1
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Ge K, Du X, Liu H, Meng R, Wu C, Zhang Z, Liang X, Yang J, Zhang H. The cytotoxicity of microcystin-LR: ultrastructural and functional damage of cells. Arch Toxicol 2024; 98:663-687. [PMID: 38252150 DOI: 10.1007/s00204-023-03676-0] [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: 10/23/2023] [Accepted: 12/20/2023] [Indexed: 01/23/2024]
Abstract
Microcystin-LR (MC-LR) is a toxin produced by cyanobacteria, which is widely distributed in eutrophic water bodies and has multi-organ toxicity. Previous cytotoxicity studies have mostly elucidated the effects of MC-LR on intracellular-related factors, proteins, and DNA at the molecular level. However, there have been few studies on the adverse effects of MC-LR on cell ultrastructure and function. Therefore, research on the cytotoxicity of MC-LR in recent years was collected and summarized. It was found that MC-LR can induce a series of cytotoxic effects, including decreased cell viability, induced autophagy, apoptosis and necrosis, altered cell cycle, altered cell morphology, abnormal cell migration and invasion as well as leading to genetic damage. The above cytotoxic effects were related to the damage of various ultrastructure and functions such as cell membranes and mitochondria. Furthermore, MC-LR can disrupt cell ultrastructure and function by inducing oxidative stress and inhibiting protein phosphatase activity. In addition, the combined toxic effects of MC-LR and other environmental pollutants were investigated. This review explored the toxic targets of MC-LR at the subcellular level, which will provide new ideas for the prevention and treatment of multi-organ toxicity caused by MC-LR.
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Affiliation(s)
- Kangfeng Ge
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Xingde Du
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Haohao Liu
- Department of Public Health, First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450001, China
| | - Ruiyang Meng
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Chunrui Wu
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Zongxin Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Xiao Liang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Jun Yang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Huizhen Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China.
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2
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Hayward D, Roberts E, Gruneberg U. MPS1 localizes to end-on microtubule-attached kinetochores to promote microtubule release. Curr Biol 2022; 32:5200-5208.e8. [PMID: 36395767 DOI: 10.1016/j.cub.2022.10.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 09/07/2022] [Accepted: 10/20/2022] [Indexed: 11/17/2022]
Abstract
In eukaryotes, the spindle assembly checkpoint protects genome stability in mitosis by preventing chromosome segregation until incorrect microtubule-kinetochore attachment geometries have been eliminated and chromosome biorientation has been completed. These error correction and checkpoint processes are linked by the conserved Aurora B and MPS1 Ser/Thr kinases.1,2 MPS1-dependent checkpoint signaling is believed to be initiated by kinetochores without end-on microtubule attachments,3,4 including those generated by Aurora B-mediated error correction. The current model posits that MPS1 competes with microtubules for binding sites at the kinetochore.3,4 MPS1 is thought to first recognize kinetochores not blocked by microtubules and then initiate checkpoint signaling. However, MPS1 is also required for chromosome biorientation and correction of microtubule-kinetochore attachment errors.5,6,7,8,9 This latter function, which must require direct interaction with microtubule-attached kinetochores, is not readily explained within the constraints of the current model. Here, we show that MPS1 transiently localizes to end-on attached kinetochores and that this recruitment depends on the relative activities of Aurora B and its counteracting phosphatase PP2A-B56 rather than microtubule-attachment state per se. MPS1 autophosphorylation also regulates MPS1 kinetochore levels but does not determine the response to microtubule attachment. At end-on attached kinetochores, MPS1 actively promotes microtubule release together with Aurora B. Furthermore, in live cells, MPS1 is detected at attached kinetochores before the removal of microtubules. During chromosome alignment, MPS1, therefore, coordinates both the resolution of incorrect microtubule-kinetochore attachments and the initiation of spindle checkpoint signaling.
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Affiliation(s)
- Daniel Hayward
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, Oxfordshire OX1 3RE, UK
| | - Emile Roberts
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, Oxfordshire OX1 3RE, UK
| | - Ulrike Gruneberg
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, Oxfordshire OX1 3RE, UK.
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3
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Teye EK, Lu S, Chen F, Yang W, Abraham T, Stairs DB, Wang HG, Yochum GS, Brodsky RA, Pu JJ. PIGN spatiotemporally regulates the spindle assembly checkpoint proteins in leukemia transformation and progression. Sci Rep 2021; 11:19022. [PMID: 34561473 PMCID: PMC8463542 DOI: 10.1038/s41598-021-98218-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 09/06/2021] [Indexed: 12/19/2022] Open
Abstract
Phosphatidylinositol glycan anchor biosynthesis class N (PIGN) has been linked to the suppression of chromosomal instability. The spindle assembly checkpoint complex is responsible for proper chromosome segregation during mitosis to prevent chromosomal instability. In this study, the novel role of PIGN as a regulator of the spindle assembly checkpoint was unveiled in leukemic patient cells and cell lines. Transient downregulation or ablation of PIGN resulted in impaired mitotic checkpoint activation due to the dysregulated expression of spindle assembly checkpoint-related proteins including MAD1, MAD2, BUBR1, and MPS1. Moreover, ectopic overexpression of PIGN restored the expression of MAD2. PIGN regulated the spindle assembly checkpoint by forming a complex with the spindle assembly checkpoint proteins MAD1, MAD2, and the mitotic kinase MPS1. Thus, PIGN could play a vital role in the spindle assembly checkpoint to suppress chromosomal instability associated with leukemic transformation and progression.
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Affiliation(s)
- Emmanuel K Teye
- Penn State Cancer Institute, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Shasha Lu
- Penn State Cancer Institute, Pennsylvania State University College of Medicine, Hershey, PA, USA.,Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Fangyuan Chen
- Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wenrui Yang
- Penn State Cancer Institute, Pennsylvania State University College of Medicine, Hershey, PA, USA.,Institute of Hematology, Peking Union Medical College, Tianjin, China
| | - Thomas Abraham
- Penn State Cancer Institute, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Douglas B Stairs
- Penn State Cancer Institute, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Hong-Gang Wang
- Penn State Cancer Institute, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Gregory S Yochum
- Penn State Cancer Institute, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Robert A Brodsky
- Division of Hematology, Johns Hopkins Medicine, Baltimore, MD, USA
| | - Jeffrey J Pu
- Penn State Cancer Institute, Pennsylvania State University College of Medicine, Hershey, PA, USA. .,University of Arizona Cancer Center, 1515 N Campbell Avenue, #1968C, Tucson, AZ, 85724, USA.
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4
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Gui P, Sedzro DM, Yuan X, Liu S, Hei M, Tian W, Zohbi N, Wang F, Yao Y, Aikhionbare FO, Gao X, Wang D, Yao X, Dou Z. Mps1 dimerization and multisite interactions with Ndc80 complex enable responsive spindle assembly checkpoint signaling. J Mol Cell Biol 2021; 12:486-498. [PMID: 32219319 PMCID: PMC7493027 DOI: 10.1093/jmcb/mjaa006] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/13/2020] [Accepted: 03/18/2020] [Indexed: 12/21/2022] Open
Abstract
Error-free mitosis depends on accurate chromosome attachment to spindle microtubules, which is monitored by the spindle assembly checkpoint (SAC) signaling. As an upstream factor of SAC, the precise and dynamic kinetochore localization of Mps1 kinase is critical for initiating and silencing SAC signaling. However, the underlying molecular mechanism remains elusive. Here, we demonstrated that the multisite interactions between Mps1 and Ndc80 complex (Ndc80C) govern Mps1 kinetochore targeting. Importantly, we identified direct interaction between Mps1 tetratricopeptide repeat domain and Ndc80C. We further identified that Mps1 C-terminal fragment, which contains the protein kinase domain and C-tail, enhances Mps1 kinetochore localization. Mechanistically, Mps1 C-terminal fragment mediates its dimerization. Perturbation of C-tail attenuates the kinetochore targeting and activity of Mps1, leading to aberrant mitosis due to compromised SAC function. Taken together, our study highlights the importance of Mps1 dimerization and multisite interactions with Ndc80C in enabling responsive SAC signaling.
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Affiliation(s)
- Ping Gui
- MOE Key Laboratory of Membraneless Organelle and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China.,Keck Center for Cellular Dynamics and Organoids Plasticity, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Divine M Sedzro
- MOE Key Laboratory of Membraneless Organelle and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Xiao Yuan
- MOE Key Laboratory of Membraneless Organelle and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Sikai Liu
- MOE Key Laboratory of Membraneless Organelle and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Mohan Hei
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Wei Tian
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Najdat Zohbi
- Keck Center for Cellular Dynamics and Organoids Plasticity, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Fangwei Wang
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou 310058, China
| | - Yihan Yao
- MOE Key Laboratory of Membraneless Organelle and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Felix O Aikhionbare
- Keck Center for Cellular Dynamics and Organoids Plasticity, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Xinjiao Gao
- MOE Key Laboratory of Membraneless Organelle and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Dongmei Wang
- MOE Key Laboratory of Membraneless Organelle and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Xuebiao Yao
- MOE Key Laboratory of Membraneless Organelle and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Zhen Dou
- MOE Key Laboratory of Membraneless Organelle and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
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5
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LIM domain only 1: an oncogenic transcription cofactor contributing to the tumorigenesis of multiple cancer types. Chin Med J (Engl) 2021; 134:1017-1030. [PMID: 33870932 PMCID: PMC8116020 DOI: 10.1097/cm9.0000000000001487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
ABSTRACT The LIM domain only 1 (LMO1) gene belongs to the LMO family of genes that encodes a group of transcriptional cofactors. This group of transcriptional cofactors regulates gene transcription by acting as a key "connector" or "scaffold" in transcription complexes. All LMOs, including LMO1, are important players in the process of tumorigenesis. Unique biological features of LMO1 distinct from other LMO members, such as its tissue-specific expression patterns, interacting proteins, and transcriptional targets, have been increasingly recognized. Studies indicated that LMO1 plays a critical oncogenic role in various types of cancers, including T-cell acute lymphoblastic leukemia, neuroblastoma, gastric cancer, lung cancer, and prostate cancer. The molecular mechanisms underlying such functions of LMO1 have also been investigated, but they are currently far from being fully elucidated. Here, we focus on reviewing the current findings on the role of LMO1 in tumorigenesis, the mechanisms of its oncogenic action, and the mechanisms that drive its aberrant activation in cancers. We also briefly review its roles in the development process and non-cancer diseases. Finally, we discuss the remaining questions and future investigations required for promoting the translation of laboratory findings to clinical applications, including cancer diagnosis and treatment.
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6
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Benzi G, Piatti S. Killing two birds with one stone: how budding yeast Mps1 controls chromosome segregation and spindle assembly checkpoint through phosphorylation of a single kinetochore protein. Curr Genet 2020; 66:1037-1044. [PMID: 32632756 DOI: 10.1007/s00294-020-01091-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/23/2020] [Accepted: 06/25/2020] [Indexed: 12/11/2022]
Abstract
During mitosis, the identical sister chromatids of each chromosome must attach through their kinetochores to microtubules emanating from opposite spindle poles. This process, referred to as chromosome biorientation, is essential for equal partitioning of the genetic information to the two daughter cells. Defects in chromosome biorientation can give rise to aneuploidy, a hallmark of cancer and genetic diseases. A conserved surveillance mechanism called spindle assembly checkpoint (SAC) prevents the onset of anaphase until biorientation is attained. Key to chromosome biorientation is an error correction mechanism that allows kinetochores to establish proper bipolar attachments by disengaging faulty kinetochore-microtubule connections. Error correction relies on the Aurora B and Mps1 kinases that also promote SAC signaling, raising the possibility that they are part of a single sensory device responding to improper attachments and concomitantly controlling both their disengagement and a temporary mitotic arrest. In budding yeast, Aurora B and Mps1 promote error correction independently from one another, but while the substrates of Aurora B in this process are at least partially known, the mechanism underlying the involvement of Mps1 in the error correction pathway is unknown. Through the characterization of a novel mps1 mutant and an unbiased genetic screen for extragenic suppressors, we recently gained evidence that a common mechanism based on Mps1-dependent phosphorylation of the Knl1/Spc105 kinetochore scaffold and subsequent recruitment of the Bub1 kinase is critical for the function of Mps1 in chromosome biorientation as well as for SAC activation (Benzi et al. EMBO Rep, 2020).
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Affiliation(s)
- Giorgia Benzi
- CRBM, University of Montpellier, CNRS, 1919 Route de Mende, 34293, Montpellier, France
| | - Simonetta Piatti
- CRBM, University of Montpellier, CNRS, 1919 Route de Mende, 34293, Montpellier, France.
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7
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Benzi G, Camasses A, Atsunori Y, Katou Y, Shirahige K, Piatti S. A common molecular mechanism underlies the role of Mps1 in chromosome biorientation and the spindle assembly checkpoint. EMBO Rep 2020; 21:e50257. [PMID: 32307893 DOI: 10.15252/embr.202050257] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/02/2020] [Accepted: 03/17/2020] [Indexed: 01/27/2023] Open
Abstract
The Mps1 kinase corrects improper kinetochore-microtubule attachments, thereby ensuring chromosome biorientation. Yet, its critical phosphorylation targets in this process remain largely elusive. Mps1 also controls the spindle assembly checkpoint (SAC), which halts chromosome segregation until biorientation is attained. Its role in SAC activation is antagonised by the PP1 phosphatase and involves phosphorylation of the kinetochore scaffold Knl1/Spc105, which in turn recruits the Bub1 kinase to promote assembly of SAC effector complexes. A crucial question is whether error correction and SAC activation are part of a single or separable pathways. Here, we isolate and characterise a new yeast mutant, mps1-3, that is severely defective in chromosome biorientation and SAC signalling. Through an unbiased screen for extragenic suppressors, we found that mutations lowering PP1 levels at Spc105 or forced association of Bub1 with Spc105 reinstate both chromosome biorientation and SAC signalling in mps1-3 cells. Our data argue that a common mechanism based on Knl1/Spc105 phosphorylation is critical for Mps1 function in error correction and SAC signalling, thus supporting the idea that a single sensory apparatus simultaneously elicits both pathways.
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Affiliation(s)
- Giorgia Benzi
- CRBM, University of Montpellier, CNRS, Montpellier, France
| | - Alain Camasses
- IGMM, University of Montpellier, CNRS, Montpellier, France
| | - Yoshimura Atsunori
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
| | - Yuki Katou
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
| | - Katsuhiko Shirahige
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
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8
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Zhang L, Jiang B, Zhu N, Tao M, Jun Y, Chen X, Wang Q, Luo C. Mitotic checkpoint kinase Mps1/TTK predicts prognosis of colon cancer patients and regulates tumor proliferation and differentiation via PKCα/ERK1/2 and PI3K/Akt pathway. Med Oncol 2019; 37:5. [PMID: 31720873 DOI: 10.1007/s12032-019-1320-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 10/04/2019] [Indexed: 01/09/2023]
Abstract
Mps1/TTK plays an important role in development of many tumors. The purpose of the present study was designed to investigate the role of TTK in colon cancer. We analyzed TTK and colon cancer in the GEO database, colon cancer tissues and normal tissues were collected to verify the results by immunohistochemistry. We detected the TTK expression in the colon cancer cell lines, and overexpressed or silenced TTK expression in colon cancer cell lines. GEO database showed that the expression of TTK was higher in the colon cancer tissues than normal tissues, higher level of TTK shows unfavourable prognosis in colon patients. Furthermore, high differentiation of colon shows the lower expression of TTK. The higher expression of TTK links with the high microsatellite status. However, the expression of TTK has no significant difference among the different stages of colon cancer patients, and has no significant relationship with recurrence or relapse. Here, we also report that the differential expression of TTK in colon cancer cells alters the intrinsic negative regulation of cell proliferation and differentiation, resulting in the difference of proliferation and differentiation capacity. TTK could activate the PKCα/ERK1/2 to influence the proliferation and inactivate the PI3K/AKT pathway to inhibition the expression of MUC2 and TFF3 that related to the differentiation of colon cells. In conclusions, TTK promote the colon cancer cell proliferation via activation of PKCα/ERK1/2 and inhibit the differentiation via inactivation of PI3K/Akt pathway. TTK inhibition may be the potential therapeutic pathway for the treatment of colon cancer.
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Affiliation(s)
- Li Zhang
- Department of Central Laboratory and Huai'an Key Laboratory of Esophageal Cancer Biobank, The Affiliated Huaian No. 1 People's Hospital, Nanjing Medical University, Huai'an, 223300, China
| | - Baofei Jiang
- Department of Gastrointestinal Surgery, The Affiliated Huaian No. 1 People's Hospital, Nanjing Medical University, Huaian, 223300, Jiangsu, China
| | - Ni Zhu
- Department of Microbiology, Hubei University of Science and Technology, Xianning, 437100, Hubei, China
| | - Mingyue Tao
- Department of Central Laboratory and Huai'an Key Laboratory of Esophageal Cancer Biobank, The Affiliated Huaian No. 1 People's Hospital, Nanjing Medical University, Huai'an, 223300, China
| | - Yali Jun
- Department of Central Laboratory and Huai'an Key Laboratory of Esophageal Cancer Biobank, The Affiliated Huaian No. 1 People's Hospital, Nanjing Medical University, Huai'an, 223300, China
| | - Xiaofei Chen
- Department of Central Laboratory and Huai'an Key Laboratory of Esophageal Cancer Biobank, The Affiliated Huaian No. 1 People's Hospital, Nanjing Medical University, Huai'an, 223300, China.
| | - Qilong Wang
- Department of Central Laboratory and Huai'an Key Laboratory of Esophageal Cancer Biobank, The Affiliated Huaian No. 1 People's Hospital, Nanjing Medical University, Huai'an, 223300, China.
| | - Chao Luo
- Department of Central Laboratory and Huai'an Key Laboratory of Esophageal Cancer Biobank, The Affiliated Huaian No. 1 People's Hospital, Nanjing Medical University, Huai'an, 223300, China.
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9
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Hayward D, Bancroft J, Mangat D, Alfonso-Pérez T, Dugdale S, McCarthy J, Barr FA, Gruneberg U. Checkpoint signaling and error correction require regulation of the MPS1 T-loop by PP2A-B56. J Cell Biol 2019; 218:3188-3199. [PMID: 31511308 PMCID: PMC6781431 DOI: 10.1083/jcb.201905026] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 07/19/2019] [Accepted: 08/06/2019] [Indexed: 01/16/2023] Open
Abstract
During mitosis, the formation of microtubule-kinetochore attachments is monitored by the serine/threonine kinase monopolar spindle 1 (MPS1). MPS1 is recruited to unattached kinetochores where it phosphorylates KNL1, BUB1, and MAD1 to initiate the spindle assembly checkpoint. This arrests the cell cycle until all kinetochores have been stably captured by microtubules. MPS1 also contributes to the error correction process rectifying incorrect kinetochore attachments. MPS1 activity at kinetochores requires autophosphorylation at multiple sites including threonine 676 in the activation segment or "T-loop." We now demonstrate that the BUBR1-bound pool of PP2A-B56 regulates MPS1 T-loop autophosphorylation and hence activation status in mammalian cells. Overriding this regulation using phosphomimetic mutations in the MPS1 T-loop to generate a constitutively active kinase results in a prolonged mitotic arrest with continuous turnover of microtubule-kinetochore attachments. Dynamic regulation of MPS1 catalytic activity by kinetochore-localized PP2A-B56 is thus critical for controlled MPS1 activity and timely cell cycle progression.
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Affiliation(s)
- Daniel Hayward
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - James Bancroft
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | | | | | - Sholto Dugdale
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Julia McCarthy
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Francis A Barr
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Ulrike Gruneberg
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
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10
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Autophosphorylation is sufficient to release Mps1 kinase from native kinetochores. Proc Natl Acad Sci U S A 2019; 116:17355-17360. [PMID: 31405987 DOI: 10.1073/pnas.1901653116] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Accurate mitosis depends on a surveillance system called the spindle assembly checkpoint. This checkpoint acts at kinetochores, which attach chromosomes to the dynamic tips of spindle microtubules. When a kinetochore is unattached or improperly attached, the protein kinase Mps1 phosphorylates kinetochore components, catalyzing the generation of a diffusible "wait" signal that delays anaphase and gives the cell time to correct the error. When a kinetochore becomes properly attached, its checkpoint signal is silenced to allow progression into anaphase. Recently, microtubules were found to compete directly against recombinant human Mps1 fragments for binding to the major microtubule-binding kinetochore element Ndc80c, suggesting a direct competition model for silencing the checkpoint signal at properly attached kinetochores. Here, by developing single-particle fluorescence-based assays, we tested whether such direct competition occurs in the context of native kinetochores isolated from yeast. Mps1 levels were not reduced on kinetochore particles bound laterally to the sides of microtubules or on particles tracking processively with disassembling tips. Instead, we found that Mps1 kinase activity was sufficient to promote its release from the isolated kinetochores. Mps1 autophosphorylation, rather than phosphorylation of other kinetochore components, was responsible for this dissociation. Our findings suggest that checkpoint silencing in yeast does not arise from a direct competition between Mps1 and microtubules, and that phosphoregulation of Mps1 may be a critical aspect of the silencing mechanism.
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11
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Alfonso-Pérez T, Hayward D, Holder J, Gruneberg U, Barr FA. MAD1-dependent recruitment of CDK1-CCNB1 to kinetochores promotes spindle checkpoint signaling. J Cell Biol 2019; 218:1108-1117. [PMID: 30674583 PMCID: PMC6446853 DOI: 10.1083/jcb.201808015] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 11/19/2018] [Accepted: 01/07/2019] [Indexed: 12/22/2022] Open
Abstract
Cyclin B-dependent kinase (CDK1-CCNB1) promotes entry into mitosis. Additionally, it inhibits mitotic exit by activating the spindle checkpoint. This latter role is mediated through phosphorylation of the checkpoint kinase MPS1 and other spindle checkpoint proteins. We find that CDK1-CCNB1 localizes to unattached kinetochores and like MPS1 is lost from these structures upon microtubule attachment. This suggests that CDK1-CCNB1 is an integral component and not only an upstream regulator of the spindle checkpoint pathway. Complementary proteomic and cell biological analysis demonstrate that the spindle checkpoint protein MAD1 is one of the major components of CCNB1 complexes, and that CCNB1 is recruited to unattached kinetochores in an MPS1-dependent fashion through interaction with the first 100 amino acids of MAD1. This MPS1 and MAD1-dependent pool of CDK1-CCNB1 creates a positive feedback loop necessary for timely recruitment of MPS1 to kinetochores during mitotic entry and for sustained spindle checkpoint arrest. CDK1-CCNB1 is therefore an integral component of the spindle checkpoint, ensuring the fidelity of mitosis.
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Affiliation(s)
| | - Daniel Hayward
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - James Holder
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Ulrike Gruneberg
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Francis A Barr
- Department of Biochemistry, University of Oxford, Oxford, UK
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12
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Pachis ST, Kops GJPL. Leader of the SAC: molecular mechanisms of Mps1/TTK regulation in mitosis. Open Biol 2019; 8:rsob.180109. [PMID: 30111590 PMCID: PMC6119859 DOI: 10.1098/rsob.180109] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 07/19/2018] [Indexed: 12/14/2022] Open
Abstract
Discovered in 1991 in a screen for genes involved in spindle pole body duplication, the monopolar spindle 1 (Mps1) kinase has since claimed a central role in processes that ensure error-free chromosome segregation. As a result, Mps1 kinase activity has become an attractive candidate for pharmaceutical companies in the search for compounds that target essential cellular processes to eliminate, for example, tumour cells or pathogens. Research in recent decades has offered many insights into the molecular function of Mps1 and its regulation. In this review, we integrate the latest knowledge regarding the regulation of Mps1 activity and its spatio-temporal distribution, highlight gaps in our understanding of these processes and propose future research avenues to address them.
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Affiliation(s)
- Spyridon T Pachis
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Geert J P L Kops
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, The Netherlands
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13
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Combes G, Alharbi I, Braga LG, Elowe S. Playing polo during mitosis: PLK1 takes the lead. Oncogene 2017; 36:4819-4827. [PMID: 28436952 DOI: 10.1038/onc.2017.113] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/16/2017] [Accepted: 03/18/2017] [Indexed: 12/18/2022]
Abstract
Polo-like kinase 1 (PLK1), the prototypical member of the polo-like family of serine/threonine kinases, is a pivotal regulator of mitosis and cytokinesis in eukaryotes. Many layers of regulation have evolved to target PLK1 to different subcellular structures and to its various mitotic substrates in line with its numerous functions during mitosis. Collective work is starting to illuminate an important set of substrates for PLK1: the mitotic kinases that together ensure the fidelity of the cell division process. Amongst these, recent developments argue that PLK1 regulates the activity of the histone kinases Aurora B and Haspin to define centromere identity, of MPS1 to initiate spindle checkpoint signaling, and of BUB1 and its pseudokinase paralog BUBR1 to coordinate spindle checkpoint activation and inactivation. Here, we review the recent work describing the regulation of these kinases by PLK1. We highlight common themes throughout and argue that a major mitotic function of PLK1 is as a master regulator of these key kinases.
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Affiliation(s)
- G Combes
- Program in Molecular and Cellular biology, Faculty of Medicine, Université Laval, Quebec City, Quebec, Canada
- Axe of Reproduction, Mother and Youth Health, CHU de Québec Research Centre, Quebec City, Quebec, Canada
| | - I Alharbi
- Program in Molecular and Cellular biology, Faculty of Medicine, Université Laval, Quebec City, Quebec, Canada
- Axe of Reproduction, Mother and Youth Health, CHU de Québec Research Centre, Quebec City, Quebec, Canada
| | - L G Braga
- Program in Molecular and Cellular biology, Faculty of Medicine, Université Laval, Quebec City, Quebec, Canada
- Axe of Reproduction, Mother and Youth Health, CHU de Québec Research Centre, Quebec City, Quebec, Canada
| | - S Elowe
- Program in Molecular and Cellular biology, Faculty of Medicine, Université Laval, Quebec City, Quebec, Canada
- Axe of Reproduction, Mother and Youth Health, CHU de Québec Research Centre, Quebec City, Quebec, Canada
- Department of Pediatrics, Faculty of Medicine, Université Laval, Quebec City, Quebec, Canada
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14
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Mechanisms of Chromosome Congression during Mitosis. BIOLOGY 2017; 6:biology6010013. [PMID: 28218637 PMCID: PMC5372006 DOI: 10.3390/biology6010013] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 01/07/2017] [Accepted: 01/28/2017] [Indexed: 12/13/2022]
Abstract
Chromosome congression during prometaphase culminates with the establishment of a metaphase plate, a hallmark of mitosis in metazoans. Classical views resulting from more than 100 years of research on this topic have attempted to explain chromosome congression based on the balance between opposing pulling and/or pushing forces that reach an equilibrium near the spindle equator. However, in mammalian cells, chromosome bi-orientation and force balance at kinetochores are not required for chromosome congression, whereas the mechanisms of chromosome congression are not necessarily involved in the maintenance of chromosome alignment after congression. Thus, chromosome congression and maintenance of alignment are determined by different principles. Moreover, it is now clear that not all chromosomes use the same mechanism for congressing to the spindle equator. Those chromosomes that are favorably positioned between both poles when the nuclear envelope breaks down use the so-called "direct congression" pathway in which chromosomes align after bi-orientation and the establishment of end-on kinetochore-microtubule attachments. This favors the balanced action of kinetochore pulling forces and polar ejection forces along chromosome arms that drive chromosome oscillatory movements during and after congression. The other pathway, which we call "peripheral congression", is independent of end-on kinetochore microtubule-attachments and relies on the dominant and coordinated action of the kinetochore motors Dynein and Centromere Protein E (CENP-E) that mediate the lateral transport of peripheral chromosomes along microtubules, first towards the poles and subsequently towards the equator. How the opposite polarities of kinetochore motors are regulated in space and time to drive congression of peripheral chromosomes only now starts to be understood. This appears to be regulated by position-dependent phosphorylation of both Dynein and CENP-E and by spindle microtubule diversity by means of tubulin post-translational modifications. This so-called "tubulin code" might work as a navigation system that selectively guides kinetochore motors with opposite polarities along specific spindle microtubule populations, ultimately leading to the congression of peripheral chromosomes. We propose an integrated model of chromosome congression in mammalian cells that depends essentially on the following parameters: (1) chromosome position relative to the spindle poles after nuclear envelope breakdown; (2) establishment of stable end-on kinetochore-microtubule attachments and bi-orientation; (3) coordination between kinetochore- and arm-associated motors; and (4) spatial signatures associated with post-translational modifications of specific spindle microtubule populations. The physiological consequences of abnormal chromosome congression, as well as the therapeutic potential of inhibiting chromosome congression are also discussed.
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15
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Asghar A, Lajeunesse A, Dulla K, Combes G, Thebault P, Nigg EA, Elowe S. Bub1 autophosphorylation feeds back to regulate kinetochore docking and promote localized substrate phosphorylation. Nat Commun 2015; 6:8364. [PMID: 26399325 PMCID: PMC4598568 DOI: 10.1038/ncomms9364] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 08/13/2015] [Indexed: 12/15/2022] Open
Abstract
During mitosis, Bub1 kinase phosphorylates histone H2A-T120 to promote centromere sister chromatid cohesion through recruitment of shugoshin (Sgo) proteins. The regulation and dynamics of H2A-T120 phosphorylation are poorly understood. Using quantitative phosphoproteomics we show that Bub1 is autophosphorylated at numerous sites. We confirm mitosis-specific autophosphorylation of a several residues and show that Bub1 activation is primed in interphase but fully achieved only in mitosis. Mutation of a single autophosphorylation site T589 alters kinetochore turnover of Bub1 and results in uniform H2A-T120 phosphorylation and Sgo recruitment along chromosome arms. Consequently, improper sister chromatid resolution and chromosome segregation errors are observed. Kinetochore tethering of Bub1-T589A refocuses H2A-T120 phosphorylation and Sgo1 to centromeres. Recruitment of the Bub1-Bub3-BubR1 axis to kinetochores has recently been extensively studied. Our data provide novel insight into the regulation and kinetochore residency of Bub1 and indicate that its localization is dynamic and tightly controlled through feedback autophosphorylation.
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Affiliation(s)
- Adeel Asghar
- Faculty of Medicine, Department of Molecular and Cellular Biology, Université Laval, Québec, Canada G1V 0A6.,Department of Reproduction, Mother and Youth Health, Centre de recherche du Centre Hospitalier Universitaire de Québec, Québec, Canada G1V 4G2
| | - Audrey Lajeunesse
- Faculty of Medicine, Department of Molecular and Cellular Biology, Université Laval, Québec, Canada G1V 0A6
| | - Kalyan Dulla
- ProQR Therapeutics N.V., Darwinweg 24, Leiden 2333 CR, The Netherlands
| | - Guillaume Combes
- Faculty of Medicine, Department of Molecular and Cellular Biology, Université Laval, Québec, Canada G1V 0A6.,Department of Reproduction, Mother and Youth Health, Centre de recherche du Centre Hospitalier Universitaire de Québec, Québec, Canada G1V 4G2
| | - Philippe Thebault
- Department of Reproduction, Mother and Youth Health, Centre de recherche du Centre Hospitalier Universitaire de Québec, Québec, Canada G1V 4G2
| | - Erich A Nigg
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, Basel CH-4056, Switzerland
| | - Sabine Elowe
- Faculty of Medicine, Department of Molecular and Cellular Biology, Université Laval, Québec, Canada G1V 0A6.,Department of Reproduction, Mother and Youth Health, Centre de recherche du Centre Hospitalier Universitaire de Québec, Québec, Canada G1V 4G2
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16
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Martinez R, Blasina A, Hallin JF, Hu W, Rymer I, Fan J, Hoffman RL, Murphy S, Marx M, Yanochko G, Trajkovic D, Dinh D, Timofeevski S, Zhu Z, Sun P, Lappin PB, Murray BW. Mitotic Checkpoint Kinase Mps1 Has a Role in Normal Physiology which Impacts Clinical Utility. PLoS One 2015; 10:e0138616. [PMID: 26398286 PMCID: PMC4580473 DOI: 10.1371/journal.pone.0138616] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/25/2015] [Indexed: 12/20/2022] Open
Abstract
Cell cycle checkpoint intervention is an effective therapeutic strategy for cancer when applied to patients predisposed to respond and the treatment is well-tolerated. A critical cell cycle process that could be targeted is the mitotic checkpoint (spindle assembly checkpoint) which governs the metaphase-to-anaphase transition and insures proper chromosomal segregation. The mitotic checkpoint kinase Mps1 was selected to explore whether enhancement in genomic instability is a viable therapeutic strategy. The basal-a subset of triple-negative breast cancer was chosen as a model system because it has a higher incidence of chromosomal instability and Mps1 expression is up-regulated. Depletion of Mps1 reduces tumor cell viability relative to normal cells. Highly selective, extremely potent Mps1 kinase inhibitors were created to investigate the roles of Mps1 catalytic activity in tumor cells and normal physiology (PF-7006, PF-3837; Ki<0.5 nM; cellular IC50 2–6 nM). Treatment of tumor cells in vitro with PF-7006 modulates expected Mps1-dependent biology as demonstrated by molecular and phenotypic measures (reduced pHH3-Ser10 levels, shorter duration of mitosis, micro-nucleation, and apoptosis). Tumor-bearing mice treated with PF-7006 exhibit tumor growth inhibition concomitant with pharmacodynamic modulation of a downstream biomarker (pHH3-Ser10). Unfortunately, efficacy only occurs at drug exposures that cause dose-limiting body weight loss, gastrointestinal toxicities, and neutropenia. Mps1 inhibitor toxicities may be mitigated by inducing G1 cell cycle arrest in Rb1-competent cells with the cyclin-dependent kinase-4/6 inhibitor palbociclib. Using an isogenic cellular model system, PF-7006 is shown to be selectively cytotoxic to Rb1-deficient cells relative to Rb1-competent cells (also a measure of kinase selectivity). Human bone marrow cells pretreated with palbociclib have decreased PF-7006-dependent apoptosis relative to cells without palbociclib pretreatment. Collectively, this study raises a concern that single agent therapies inhibiting Mps1 will not be well-tolerated clinically but may be when combined with a selective CDK4/6 drug.
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Affiliation(s)
- Ricardo Martinez
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10724 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Alessandra Blasina
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10724 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Jill F. Hallin
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10724 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Wenyue Hu
- Drug Safety Research and Development, Pfizer Worldwide Research and Development, 10646 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Isha Rymer
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10724 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Jeffery Fan
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10724 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Robert L. Hoffman
- Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 10724 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Sean Murphy
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10724 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Matthew Marx
- Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 10724 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Gina Yanochko
- Drug Safety Research and Development, Pfizer Worldwide Research and Development, 10646 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Dusko Trajkovic
- Drug Safety Research and Development, Pfizer Worldwide Research and Development, 10646 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Dac Dinh
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10724 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Sergei Timofeevski
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10724 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Zhou Zhu
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10724 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Peiquing Sun
- Department of Cell and Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, United States of America
| | - Patrick B. Lappin
- Drug Safety Research and Development, Pfizer Worldwide Research and Development, 10646 Science Center Drive, San Diego, CA, 92121, United States of America
| | - Brion W. Murray
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10724 Science Center Drive, San Diego, CA, 92121, United States of America
- * E-mail:
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17
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Dynamic localization of Mps1 kinase to kinetochores is essential for accurate spindle microtubule attachment. Proc Natl Acad Sci U S A 2015; 112:E4546-55. [PMID: 26240331 DOI: 10.1073/pnas.1508791112] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The spindle assembly checkpoint (SAC) is a conserved signaling pathway that monitors faithful chromosome segregation during mitosis. As a core component of SAC, the evolutionarily conserved kinase monopolar spindle 1 (Mps1) has been implicated in regulating chromosome alignment, but the underlying molecular mechanism remains unclear. Our molecular delineation of Mps1 activity in SAC led to discovery of a previously unidentified structural determinant underlying Mps1 function at the kinetochores. Here, we show that Mps1 contains an internal region for kinetochore localization (IRK) adjacent to the tetratricopeptide repeat domain. Importantly, the IRK region determines the kinetochore localization of inactive Mps1, and an accumulation of inactive Mps1 perturbs accurate chromosome alignment and mitotic progression. Mechanistically, the IRK region binds to the nuclear division cycle 80 complex (Ndc80C), and accumulation of inactive Mps1 at the kinetochores prevents a dynamic interaction between Ndc80C and spindle microtubules (MTs), resulting in an aberrant kinetochore attachment. Thus, our results present a previously undefined mechanism by which Mps1 functions in chromosome alignment by orchestrating Ndc80C-MT interactions and highlight the importance of the precise spatiotemporal regulation of Mps1 kinase activity and kinetochore localization in accurate mitotic progression.
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18
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von Schubert C, Cubizolles F, Bracher JM, Sliedrecht T, Kops GJPL, Nigg EA. Plk1 and Mps1 Cooperatively Regulate the Spindle Assembly Checkpoint in Human Cells. Cell Rep 2015; 12:66-78. [PMID: 26119734 DOI: 10.1016/j.celrep.2015.06.007] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 05/14/2015] [Accepted: 06/01/2015] [Indexed: 01/13/2023] Open
Abstract
Equal mitotic chromosome segregation is critical for genome integrity and is monitored by the spindle assembly checkpoint (SAC). We have previously shown that the consensus phosphorylation motif of the essential SAC kinase Monopolar spindle 1 (Mps1) is very similar to that of Polo-like kinase 1 (Plk1). This prompted us to ask whether human Plk1 cooperates with Mps1 in SAC signaling. Here, we demonstrate that Plk1 promotes checkpoint signaling at kinetochores through the phosphorylation of at least two Mps1 substrates, including KNL-1 and Mps1 itself. As a result, Plk1 activity enhances Mps1 catalytic activity as well as the recruitment of the SAC components Mad1:C-Mad2 and Bub3:BubR1 to kinetochores. We conclude that Plk1 strengthens the robustness of SAC establishment at the onset of mitosis and supports SAC maintenance during prolonged mitotic arrest.
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Affiliation(s)
- Conrad von Schubert
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Fabien Cubizolles
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Jasmine M Bracher
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Tale Sliedrecht
- Molecular Cancer Research, University Medical Center Utrecht, 3584 CG, Utrecht, the Netherlands; Center for Molecular Medicine, University Medical Center Utrecht, 3584 CG, Utrecht, the Netherlands; Cancer Genomics Netherlands, University Medical Center Utrecht, 3584 CG, Utrecht, the Netherlands
| | - Geert J P L Kops
- Molecular Cancer Research, University Medical Center Utrecht, 3584 CG, Utrecht, the Netherlands; Center for Molecular Medicine, University Medical Center Utrecht, 3584 CG, Utrecht, the Netherlands; Cancer Genomics Netherlands, University Medical Center Utrecht, 3584 CG, Utrecht, the Netherlands
| | - Erich A Nigg
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.
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