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Audett MR, Johnson EL, McGory JM, Barcelos DM, Szalai EO, Przewloka MR, Maresca TJ. The microtubule- and PP1-binding activities of Drosophila melanogaster Spc105 control the kinetics of SAC satisfaction. Mol Biol Cell 2022; 33:ar1. [PMID: 34705493 PMCID: PMC8886820 DOI: 10.1091/mbc.e21-06-0307-t] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/31/2021] [Accepted: 10/22/2021] [Indexed: 11/18/2022] Open
Abstract
KNL1 is a large intrinsically disordered kinetochore (KT) protein that recruits spindle assembly checkpoint (SAC) components to mediate SAC signaling. The N-terminal region (NTR) of KNL1 possesses two activities that have been implicated in SAC silencing: microtubule (MT) binding and protein phosphatase 1 (PP1) recruitment. The NTR of Drosophila melanogaster KNL1 (Spc105) has never been shown to bind MTs or to recruit PP1. Furthermore, the phosphoregulatory mechanisms known to control SAC protein binding to KNL1 orthologues is absent in D. melanogaster. Here, these apparent discrepancies are resolved using in vitro and cell-based assays. A phosphoregulatory circuit that utilizes Aurora B kinase promotes SAC protein binding to the central disordered region of Spc105 while the NTR binds directly to MTs in vitro and recruits PP1-87B to KTs in vivo. Live-cell assays employing an optogenetic oligomerization tag and deletion/chimera mutants are used to define the interplay of MT and PP1 binding by Spc105 and the relative contributions of both activities to the kinetics of SAC satisfaction.
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Affiliation(s)
- Margaux R. Audett
- Biology Department, University of Massachusetts, Amherst, Amherst MA 01003
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Amherst MA 01003
| | - Erin L. Johnson
- Biology Department, University of Massachusetts, Amherst, Amherst MA 01003
| | - Jessica M. McGory
- Biology Department, University of Massachusetts, Amherst, Amherst MA 01003
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Amherst MA 01003
| | - Dylan M. Barcelos
- Biology Department, University of Massachusetts, Amherst, Amherst MA 01003
| | - Evelin Oroszne Szalai
- Institute for Life Sciences, School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Marcin R. Przewloka
- Institute for Life Sciences, School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Thomas J. Maresca
- Biology Department, University of Massachusetts, Amherst, Amherst MA 01003
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Amherst MA 01003
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Nabi D, Drechsler H, Pschirer J, Korn F, Schuler N, Diez S, Jessberger R, Chacón M. CENP-V is required for proper chromosome segregation through interaction with spindle microtubules in mouse oocytes. Nat Commun 2021; 12:6547. [PMID: 34764261 PMCID: PMC8586017 DOI: 10.1038/s41467-021-26826-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 10/21/2021] [Indexed: 11/08/2022] Open
Abstract
Proper chromosome segregation is essential to avoid aneuploidy, yet this process fails with increasing age in mammalian oocytes. Here we report a role for the scarcely described protein CENP-V in oocyte spindle formation and chromosome segregation. We show that depending on the oocyte maturation state, CENP-V localizes to centromeres, to microtubule organizing centers, and to spindle microtubules. We find that Cenp-V-/- oocytes feature severe deficiencies, including metaphase I arrest, strongly reduced polar body extrusion, increased numbers of mis-aligned chromosomes and aneuploidy, multipolar spindles, unfocused spindle poles and loss of kinetochore spindle fibres. We also show that CENP-V protein binds, diffuses along, and bundles microtubules in vitro. The spindle assembly checkpoint arrests about half of metaphase I Cenp-V-/- oocytes from young adults only. This finding suggests checkpoint weakening in ageing oocytes, which mature despite carrying mis-aligned chromosomes. Thus, CENP-V is a microtubule bundling protein crucial to faithful oocyte meiosis, and Cenp-V-/- oocytes reveal age-dependent weakening of the spindle assembly checkpoint.
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Affiliation(s)
- Dalileh Nabi
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Department of Neuropediatrics Charité-Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Hauke Drechsler
- B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Johannes Pschirer
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Franz Korn
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Nadine Schuler
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Stefan Diez
- B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany
- Cluster of Excellence Physics of Life, Technische Universität Dresden, Dresden, Germany
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Rolf Jessberger
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
| | - Mariola Chacón
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
- CABIMER, Centro Andaluz de Biología Molecular & Medicina Regenerativa, Sevilla, Spain.
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Zhou C, Miao Y, Zhang X, Xiong B. WAPL orchestrates porcine oocyte meiotic progression via control of spindle assembly checkpoint activity. Reprod Biol Endocrinol 2021; 19:57. [PMID: 33874950 PMCID: PMC8054420 DOI: 10.1186/s12958-021-00740-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 04/07/2021] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND In mitotic cells, WAPL acts as a cohesin release factor to remove cohesin complexes from chromosome arms during prophase to allow the accurate chromosome segregation in anaphase. However, we have recently documented that Wapl exerts a unique meiotic function in the spindle assembly checkpoint (SAC) control through maintaining Bub3 stability during mouse oocyte meiosis I. Whether this noncanonical function is conserved among species is still unknown. METHODS We applied RNAi-based gene silencing approach to deplete WAPL in porcine oocytes, validating the conserved roles of WAPL in the regulation of SAC activity during mammalian oocyte maturation. We also employed immunostaining, immunoblotting and image quantification analyses to test the WAPL depletion on the meiotic progression, spindle assembly, chromosome alignment and dynamics of SAC protein in porcine oocytes. RESULTS We showed that depletion of WAPL resulted in the accelerated meiotic progression by displaying the precocious polar body extrusion and compromised spindle assembly and chromosome alignment. Notably, we observed that the protein level of BUB3 was substantially reduced in WAPL-depleted oocytes, especially at kinetochores. CONCLUSIONS Collectively, our data demonstrate that WAPL participates in the porcine oocyte meiotic progression through maintenance of BUB3 protein levels and SAC activity. This meiotic function of WAPL in oocytes is highly conserved between pigs and mice.
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Affiliation(s)
- Changyin Zhou
- College of Animal Science and Technology, Nanjing Agricultural University, 210095, Nanjing, China
| | - Yilong Miao
- College of Animal Science and Technology, Nanjing Agricultural University, 210095, Nanjing, China
| | - Xue Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, 210095, Nanjing, China
| | - Bo Xiong
- College of Animal Science and Technology, Nanjing Agricultural University, 210095, Nanjing, China.
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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: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Liu M, Wu L, Cai C, Liu L, Xu Y. MicroRNA-187 suppresses the proliferation migration and invasion of human osteosarcoma cells by targeting MAPK7. J BUON 2020; 25:472-478. [PMID: 32277671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
PURPOSE Osteosarcoma is one of the rare but fatal malignancies. The high metastatic rate, late diagnosis, emergence of drug resistance against drugs such as doxorubicin, and the lack of therapeutic targets obstructs the treatment of osteosarcoma. This study was undertaken to investigate the role and therapeutic potential of miR-187 in human osteosarcoma cells. METHODS The WST-1 proliferation assay was used for investigation of cell viability. Transfections were carried out by Lipofectamine 2000 reagent. The qRT-PCR was used for expression analysis. DAPI, acridine orange (AO)/ethidium bromide (EB) and Annexin V/propidium iodide (PI) assay were used for apoptosis. Western blot analysis was used for the determination of protein expression. RESULTS The expression of miR-187 was significantly downregulated in human osteosarcoma cells. Out of all osteosarcoma cell lines the SAOS-2 showed the lowest expression of miR-187 and therefore this cell line was selected for further studies. Overexpression of miR-187 caused significant inhibition in the proliferation of SAOS-2 osteosarcoma cells. The miR-187-triggered growth inhibition was found to be mainly due to induction of G2/M phase cell cycle arrest of the SAOS-2 cells. The G2/M cell cycle arrest was also accompanied by depletion of Cyclin-B1 expression. Additionally, miR-187 enhanced the chemosensitivity of the osteosarcoma cells to doxorubicin. The wound healing and transwell assay showed that miR-187 overexpression resulted in the suppression of migration and invasion of the SAOS-2 osteosarcoma cells. In silico analysis showed that miR-187 exerts its effects by inhibiting mitogen activated protein kinase 7 (MAPK7). The expression of MAPK7 was found to be significantly upregulated in osteosarcoma cells and overexpression of MAPK7 could nullify the effects of miR-187 on the proliferation of the osteosarcoma cells.
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Affiliation(s)
- Min Liu
- Department of Orthopaedics, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215101, China
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6
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Zhang Y, Tu L, Zhou X, Li B. MicroRNA-22 regulates the proliferation, drug sensitivity and metastasis of human glioma cells by targeting SNAIL1. J BUON 2020; 25:491-496. [PMID: 32277674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
PURPOSE Gliomas are aggressive brain tumors accounting for significant mortality across the globe. Biomarkers for early detection and therapeutic targets for efficient treatment are lacking for glioma. This study was undertaken to investigate the role and therapeutic implications of miR-22 in glioma. METHODS U-87 glioma cell line was used in this study. qRT-PCR was employed for expression analysis. MTT assay was used for determination of cell viability. Lipofectamine 2000 was used for transfection. Flow cytometry was used for cell analysis. Wound healing assay and transwell assay were used for monitoring cell migration and invasion. Western blot analysis was used for estimation of protein expression. RESULTS The miR-22 expression was found decreased in glioma cells. Overexpression of miR-22 resulted in arrest of the U-87 glioma cells at G2/M checkpoint of the cell cycle. The percentage of apoptotic U-87 cells in G2/M phase were 13.05% in negative control (NC) and 29.06% in miR-22 mimics transfected cells. The cell cycle arrest promoted by miR-22 overexpression was also associated with depletion of cyclin B1 expression in U-87 cells. Furthermore, miR-22 could also significantly increase the sensitivity of glioma U-87 cells to cisplatin. The TargetScan analysis and dual luciferase assay showed SNAIL1 to be the target of miR-22. The expression of SNAIL1 was also enhanced in all the glioma cells and miR-22 overexpression could cause suppression of the SNAIL1 expression in U-87 cells. Furthermore, SNAIL1 silencing could also cause decline in the viability of the U-87 cells. The wound healing assay showed that miR-5 overexpression caused decrease in the migration of U-87 cells, while the transwell assay showed decline in the invasion of miR-22 mimics transfected U-87 cells. CONCLUSION Taken together, miR-22 may exhibit therapeutic implications in glioma and may prove useful in glioma treatment.
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Affiliation(s)
- Yunqiang Zhang
- Department of Neurosurgery, Chenzhou No.1 People's Hospital, Chenzhou, Hunan, China, 423000
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7
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Yang S, Yang R, Lin R, Si L. MicroRNA-375 inhibits the growth, drug sensitivity and metastasis of human ovarian cancer cells by targeting PAX2. J BUON 2019; 24:2341-2346. [PMID: 31983104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
PURPOSE Ovarian cancer is responsible for a significant number of deaths in women and there is urgent need to develop efficient treatment strategies for this disease. Studies have shown microRNAs (miRs) are involved in diverse cellular processes and exhibit therapeutic implications. Herein, the role of miR-375 in ovarian cancer was explored. METHODS OVACAR-3 cell line was mainly used in this research. Expression analysis was performed by qRT-PCR. Cell viability was determined by MTT assay. Cell cycle analysis was carried out by flow cytometry. Transwell assay was used for cell migration and invasion. Western blot analysis was used to determine the protein expression. RESULTS Gene expression analysis carried out by qRT-PCR of ovarian cancer cell lines and tissues revealed significant downregulation of miR-375. Ectopic expression of miR-375 halted the growth of the OVACAR-3 cells by triggering G2/M cell cycle arrest. Moreover, miR-375 also caused a significant decrease in the migratory and invasive potential of the OAVACAR-3 cells and enhanced their chemosensitivity to cisplatin. Bioinformatic analysis and the dual luciferase showed that miR-375 targets PAX2 in OVACAR-3 cells. Suppression of PAX2 inhibits the growth of the OVACAR-3 cells while PAX2 overexpression could avoid the growth inhibitory effects of miR-375 in OVACAR-3 cells. CONCLUSION miR-375 may prove to be an important therapeutic target in ovarian cancer and warrants further research endeavors.
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Affiliation(s)
- Shuli Yang
- Department of Obstetrics and Gynecology, Second Hospital of Jilin University, Changchun, 130041, P.R. China
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8
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Zhang S, Tischer T, Barford D. Cyclin A2 degradation during the spindle assembly checkpoint requires multiple binding modes to the APC/C. Nat Commun 2019; 10:3863. [PMID: 31455778 PMCID: PMC6712056 DOI: 10.1038/s41467-019-11833-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 07/29/2019] [Indexed: 12/19/2022] Open
Abstract
The anaphase-promoting complex/cyclosome (APC/C) orchestrates cell cycle progression by controlling the temporal degradation of specific cell cycle regulators. Although cyclin A2 and cyclin B1 are both targeted for degradation by the APC/C, during the spindle assembly checkpoint (SAC), the mitotic checkpoint complex (MCC) represses APC/C's activity towards cyclin B1, but not cyclin A2. Through structural, biochemical and in vivo analysis, we identify a non-canonical D box (D2) that is critical for cyclin A2 ubiquitination in vitro and degradation in vivo. During the SAC, cyclin A2 is ubiquitinated by the repressed APC/C-MCC, mediated by the cooperative engagement of its KEN and D2 boxes, ABBA motif, and the cofactor Cks. Once the SAC is satisfied, cyclin A2 binds APC/C-Cdc20 through two mutually exclusive binding modes, resulting in differential ubiquitination efficiency. Our findings reveal that a single substrate can engage an E3 ligase through multiple binding modes, affecting its degradation timing and efficiency.
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Affiliation(s)
- Suyang Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
- Max Planck Institute for Biophysical Chemistry, Göttingen, 37077, Germany
| | - Thomas Tischer
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK.
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Shimoi G, Tomita M, Kataoka M, Kameyama Y. Destabilization of spindle assembly checkpoint causes aneuploidy during meiosis II in murine post-ovulatory aged oocytes. J Reprod Dev 2019; 65:57-66. [PMID: 30464155 PMCID: PMC6379765 DOI: 10.1262/jrd.2018-056] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 11/02/2018] [Indexed: 11/20/2022] Open
Abstract
Mammalian oocyte quality degrades over time after ovulation in vitro, which can cause fatal defects such as chromosomal aneuploidy. As various oocyte manipulations employed in assisted reproductive technology are time consuming, post-ovulatory aging is a serious problem to overcome in reproductive medicine or ova research. In this study, we investigated the effects of postovulatory aging on the incidence of chromosome aneuploidy during meiosis II, with a focus on the expression of functional proteins from the spindle assembly checkpoint (SAC). Chromosome analysis was used to assess the rate of aneuploidy in in vitro aged oocytes, or in early embryos derived from aged oocytes. Immunofluorescent staining was used to detect the localization of MAD2, which is a SAC signal that monitors the correct segregation of sister chromatids. Immunoblotting was used to quantify cohesin subunits, which are adhesion factors connecting sister chromatids at the metaphase II (MII) centromere. It was shown that post-ovulatory oocyte aging inhibits MAD2 localization to the sister kinetochore. Furthermore, oocyte aging prevented cohesin subunits from being maintained or degraded at the appropriate time. These data suggest that the destabilization of SAC signaling causes sister chromatid segregation errors in MII oocytes, and consequently increases the incidence of aneuploidy in early embryos. Our findings have provided distinct evidence that the post-ovulatory aging of oocytes might also be a risk factor for aneuploidy, irrespective of maternal age.
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Affiliation(s)
- Gaku Shimoi
- Laboratory of Animal Resources and Development, Department of Northern Biosphere Agriculture, Faculty of Bioindustry, Tokyo University of Agriculture, Hokkaido 099-2493, Japan
| | - Masaru Tomita
- Laboratory of Animal Resources and Development, Department of Northern Biosphere Agriculture, Faculty of Bioindustry, Tokyo University of Agriculture, Hokkaido 099-2493, Japan
| | - Marino Kataoka
- Laboratory of Animal Resources and Development, Department of Northern Biosphere Agriculture, Faculty of Bioindustry, Tokyo University of Agriculture, Hokkaido 099-2493, Japan
| | - Yuichi Kameyama
- Laboratory of Animal Resources and Development, Department of Northern Biosphere Agriculture, Faculty of Bioindustry, Tokyo University of Agriculture, Hokkaido 099-2493, Japan
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Bonaiuti P, Chiroli E, Gross F, Corno A, Vernieri C, Štefl M, Cosentino Lagomarsino M, Knop M, Ciliberto A. Cells Escape an Operational Mitotic Checkpoint through a Stochastic Process. Curr Biol 2017; 28:28-37.e7. [PMID: 29249657 DOI: 10.1016/j.cub.2017.11.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 10/23/2017] [Accepted: 11/13/2017] [Indexed: 11/18/2022]
Abstract
Improperly attached chromosomes activate the mitotic checkpoint that arrests cell division before anaphase. Cells can maintain an arrest for several hours but eventually will resume proliferation, a process we refer to as adaptation. Whether adapting cells bypass an active block or whether the block has to be removed to resume proliferation is not clear. Likewise, it is not known whether all cells of a genetically homogeneous population are equally capable to adapt. Here, we show that the mitotic checkpoint is operational when yeast cells adapt and that each cell has the same propensity to adapt. Our results are consistent with a model of the mitotic checkpoint where adaptation is driven by random fluctuations of APC/CCdc20, the molecular species inhibited by the checkpoint. Our data provide a quantitative framework for understanding how cells overcome a constant stimulus that halts cell cycle progression.
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Affiliation(s)
- Paolo Bonaiuti
- Istituto Firc di Oncologia Molecolare, IFOM, via Adamello 16, 20139 Milan, Italy
| | - Elena Chiroli
- Istituto Firc di Oncologia Molecolare, IFOM, via Adamello 16, 20139 Milan, Italy
| | - Fridolin Gross
- Istituto Firc di Oncologia Molecolare, IFOM, via Adamello 16, 20139 Milan, Italy
| | - Andrea Corno
- Istituto Firc di Oncologia Molecolare, IFOM, via Adamello 16, 20139 Milan, Italy
| | - Claudio Vernieri
- Istituto Firc di Oncologia Molecolare, IFOM, via Adamello 16, 20139 Milan, Italy; Medical Oncology Department, Fondazione IRCCS Istituto Nazionale Tumori, via Venezian 1, 20133 Milan, Italy
| | - Martin Štefl
- DKFZ-ZMBH Alliance, Centre for Molecular Biology (ZMBH), University of Heidelberg, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Marco Cosentino Lagomarsino
- Istituto Firc di Oncologia Molecolare, IFOM, via Adamello 16, 20139 Milan, Italy; Sorbonne Universités, UPMC Univ Paris 06, 5 Place Jussieu, 75005 Paris, France; CNRS, UMR 7238 "Biologie Computationnelle et Quantitative," UPMC, Institut de Biologie Paris Seine, 4 Place Jussieu, 75005 Paris, France
| | - Michael Knop
- DKFZ-ZMBH Alliance, Centre for Molecular Biology (ZMBH), University of Heidelberg, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany; DKFZ-ZMBH Alliance, Department of Cell and Tumour Biology, German Cancer Research Centre (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Andrea Ciliberto
- Istituto Firc di Oncologia Molecolare, IFOM, via Adamello 16, 20139 Milan, Italy; Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche (IGM-CNR), via Abbiategrasso 207, 27100 Pavia, Italy.
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11
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Komaki S, Schnittger A. The spindle checkpoint in plants-a green variation over a conserved theme? Curr Opin Plant Biol 2016; 34:84-91. [PMID: 27816818 DOI: 10.1016/j.pbi.2016.10.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 10/13/2016] [Accepted: 10/14/2016] [Indexed: 06/06/2023]
Abstract
The spindle checkpoint, also called spindle assembly checkpoint (SAC), is a crucial control instance in animals and yeast that surveys the correct attachment of chromosomes to the spindle assuring their equal distribution in mitosis and meiosis. The presence of homologs of all core SAC components in plants indicates that these regulators have an ancient function. However, the fact that mutants of SAC components in plants are usually fully viable together with the observation that plants can be readily made polyploid raises the question whether plants have an efficient SAC. Recently, the role and regulation of a putative SAC in plants has been addressed. Interestingly, these studies also revealed that SAC genes are involved in several other cellular and developmental processes outside of chromosome distribution control.
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Affiliation(s)
- Shinichiro Komaki
- University of Hamburg, Biozentrum Klein Flottbek, Department of Developmental Biology, Ohnhorststr. 18, D-22609 Hamburg, Germany
| | - Arp Schnittger
- University of Hamburg, Biozentrum Klein Flottbek, Department of Developmental Biology, Ohnhorststr. 18, D-22609 Hamburg, Germany.
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12
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Alfieri C, Chang L, Zhang Z, Yang J, Maslen S, Skehel M, Barford D. Molecular basis of APC/C regulation by the spindle assembly checkpoint. Nature 2016; 536:431-436. [PMID: 27509861 PMCID: PMC5019344 DOI: 10.1038/nature19083] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 07/06/2016] [Indexed: 12/12/2022]
Abstract
In the dividing eukaryotic cell, the spindle assembly checkpoint (SAC) ensures that each daughter cell inherits an identical set of chromosomes. The SAC coordinates the correct attachment of sister chromatid kinetochores to the mitotic spindle with activation of the anaphase-promoting complex (APC/C), the E3 ubiquitin ligase responsible for initiating chromosome separation. In response to unattached kinetochores, the SAC generates the mitotic checkpoint complex (MCC), which inhibits the APC/C and delays chromosome segregation. By cryo-electron microscopy, here we determine the near-atomic resolution structure of a human APC/C–MCC complex (APC/C(MCC)). Degron-like sequences of the MCC subunit BubR1 block degron recognition sites on Cdc20, the APC/C coactivator subunit responsible for substrate interactions. BubR1 also obstructs binding of the initiating E2 enzyme UbcH10 to repress APC/C ubiquitination activity. Conformational variability of the complex enables UbcH10 association, and structural analysis shows how the Cdc20 subunit intrinsic to the MCC (Cdc20(MCC)) is ubiquitinated, a process that results in APC/C reactivation when the SAC is silenced.
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Affiliation(s)
- Claudio Alfieri
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Leifu Chang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Ziguo Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Jing Yang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Sarah Maslen
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Mark Skehel
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
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13
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Sabir SR, Sahota NK, Jones GDD, Fry AM. Loss of Nek11 Prevents G2/M Arrest and Promotes Cell Death in HCT116 Colorectal Cancer Cells Exposed to Therapeutic DNA Damaging Agents. PLoS One 2015; 10:e0140975. [PMID: 26501353 PMCID: PMC4621075 DOI: 10.1371/journal.pone.0140975] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 10/03/2015] [Indexed: 11/19/2022] Open
Abstract
The Nek11 kinase is a potential mediator of the DNA damage response whose expression is upregulated in early stage colorectal cancers (CRCs). Here, using RNAi-mediated depletion, we examined the role of Nek11 in HCT116 WT and p53-null CRC cells exposed to ionizing radiation (IR) or the chemotherapeutic drug, irinotecan. We demonstrate that depletion of Nek11 prevents the G2/M arrest induced by these genotoxic agents and promotes p53-dependent apoptosis both in the presence and absence of DNA damage. Interestingly, Nek11 depletion also led to long-term loss of cell viability that was independent of p53 and exacerbated following IR exposure. CRC cells express four splice variants of Nek11 (L/S/C/D). These are predominantly cytoplasmic, but undergo nucleocytoplasmic shuttling mediated through adjacent nuclear import and export signals in the C-terminal non-catalytic domain. In HCT116 cells, Nek11S in particular has an important role in the DNA damage response. These data provide strong evidence that Nek11 contributes to the response of CRC cells to genotoxic agents and is essential for survival either with or without exposure to DNA damage.
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Affiliation(s)
- Sarah R. Sabir
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 9HN, United Kingdom
| | - Navdeep K. Sahota
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 9HN, United Kingdom
| | - George D. D. Jones
- Department of Cancer Studies, University of Leicester, Leicester LE2 7LX, United Kingdom
| | - Andrew M. Fry
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 9HN, United Kingdom
- * E-mail:
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14
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Trakala M, Partida D, Salazar-Roa M, Maroto M, Wachowicz P, de Cárcer G, Malumbres M. Activation of the endomitotic spindle assembly checkpoint and thrombocytopenia in Plk1-deficient mice. Blood 2015; 126:1707-14. [PMID: 26185128 DOI: 10.1182/blood-2015-03-634402] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 07/09/2015] [Indexed: 12/12/2022] Open
Abstract
Polyploidization in megakaryocytes is achieved by endomitosis, a specialized cell cycle in which DNA replication is followed by aberrant mitosis. Typical mitotic regulators such as Aurora kinases or Cdk1 are dispensable for megakaryocyte maturation, and inhibition of mitotic kinases may in fact promote megakaryocyte maturation. However, we show here that Polo-like kinase 1 (Plk1) is required for endomitosis, and ablation of the Plk1 gene in megakaryocytes results in defective polyploidization accompanied by mitotic arrest and cell death. Lack of Plk1 results in defective centrosome maturation and aberrant spindle pole formation, thus impairing the formation of multiple poles typically found in megakaryocytes. In these conditions, megakaryocytes arrest for a long time in mitosis and frequently die. Mitotic arrest in wild-type megakaryocytes treated with Plk1 inhibitors or Plk1-null cells is triggered by the spindle assembly checkpoint (SAC), and can be rescued in the presence of SAC inhibitors. These data suggest that, despite the dispensability of proper chromosome segregation in megakaryocytes, an endomitotic SAC is activated in these cells upon Plk1 inhibition. SAC activation results in defective maturation of megakaryocytes and cell death, thus raising a note of caution in the use of Plk1 inhibitors in therapeutic strategies based on polyploidization regulators.
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Affiliation(s)
- Marianna Trakala
- Cell Division and Cancer Group, Centro Nacional de Investigaciones Oncológicas, Madrid, Spain
| | - David Partida
- Cell Division and Cancer Group, Centro Nacional de Investigaciones Oncológicas, Madrid, Spain
| | - María Salazar-Roa
- Cell Division and Cancer Group, Centro Nacional de Investigaciones Oncológicas, Madrid, Spain
| | - María Maroto
- Cell Division and Cancer Group, Centro Nacional de Investigaciones Oncológicas, Madrid, Spain
| | - Paulina Wachowicz
- Cell Division and Cancer Group, Centro Nacional de Investigaciones Oncológicas, Madrid, Spain
| | - Guillermo de Cárcer
- Cell Division and Cancer Group, Centro Nacional de Investigaciones Oncológicas, Madrid, Spain
| | - Marcos Malumbres
- Cell Division and Cancer Group, Centro Nacional de Investigaciones Oncológicas, Madrid, Spain
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15
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Abstract
The majority of human cancer cells are highly aneuploid harboring chromosome numbers deviating from the modal number of 46. In cancer, aneuploidy is a consequence of an increased rate of whole chromosome missegregation during mitosis, a process known as chromosomal instability (CIN). In fact, CIN is a hallmark of human cancer and is thought to contribute to tumorigenesis, tumor progression, and the development of therapy resistance by providing a high genetic variability that might foster rapid adaptation processes. However, the molecular mechanisms that cause chromosome missegregation in cancer cells are still poorly understood. So far, several mechanisms underlying CIN have been proposed and some of them are indeed detectable in human cancer cells exhibiting CIN. Examples include, for instance, weakened spindle checkpoint signaling, supernumerary centrosomes, defects in chromatid cohesion, abnormal kinetochore-microtubule attachments and increased spindle microtubule dynamics. Here, the mechanisms leading to CIN in human cancer cells are summarized.
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Affiliation(s)
- Holger Bastians
- Goettingen Center for Molecular Biosciences (GZMB), University Medical Center, Institute of Molecular Oncology, Section for Cellular Oncology, Georg-August University Goettingen, Grisebachstrasse 8, 37077, Goettingen, Germany.
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16
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Li L, Tan Y, Chen X, Xu Z, Yang S, Ren F, Guo H, Wang X, Chen Y, Li G, Wang H. MDM4 overexpressed in acute myeloid leukemia patients with complex karyotype and wild-type TP53. PLoS One 2014; 9:e113088. [PMID: 25405759 PMCID: PMC4236138 DOI: 10.1371/journal.pone.0113088] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 10/20/2014] [Indexed: 12/18/2022] Open
Abstract
Acute myeloid leukemia patients with complex karyotype (CK-AML) account for approximately 10–15% of adult AML cases, and are often associated with a poor prognosis. Except for about 70% of CK-AML patients with biallelic inactivation of TP53, the leukemogenic mechanism in the nearly 30% of CK-AML patients with wild-type TP53 has remained elusive. In this study, 15 cases with complex karyotype and wild-type TP53 were screened out of 140 de novo AML patients and the expression levels of MDM4, a main negative regulator of p53-signaling pathway, were detected. We ruled out mutations in genes associated with a poor prognosis of CK-AML, including RUNX1 or FLT3-ITD. The mRNA expression levels of the full-length of MDM4 (MDM4FL) and short isoform MDM4 (MDM4S) were elevated in CK-AML relative to normal karyotype AML (NK-AML) patients. We also explored the impact of MDM4 overexpression on the cell cycle, cell proliferation and the spindle checkpoint of HepG2 cells, which is a human cancer cell line with normal MDM4 and TP53 expression. The mitotic index and the expression of p21, BubR1 and Securin were all reduced following Nocodazole treatment. Moreover, karyotype analysis showed that MDM4 overexpression might lead to aneuploidy or polyploidy. These results suggest that MDM4 overexpression is related to CK-AML with wild-type TP53 and might play a pathogenic role by inhibiting p53-signal pathway.
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Affiliation(s)
- Li Li
- Department of Hematology, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, P.R. China
- Department of biology, School of Basic Medicine, Shanxi Medical University, Taiyuan, Shanxi, P.R. China
| | - Yanhong Tan
- Department of Hematology, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, P.R. China
| | - Xiuhua Chen
- Department of Hematology, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, P.R. China
| | - Zhifang Xu
- Department of Hematology, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, P.R. China
| | - Siyao Yang
- Department of Hematology, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, P.R. China
| | - Fanggang Ren
- Department of Hematology, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, P.R. China
| | - Haixiu Guo
- Department of biology, School of Basic Medicine, Shanxi Medical University, Taiyuan, Shanxi, P.R. China
| | - Xiaojuan Wang
- Department of Hematology, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, P.R. China
| | - Yi Chen
- Department of Hematology, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, P.R. China
| | - Guoxia Li
- Department of Hematology, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, P.R. China
| | - Hongwei Wang
- Department of Hematology, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, P.R. China
- * E-mail:
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17
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Abstract
To guarantee genomic integrity and viability, the cell must ensure proper distribution of the replicated chromosomes among the two daughter cells in mitosis. The mitotic spindle assembly checkpoint (SAC) is a central regulatory mechanism to achieve this goal. A dysfunction of this checkpoint may lead to aneuploidy and likely contributes to the development of cancer. Kinetochores of unattached or misaligned chromosomes are thought to generate a diffusible “wait-anaphase” signal, which is the basis for downstream events to inhibit the anaphase promoting complex/cyclosome (APC/C). The rate of Cdc20:C-Mad2 complex formation at the kinetochore is a key regulatory factor in the context of APC/C inhibition. Computer simulations of a quantitative SAC model show that the formation of Cdc20:C-Mad2 is too slow for checkpoint maintenance when cytosolic O-Mad2 has to encounter kinetochores by diffusion alone. Here, we show that an active transport of O-Mad2 towards the spindle mid-zone increases the efficiency of Mad2-activation. Our in-silico data indicate that this mechanism can greatly enhance the formation of Cdc20:Mad2 and furthermore gives an explanation on how the “wait-anaphase” signal can dissolve abruptly within a short time. Our results help to understand parts of the SAC mechanism that remain unclear.
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Affiliation(s)
- Bashar Ibrahim
- Al-Qunfudah University College, Umm Al-Qura University, 1109 Makkah Al-Mukarramah, Saudi Arabia.
| | - Richard Henze
- Bio Systems Analysis Group, Institute of Computer Science, Jena Center for Bioinformatics and Friedrich Schiller University, 07743 Jena, Germany.
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18
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Vázquez-Novelle MD, Sansregret L, Dick AE, Smith CA, McAinsh AD, Gerlich DW, Petronczki M. Cdk1 inactivation terminates mitotic checkpoint surveillance and stabilizes kinetochore attachments in anaphase. Curr Biol 2014; 24:638-45. [PMID: 24583019 PMCID: PMC3969148 DOI: 10.1016/j.cub.2014.01.034] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 12/24/2013] [Accepted: 01/14/2014] [Indexed: 12/19/2022]
Abstract
Two mechanisms safeguard the bipolar attachment of chromosomes in mitosis. A correction mechanism destabilizes erroneous attachments that do not generate tension across sister kinetochores [1]. In response to unattached kinetochores, the mitotic checkpoint delays anaphase onset by inhibiting the anaphase-promoting complex/cyclosome (APC/C(Cdc20)) [2]. Upon satisfaction of both pathways, the APC/C(Cdc20) elicits the degradation of securin and cyclin B [3]. This liberates separase triggering sister chromatid disjunction and inactivates cyclin-dependent kinase 1 (Cdk1) causing mitotic exit. How eukaryotic cells avoid the engagement of attachment monitoring mechanisms when sister chromatids split and tension is lost at anaphase is poorly understood [4]. Here we show that Cdk1 inactivation disables mitotic checkpoint surveillance at anaphase onset in human cells. Preventing cyclin B1 proteolysis at the time of sister chromatid disjunction destabilizes kinetochore-microtubule attachments and triggers the engagement of the mitotic checkpoint. As a consequence, mitotic checkpoint proteins accumulate at anaphase kinetochores, the APC/C(Cdc20) is inhibited, and securin reaccumulates. Conversely, acute pharmacological inhibition of Cdk1 abrogates the engagement and maintenance of the mitotic checkpoint upon microtubule depolymerization. We propose that the simultaneous destruction of securin and cyclin B elicited by the APC/C(Cdc20) couples chromosome segregation to the dissolution of attachment monitoring mechanisms during mitotic exit.
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Affiliation(s)
- María Dolores Vázquez-Novelle
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, Blanche Lane, South Mimms, Hertfordshire EN6 3LD, UK.
| | - Laurent Sansregret
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, Blanche Lane, South Mimms, Hertfordshire EN6 3LD, UK
| | - Amalie E Dick
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Christopher A Smith
- Centre for Mechanochemical Cell Biology, Division of Biomedical Cell Biology, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Andrew D McAinsh
- Centre for Mechanochemical Cell Biology, Division of Biomedical Cell Biology, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Daniel W Gerlich
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Mark Petronczki
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, Blanche Lane, South Mimms, Hertfordshire EN6 3LD, UK.
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19
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Yang GD, Yang XM, Lu H, Ren Y, Ma MZ, Zhu LY, Wang JH, Song WW, Zhang WM, Zhang R, Zhang ZG. SERPINA3 promotes endometrial cancer cells growth by regulating G2/M cell cycle checkpoint and apoptosis. Int J Clin Exp Pathol 2014; 7:1348-1358. [PMID: 24817931 PMCID: PMC4014215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 03/10/2014] [Indexed: 06/03/2023]
Abstract
Endometrial carcinoma (EC) is the most common gynecologic cancer worldwide and is one of the leading causes of death in women. Therefore, it is urgent to elucidate the pathological mechanisms of EC. SERPINA3 is a member of the serpin super-family of protease inhibitors. Its aberrant expression has been observed in various tumor cells. However, its clinical significance and biological function in endometrial cancer remains unknown. In the present study, we demonstrated that SERPINA3 expression was significantly up-regulated in EC samples and was closely correlated with lower differentiation, higher stage, positive lymph node or vascular thrombosis and negative estrogen receptor (ER), indicating a poor prognosis. We then demonstrated that SERPINA3 promoted EC cells proliferation by regulating G2/M checkpoint in cell cycle and inhibited cells apoptosis, and we further uncovered that the pro-proliferative effect of SERPINA3 on EC was likely ascribed to the activation of MAPK/ERK1/2 and PI3K/AKT signaling. The results of our study may provide insight into the application of SERPINA3 as a novel predictor of clinical outcomes and a potential therapeutic target of EC.
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Affiliation(s)
- Guang-Dong Yang
- Department of Obstetrics and Gynecology, Fengxian Hospital, Southern Medical University201499 Shanghai, P.R. China
| | - Xiao-Mei Yang
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine200240 Shanghai, P.R. China
| | - Huan Lu
- Department of Obstetrics and Gynecology, Fengxian Hospital, Southern Medical University201499 Shanghai, P.R. China
| | - Yuan Ren
- Department of Obstetrics and Gynecology, Changzhou Maternal and Child Care HospitalChangzhou, 213003, Jiangsu, P.R. China
| | - Ming-Ze Ma
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine200240 Shanghai, P.R. China
| | - Lin-Yan Zhu
- Department of Obstetrics and Gynecology, Fengxian Hospital, Southern Medical University201499 Shanghai, P.R. China
| | - Jing-Hao Wang
- Department of Obstetrics and Gynecology, Fengxian Hospital, Southern Medical University201499 Shanghai, P.R. China
| | - Wei-Wei Song
- Department of Obstetrics and Gynecology, Fengxian Hospital, Southern Medical University201499 Shanghai, P.R. China
| | - Wen-Ming Zhang
- Fudan University Shanghai Cancer Center200032 Shanghai, P.R. China
| | - Rong Zhang
- Department of Obstetrics and Gynecology, Fengxian Hospital, Southern Medical University201499 Shanghai, P.R. China
| | - Zhi-Gang Zhang
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine200240 Shanghai, P.R. China
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20
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Abstract
Specific interactions within the cell must occur in a crowded environment and often in a narrow time-space framework to ensure cell survival. In the light that up to 10% of individual protein molecules present at one time in mammalian cells mediate signal transduction, the establishment of productive, specific interactions is a remarkable achievement. The spindle assembly checkpoint (SAC) is an evolutionarily conserved and essential self-monitoring system of the eukaryotic cell cycle that ensures the high fidelity of chromosome segregation by delaying the onset of anaphase until all chromosomes are properly bi-oriented on the mitotic spindle. The function of the SAC involves communication with the kinetochore, an essential multiprotein complex crucial for chromosome segregation that assembles on mitotic or meiotic centromeres to link centromeric DNA with microtubules. Interactions in the SAC and kinetochore-microtubule network often involve the reversible assembly of large multiprotein complexes in which regions of the polypeptide chain that exhibit low structure complexity undergo a disorder-to-order transition. The confinement and high density of protein molecules in the cell has a profound effect on the stability, folding rate, and biological functions of individual proteins and protein assemblies. Here, I discuss the role of large and highly flexible surfaces that mediate productive intermolecular interactions in SAC signaling and postulate that macromolecular crowding contributes to the exquisite regulation that is required for the timely and accurate segregation of chromosomes in higher organisms.
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Affiliation(s)
- Victor M Bolanos-Garcia
- Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, United Kingdom.
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21
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Abstract
Membrane trafficking and mitosis are two essential processes in eukaryotic cells. Surprisingly, many proteins best known for their role in membrane trafficking have additional 'moonlighting' functions in mitosis. Despite having proteins in common, there is insufficient evidence for a specific connection between these two processes. Instead, these phenomena demonstrate the adaptability of the membrane trafficking machinery that allows its repurposing for different cellular functions.
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Affiliation(s)
- Stephen J Royle
- Division of Biomedical Cell Biology, Warwick Medical School, Gibbet Hill Road, Coventry, CV4 7AL, UK.
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22
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Wang L, Gallo KA, Conrad SE. Targeting mixed lineage kinases in ER-positive breast cancer cells leads to G2/M cell cycle arrest and apoptosis. Oncotarget 2013; 4:1158-71. [PMID: 23902710 PMCID: PMC3787148 DOI: 10.18632/oncotarget.1093] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 07/05/2013] [Indexed: 12/25/2022] Open
Abstract
Estrogen receptor (ER)-positive tumors represent the most common type of breast cancer, and ER-targeted therapies such as antiestrogens and aromatase inhibitors have therefore been widely used in breast cancer treatment. While many patients have benefited from these therapies, both innate and acquired resistance continue to be causes of treatment failure. Novel targeted therapeutics that could be used alone or in combination with endocrine agents to treat resistant tumors or to prevent their development are therefore needed. In this report, we examined the effects of inhibiting mixed-lineage kinase (MLK) activity on ER-positive breast cancer cells and non-tumorigenic mammary epithelial cells. Inhibition of MLK activity with the pan-MLK inhibitor CEP-1347 blocked cell cycle progression in G2 and early M phase, and induced apoptosis in three ER-positive breast cancer cell lines, including one with acquired antiestrogen resistance. In contrast, it had no effect on the cell cycle or apoptosis in two non-tumorigenic mammary epithelial cell lines. CEP-1347 treatment did not decrease the level of active ERK or p38 in any of the cell lines tested. However, it resulted in decreased JNK and NF-κB activity in the breast cancer cell lines. A JNK inhibitor mimicked the effects of CEP-1347 in breast cancer cells, and overexpression of c-Jun rescued CEP-1347-induced Bax expression. These results indicate that proliferation and survival of ER-positive breast cancer cells are highly dependent on MLK activity, and suggest that MLK inhibitors may have therapeutic efficacy for ER-positive breast tumors, including ones that are resistant to current endocrine therapies.
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Affiliation(s)
- Limin Wang
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing MI
| | - Kathleen A. Gallo
- Department of Physiology, Michigan State University, East Lansing MI
| | - Susan E. Conrad
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing MI
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23
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Sedgwick GG, Hayward DG, Di Fiore B, Pardo M, Yu L, Pines J, Nilsson J. Mechanisms controlling the temporal degradation of Nek2A and Kif18A by the APC/C-Cdc20 complex. EMBO J 2013; 32:303-14. [PMID: 23288039 PMCID: PMC3553385 DOI: 10.1038/emboj.2012.335] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 11/26/2012] [Indexed: 12/23/2022] Open
Abstract
The Anaphase Promoting Complex/Cyclosome (APC/C) in complex with its co-activator Cdc20 is responsible for targeting proteins for ubiquitin-mediated degradation during mitosis. The activity of APC/C-Cdc20 is inhibited during prometaphase by the Spindle Assembly Checkpoint (SAC) yet certain substrates escape this inhibition. Nek2A degradation during prometaphase depends on direct binding of Nek2A to the APC/C via a C-terminal MR dipeptide but whether this motif alone is sufficient is not clear. Here, we identify Kif18A as a novel APC/C-Cdc20 substrate and show that Kif18A degradation depends on a C-terminal LR motif. However in contrast to Nek2A, Kif18A is not degraded until anaphase showing that additional mechanisms contribute to Nek2A degradation. We find that dimerization via the leucine zipper, in combination with the MR motif, is required for stable Nek2A binding to and ubiquitination by the APC/C. Nek2A and the mitotic checkpoint complex (MCC) have an overlap in APC/C subunit requirements for binding and we propose that Nek2A binds with high affinity to apo-APC/C and is degraded by the pool of Cdc20 that avoids inhibition by the SAC.
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Affiliation(s)
- Garry G Sedgwick
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
- BRIC, University of Copenhagen, Copenhagen, Denmark
| | - Daniel G Hayward
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
- BRIC, University of Copenhagen, Copenhagen, Denmark
| | - Barbara Di Fiore
- The Gurdon Institute and Department of Zoology, University of Cambridge, Cambridge, UK
| | - Mercedes Pardo
- Proteomics Mass Spectrometry Laboratory, The Wellcome Trust Sanger Institute, Cambridge, UK
| | - Lu Yu
- Proteomics Mass Spectrometry Laboratory, The Wellcome Trust Sanger Institute, Cambridge, UK
| | - Jonathon Pines
- The Gurdon Institute and Department of Zoology, University of Cambridge, Cambridge, UK
| | - Jakob Nilsson
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
- BRIC, University of Copenhagen, Copenhagen, Denmark
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24
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Alushin GM, Musinipally V, Matson D, Tooley J, Stukenberg PT, Nogales E. Multimodal microtubule binding by the Ndc80 kinetochore complex. Nat Struct Mol Biol 2012; 19:1161-7. [PMID: 23085714 PMCID: PMC3492541 DOI: 10.1038/nsmb.2411] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 09/12/2012] [Indexed: 01/13/2023]
Abstract
The Ndc80 complex is a key site of kinetochore-microtubule attachment during cell division. The human complex engages microtubules with a globular 'head' formed by tandem calponin-homology domains and an 80-amino-acid unstructured 'tail' that contains sites of phosphoregulation by the Aurora B kinase. Using biochemical, cell biological and electron microscopy analyses, we dissected the roles of the tail in binding of microtubules and mediation of cooperative interactions between Ndc80 complexes. Two segments of the tail that contain Aurora B phosphorylation sites become ordered at interfaces; one with tubulin and the second with an adjacent Ndc80 head on the microtubule surface, forming interactions that are disrupted by phosphorylation. We propose a model in which Ndc80's interaction with either growing or shrinking microtubule ends can be tuned by the phosphorylation state of its tail.
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Affiliation(s)
- Gregory M Alushin
- Biophysics Graduate Group, University of California Berkeley, Berkeley, California, USA
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25
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Liu D, Davydenko O, Lampson MA. Polo-like kinase-1 regulates kinetochore-microtubule dynamics and spindle checkpoint silencing. J Cell Biol 2012; 198:491-9. [PMID: 22908307 PMCID: PMC3514039 DOI: 10.1083/jcb.201205090] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 07/17/2012] [Indexed: 12/29/2022] Open
Abstract
Polo-like kinase-1 (Plk1) is a highly conserved kinase with multiple mitotic functions. Plk1 localizes to prometaphase kinetochores and is reduced at metaphase kinetochores, similar to many checkpoint signaling proteins, but Plk1 is not required for spindle checkpoint function. Plk1 is also implicated in stabilizing kinetochore-microtubule attachments, but these attachments are most stable when kinetochore Plk1 levels are low at metaphase. Therefore, it is unclear how Plk1 function at kinetochores can be understood in the context of its dynamic localization. In this paper, we show that Plk1 activity suppresses kinetochore-microtubule dynamics to stabilize initial attachments in prometaphase, and Plk1 removal from kinetochores is necessary to maintain dynamic microtubules in metaphase. Constitutively targeting Plk1 to kinetochores maintained high activity at metaphase, leading to reduced interkinetochore tension and intrakinetochore stretch, a checkpoint-dependent mitotic arrest, and accumulation of microtubule attachment errors. Together, our data show that Plk1 dynamics at kinetochores control two critical mitotic processes: initially establishing correct kinetochore-microtubule attachments and subsequently silencing the spindle checkpoint.
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Affiliation(s)
- Dan Liu
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
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26
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Abstract
Trisomic and monosomic (aneuploid) embryos account for at least 10% of human pregnancies and, for women nearing the end of their reproductive lifespan, the incidence may exceed 50%. The errors that lead to aneuploidy almost always occur in the oocyte but, despite intensive investigation, the underlying molecular basis has remained elusive. Recent studies of humans and model organisms have shed new light on the complexity of meiotic defects, providing evidence that the age-related increase in errors in the human female is not attributable to a single factor but to an interplay between unique features of oogenesis and a host of endogenous and exogenous factors.
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Affiliation(s)
- So I Nagaoka
- School of Molecular Biosciences, Center for Reproductive Biology, Washington State University, Pullman, Washington 99164, USA
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27
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Dupont C, Harvey AJ, Armant DR, Zelinski MB, Brenner CA. Expression profiles of cohesins, shugoshins and spindle assembly checkpoint genes in rhesus macaque oocytes predict their susceptibility for aneuploidy during embryonic development. Cell Cycle 2012; 11:740-8. [PMID: 22327397 PMCID: PMC3318107 DOI: 10.4161/cc.11.4.19207] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 12/23/2011] [Accepted: 12/29/2011] [Indexed: 01/09/2023] Open
Abstract
High frequencies of chromosomal anomalies are reported in human and non-human primate in vitro-produced preimplantation embryos. It is unclear why certain embryos develop aneuploidies while others remain euploid. A differential susceptibility to aneuploidy is most likely a consequence of events that occur before oocyte collection. One hypothesis is that the relative transcript levels of cohesins, shugoshins and spindle assembly checkpoint genes are correlated with the occurrence of chromosomal anomalies. Transcript levels of these genes were quantified in individual oocytes that were either mature (group 1, low aneuploidy rate) or immature (group 2, high aneuploidy rate) at retrieval, utilizing TaqMan-based real-time PCR. The transcript level in each oocyte was categorized as absent, below the median or above the median in order to conduct comparisons. Statistically significant differences were observed between group 1 and group 2 for SGOL1 and BUB1. There were more oocytes with SGOL1 expression levels above the median in group 1, while oocytes lacking BUB1 were only observed in group 1. These findings suggest that higher SGOL1 levels in group 1 oocytes could better protect against a premature separation of sister chromatids than in embryos derived from group 2 oocytes. The absence of BUB1 transcripts in group 1 was frequently associated with reduced expression of either mitotic cohesins or shugoshins. We hypothesize that ablation of BUB1 could induce mitotic arrest in oocytes that fail to express a complete complement of cohesins and shugoshins, thereby reducing the number of developing aneuploid preimplantation embryos.
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Affiliation(s)
- Catherine Dupont
- Department of Physiology, School of Medicine, Wayne State University, Detroit, MI, USA
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28
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Yang F, Huang Y, Dai W. Sumoylated BubR1 plays an important role in chromosome segregation and mitotic timing. Cell Cycle 2012; 11:797-806. [PMID: 22374677 PMCID: PMC3318109 DOI: 10.4161/cc.11.4.19307] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 01/09/2012] [Accepted: 01/09/2012] [Indexed: 11/19/2022] Open
Abstract
BubR1 is an important component of the spindle assembly checkpoint, and deregulated BubR1 functions frequently result in chromosomal instability and malignant transformation. We recently demonstrated that BubR1 was modified by sumoylation, and that lysine 250 (K250) functions as the crucial site for this modification. BubR1 sumoylation was neither required for its activation nor for binding to kinetochores. However, ectopically expressed sumoylation-deficient BubR1 mutants were retained on the kintochores even after apparent chromosome congression. The kinetochore retention of the sumoylation-deficient mutant of BubR1 caused an anaphase delay coupled with premature sister chromatid separation. Moreover, BubR1 interacted with unphosphorylated Sgo1, and its sumoylation facilitated the interaction. BubR1 sumoylation was inversely associated with its acetylation during mitotic progression. Trichostatin A, a protein deacetylase inhibitor, significantly compromised BubR1 sumoylation. Combined, these results reveal that BubR1 sumoylation plays an important role in its timely removal from the kinetochores and the checkpoint inactivation, thus allowing normal anaphase entry and chromosome segregation.
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Affiliation(s)
- Feikun Yang
- Departments of Environmental Medicine and Pharmacology; New York University School of Medicine; Tuxedo, NY USA
| | - Ying Huang
- Department of Pathophysiology; Shanghai Jiaotong University School of Medicine; Shanghai, China
| | - Wei Dai
- Departments of Environmental Medicine and Pharmacology; New York University School of Medicine; Tuxedo, NY USA
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29
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Endo H, Ikeda K, Urano T, Horie-Inoue K, Inoue S. Terf/TRIM17 stimulates degradation of kinetochore protein ZWINT and regulates cell proliferation. J Biochem 2011; 151:139-44. [PMID: 22023800 DOI: 10.1093/jb/mvr128] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Terf/TRIM17 is a tripartite motif protein that has been originally isolated from testis. Terf has been characterized to exhibit an E3 ubiquitin ligase activity and to undergo self-ubiquitination. The cellular function of terf and its substrates, however, remain elusive. In the present study, we performed a yeast two-hybrid screening assay using terf as bait and identified a positive clone coding for ZW10 interacting protein (ZWINT), a known component of the kinetochore complex required for the mitotic spindle checkpoint. Immunoprecipitation and western blot analyses showed that terf interacted with ZWINT and that overexpression of terf caused down-regulation of protein levels of ZWINT in mammalian cells. In addition, the coiled-coil domain of terf was required for the interaction with ZWINT. In a cell growth assay, stable transfection with terf decreased proliferation of MCF7 breast cancer cells. In contrast, the growth rate of MCF7 cells was increased by stable expression of ZWINT. Specific siRNAs targeting terf and ZWINT dampened these negative and positive effects of terf and ZWINT on cell proliferation, respectively. These results suggest that the E3 ubiquitin ligase terf causes protein degradation of ZWINT and negatively regulates cell proliferation.
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Affiliation(s)
- Hiroshi Endo
- Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka-shi, Saitama 350-1241, Japan
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30
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Abstract
Tumor cells are commonly aneuploid, a condition contributing to cancer progression and drug resistance. Understanding how chromatids are linked and separated at the appropriate time will help uncover the basis of aneuploidy and will shed light on the behavior of tumor cells. Cohesion of sister chromatids is maintained by the multi-protein complex cohesin, consisting of Smc1, Smc3, Scc1 and Scc3. Sororin associates with the cohesin complex and regulates the segregation of sister chromatids. Sororin is phosphorylated in mitosis; however, the role of this modification is unclear. Here we show that mutation of potential cyclin-dependent kinase 1 (Cdk1) phosphorylation sites leaves sororin stranded on chromosomes and bound to cohesin throughout mitosis. Sororin can be precipitated from cell lysates with DNA-cellulose, and only the hypophosphorylated form of sororin shows this association. These results suggest that phosphorylation of sororin causes its release from chromatin in mitosis. Also, the hypophosphorylated form of sororin increases cohesion between sister chromatids, suggesting that phosphorylation of sororin by Cdk1 influences sister chromatid cohesion. Finally, phosphorylation-deficient sororin can alleviate the mitotic block that occurs upon knockdown of endogenous sororin. This mitotic block is abolished by ZM447439, an Aurora kinase inhibitor, suggesting that prematurely separated sister chromatids activate the spindle assembly checkpoint through an Aurora kinase-dependent pathway.
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Affiliation(s)
- Megan R. Dreier
- Department of Biological Sciences, University of Toledo, 2801 W. Bancroft Street, MS 601, Toledo, OH 43606, USA
| | - Michael E. Bekier
- Department of Biological Sciences, University of Toledo, 2801 W. Bancroft Street, MS 601, Toledo, OH 43606, USA
| | - William R. Taylor
- Department of Biological Sciences, University of Toledo, 2801 W. Bancroft Street, MS 601, Toledo, OH 43606, USA
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