1 activity. PP1 therefore facilitates the metaphase-to-anaphase transition by promoting APC/CCDC20-dependent destruction of cyclin B in human cells.
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Affiliation(s)
- James Bancroft
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - James Holder
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Zoë Geraghty
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | | | - Daniel Murphy
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Francis A. Barr
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Ulrike Gruneberg
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
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49
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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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50
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Kuijt TEF, Lambers MLA, Weterings S, Ponsioen B, Bolhaqueiro ACF, Staijen DHM, Kops GJPL. A Biosensor for the Mitotic Kinase MPS1 Reveals Spatiotemporal Activity Dynamics and Regulation. Curr Biol 2020; 30:3862-3870.e6. [PMID: 32888483 DOI: 10.1016/j.cub.2020.07.062] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 06/18/2020] [Accepted: 07/14/2020] [Indexed: 01/10/2023]
Abstract
Accurate chromosome segregation during cell division critically depends on error correction of chromosome-spindle interactions and the spindle assembly checkpoint (SAC) [1-3]. The kinase MPS1 is an essential regulator of both processes, ensuring full chromosome biorientation before anaphase onset [3, 4]. To understand when and where MPS1 activation occurs and how MPS1 signaling is modulated during mitosis, we developed MPS1sen, a sensitive and specific FRET-based biosensor for MPS1 activity. By placing MPS1sen at different subcellular locations, we show that MPS1 activity initiates in the nucleus ∼9-12 min prior to nuclear envelope breakdown (NEB) in a kinetochore-dependent manner and reaches the cytoplasm at the start of NEB. Soon after initiation, MPS1 activity increases with switch-like kinetics, peaking at completion of NEB. We further show that timing and extent of pre-NEB MPS1 activity is regulated by Aurora B and PP2A-B56. MPS1sen phosphorylation declines in prometaphase as a result of formation of kinetochore-microtubule attachments, reaching low but still detectable levels at metaphase. Finally, leveraging the sensitivity and dynamic range of MPS1sen, we show deregulated MPS1 signaling dynamics in colorectal cancer cell lines and tumor organoids with diverse genomic instability phenotypes.
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Affiliation(s)
- Timo E F Kuijt
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Centre Utrecht, 3584CT Utrecht, the Netherlands
| | - Maaike L A Lambers
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Centre Utrecht, 3584CT Utrecht, the Netherlands
| | - Sonja Weterings
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Centre Utrecht, 3584CT Utrecht, the Netherlands
| | - Bas Ponsioen
- Cancer Genomics Netherlands, UMC Utrecht, 3584CG Utrecht, the Netherlands; Molecular Cancer Research, Centre for Molecular Medicine, UMC Utrecht, 3584CG Utrecht, the Netherlands
| | - Ana C F Bolhaqueiro
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Centre Utrecht, 3584CT Utrecht, the Netherlands
| | - Debbie H M Staijen
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Centre Utrecht, 3584CT Utrecht, the Netherlands
| | - Geert J P L Kops
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Centre Utrecht, 3584CT Utrecht, the Netherlands.
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