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Schatten H. The Centrosome Cycle within the Cell Cycle. THE CENTROSOME AND ITS FUNCTIONS AND DYSFUNCTIONS 2022; 235:17-35. [DOI: 10.1007/978-3-031-20848-5_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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2
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Argenty J, Rouquié N, Bories C, Mélique S, Duplan-Eche V, Saoudi A, Fazilleau N, Lesourne R. A selective LIS1 requirement for mitotic spindle assembly discriminates distinct T-cell division mechanisms within the T-cell lineage. eLife 2022; 11:80277. [PMID: 36519536 PMCID: PMC9797186 DOI: 10.7554/elife.80277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
The ability to proliferate is a common feature of most T-cell populations. However, proliferation follows different cell-cycle dynamics and is coupled to different functional outcomes according to T-cell subsets. Whether the mitotic machineries supporting these qualitatively distinct proliferative responses are identical remains unknown. Here, we show that disruption of the microtubule-associated protein LIS1 in mouse models leads to proliferative defects associated with a blockade of T-cell development after β-selection and of peripheral CD4+ T-cell expansion after antigen priming. In contrast, cell divisions in CD8+ T cells occurred independently of LIS1 following T-cell antigen receptor stimulation, although LIS1 was required for proliferation elicited by pharmacological activation. In thymocytes and CD4+ T cells, LIS1 deficiency did not affect signaling events leading to activation but led to an interruption of proliferation after the initial round of division and to p53-induced cell death. Proliferative defects resulted from a mitotic failure, characterized by the presence of extra-centrosomes and the formation of multipolar spindles, causing abnormal chromosomes congression during metaphase and separation during telophase. LIS1 was required to stabilize dynein/dynactin complexes, which promote chromosome attachment to mitotic spindles and ensure centrosome integrity. Together, these results suggest that proliferative responses are supported by distinct mitotic machineries across T-cell subsets.
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Affiliation(s)
- Jérémy Argenty
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), INSERM UMR1291, CNRS UMR5051, University Toulouse IIIToulouseFrance
| | - Nelly Rouquié
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), INSERM UMR1291, CNRS UMR5051, University Toulouse IIIToulouseFrance
| | - Cyrielle Bories
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), INSERM UMR1291, CNRS UMR5051, University Toulouse IIIToulouseFrance
| | - Suzanne Mélique
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), INSERM UMR1291, CNRS UMR5051, University Toulouse IIIToulouseFrance
| | - Valérie Duplan-Eche
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), INSERM UMR1291, CNRS UMR5051, University Toulouse IIIToulouseFrance
| | - Abdelhadi Saoudi
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), INSERM UMR1291, CNRS UMR5051, University Toulouse IIIToulouseFrance
| | - Nicolas Fazilleau
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), INSERM UMR1291, CNRS UMR5051, University Toulouse IIIToulouseFrance
| | - Renaud Lesourne
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), INSERM UMR1291, CNRS UMR5051, University Toulouse IIIToulouseFrance
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Fujiwara D, Mihara K, Takayama R, Nakamura Y, Ueda M, Tsumuraya T, Fujii I. Chemical Modification of Phage-Displayed Helix-Loop-Helix Peptides to Construct Kinase-Focused Libraries. Chembiochem 2021; 22:3406-3409. [PMID: 34605137 PMCID: PMC9297947 DOI: 10.1002/cbic.202100450] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/01/2021] [Indexed: 11/11/2022]
Abstract
Conformationally constrained peptides hold promise as molecular tools in chemical biology and as a new modality in drug discovery. The construction and screening of a target-focused library could be a promising approach for the generation of de novo ligands or inhibitors against target proteins. Here, we have prepared a protein kinase-focused library by chemically modifying helix-loop-helix (HLH) peptides displayed on phage and subsequently tethered to adenosine. The library was screened against aurora kinase A (AurA). The selected HLH peptide Bip-3 retained the α-helical structure and bound to AurA with a KD value of 13.7 μM. Bip-3 and the adenosine-tethered peptide Bip-3-Adc provided IC50 values of 103 μM and 7.7 μM, respectively, suggesting that Bip-3-Adc bivalently inhibited AurA. In addition, the selectivity of Bip-3-Adc to several protein kinases was tested, and was highest against AurA. These results demonstrate that chemical modification can enable the construction of a kinase-focused library of phage-displayed HLH peptides.
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Affiliation(s)
- Daisuke Fujiwara
- Department of Biological ScienceGraduate School of ScienceOsaka Prefecture University1-1, Gakuen-cho, Naka-ku, SakaiOsaka599-8531Japan
| | - Kousuke Mihara
- Department of Biological ScienceGraduate School of ScienceOsaka Prefecture University1-1, Gakuen-cho, Naka-ku, SakaiOsaka599-8531Japan
| | - Ryo Takayama
- Department of Biological ScienceGraduate School of ScienceOsaka Prefecture University1-1, Gakuen-cho, Naka-ku, SakaiOsaka599-8531Japan
| | - Yusuke Nakamura
- Department of Biological ScienceGraduate School of ScienceOsaka Prefecture University1-1, Gakuen-cho, Naka-ku, SakaiOsaka599-8531Japan
| | - Mitsuhiro Ueda
- Department of ChemistryGraduate School of ScienceOsaka Prefecture University1-1, Gakuen-cho, Naka-ku, SakaiOsaka599-8531Japan
| | - Takeshi Tsumuraya
- Department of Biological ScienceGraduate School of ScienceOsaka Prefecture University1-1, Gakuen-cho, Naka-ku, SakaiOsaka599-8531Japan
| | - Ikuo Fujii
- Department of Biological ScienceGraduate School of ScienceOsaka Prefecture University1-1, Gakuen-cho, Naka-ku, SakaiOsaka599-8531Japan
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Alafate W, Xu D, Wu W, Xiang J, Ma X, Xie W, Bai X, Wang M, Wang J. Loss of PLK2 induces acquired resistance to temozolomide in GBM via activation of notch signaling. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2020; 39:239. [PMID: 33176854 PMCID: PMC7657349 DOI: 10.1186/s13046-020-01750-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/26/2020] [Indexed: 12/14/2022]
Abstract
Background Glioblastoma (GBM) is a lethal type of primary brain tumor with a median survival less than 15 months. Despite the recent improvements of comprehensive strategies, the outcomes for GBM patients remain dismal. Accumulating evidence indicates that rapid acquired chemoresistance is the major cause of GBM recurrence thus leads to worse clinical outcomes. Therefore, developing novel biomarkers and therapeutic targets for chemoresistant GBM is crucial for long-term cures. Methods Transcriptomic profiles of glioblastoma were downloaded from gene expression omnibus (GEO) and TCGA database. Differentially expressed genes were analyzed and candidate gene PLK2 was selected for subsequent validation. Clinical samples and corresponding data were collected from our center and measured using immunohistochemistry analysis. Lentiviral transduction and in vivo xenograft transplantation were used to validate the bioinformatic findings. GSEA analyses were conducted to identify potential signaling pathways related to PLK2 expression and further confirmed by in vitro mechanistic assays. Results In this study, we identified PLK2 as an extremely suppressed kinase-encoding gene in GBM samples, particularly in therapy resistant GBM. Additionally, reduced PLK2 expression implied poor prognosis and TMZ resistance in GBM patients. Functionally, up-regulated PLK2 attenuated cell proliferation, migration, invasion, and tumorigenesis of GBM cells. Besides, exogenous overexpression of PLK2 reduced acquired TMZ resistance of GBM cells. Furthermore, bioinformatics analysis indicated that PLK2 was negatively correlated with Notch signaling pathway in GBM. Mechanically, loss of PLK2 activated Notch pathway through negative transcriptional regulation of HES1 and degradation of Notch1. Conclusion Loss of PLK2 enhances aggressive biological behavior of GBM through activation of Notch signaling, indicating that PLK2 could be a prognostic biomarker and potential therapeutic target for chemoresistant GBM.
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Affiliation(s)
- Wahafu Alafate
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, Shaanxi, 710061, P.R. China.,Center of Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, Shaanxi, China
| | - Dongze Xu
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, Shaanxi, 710061, P.R. China
| | - Wei Wu
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, Shaanxi, 710061, P.R. China.,Center of Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, Shaanxi, China
| | - Jianyang Xiang
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, Shaanxi, 710061, P.R. China.,Center of Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, Shaanxi, China
| | - Xudong Ma
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, Shaanxi, 710061, P.R. China.,Center of Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, Shaanxi, China
| | - Wanfu Xie
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, Shaanxi, 710061, P.R. China
| | - Xiaobin Bai
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, Shaanxi, 710061, P.R. China
| | - Maode Wang
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, Shaanxi, 710061, P.R. China. .,Center of Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, Shaanxi, China.
| | - Jia Wang
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, Shaanxi, 710061, P.R. China. .,Center of Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, Shaanxi, China.
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Sosunov A, Wu X, McGovern R, Mikell C, McKhann GM, Goldman JE. Abnormal mitosis in reactive astrocytes. Acta Neuropathol Commun 2020; 8:47. [PMID: 32293551 PMCID: PMC7158149 DOI: 10.1186/s40478-020-00919-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 03/17/2020] [Indexed: 12/21/2022] Open
Abstract
Although abnormal mitosis with disarranged metaphase chromosomes or many micronuclei in astrocytes (named "Alzheimer I type astrocytes" and later "Creutzfeldt-Peters cells") have been known for nearly 100 years, the origin and mechanisms of this pathology remain elusive. In experimental brain insults in rats, we show that abnormal mitoses that are not followed by cytokinesis are typical for reactive astrocytes. The pathology originates due to the inability of the cells to form normal mitotic spindles with subsequent metaphase chromosome congression, which, in turn may be due to shape constraints aggravated by cellular enlargement and to the accumulation of large amounts of cytosolic proteins. Many astrocytes escape from arrested mitosis by producing micronuclei. These polyploid astrocytes can survive for long periods of time and enter into new cell cycles.
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Affiliation(s)
- Alexander Sosunov
- Department of Neurosurgery, Columbia University, 630 W. 168th St, P&S 15-405, New York, NY 10032 USA
| | - Xiaoping Wu
- Department of Neurosurgery, Columbia University, 630 W. 168th St, P&S 15-405, New York, NY 10032 USA
| | - Robert McGovern
- Department of Neurosurgery, University of Minnesota, Minneapolis, MN 55455 USA
| | - Charles Mikell
- Department of Neurosurgery, Stony Brook University School of Medicine, Stony Brook, NY USA
| | - Guy M. McKhann
- Department of Neurosurgery, Columbia University, 630 W. 168th St, P&S 15-405, New York, NY 10032 USA
| | - James E. Goldman
- Pathology & Cell Biology, Columbia University, New York, NY 10032 USA
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Li M, Gao K, Chu L, Zheng J, Yang J. The role of Aurora-A in cancer stem cells. Int J Biochem Cell Biol 2018; 98:89-92. [DOI: 10.1016/j.biocel.2018.03.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 03/10/2018] [Accepted: 03/12/2018] [Indexed: 01/17/2023]
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Chen L, Liu S, Xu F, Kong Y, Wan L, Zhang Y, Zhang Z. Inhibition of Proteasome Activity Induces Aggregation of IFIT2 in the Centrosome and Enhances IFIT2-Induced Cell Apoptosis. Int J Biol Sci 2017; 13:383-390. [PMID: 28367102 PMCID: PMC5370445 DOI: 10.7150/ijbs.17236] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 12/27/2016] [Indexed: 01/18/2023] Open
Abstract
IFN-induced protein with tetratricopeptide repeats 2 (IFIT2), one of the most highly responsive interferon-stimulated genes, inhibits the proliferation and migration of cancer cells and regulates viral replication. IFIT2 has been demonstrated to be a cytoskeleton-associated protein that becomes enriched in the mitotic spindle of cells. However, the molecular mechanisms by which IFIT2 executes biological functions are largely unclear. The findings of this study showed that inhibiting the activation of proteasome led to the enrichment of IFIT2 and induced the aggregation of IFIT2 protein in the centrosome. Microtubule inhibitor colchicine and dynein inhibitor ciliobrevin inhibited the proteasome inhibitor-induced aggregation of IFIT2 protein in the centrosome. Intriguingly, IFIT2 and proteasome inhibitor worked together to induce the apoptosis of cancer cells. The results of the present study revealed that the inhibition of proteasome activity blocked the degradation of IFIT2 and promoted the aggregation of IFIT2 in the centrosome, which in turn induced cell apoptosis. In short, IFIT2 may be a potential target for cancer therapeutics.
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Affiliation(s)
- Limin Chen
- Department of Clinical laboratory, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China;; Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China
| | - Shuyuan Liu
- Department of Clinical laboratory, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China
| | - Fen Xu
- Department of Clinical Laboratory Technology, Jiangxi Medical College, Shangrao, Jiangxi 334000, China
| | - Yunyuan Kong
- Department of Clinical laboratory, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China
| | - Lagen Wan
- Department of Clinical laboratory, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China
| | - Yonglu Zhang
- Department of Clinical laboratory, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China
| | - Zhanglin Zhang
- Department of Clinical laboratory, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China
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8
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Madarampalli B, Yuan Y, Liu D, Lengel K, Xu Y, Li G, Yang J, Liu X, Lu Z, Liu DX. ATF5 Connects the Pericentriolar Materials to the Proximal End of the Mother Centriole. Cell 2015. [PMID: 26213385 DOI: 10.1016/j.cell.2015.06.055] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Although it is known that the centrioles play instructive roles in pericentriolar material (PCM) assembly and that the PCM is essential for proper centriole formation, the mechanism that governs centriole-PCM interaction is poorly understood. Here, we show that ATF5 forms a characteristic 9-fold symmetrical ring structure in the inner layer of the PCM outfitting the proximal end of the mother centriole. ATF5 controls the centriole-PCM interaction in a cell-cycle- and centriole-age-dependent manner. Interaction of ATF5 with polyglutamylated tubulin (PGT) on the mother centriole and with PCNT in the PCM renders ATF5 as a required molecule in mother centriole-directed PCM accumulation and in PCM-dependent centriole formation. ATF5 depletion blocks PCM accumulation at the centrosome and causes fragmentation of centrioles, leading to the formation of multi-polar mitotic spindles and genomic instability. These data show that ATF5 is an essential structural protein that is required for the interaction between the mother centriole and the PCM.
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Affiliation(s)
- Bhanupriya Madarampalli
- Department of Pharmaceutical Sciences, Washington State University College of Pharmacy, Spokane, WA 99202, USA
| | - Yunsheng Yuan
- Department of Pharmaceutical Sciences, Washington State University College of Pharmacy, Spokane, WA 99202, USA
| | - Dan Liu
- Department of Pharmaceutical Sciences, Washington State University College of Pharmacy, Spokane, WA 99202, USA
| | - Kathleen Lengel
- Department of Pharmaceutical Sciences, Washington State University College of Pharmacy, Spokane, WA 99202, USA
| | - Yidi Xu
- Department of Pharmaceutical Sciences, Washington State University College of Pharmacy, Spokane, WA 99202, USA
| | - Guangfu Li
- Department of Pharmaceutical Sciences, Washington State University College of Pharmacy, Spokane, WA 99202, USA
| | - Jinming Yang
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Xinyuan Liu
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China; Xinyuan Institute of Medicine and Biotechnology, College of Life Science, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Zhimin Lu
- Brain Tumor Center and Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - David X Liu
- Department of Pharmaceutical Sciences, Washington State University College of Pharmacy, Spokane, WA 99202, USA.
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Whalley HJ, Porter AP, Diamantopoulou Z, White GRM, Castañeda-Saucedo E, Malliri A. Cdk1 phosphorylates the Rac activator Tiam1 to activate centrosomal Pak and promote mitotic spindle formation. Nat Commun 2015; 6:7437. [PMID: 26078008 PMCID: PMC4490568 DOI: 10.1038/ncomms8437] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 05/08/2015] [Indexed: 01/13/2023] Open
Abstract
Centrosome separation is critical for bipolar spindle formation and the accurate segregation of chromosomes during mammalian cell mitosis. Kinesin-5 (Eg5) is a microtubule motor essential for centrosome separation, and Tiam1 and its substrate Rac antagonize Eg5-dependent centrosome separation in early mitosis promoting efficient chromosome congression. Here we identify S1466 of Tiam1 as a novel Cdk1 site whose phosphorylation is required for the mitotic function of Tiam1. We find that this phosphorylation of Tiam1 is required for the activation of group I p21-activated kinases (Paks) on centrosomes in prophase. Further, we show that both Pak1 and Pak2 counteract centrosome separation in a kinase-dependent manner and demonstrate that they act downstream of Tiam1. We also show that depletion of Pak1/2 allows cells to escape monopolar arrest by Eg5 inhibition, highlighting the potential importance of this signalling pathway for the development of Eg5 inhibitors as cancer therapeutics.
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Affiliation(s)
- Helen J. Whalley
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M20 4BX, UK
| | - Andrew P. Porter
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M20 4BX, UK
| | - Zoi Diamantopoulou
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M20 4BX, UK
| | - Gavin R. M. White
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M20 4BX, UK
| | - Eduardo Castañeda-Saucedo
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M20 4BX, UK
| | - Angeliki Malliri
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M20 4BX, UK
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10
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Scheer U. Historical roots of centrosome research: discovery of Boveri's microscope slides in Würzburg. Philos Trans R Soc Lond B Biol Sci 2015; 369:rstb.2013.0469. [PMID: 25047623 DOI: 10.1098/rstb.2013.0469] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Boveri's visionary monograph 'Ueber die Natur der Centrosomen' (On the nature of centrosomes) in 1900 was founded primarily on microscopic observations of cleaving eggs of sea urchins and the roundworm parasite Ascaris. As Boveri wrote in the introductory paragraph, his interests were less about morphological aspects of centrosomes, but rather aimed at an understanding of their physiological role during cell division. The remarkable transition from observations of tiny dot-like structures in fixed and sectioned material to a unified theory of centrosome function (which in essence still holds true today) cannot be fully appreciated without examining Boveri's starting material, the histological specimens. It was generally assumed that the microscope slides were lost during the bombing of the Zoological Institute in Würzburg at the end of WWII. Here, I describe the discovery of a number of Boveri's original microscope slides with serial sections of early sea urchin and Ascaris embryos, stained by Heidenhain's iron haematoxylin method. Some slides bear handwritten notes and sketches by Boveri. Evidence is presented that the newly discovered slides are part of the original material used by Boveri for his seminal centrosome monograph.
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Affiliation(s)
- Ulrich Scheer
- Cell and Developmental Biology, Theodor-Boveri-Institute, Biocentre of the University of Würzburg, Würzburg, Germany
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11
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Abstract
The centrosome was discovered in the late 19th century when mitosis was first described. Long recognized as a key organelle of the spindle pole, its core component, the centriole, was realized more than 50 or so years later also to comprise the basal body of the cilium. Here, we chart the more recent acquisition of a molecular understanding of centrosome structure and function. The strategies for gaining such knowledge were quickly developed in the yeasts to decipher the structure and function of their distinctive spindle pole bodies. Only within the past decade have studies with model eukaryotes and cultured cells brought a similar degree of sophistication to our understanding of the centrosome duplication cycle and the multiple roles of this organelle and its component parts in cell division and signaling. Now as we begin to understand these functions in the context of development, the way is being opened up for studies of the roles of centrosomes in human disease.
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Affiliation(s)
- Jingyan Fu
- Cancer Research UK Cell Cycle Genetics Group, Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
| | - Iain M Hagan
- Cancer Research UK Manchester Institute, University of Manchester, Withington, Manchester M20 4BX, United Kingdom
| | - David M Glover
- Cancer Research UK Cell Cycle Genetics Group, Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
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12
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Tollenaere MAX, Mailand N, Bekker-Jensen S. Centriolar satellites: key mediators of centrosome functions. Cell Mol Life Sci 2015; 72:11-23. [PMID: 25173771 PMCID: PMC11114028 DOI: 10.1007/s00018-014-1711-3] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 08/01/2014] [Accepted: 08/25/2014] [Indexed: 01/18/2023]
Abstract
Centriolar satellites are small, microscopically visible granules that cluster around centrosomes. These structures, which contain numerous proteins directly involved in centrosome maintenance, ciliogenesis, and neurogenesis, have traditionally been viewed as vehicles for protein trafficking towards the centrosome. However, the recent identification of several new centriolar satellite components suggests that this model offers only an incomplete picture of their cellular functions. While the mechanisms controlling centriolar satellite status and function are not yet understood in detail, emerging evidence points to these structures as important hubs for dynamic, multi-faceted regulation in response to a variety of cues. In this review, we summarize the current knowledge of the roles of centriolar satellites in regulating centrosome functions, ciliogenesis, and neurogenesis. We also highlight newly discovered regulatory mechanisms targeting centriolar satellites and their functional status, and we discuss how defects in centriolar satellite components are intimately linked to a wide spectrum of human diseases.
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Affiliation(s)
- Maxim A. X. Tollenaere
- Faculty of Health Sciences, Ubiquitin Signaling Group, The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Niels Mailand
- Faculty of Health Sciences, Ubiquitin Signaling Group, The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Simon Bekker-Jensen
- Faculty of Health Sciences, Ubiquitin Signaling Group, The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
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13
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Abstract
Proper cell division requires the formation of the microtubule-based mitotic spindle, which mediates the dynamic movement and alignment of chromosomes to the metaphase plate and their equal transmission to daughter cells. Kinesins are molecular motors that utilize ATP hydrolysis to perform their functions and are instrumental in spindle assembly and function. Of the over 45 kinesins encoded in the human genome, only two are specifically enriched at the centrioles, Kif24 at the mother centriole and STARD9/Kif16a at the daughter centriole. While Kif24 possesses centriolar microtubule-depolymerizing activity and has been implicated in regulating cilia formation, our recent study implicates STARD9 in maintaining pericentriolar material (PCM) cohesion during early mitosis. However, very little is known about how STARD9 performs its function, including the mechanisms that recruit or retain STARD9 at the centrioles and how it cooperates with centrosome components to regulate PCM stability. Additionally, the signals leading to apoptosis in the absence of STARD9 remain to be explored.
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Affiliation(s)
- Jorge Z Torres
- Department of Chemistry and Biochemistry; Jonsson Comprehensive Cancer Center; Molecular Biology Institute; University of California; Los Angeles, CA USA
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14
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Kimura H, Miki Y, Nakanishi A. Centrosomes at M phase act as a scaffold for the accumulation of intracellular ubiquitinated proteins. Cell Cycle 2014; 13:1928-37. [PMID: 24743317 DOI: 10.4161/cc.28896] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Centrosome size varies considerably during the cell cycle; it is greatest during metaphase, partly because of pericentriolar matrix recruitment and an increase in microtubule-organizing activity. However, the mechanism of centrosome maturation during M phase is poorly defined. In the present study, we identified and quantified centrosomal proteins during S and M phases using stable isotope labeling by amino acids in cell culture (SILAC) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). We identified 991 proteins, of which 310 and 325 proteins were upregulated during S and M phases, respectively. Ubiquitinated proteins containing K48- and K63-linked polyubiquitin chains accumulated in the centrosomes during M phase, although 26S proteasome activity in the centrosomes did not markedly differ between S and M phases. Conversely, cytoplasmic dynein, which transports ubiquitinated proteins to the centrosomes, increased 2-fold in the centrosomes during M phase relative to S phase. Furthermore, PYR-41, a ubiquitin E1 inhibitor, reduced centrosome size during metaphase, causing increased aneuploidy. RNA interference suppression of Ecm29, which inhibits proteasome activity, decreased the accumulation of ubiquitinated proteins in the centrosomes. These results show that accumulation of ubiquitinated proteins promotes centrosome maturation during M phase and further suggest a novel function of centrosomes as a scaffold temporarily gathering intracellular ubiquitinated proteins.
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Affiliation(s)
- Hitomi Kimura
- Department of Molecular Genetics; Medical Research Institute; Tokyo Medical and Dental University (TMDU); Bunkyo-ku, Tokyo, Japan
| | - Yoshio Miki
- Department of Molecular Genetics; Medical Research Institute; Tokyo Medical and Dental University (TMDU); Bunkyo-ku, Tokyo, Japan; Department of Genetic Diagnosis; The Cancer Institute; Japanese Foundation for Cancer Research; Koto-ku, Tokyo, Japan
| | - Akira Nakanishi
- Department of Molecular Genetics; Medical Research Institute; Tokyo Medical and Dental University (TMDU); Bunkyo-ku, Tokyo, Japan
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15
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Conduit PT, Feng Z, Richens JH, Baumbach J, Wainman A, Bakshi SD, Dobbelaere J, Johnson S, Lea SM, Raff JW. The centrosome-specific phosphorylation of Cnn by Polo/Plk1 drives Cnn scaffold assembly and centrosome maturation. Dev Cell 2014; 28:659-69. [PMID: 24656740 PMCID: PMC3988887 DOI: 10.1016/j.devcel.2014.02.013] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 01/27/2014] [Accepted: 02/16/2014] [Indexed: 02/02/2023]
Abstract
Centrosomes are important cell organizers. They consist of a pair of centrioles surrounded by pericentriolar material (PCM) that expands dramatically during mitosis-a process termed centrosome maturation. How centrosomes mature remains mysterious. Here, we identify a domain in Drosophila Cnn that appears to be phosphorylated by Polo/Plk1 specifically at centrosomes during mitosis. The phosphorylation promotes the assembly of a Cnn scaffold around the centrioles that is in constant flux, with Cnn molecules recruited continuously around the centrioles as the scaffold spreads slowly outward. Mutations that block Cnn phosphorylation strongly inhibit scaffold assembly and centrosome maturation, whereas phosphomimicking mutations allow Cnn to multimerize in vitro and to spontaneously form cytoplasmic scaffolds in vivo that organize microtubules independently of centrosomes. We conclude that Polo/Plk1 initiates the phosphorylation-dependent assembly of a Cnn scaffold around centrioles that is essential for efficient centrosome maturation in flies.
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Affiliation(s)
- Paul T Conduit
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Zhe Feng
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Jennifer H Richens
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Janina Baumbach
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Alan Wainman
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Suruchi D Bakshi
- Centre for Mathematical Biology, Mathematical Institute, 24-29 St Giles, Oxford OX1 3LB, UK
| | | | - Steven Johnson
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Susan M Lea
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Jordan W Raff
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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16
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Casimiro MC, Velasco-Velázquez M, Aguirre-Alvarado C, Pestell RG. Overview of cyclins D1 function in cancer and the CDK inhibitor landscape: past and present. Expert Opin Investig Drugs 2014; 23:295-304. [PMID: 24387133 DOI: 10.1517/13543784.2014.867017] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Intensive efforts, over the last decade, have been made to inhibit the kinase activity of cyclins that act as mediators during cell-cycle progression. Activation of the cyclin D1 oncogene, often by amplification or rearrangement, is a major driver of multiple types of human tumors including breast and squamous cell cancers, B-cell lymphoma, myeloma and parathyroid adenoma. AREAS COVERED In this review, the authors summarize the activity of cyclins and cyclin-dependent kinases in cell-cycle progression and transcription. They focus on cyclin D1/CDK4/CDK6, a central mediator in the transition from G1 to S phase. Furthermore, the authors discuss the first generation of pan-cyclin-dependent kinase inhibitors that failed to meet expectation and discuss, in detail, the second generation of highly specific cyclin D1/CDK4/CDK6 inhibitors that are proving to be more efficacious. EXPERT OPINION The mechanism by which cyclin D1 drives tumorigenesis may be dependent on kinase and kinase-independent functions. Further evidence is necessary to delineate the roles of cyclin D1 in early pre-neoplastic lesions where its overexpression may promote genomic instability in a kinase-independent manner.
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Affiliation(s)
- Mathew C Casimiro
- Thomas Jefferson University & Hospital, Department of Cancer Biology , 233 South 10th Street, Philadelphia, PA 19107 , USA
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17
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Thomas Y, Peter M, Mechali F, Blanchard JM, Coux O, Baldin V. Kizuna is a novel mitotic substrate for CDC25B phosphatase. Cell Cycle 2014; 13:3867-77. [PMID: 25558830 PMCID: PMC4615109 DOI: 10.4161/15384101.2014.972882] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 09/26/2014] [Accepted: 09/30/2014] [Indexed: 11/29/2022] Open
Abstract
CDC25 dual-specificity phosphatases play a central role in cell cycle control through the activation of Cyclin-Dependent Kinases (CDKs). Expression during mitosis of a stabilized CDC25B mutant (CDC25B-DDA), which cannot interact with the F-box protein βTrCP for proteasome-dependent degradation, causes mitotic defects and chromosome segregation errors in mammalian cells. We found, using the same CDC25B mutant, that stabilization and failure to degrade CDC25B during mitosis lead to the appearance of multipolar spindle cells resulting from a fragmentation of pericentriolar material (PCM) and abolish mitotic Plk1-dependent phosphorylation of Kizuna (Kiz), which is essential for the function of Kiz in maintaining spindle pole integrity. Thus, in mitosis Kiz is a new substrate of CDC25B whose dephosphorylation following CDC25B stabilization leads to the formation of multipolar spindles. Furthermore, endogenous Kiz and CDC25B interact only in mitosis, suggesting that Kiz phosphorylation depends on a balance between CDC25B and Plk1 activities. Our data identify a novel mitotic substrate of CDC25B phosphatase that plays a key role in mitosis control.
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Affiliation(s)
- Yann Thomas
- Centre de Recherche de Biochimie Macromoléculaire (CRBM);; Montpellier, France
- Université Montpellier 2; Montpellier, France
- Université Montpellier 1; Montpellier, France
- The MRC Protein Phosphorylation and Ubiquitylation Unit; College of Life Sciences; University of Dundee; Dundee, Scotland
| | - Marion Peter
- Université Montpellier 1; Montpellier, France
- The MRC Protein Phosphorylation and Ubiquitylation Unit; College of Life Sciences; University of Dundee; Dundee, Scotland
- Institut de Génétique Moléculaire de Montpellier (IGMM); Center National de la Recherche Scientifique (CNRS); Montpellier, France
| | - Francisca Mechali
- Centre de Recherche de Biochimie Macromoléculaire (CRBM);; Montpellier, France
- Université Montpellier 2; Montpellier, France
- Université Montpellier 1; Montpellier, France
| | - Jean-Marie Blanchard
- Université Montpellier 1; Montpellier, France
- The MRC Protein Phosphorylation and Ubiquitylation Unit; College of Life Sciences; University of Dundee; Dundee, Scotland
- Institut de Génétique Moléculaire de Montpellier (IGMM); Center National de la Recherche Scientifique (CNRS); Montpellier, France
| | - Olivier Coux
- Centre de Recherche de Biochimie Macromoléculaire (CRBM);; Montpellier, France
- Université Montpellier 2; Montpellier, France
- Université Montpellier 1; Montpellier, France
| | - Véronique Baldin
- Centre de Recherche de Biochimie Macromoléculaire (CRBM);; Montpellier, France
- Université Montpellier 2; Montpellier, France
- Université Montpellier 1; Montpellier, France
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18
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Li J, Hu H, Lang Q, Zhang H, Huang Q, Wu Y, Yu L. A thienopyrimidine derivative induces growth inhibition and apoptosis in human cancer cell lines via inhibiting Aurora B kinase activity. Eur J Med Chem 2013; 65:151-7. [DOI: 10.1016/j.ejmech.2013.04.058] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 04/23/2013] [Accepted: 04/25/2013] [Indexed: 10/26/2022]
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19
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Fu J, Glover DM. Structured illumination of the interface between centriole and peri-centriolar material. Open Biol 2013; 2:120104. [PMID: 22977736 PMCID: PMC3438536 DOI: 10.1098/rsob.120104] [Citation(s) in RCA: 190] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 08/02/2012] [Indexed: 12/22/2022] Open
Abstract
The increase in centrosome size in mitosis was described over a century ago, and yet it is poorly understood how centrioles, which lie at the core of centrosomes, organize the pericentriolar material (PCM) in this process. Now, structured illumination microscopy reveals in Drosophila that, before clouds of PCM appear, its proteins are closely associated with interphase centrioles in two tube-like layers: an inner layer occupied by centriolar microtubules, Sas-4, Spd-2 and Polo kinase; and an outer layer comprising Pericentrin-like protein (Dplp), Asterless (Asl) and Plk4 kinase. Centrosomin (Cnn) and γ-tubulin associate with this outer tube in G2 cells and, upon mitotic entry, Polo activity is required to recruit them together with Spd-2 into PCM clouds. Cnn is required for Spd-2 to expand into the PCM during this maturation process but can itself contribute to PCM independently of Spd-2. By contrast, the centrioles of spermatocytes elongate from a pre-existing proximal unit during the G2 preceding meiosis. Sas-4 is restricted to the microtubule-associated, inner cylinder and Dplp and Cnn to the outer cylinder of this proximal part. γ-Tubulin and Asl associate with the outer cylinder and Spd-2 with the inner cylinder throughout the entire G2 centriole. Although they occupy different spatial compartments on the G2 centriole, Cnn, Spd-2 and γ-tubulin become diminished at the centriole upon entry into meiosis to become part of PCM clouds.
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Affiliation(s)
- Jingyan Fu
- Cancer Research UK Cell Cycle Genetics Group, Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK.
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20
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Patel H, Zich J, Serrels B, Rickman C, Hardwick KG, Frame MC, Brunton VG. Kindlin-1 regulates mitotic spindle formation by interacting with integrins and Plk-1. Nat Commun 2013; 4:2056. [PMID: 23804033 DOI: 10.1038/ncomms3056] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 05/24/2013] [Indexed: 11/08/2022] Open
Abstract
Kindlin-1 binds to integrins and regulates integrin activation at cell adhesions. Here we report a new function of Kindlin-1 in regulating spindle assembly. We show that Kindlin-1 localizes to centrosomes, its concentration peaking during G2/M, where it associates with various pericentriolar material proteins, including Polo-like kinase 1. Short interfering RNA-mediated depletion of Kindlin-1 increases formation of abnormal mitotic spindles and decreases cellular survival. This effect is dependent not only on the ability of Kindlin-1 to bind integrins but also on Polo-like kinase 1-mediated Kindlin-1 phosphorylation. We demonstrate that a subcellular pool of phosphorylated Kindlin-1 is located exclusively at centrosomes. Our work identifies a novel cellular role for Kindlin-1 in ensuring mitotic spindle assembly and cellular survival that is controlled by phosphorylation via Polo-like kinase 1.
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Affiliation(s)
- Hitesh Patel
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, UK
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21
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Abstract
Centrioles are the key foundation of centrosomes and cilia, yet a molecular understanding of how they form has only recently begun to emerge. Building a fully functional centriole that can form a centrosome and cilium requires two cell cycles. Centriole building starts with procentriole nucleation, a process that is coordinated by the conserved proteins Plk4/Zyg-1, and Asterless/Cep152. Subsequently, Sas-6, a conserved procentriole protein, self-assembles to provide nine-fold symmetry to the centriole scaffold. The procentriole then continues to elongate into a centriole, a process controlled by Sas-4/CPAP and CP110. Then, centrioles recruit Sas-4-mediated pre-assembled centrosomal complexes from the cytoplasm to form the pericentriolar material (PCM). Finally, CP110 and its interacting proteins are involved in controlling the timing of centriole templating of the cilium.
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Affiliation(s)
- Tomer Avidor-Reiss
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606, USA.
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22
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Sonnen KF, Schermelleh L, Leonhardt H, Nigg EA. 3D-structured illumination microscopy provides novel insight into architecture of human centrosomes. Biol Open 2012; 1:965-76. [PMID: 23213374 PMCID: PMC3507176 DOI: 10.1242/bio.20122337] [Citation(s) in RCA: 252] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 07/03/2012] [Indexed: 02/05/2023] Open
Abstract
Centrioles are essential for the formation of cilia and flagella. They also form the core of the centrosome, which organizes microtubule arrays important for cell shape, polarity, motility and division. Here, we have used super-resolution 3D-structured illumination microscopy to analyse the spatial relationship of 18 centriole and pericentriolar matrix (PCM) components of human centrosomes at different cell cycle stages. During mitosis, PCM proteins formed extended networks with interspersed γ-Tubulin. During interphase, most proteins were arranged at specific distances from the walls of centrioles, resulting in ring staining, often with discernible density masses. Through use of site-specific antibodies, we found the C-terminus of Cep152 to be closer to centrioles than the N-terminus, illustrating the power of 3D-SIM to study protein disposition. Appendage proteins showed rings with multiple density masses, and the number of these masses was strongly reduced during mitosis. At the proximal end of centrioles, Sas-6 formed a dot at the site of daughter centriole assembly, consistent with its role in cartwheel formation. Plk4 and STIL co-localized with Sas-6, but Cep135 was associated mostly with mother centrioles. Remarkably, Plk4 formed a dot on the surface of the mother centriole before Sas-6 staining became detectable, indicating that Plk4 constitutes an early marker for the site of nascent centriole formation. Our study provides novel insights into the architecture of human centrosomes and illustrates the power of super-resolution microscopy in revealing the relative localization of centriole and PCM proteins in unprecedented detail.
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Affiliation(s)
- Katharina F Sonnen
- Biozentrum, University of Basel , Klingelbergstrasse 50/70, CH-4056 Basel , Switzerland
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23
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Ozaki Y, Matsui H, Asou H, Nagamachi A, Aki D, Honda H, Yasunaga S, Takihara Y, Yamamoto T, Izumi S, Ohsugi M, Inaba T. Poly-ADP ribosylation of Miki by tankyrase-1 promotes centrosome maturation. Mol Cell 2012; 47:694-706. [PMID: 22864114 DOI: 10.1016/j.molcel.2012.06.033] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 02/28/2012] [Accepted: 06/19/2012] [Indexed: 11/26/2022]
Abstract
During prometaphase, dense microtubule nucleation sites at centrosomes form robust spindles that align chromosomes promptly. Failure of centrosome maturation leaves chromosomes scattered, as seen routinely in cancer cells, including myelodysplastic syndrome (MDS). We previously reported that the Miki (LOC253012) gene is frequently deleted in MDS patients, and that low levels of Miki are associated with abnormal mitosis. Here we demonstrate that Miki localizes to the Golgi apparatus and is poly(ADP-ribosyl)ated by tankyrase-1 during late G2 and prophase. PARsylated Miki then translocates to mitotic centrosomes and anchors CG-NAP, a large scaffold protein of the γ-tubulin ring complex. Due to impairment of microtubule aster formation, cells in which tankyrase-1, Miki, or CG-NAP expression is downregulated all show prometaphase disturbances, including scattered and lagging chromosomes. Our data suggest that PARsylation of Miki by tankyrase-1 is a key initial event promoting prometaphase.
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Affiliation(s)
- Yuko Ozaki
- Department of Molecular Oncology and Leukemia Program Project, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima 734-8553, Japan
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24
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Meunier S, Vernos I. Microtubule assembly during mitosis - from distinct origins to distinct functions? J Cell Sci 2012; 125:2805-14. [PMID: 22736044 DOI: 10.1242/jcs.092429] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The mitotic spindle is structurally and functionally defined by its main component, the microtubules (MTs). The MTs making up the spindle have various functions, organization and dynamics: astral MTs emanate from the centrosome and reach the cell cortex, and thus have a major role in spindle positioning; interpolar MTs are the main constituent of the spindle and are key for the establishment of spindle bipolarity, chromosome congression and central spindle assembly; and kinetochore-fibers are MT bundles that connect the kinetochores with the spindle poles and segregate the sister chromatids during anaphase. The duplicated centrosomes were long thought to be the origin of all of these MTs. However, in the last decade, a number of studies have contributed to the identification of non-centrosomal pathways that drive MT assembly in dividing cells. These pathways are now known to be essential for successful spindle assembly and to participate in various processes such as K-fiber formation and central spindle assembly. In this Commentary, we review the recent advances in the field and discuss how different MT assembly pathways might cooperate to successfully form the mitotic spindle.
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Affiliation(s)
- Sylvain Meunier
- Microtubule Function and Cell Division group, Cell and Developmental Biology Program, Centre for Genomic Regulation (CRG) and UPF, Dr. Aiguader 88, 08003 Barcelona, Spain
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25
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Wu Q, He R, Zhou H, Yu ACH, Zhang B, Teng J, Chen J. Cep57, a NEDD1-binding pericentriolar material component, is essential for spindle pole integrity. Cell Res 2012; 22:1390-401. [PMID: 22508265 DOI: 10.1038/cr.2012.61] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Formation of a bipolar spindle is indispensable for faithful chromosome segregation and cell division. Spindle integrity is largely dependent on the centrosome and the microtubule network. Centrosome protein Cep57 can bundle microtubules in mammalian cells. Its related protein (Cep57R) in Xenopus was characterized as a stabilization factor for microtubule-kinetochore attachment. Here we show that Cep57 is a pericentriolar material (PCM) component. Its interaction with NEDD1 is necessary for the centrosome localization of Cep57. Depletion of Cep57 leads to unaligned chromosomes and a multipolar spindle, which is induced by PCM fragmentation. In the absence of Cep57, centrosome microtubule array assembly activity is weakened, and the spindle length and microtubule density decrease. As a spindle microtubule-binding protein, Cep57 is also responsible for the proper organization of the spindle microtubule and localization of spindle pole focusing proteins. Collectively, these results suggest that Cep57, as a NEDD1-binding centrosome component, could function as a spindle pole- and microtubule-stabilizing factor for establishing robust spindle architecture.
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Affiliation(s)
- Qixi Wu
- The State Key Laboratory of Biomembrane and Membrane Bioengineering and The Key Laboratory of Cell Proliferation and Differentiation of Ministry of Education, College of Life Sciences, Peking University, Beijing 100871, China
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26
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Mahen R, Venkitaraman AR. Pattern formation in centrosome assembly. Curr Opin Cell Biol 2012; 24:14-23. [PMID: 22245706 DOI: 10.1016/j.ceb.2011.12.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 12/21/2011] [Accepted: 12/23/2011] [Indexed: 01/01/2023]
Abstract
A striking but poorly explained feature of cell division is the ability to assemble and maintain organelles not bounded by membranes, from freely diffusing components in the cytosol. This process is driven by information transfer across biological scales such that interactions at the molecular scale allow pattern formation at the scale of the organelle. One important example of such an organelle is the centrosome, which is the main microtubule organising centre in the cell. Centrosomes consist of two centrioles surrounded by a cloud of proteins termed the pericentriolar material (PCM). Profound structural and proteomic transitions occur in the centrosome during specific cell cycle stages, underlying events such as centrosome maturation during mitosis, in which the PCM increases in size and microtubule nucleating capacity. Here we use recent insights into the spatio-temporal behaviour of key regulators of centrosomal maturation, including Polo-like kinase 1, CDK5RAP2 and Aurora-A, to propose a model for the assembly and maintenance of the PCM through the mobility and local interactions of its constituent proteins. We argue that PCM structure emerges as a pattern from decentralised self-organisation through a reaction-diffusion mechanism, with or without an underlying template, rather than being assembled from a central structural template alone. Self-organisation of this kind may have broad implications for the maintenance of mitotic structures, which, like the centrosome, exist stably as supramolecular assemblies on the micron scale, based on molecular interactions at the nanometer scale.
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Affiliation(s)
- Robert Mahen
- The Medical Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, Hills Road, Cambridge, CB2 OXZ, United Kingdom.
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27
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Smith E, Hégarat N, Vesely C, Roseboom I, Larch C, Streicher H, Straatman K, Flynn H, Skehel M, Hirota T, Kuriyama R, Hochegger H. Differential control of Eg5-dependent centrosome separation by Plk1 and Cdk1. EMBO J 2011; 30:2233-45. [PMID: 21522128 PMCID: PMC3117641 DOI: 10.1038/emboj.2011.120] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Accepted: 03/25/2011] [Indexed: 11/29/2022] Open
Abstract
Cyclin-dependent kinase 1 (Cdk1) is thought to trigger centrosome separation in late G2 phase by phosphorylating the motor protein Eg5 at Thr927. However, the precise control mechanism of centrosome separation remains to be understood. Here, we report that in G2 phase polo-like kinase 1 (Plk1) can trigger centrosome separation independently of Cdk1. We find that Plk1 is required for both C-Nap1 displacement and for Eg5 localization on the centrosome. Moreover, Cdk2 compensates for Cdk1, and phosphorylates Eg5 at Thr927. Nevertheless, Plk1-driven centrosome separation is slow and staggering, while Cdk1 triggers fast movement of the centrosomes. We find that actin-dependent Eg5-opposing forces slow down separation in G2 phase. Strikingly, actin depolymerization, as well as destabilization of interphase microtubules (MTs), is sufficient to remove this obstruction and to speed up Plk1-dependent separation. Conversely, MT stabilization in mitosis slows down Cdk1-dependent centrosome movement. Our findings implicate the modulation of MT stability in G2 and M phase as a regulatory element in the control of centrosome separation.
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Affiliation(s)
- Ewan Smith
- Genome Damage and Stability Centre, University of Sussex, Brighton, UK
| | - Nadia Hégarat
- Genome Damage and Stability Centre, University of Sussex, Brighton, UK
| | - Clare Vesely
- Genome Damage and Stability Centre, University of Sussex, Brighton, UK
| | - Isaac Roseboom
- Department of Physics and Astronomy, University of Sussex, Brigthon, UK
| | - Chris Larch
- Department of Chemistry and Biochemistry, University of Sussex, Brighton, UK
| | - Hansjörg Streicher
- Department of Chemistry and Biochemistry, University of Sussex, Brighton, UK
| | | | - Helen Flynn
- CRUK London Research Institutes Clare Hall, South Mimms, UK
| | - Mark Skehel
- CRUK London Research Institutes Clare Hall, South Mimms, UK
| | - Toru Hirota
- The Cancer Institute, Japanese Foundation for Cancer Research, Ariake, Tokyo, Japan
| | - Ryoko Kuriyama
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Helfrid Hochegger
- Genome Damage and Stability Centre, University of Sussex, Brighton, UK
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28
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Mahen R, Jeyasekharan AD, Barry NP, Venkitaraman AR. Continuous polo-like kinase 1 activity regulates diffusion to maintain centrosome self-organization during mitosis. Proc Natl Acad Sci U S A 2011; 108:9310-5. [PMID: 21576470 PMCID: PMC3107272 DOI: 10.1073/pnas.1101112108] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Whether mitotic structures like the centrosome can self-organize from the regulated mobility of their dynamic protein components remains unclear. Here, we combine fluorescence spectroscopy and chemical genetics to study in living cells the diffusion of polo-like kinase 1 (PLK1), an enzyme critical for centrosome maturation at the onset of mitosis. The cytoplasmic diffusion of a functional EGFP-PLK1 fusion correlates inversely with known changes in its enzymatic activity during the cell cycle. Specific EGFP-PLK1 inhibition using chemical genetics enhances mobility, as do point mutations inactivating the polo-box or kinase domains responsible for substrate recognition and catalysis. Spatial mapping of EGFP-PLK1 diffusion across living cells, using raster image correlation spectroscopy and line scanning, detects regions of low mobility in centrosomes. These regions exhibit characteristics of increased transient recursive EGFP-PLK1 binding, distinct from the diffusion of stable EGFP-PLK1-containing complexes in the cytoplasm. Chemical genetic suppression of mitotic EGFP-PLK1 activity, even after centrosome maturation, causes defects in centrosome structure, which recover when activity is restored. Our findings imply that continuous PLK1 activity during mitosis maintains centrosome self-organization by a mechanism dependent on its reaction and diffusion, suggesting a model for the formation of stable mitotic structures using dynamic protein kinases.
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Affiliation(s)
- Robert Mahen
- Medical Research Council Cancer Cell Unit, Hutchison/Medical Research Council Research Centre and
| | - Anand D. Jeyasekharan
- Medical Research Council Cancer Cell Unit, Hutchison/Medical Research Council Research Centre and
| | - Nicholas P. Barry
- Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 OXZ, United Kingdom
| | - Ashok R. Venkitaraman
- Medical Research Council Cancer Cell Unit, Hutchison/Medical Research Council Research Centre and
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Matsumura F, Yamakita Y, Yamashiro S. Myosin phosphatase-targeting subunit 1 controls chromatid segregation. J Biol Chem 2011; 286:10825-33. [PMID: 21252232 PMCID: PMC3060533 DOI: 10.1074/jbc.m110.169722] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 12/27/2010] [Indexed: 11/06/2022] Open
Abstract
Myosin phosphatase is a heterotrimeric holoenzyme consisting of myosin phosphatase-targeting subunit 1 (MYPT1), a catalytic subunit of PP1Cβ, and a 20-kDa subunit of an unknown function. We have previously reported that myosin phosphatase also controls mitosis, apparently by antagonizing polo-like kinase 1 (PLK1). Here we found that depletion of MYPT1 by siRNA led to precocious chromatid segregation when HeLa cells were arrested at metaphase by a proteasome inhibitor, MG132, or by Cdc20 depletion. Consistently, cyclin B1 and securin were not degraded, indicating that the chromatid segregation is independent of the anaphase-promoting complex/cyclosome. Precocious segregation induced by MYPT1 depletion requires PLK1 activity because a PLK1 inhibitor, BI-2536, blocked precocious segregation. Furthermore, the expression of an unphosphorylatable mutant of SA2 (SCC3 homologue 2), a subunit of the cohesin complex, prevented precocious chromatid segregation induced by MYPT1 depletion. It has been shown that SA2 at centromeres is protected from phosphorylation by PP2A phosphatase recruited by Shugoshin (Sgo1), whereas SA2 along chromosome arms is phosphorylated by PLK1, leading to SA2 dissociation at chromosome arms. Taken together, our results suggest that hyperactivation of PLK1 caused by MYPT1 reduction could override the counteracting PP2A phosphatase, resulting in precocious chromatid segregation. We propose that SA2 at the centromeres is protected by two phosphatases. One is PP2A directly dephosphorylating SA2, and the other is myosin phosphatase counteracting PLK1.
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Affiliation(s)
- Fumio Matsumura
- From the Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey 08854
| | - Yoshihiko Yamakita
- From the Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey 08854
| | - Shigeko Yamashiro
- From the Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey 08854
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Ma N, Matsunaga S, Morimoto A, Sakashita G, Urano T, Uchiyama S, Fukui K. The nuclear scaffold protein SAF-A is required for kinetochore-microtubule attachment and contributes to the targeting of Aurora-A to mitotic spindles. J Cell Sci 2011; 124:394-404. [PMID: 21242313 DOI: 10.1242/jcs.063347] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Segregation of chromosomes during cell division requires correct formation of mitotic spindles. Here, we show that a scaffold attachment factor A (SAF-A), also known as heterogeneous nuclear ribonucleoprotein-U, contributes to the attachment of spindle microtubules (MTs) to kinetochores and spindle organization. During mitosis, SAF-A was localized at the spindles, spindle midzone and cytoplasmic bridge. Depletion of SAF-A by RNA interference induced mitotic delay and defects in chromosome alignment and spindle assembly. We found that SAF-A specifically co-immunoprecipitated with the chromosome peripheral protein nucleolin and the spindle regulators Aurora-A and TPX2, indicating that SAF-A is associated with nucleolin and the Aurora-A-TPX2 complex. SAF-A was colocalized with TPX2 and Aurora-A in spindle poles and MTs. Elimination of TPX2 or Aurora-A from cells abolished the association of SAF-A with the mitotic spindle. Interestingly, SAF-A can bind to MTs and contributes to the targeting of Aurora-A to mitotic spindle MTs. Our finding indicates that SAF-A is a novel spindle regulator that plays an essential role in kinetochore-MT attachment and mitotic spindle organization.
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Affiliation(s)
- Nan Ma
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan
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31
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Santamaria A, Wang B, Elowe S, Malik R, Zhang F, Bauer M, Schmidt A, Silljé HHW, Körner R, Nigg EA. The Plk1-dependent phosphoproteome of the early mitotic spindle. Mol Cell Proteomics 2011; 10:M110.004457. [PMID: 20860994 PMCID: PMC3013462 DOI: 10.1074/mcp.m110.004457] [Citation(s) in RCA: 190] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Indexed: 12/31/2022] Open
Abstract
Polo-like kinases regulate many aspects of mitotic and meiotic progression from yeast to man. In early mitosis, mammalian Polo-like kinase 1 (Plk1) controls centrosome maturation, spindle assembly, and microtubule attachment to kinetochores. However, despite the essential and diverse functions of Plk1, the full range of Plk1 substrates remains to be explored. To investigate the Plk1-dependent phosphoproteome of the human mitotic spindle, we combined stable isotope labeling by amino acids in cell culture with Plk1 inactivation or depletion followed by spindle isolation and mass spectrometry. Our study identified 358 unique Plk1-dependent phosphorylation sites on spindle proteins, including novel substrates, illustrating the complexity of the Plk1-dependent signaling network. Over 100 sites were validated by in vitro phosphorylation of peptide arrays, resulting in a broadening of the Plk1 consensus motif. Collectively, our data provide a rich source of information on Plk1-dependent phosphorylation, Plk1 docking to substrates, the influence of phosphorylation on protein localization, and the functional interaction between Plk1 and Aurora A on the early mitotic spindle.
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Affiliation(s)
- Anna Santamaria
- Department of Cell Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.
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Zhao L, Jin C, Chu Y, Varghese C, Hua S, Yan F, Miao Y, Liu J, Mann D, Ding X, Zhang J, Wang Z, Dou Z, Yao X. Dimerization of CPAP orchestrates centrosome cohesion plasticity. J Biol Chem 2009; 285:2488-97. [PMID: 19889632 DOI: 10.1074/jbc.m109.042614] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Centrosome cohesion and segregation are accurately regulated to prevent an aberrant separation of duplicated centrosomes and to ensure the correct formation of bipolar spindles by a tight coupling with cell cycle machinery. CPAP is a centrosome protein with five coiled-coil domains and plays an important role in the control of brain size in autosomal recessive primary microcephaly. Previous studies showed that CPAP interacts with tubulin and controls centriole length. Here, we reported that CPAP forms a homodimer during interphase, and the fifth coiled-coil domain of CPAP is required for its dimerization. Moreover, this self-interaction is required for maintaining centrosome cohesion and preventing the centrosome from splitting before the G(2)/M phase. Our biochemical studies show that CPAP forms homodimers in vivo. In addition, both monomeric and dimeric CPAP are required for accurate cell division, suggesting that the temporal dynamics of CPAP homodimerization is tightly regulated during the cell cycle. Significantly, our results provide evidence that CPAP is phosphorylated during mitosis, and this phosphorylation releases its intermolecular interaction. Taken together, these results suggest that cell cycle-regulated phosphorylation orchestrates the dynamics of CPAP molecular interaction and centrosome splitting to ensure genomic stability in cell division.
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Affiliation(s)
- Lingli Zhao
- Anhui Key Laboratory for Cellular Dynamics and Chemical Biology and Hefei National Laboratory for Physical Sciences at Nanoscale, Hefei 230027, China
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Lee J, Kim S, Jeong Y, Rhee K. Centrobin/Nip2 expression in vivo suggests its involvement in cell proliferation. Mol Cells 2009; 28:31-6. [PMID: 19533028 DOI: 10.1007/s10059-009-0097-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 04/29/2009] [Accepted: 05/06/2009] [Indexed: 12/01/2022] Open
Abstract
Centrobin/Nip2 was initially identified as a centrosome protein that is critical for centrosome duplication and spindle assembly. In the present study, we determined the expression and subcellular localization of centrobin in selected mouse tissues. Immunoblot analysis revealed that the centrobin-specific band of 100 kDa was detected in all tissues tested but most abundantly in the thymus, spleen and testis. In the testis, centrobin was localized at the centrosomes of spermatocytes and early round spermatids, but no specific signal was detected in late round spermatids and elongated spermatids. Our results also revealed that the centrosome duplication occurs at interphase of the second meiotic division of the mouse male germ cells. The centrobin protein was more abundant in the mitotically active ovarian follicular cells and thymic cortex cells than in non-proliferating corpus luteal cells and thymic medullary cells. The expression pattern of centrobin suggests that the biological functions of centrobin are related to cell proliferation. Consistent with the proposal, we observed reduction of the centrobin levels when NIH3T3 became quiescent in the serum-starved culture conditions. However, a residual amount of centrobin was also detected at the centrosomes of the resting cells, suggesting its role for maintaining integrity of the centrosome, especially of the daughter centriole in the cells.
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Affiliation(s)
- Jungmin Lee
- Department of Biological Sciences, Seoul National University, Seoul 151-747, Korea
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Lim HH, Zhang T, Surana U. Regulation of centrosome separation in yeast and vertebrates: common threads. Trends Cell Biol 2009; 19:325-33. [PMID: 19576775 DOI: 10.1016/j.tcb.2009.03.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 03/04/2009] [Accepted: 03/05/2009] [Indexed: 02/06/2023]
Abstract
The assembly of a bipolar spindle is crucial for symmetric partitioning of duplicated chromosomes during cell division. Centrosomes (spindle pole body [SPB] in yeast) constitute the two poles of this bipolar structure and serve as microtubule nucleation centers. A eukaryotic cell enters the division cycle with one centrosome and duplicates it before spindle formation. A proteinaceous link keeps duplicated centrosomes together until it is severed at onset of mitosis, enabling centrosomes to migrate away from each other and assemble a characteristic mitotic spindle. Hence, centrosome separation is crucial in assembly of a bipolar spindle. Whereas centrosome (or SPB) duplication has been characterized in some detail, the separation process is less well understood. Here, we review recent studies that uncover new players and provide a greater understanding of the regulation of centrosome (or SPB) separation.
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Affiliation(s)
- Hong Hwa Lim
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Proteos, 138673 Singapore
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Zhang X, Chen Q, Feng J, Hou J, Yang F, Liu J, Jiang Q, Zhang C. Sequential phosphorylation of Nedd1 by Cdk1 and Plk1 is required for targeting of the gammaTuRC to the centrosome. J Cell Sci 2009; 122:2240-51. [PMID: 19509060 DOI: 10.1242/jcs.042747] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Nedd1 is a new member of the gamma-tubulin ring complex (gammaTuRC) and targets the gammaTuRC to the centrosomes for microtubule nucleation and spindle assembly in mitosis. Although its role is known, its functional regulation mechanism remains unclear. Here we report that the function of Nedd1 is regulated by Cdk1 and Plk1. During mitosis, Nedd1 is firstly phosphorylated at T550 by Cdk1, which creates a binding site for the polo-box domain of Plk1. Then, Nedd1 is further phosphorylated by Plk1 at four sites: T382, S397, S637 and S426. The sequential phosphorylation of Nedd1 by Cdk1 and Plk1 promotes its interaction with gamma-tubulin for targeting the gammaTuRC to the centrosome and is important for spindle formation. Knockdown of Plk1 by RNAi decreases Nedd1 phosphorylation and attenuates Nedd1 accumulation at the spindle pole and subsequent gamma-tubulin recruitment at the spindle pole for microtubule nucleation. Taken together, we propose that the sequential phosphorylation of Nedd1 by Cdk1 and Plk1 plays a pivotal role in targeting gammaTuRC to the centrosome by promoting the interaction of Nedd1 with the gammaTuRC component gamma-tubulin, during mitosis.
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Affiliation(s)
- Xiaoyan Zhang
- The MOE Key Laboratory of Cell Proliferation and Differentiation and the State Key Laboratory of Bio-membrane and Membrane Bio-engineering, College of Life Sciences, Peking University, Beijing 100871, China
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Oshimori N, Li X, Ohsugi M, Yamamoto T. Cep72 regulates the localization of key centrosomal proteins and proper bipolar spindle formation. EMBO J 2009; 28:2066-76. [PMID: 19536135 DOI: 10.1038/emboj.2009.161] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Accepted: 05/22/2009] [Indexed: 12/21/2022] Open
Abstract
Microtubule-nucleation activity and structural integrity of the centrosome are critical for various cellular functions. The gamma-tubulin ring complexes (gammaTuRCs) localizing to the pericentriolar matrix (PCM) of the centrosome are major sites of microtubule nucleation. The PCM is thought to be created by two cognate large coiled-coil proteins, pericentrin/kendrin and CG-NAP/AKAP450, and its stabilization by Kizuna is essential for bipolar spindle formation. However, the mechanisms by which these proteins are recruited and organized into a proper structure with microtubule-organizing activity are poorly understood. Here we identify a centrosomal protein Cep72 as a Kizuna-interacting protein. Interestingly, Cep72 is essential for the localization of CG-NAP and Kizuna. Cep72 is also involved in gammaTuRC recruitment to the centrosome and CG-NAP confers the microtubule-nucleation activity on the gammaTuRCs. During mitosis, Cep72-mediated microtubule organization is important for converging spindle microtubules to the centrosomes, which is needed for chromosome alignment and tension generation between kinetochores. Our findings show that Cep72 is the key protein essential for maintaining microtubule-organizing activity and structural integrity of the centrosome.
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Affiliation(s)
- Naoki Oshimori
- Division of Oncology, Department of Cancer Biology, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
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Jin S, Gao H, Mazzacurati L, Wang Y, Fan W, Chen Q, Yu W, Wang M, Zhu X, Zhang C, Zhan Q. BRCA1 interaction of centrosomal protein Nlp is required for successful mitotic progression. J Biol Chem 2009; 284:22970-7. [PMID: 19509300 DOI: 10.1074/jbc.m109.009134] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Breast cancer susceptibility gene BRCA1 is implicated in the control of mitotic progression, although the underlying mechanism(s) remains to be further defined. Deficiency of BRCA1 function leads to disrupted mitotic machinery and genomic instability. Here, we show that BRCA1 physically interacts and colocalizes with Nlp, an important molecule involved in centrosome maturation and spindle formation. Interestingly, Nlp centrosomal localization and its protein stability are regulated by normal cellular BRCA1 function because cells containing BRCA1 mutations or silenced for endogenous BRCA1 exhibit disrupted Nlp colocalization to centrosomes and enhanced Nlp degradation. Its is likely that the BRCA1 regulation of Nlp stability involves Plk1 suppression. Inhibition of endogenous Nlp via the small interfering RNA approach results in aberrant spindle formation, aborted chromosomal segregation, and aneuploidy, which mimic the phenotypes of disrupted BRCA1. Thus, BRCA1 interaction of Nlp might be required for the successful mitotic progression, and abnormalities of Nlp lead to genomic instability.
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Affiliation(s)
- Shunqian Jin
- State Key Laboratory of Molecular Oncology, Cancer Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
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Abstract
The cell cycle governs the transition from quiescence through cell growth to proliferation. The key parts of the cell cycle machinery are the cyclin-dependent kinases (CDKS) and the regulatory proteins called cyclins. The CDKS are rational targets for cancer therapy because their expression in cancer cells is often aberrant and their inhibition can induce cell death. Inhibitors of CDKS can also block transcription.Several drugs targeting the cell cycle have entered clinical trials. These agents include flavopiridol, indisulam, AZD5438, SNS-032, bryostatin-1, seliciclib, PD 0332991, and SCH 727965. Phase i studies have demonstrated that these drugs can generally be administered safely. Phase ii studies have shown little single-agent activity in solid tumors, but combination studies with cytotoxic chemotherapy have been more promising. In hematologic malignancies, reports have shown encouraging single-agent and combination activity. Pharmacodynamic studies show that the dose and schedule of these drugs are crucial to permit maximum therapeutic effect.
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Affiliation(s)
- M.A. Dickson
- Department of Medicine, Division of Solid Tumor Oncology, Melanoma and Sarcoma Service, and Laboratory of New Drug Development, Memorial Sloan–Kettering Cancer Center, New York, NY, U.S.A
| | - G.K. Schwartz
- Department of Medicine, Division of Solid Tumor Oncology, Melanoma and Sarcoma Service, and Laboratory of New Drug Development, Memorial Sloan–Kettering Cancer Center, New York, NY, U.S.A
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Abstract
The formation of a bipolar spindle is essential for the equal segregation of duplicated DNA into two daughter cells during mitosis. Spindle bipolarity is largely dependent on the mitotic cell possessing two centrosomes that can each establish one spindle pole. The centrosome is also now known to regulate many other aspects of cell cycle progression, including G1/S progression, spindle orientation and symmetry, cytokinesis, and checkpoint signalling. As a result, defects in centrosome arrangement or number can lead to loss of cell polarity, defective cell division, and abnormal chromosome segregation, all events that are typical of cancer cells. Indeed, cancer cells often exhibit overduplicated centrosomes and multipolar spindles. Here, we outline a number of fluorescence imaging methodologies that can be used to study events of the centrosome duplication cycle, as well as the dynamics of individual centrosome proteins. Specifically, we discuss the generation and imaging of cell lines with fluorescently labelled centrosomes, the use of photobleaching methods to measure the dynamics of centrosome proteins, and assays for observing centrosome overduplication and centrosome separation in fixed and live cells. These experimental approaches can provide important information on the regulation of centrosomes, their role in normal cell cycle progression and how their deregulation might contribute to the deleterious phenotypes of malignant cancer cells.
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Chan EHY, Santamaria A, Silljé HHW, Nigg EA. Plk1 regulates mitotic Aurora A function through betaTrCP-dependent degradation of hBora. Chromosoma 2008; 117:457-69. [PMID: 18521620 PMCID: PMC2921497 DOI: 10.1007/s00412-008-0165-5] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Revised: 04/22/2008] [Accepted: 04/23/2008] [Indexed: 11/16/2022]
Abstract
Polo-like kinase 1 (Plk1) and Aurora A play key roles in centrosome maturation, spindle assembly, and chromosome segregation during cell division. Here we show that the functions of these kinases during early mitosis are coordinated through Bora, a partner of Aurora A first identified in Drosophila. Depletion of human Bora (hBora) results in spindle defects, accompanied by increased spindle recruitment of Aurora A and its partner TPX2. Conversely, hBora overexpression induces mislocalization of Aurora A and monopolar spindle formation, reminiscent of the phenotype seen in Plk1-depleted cells. Indeed, Plk1 regulates hBora. Following Cdk1-dependent recruitment, Plk1 triggers hBora destruction by phosphorylating a recognition site for SCF(Beta-TrCP). Plk1 depletion or inhibition results in a massive accumulation of hBora, concomitant with displacement of Aurora A from spindle poles and impaired centrosome maturation, but remarkably, co-depletion of hBora partially restores Aurora A localization and bipolar spindle formation. This suggests that Plk1 controls Aurora A localization and function by regulating cellular levels of hBora.
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Affiliation(s)
- Eunice H. Y. Chan
- Department of Cell Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
- Present Address: Apoptosis and Proliferation Control Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln’s Inn Fields, London, WC2A 3PX UK
| | - Anna Santamaria
- Department of Cell Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Herman H. W. Silljé
- Department of Cell Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
- Present Address: Kiadis Pharma, Zernikepark 6-8, 9747 AN Groningen, The Netherlands
| | - Erich A. Nigg
- Department of Cell Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
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Venoux M, Delmouly K, Milhavet O, Vidal-Eychenié S, Giorgi D, Rouquier S. Gene organization, evolution and expression of the microtubule-associated protein ASAP (MAP9). BMC Genomics 2008; 9:406. [PMID: 18782428 PMCID: PMC2551623 DOI: 10.1186/1471-2164-9-406] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Accepted: 09/09/2008] [Indexed: 11/10/2022] Open
Abstract
Background ASAP is a newly characterized microtubule-associated protein (MAP) essential for proper cell-cycling. We have previously shown that expression deregulation of human ASAP results in profound defects in mitotic spindle formation and mitotic progression leading to aneuploidy, cytokinesis defects and/or cell death. In the present work we analyze the structure and evolution of the ASAP gene, as well as the domain composition of the encoded protein. Mouse and Xenopus cDNAs were cloned, the tissue expression characterized and the overexpression profile analyzed. Results Bona fide ASAP orthologs are found in vertebrates with more distantly related potential orthologs in invertebrates. This single-copy gene is conserved in mammals where it maps to syntenic chromosomal regions, but is also clearly identified in bird, fish and frog. The human gene is strongly expressed in brain and testis as a 2.6 Kb transcript encoding a ~110 KDa protein. The protein contains MAP, MIT-like and THY domains in the C-terminal part indicative of microtubule interaction, while the N-terminal part is more divergent. ASAP is composed of ~42% alpha helical structures, and two main coiled-coil regions have been identified. Different sequence features may suggest a role in DNA damage response. As with human ASAP, the mouse and Xenopus proteins localize to the microtubule network in interphase and to the mitotic spindle during mitosis. Overexpression of the mouse protein induces mitotic defects similar to those observed in human. In situ hybridization in testis localized ASAP to the germ cells, whereas in culture neurons ASAP localized to the cell body and growing neurites. Conclusion The conservation of ASAP indicated in our results reflects an essential function in vertebrates. We have cloned the ASAP orthologs in mouse and Xenopus, two valuable models to study the function of ASAP. Tissue expression of ASAP revealed a high expression in brain and testis, two tissues rich in microtubules. ASAP associates to the mitotic spindle and cytoplasmic microtubules, and represents a key factor of mitosis with possible involvement in other cell cycle processes. It may have a role in spermatogenesis and also represents a potential new target for antitumoral drugs. Possible involvement in neuron dynamics also highlights ASAP as a candidate target in neurodegenerative diseases.
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Affiliation(s)
- Magali Venoux
- Groupe Microtubules et Cycle Cellulaire, Institut de Génétique Humaine, CNRS UPR 1142, rue de cardonille, 34396 Montpellier cédex 5, France.
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Abstract
Mitotic spindle assembly is a highly regulated process, crucial to ensure the correct segregation of duplicated chromosomes in daughter cells and to avoid aneuploidy, a common feature of tumors. Among the most important spindle regulators is Aurora-A, a mitotic centrosomal kinase frequently overexpressed in tumors. Here, we investigated the role of Aurora-A in spindle pole organization in human cells. We show that RNA interference-mediated Aurora-A inactivation causes pericentriolar material fragmentation in prometaphase, yielding the formation of spindles with supernumerary poles. This fragmentation does not necessarily involve centrioles and requires microtubules (MTs). Aurora-A-depleted prometaphases mislocalize the MT-stabilizing protein colonic hepatic tumor-overexpressed gene (ch-TOG), which abnormally accumulates at spindle poles, as well as the mitotic centromere-associated kinesin (MCAK), the major functional antagonist of ch-TOG, which delocalizes from poles. ch-TOG is required for extrapole formation in prometaphases lacking Aurora-A, because co-depletion of Aurora-A and ch-TOG mitigates the fragmented pole phenotype. These results indicate a novel function of Aurora-A, the regulation of ch-TOG and MCAK localization, and highlight a common pathway involving the three factors in control of spindle pole integrity.
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Yamashiro S, Yamakita Y, Totsukawa G, Goto H, Kaibuchi K, Ito M, Hartshorne DJ, Matsumura F. Myosin phosphatase-targeting subunit 1 regulates mitosis by antagonizing polo-like kinase 1. Dev Cell 2008; 14:787-97. [PMID: 18477460 PMCID: PMC2680213 DOI: 10.1016/j.devcel.2008.02.013] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2006] [Revised: 01/28/2008] [Accepted: 02/22/2008] [Indexed: 01/15/2023]
Abstract
Myosin phosphatase-targeting subunit 1 (MYPT1) binds to the catalytic subunit of protein phosphatase 1 (PP1C). This binding is believed to target PP1C to specific substrates including myosin II, thus controlling cellular contractility. Surprisingly, we found that during mitosis, mammalian MYPT1 binds to polo-like kinase 1 (PLK1). MYPT1 is phosphorylated during mitosis by proline-directed kinases including cdc2, which generates the binding motif for the polo box domain of PLK1. Depletion of PLK1 by small interfering RNAs is known to result in loss of gamma-tubulin recruitment to the centrosomes, blocking centrosome maturation and leading to mitotic arrest. We found that codepletion of MYPT1 and PLK1 reinstates gamma-tubulin at the centrosomes, rescuing the mitotic arrest. MYPT1 depletion increases phosphorylation of PLK1 at its activating site (Thr210) in vivo, explaining, at least in part, the rescue phenotype by codepletion. Taken together, our results identify a previously unrecognized role for MYPT1 in regulating mitosis by antagonizing PLK1.
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Affiliation(s)
- Shigeko Yamashiro
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854, USA.
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Toyo-oka K, Mori D, Yano Y, Shiota M, Iwao H, Goto H, Inagaki M, Hiraiwa N, Muramatsu M, Wynshaw-Boris A, Yoshiki A, Hirotsune S. Protein phosphatase 4 catalytic subunit regulates Cdk1 activity and microtubule organization via NDEL1 dephosphorylation. ACTA ACUST UNITED AC 2008; 180:1133-47. [PMID: 18347064 PMCID: PMC2290842 DOI: 10.1083/jcb.200705148] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Protein phosphatase 4 catalytic subunit (PP4c) is a PP2A-related protein serine/threonine phosphatase with important functions in a variety of cellular processes, including microtubule (MT) growth/organization, apoptosis, and tumor necrosis factor signaling. In this study, we report that NDEL1 is a substrate of PP4c, and PP4c selectively dephosphorylates NDEL1 at Cdk1 sites. We also demonstrate that PP4c negatively regulates Cdk1 activity at the centrosome. Targeted disruption of PP4c reveals disorganization of MTs and disorganized MT array. Loss of PP4c leads to an unscheduled activation of Cdk1 in interphase, which results in the abnormal phosphorylation of NDEL1. In addition, abnormal NDEL1 phosphorylation facilitates excessive recruitment of katanin p60 to the centrosome, suggesting that MT defects may be attributed to katanin p60 in excess. Inhibition of Cdk1, NDEL1, or katanin p60 rescues the defective MT organization caused by PP4 inhibition. Our work uncovers a unique regulatory mechanism of MT organization by PP4c through its targets Cdk1 and NDEL1 via regulation of katanin p60 distribution.
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Affiliation(s)
- Kazuhito Toyo-oka
- Department of Genetic Disease Research and 2Department of Pharmacology, Osaka City University Graduate School of Medicine, Osaka 545-8586, Japan
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Abe H, Kamai T, Shirataki H, Oyama T, Arai K, Yoshida KI. High expression of Ran GTPase is associated with local invasion and metastasis of human clear cell renal cell carcinoma. Int J Cancer 2008; 122:2391-7. [DOI: 10.1002/ijc.23400] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Cunningham LA, Kahn RA. Cofactor D functions as a centrosomal protein and is required for the recruitment of the gamma-tubulin ring complex at centrosomes and organization of the mitotic spindle. J Biol Chem 2008; 283:7155-65. [PMID: 18171676 DOI: 10.1074/jbc.m706753200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Microtubules are highly dynamic structures, composed of alpha/beta-tubulin heterodimers. Biosynthesis of the functional dimer involves the participation of several chaperones, termed cofactors A-E, that act on folding intermediates downstream of the cytosolic chaperonin CCT (1, 2). We show that cofactor D is also a centrosomal protein and that overexpression of either the full-length protein or either of two centrosome localization domains leads to the loss of anchoring of the gamma-tubulin ring complex and of nucleation of microtubule growth at centrosomes. In contrast, depletion of cofactor D by short interfering RNA results in mitotic spindle defects. Because none of these changes in cofactor D activity produced a change in the levels of alpha-or beta-tubulin, we conclude that these newly discovered functions for cofactor D are distinct from its previously described role in tubulin folding. Thus, we describe a new role for cofactor D at centrosomes that is important to its function in polymerization of tubulin and organization of the mitotic spindle.
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Affiliation(s)
- Leslie A Cunningham
- Department of Biochemistry and the Biochemistry, Cell, and Developmental Biology Program, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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Affiliation(s)
- Juliette Azimzadeh
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143, USA.
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Wiese C. Distinct Dgrip84 isoforms correlate with distinct gamma-tubulins in Drosophila. Mol Biol Cell 2007; 19:368-77. [PMID: 18003974 DOI: 10.1091/mbc.e07-08-0801] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Gamma-tubulin is an indispensable component of the animal centrosome and is required for proper microtubule organization. Within the cell, gamma-tubulin exists in a multiprotein complex containing between two (some yeasts) and six or more (metazoa) additional highly conserved proteins named gamma ring proteins (Grips) or gamma complex proteins (GCPs). gamma-Tubulin containing complexes isolated from Xenopus eggs or Drosophila embryos appear ring-shaped and have therefore been named the gamma-tubulin ring complex (gammaTuRC). Curiously, many organisms (including humans) have two distinct gamma-tubulin genes. In Drosophila, where the two gamma-tubulin isotypes have been studied most extensively, the gamma-tubulin genes are developmentally regulated: the "maternal" gamma-tubulin isotype (named gammaTub37CD according to its location on the genetic map) is expressed in the ovary and is deposited in the egg, where it is thought to orchestrate the meiotic and early embryonic cleavages. The second gamma-tubulin isotype (gammaTub23C) is ubiquitously expressed and persists in most of the cells of the adult fly. In those rare cases where both gamma-tubulins coexist in the same cell, they show distinct subcellular distributions and cell-cycle-dependent changes: gammaTub37CD mainly localizes to the centrosome, where its levels vary only slightly with the cell cycle. In contrast, the level of gammaTub23C at the centrosome increases at the beginning of mitosis, and gammaTub23C also associates with spindle pole microtubules. Here, we show that gammaTub23C forms discrete complexes that closely resemble the complexes formed by gammaTub37CD. Surprisingly, however, gammaTub23C associates with a distinct, longer splice variant of Dgrip84. This may reflect a role for Dgrip84 in regulating the activity and/or the location of the gamma-tubulin complexes formed with gammaTub37CD and gammaTub23C.
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Affiliation(s)
- Christiane Wiese
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
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Park JH, Jong HS, Kim SG, Jung Y, Lee KW, Lee JH, Kim DK, Bang YJ, Kim TY. Inhibitors of histone deacetylases induce tumor-selective cytotoxicity through modulating Aurora-A kinase. J Mol Med (Berl) 2007; 86:117-28. [PMID: 17851643 DOI: 10.1007/s00109-007-0260-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Revised: 08/09/2007] [Accepted: 08/13/2007] [Indexed: 10/22/2022]
Abstract
The molecular basis of the antitumor selectivity of histone deacetylase inhibitors (HDIs) remains unclear. Centrosomal Aurora-A kinase regulates chromosomal segregation during mitosis. The overexpression or amplification of Aurora-A leads to genetic instability, and its inhibition has shown significant antitumor effects. In this paper, we report that structurally related hydroxamate LAQ824 and SK-7068 induce tumor-selective mitotic defects by depleting Aurora-A. We found that HDI-treated cancer cells, unlike nontransformed cells, exhibit defective mitotic spindles. After HDI, Aurora-A was selectively downregulated in cancer cells, whereas Aurora-B remained unchanged in both cancer and nontransformed cells. LAQ824 or SK-7068 treatment inhibited histone deacetylase (HDAC) 6 present in Aurora-A/heat shock protein (Hsp) 90 complex. Inhibition of HDAC6 acetylated Hsp90 and resulted in dissociation of acetylated Hsp90 from Aurora-A. As a result, Hsp70 binding to Aurora-A was enhanced in cancer cells, leading to proteasomal degradation of Aurora-A. Overall, these provide a novel molecular basis of tumor selectivity of HDI. LAQ824 and SK-7068 might be more effective HDIs in cancer cells with Aurora-A overexpression.
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Affiliation(s)
- Jung-Hyun Park
- National Research Laboratory for Cancer Epigenetics, Cancer Research Institute, Seoul National University College of Medicine, Seoul, South Korea
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