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Hsieh Y, Du J, Yang P. Repositioning VU-0365114 as a novel microtubule-destabilizing agent for treating cancer and overcoming drug resistance. Mol Oncol 2024; 18:386-414. [PMID: 37842807 PMCID: PMC10850822 DOI: 10.1002/1878-0261.13536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 09/26/2023] [Accepted: 10/12/2023] [Indexed: 10/17/2023] Open
Abstract
Microtubule-targeting agents represent one of the most successful classes of anticancer agents. However, the development of drug resistance and the appearance of adverse effects hamper their clinical implementation. Novel microtubule-targeting agents without such limitations are urgently needed. By employing a gene expression-based drug repositioning strategy, this study identifies VU-0365114, originally synthesized as a positive allosteric modulator of human muscarinic acetylcholine receptor M5 (M5 mAChR), as a novel type of tubulin inhibitor by destabilizing microtubules. VU-0365114 exhibits a broad-spectrum in vitro anticancer activity, especially in colorectal cancer cells. A tumor xenograft study in nude mice shows that VU-0365114 slowed the in vivo colorectal tumor growth. The anticancer activity of VU-0365114 is not related to its original target, M5 mAChR. In addition, VU-0365114 does not serve as a substrate of multidrug resistance (MDR) proteins, and thus, it can overcome MDR. Furthermore, a kinome analysis shows that VU-0365114 did not exhibit other significant off-target effects. Taken together, our study suggests that VU-0365114 primarily targets microtubules, offering potential for repurposing in cancer treatment, although more studies are needed before further drug development.
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Affiliation(s)
- Yao‐Yu Hsieh
- Division of Hematology and OncologyTaipei Medical University Shuang Ho HospitalNew Taipei CityTaiwan
- Division of Hematology and Oncology, Department of Internal Medicine, School of Medicine, College of MedicineTaipei Medical UniversityTaipeiTaiwan
- Taipei Cancer CenterTaipei Medical UniversityTaipeiTaiwan
- TMU and Affiliated Hospitals Pancreatic Cancer GroupsTaipei Medical UniversityTaipeiTaiwan
| | - Jia‐Ling Du
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and TechnologyTaipei Medical UniversityNew Taipei CityTaiwan
| | - Pei‐Ming Yang
- Taipei Cancer CenterTaipei Medical UniversityTaipeiTaiwan
- TMU and Affiliated Hospitals Pancreatic Cancer GroupsTaipei Medical UniversityTaipeiTaiwan
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and TechnologyTaipei Medical UniversityNew Taipei CityTaiwan
- Ph.D. Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and TechnologyTaipei Medical UniversityNew Taipei CityTaiwan
- TMU Research Center of Cancer Translational MedicineTaipeiTaiwan
- Cancer Center, Wan Fang HospitalTaipei Medical UniversityTaipeiTaiwan
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2
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Wen J, Wang Q, Zhang W, Wang W. TUBA1A licenses APC/C-mediated mitotic progression to drive glioblastoma growth by inhibiting PLK3. FEBS Lett 2023; 597:3072-3086. [PMID: 37873730 DOI: 10.1002/1873-3468.14764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 10/05/2023] [Indexed: 10/25/2023]
Abstract
Glioblastoma (GBM) is the most common, aggressive, and chemorefractory primary brain tumor in adults. Identifying novel drug targets is crucial for GBM treatment. Here, we demonstrate that tubulin alpha 1a (TUBA1A) is significantly upregulated in GBM compared to low-grade gliomas (LGG) and normal tissues. High TUBA1A expression is associated with poor survival in GBM patients. TUBA1A knockdown results in mitotic arrest and reduces tumor growth in mice. TUBA1A interacts with the polo-like kinase 3 (PLK3) in the cytoplasm to inhibit its activation. This interaction licenses activation of the anaphase-promoting complex or cyclosome (APC/C) to ensure proper Foxm1-mediated metaphase-to-anaphase transition and mitotic exit. Overall, our findings demonstrate that targeting TUBA1A attenuates GBM cell growth by suppressing mitotic progression in a PLK3-dependent manner.
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Affiliation(s)
- Jiaqi Wen
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou, China
- Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, China
| | - Qiuke Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou, China
- Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, China
| | - Wenyi Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou, China
- Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, China
| | - Weizhang Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou, China
- Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, China
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Wang Z, Zou J, Zhang L, Liu H, Jiang B, Liang Y, Zhang Y. Comprehensive analysis of the progression mechanisms of CRPC and its inhibitor discovery based on machine learning algorithms. Front Genet 2023; 14:1184704. [PMID: 37476415 PMCID: PMC10354439 DOI: 10.3389/fgene.2023.1184704] [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: 03/12/2023] [Accepted: 06/27/2023] [Indexed: 07/22/2023] Open
Abstract
Background: Almost all patients treated with androgen deprivation therapy (ADT) eventually develop castration-resistant prostate cancer (CRPC). Our research aims to elucidate the potential biomarkers and molecular mechanisms that underlie the transformation of primary prostate cancer into CRPC. Methods: We collected three microarray datasets (GSE32269, GSE74367, and GSE66187) from the Gene Expression Omnibus (GEO) database for CRPC. Differentially expressed genes (DEGs) in CRPC were identified for further analyses, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA). Weighted gene coexpression network analysis (WGCNA) and two machine learning algorithms were employed to identify potential biomarkers for CRPC. The diagnostic efficiency of the selected biomarkers was evaluated based on gene expression level and receiver operating characteristic (ROC) curve analyses. We conducted virtual screening of drugs using AutoDock Vina. In vitro experiments were performed using the Cell Counting Kit-8 (CCK-8) assay to evaluate the inhibitory effects of the drugs on CRPC cell viability. Scratch and transwell invasion assays were employed to assess the effects of the drugs on the migration and invasion abilities of prostate cancer cells. Results: Overall, a total of 719 DEGs, consisting of 513 upregulated and 206 downregulated genes, were identified. The biological functional enrichment analysis indicated that DEGs were mainly enriched in pathways related to the cell cycle and metabolism. CCNA2 and CKS2 were identified as promising biomarkers using a combination of WGCNA, LASSO logistic regression, SVM-RFE, and Venn diagram analyses. These potential biomarkers were further validated and exhibited a strong predictive ability. The results of the virtual screening revealed Aprepitant and Dolutegravir as the optimal targeted drugs for CCNA2 and CKS2, respectively. In vitro experiments demonstrated that both Aprepitant and Dolutegravir exerted significant inhibitory effects on CRPC cells (p < 0.05), with Aprepitant displaying a superior inhibitory effect compared to Dolutegravir. Discussion: The expression of CCNA2 and CKS2 increases with the progression of prostate cancer, which may be one of the driving factors for the progression of prostate cancer and can serve as diagnostic biomarkers and therapeutic targets for CRPC. Additionally, Aprepitant and Dolutegravir show potential as anti-tumor drugs for CRPC.
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Affiliation(s)
- Zhen Wang
- College of Basic Medical Sciences, Dali University, Dali, Yunnan, China
| | - Jing Zou
- The First Affiliated Hospital of Dali University, Dali, Yunnan, China
| | - Le Zhang
- College of Basic Medical Sciences, Dali University, Dali, Yunnan, China
| | - Hongru Liu
- College of Basic Medical Sciences, Dali University, Dali, Yunnan, China
| | - Bei Jiang
- Yunnan Key Laboratory of Screening and Research on Anti-pathogenic Plant Resources from West Yunnan (Cultivation), Dali, Yunnan, China
| | - Yi Liang
- Princess Margaret Cancer Centre, TMDT-MaRS Centre, University Health Network, Toronto, ON, Canada
| | - Yuzhe Zhang
- College of Basic Medical Sciences, Dali University, Dali, Yunnan, China
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4
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HN1 Is Enriched in the S-Phase, Phosphorylated in Mitosis, and Contributes to Cyclin B1 Degradation in Prostate Cancer Cells. BIOLOGY 2023; 12:biology12020189. [PMID: 36829467 PMCID: PMC9952942 DOI: 10.3390/biology12020189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/18/2023] [Accepted: 01/24/2023] [Indexed: 01/28/2023]
Abstract
HN1 has previously been shown as overexpressed in various cancers. In Prostate cancer, it regulates AR signaling and centrosome-related functions. Previously, in two different studies, HN1 expression has been observed as inversely correlated with Cyclin B1. However, HN1 interacting partners and the role of HN1 interactions in cell cycle pathways have not been completely elucidated. Therefore, we used Prostate cancer cell lines again and utilized both transient and stable inducible overexpression systems to delineate the role of HN1 in the cell cycle. HN1 characterization was performed using treatments of kinase inhibitors, western blotting, flow cytometry, immunofluorescence, cellular fractionation, and immunoprecipitation approaches. Our findings suggest that HN1 overexpression before mitosis (post-G2), using both transient and stable expression systems, leads to S-phase accumulation and causes early mitotic exit after post-G2 overexpression. Mechanistically, HN1 interacted with Cyclin B1 and increased its degradation via ubiquitination through stabilized Cdh1, which is a co-factor of the APC/C complex. Stably HN1-expressing cells exhibited a reduced Cdt1 loading onto chromatin, demonstrating an exit from a G1 to S phenotype. We found HN1 and Cdh1 interaction as a new regulator of the Cyclin B1/CDK1 axis in mitotic regulation which can be explored further to dissect the roles of HN1 in the cell cycle.
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Tan T, Wu C, Liu B, Pan BF, Hawke DH, Su Z, Liu S, Zhang W, Wang R, Lin SH, Kuang J. Revisiting the multisite phosphorylation that produces the M-phase supershift of key mitotic regulators. Mol Biol Cell 2022; 33:ar115. [PMID: 35976701 PMCID: PMC9635296 DOI: 10.1091/mbc.e22-04-0118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The term M-phase supershift denotes the phosphorylation-dependent substantial increase in the apparent molecular weight of numerous proteins of varied biological functions during M-phase induction. Although the M-phase supershift of multiple key mitotic regulators has been attributed to the multisite phosphorylation catalyzed by the Cdk1/cyclin B/Cks complex, this view is challenged by multiple lines of paradoxical observations. To solve this problem, we reconstituted the M-phase supershift of Xenopus Cdc25C, Myt1, Wee1A, APC3 and Greatwall in Xenopus egg extracts and characterized the supershift-producing phosphorylations. Our results demonstrate that their M-phase supershifts are each due to simultaneous phosphorylation of a considerable portion of S/T/Y residues in a long intrinsically disordered region that is enriched in both S/T residues and S/TP motifs. Although the major mitotic kinases in Xenopus egg extracts, Cdk1, MAPK, Plx1 and RSK2, are able to phosphorylate the five mitotic regulators, they are neither sufficient nor required to produce the M-phase supershift. Accordingly, inhibition of the four major mitotic kinase activities in Xenopus oocytes did not inhibit the M-phase supershift in okadaic acid-induced oocyte maturation. These findings indicate that the M-phase supershift is produced by a previously unrecognized category of mitotic phosphorylation that likely plays important roles in M-phase induction.
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Affiliation(s)
- Tan Tan
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.,Department of Biochemistry and Molecular Biology, Hengyang Medical School, The University of South China, Hengyang, Hunan 421001, China
| | - Chuanfen Wu
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Boye Liu
- Key Laboratory for Biodiversity and Ecological Engineering of Ministry of Education
| | - Bih-Fang Pan
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - David H Hawke
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Zehao Su
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Shuaishuai Liu
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Wei Zhang
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Ruoning Wang
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sue-Hwa Lin
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jian Kuang
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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6
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Barbiero M, Cirillo L, Veerapathiran S, Coates C, Ruffilli C, Pines J. Cell cycle-dependent binding between Cyclin B1 and Cdk1 revealed by time-resolved fluorescence correlation spectroscopy. Open Biol 2022; 12:220057. [PMID: 35765818 PMCID: PMC9240681 DOI: 10.1098/rsob.220057] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 06/07/2022] [Indexed: 01/04/2023] Open
Abstract
Measuring the dynamics with which the regulatory complexes assemble and disassemble is a crucial barrier to our understanding of how the cell cycle is controlled that until now has been difficult to address. This considerable gap in our understanding is due to the difficulty of reconciling biochemical assays with single cell-based techniques, but recent advances in microscopy and gene editing techniques now enable the measurement of the kinetics of protein-protein interaction in living cells. Here, we apply fluorescence correlation spectroscopy and fluorescence cross-correlation spectroscopy to study the dynamics of the cell cycle machinery, beginning with Cyclin B1 and its binding to its partner kinase Cdk1 that together form the major mitotic kinase. Although Cyclin B1 and Cdk1 are known to bind with high affinity, our results reveal that in living cells there is a pool of Cyclin B1 that is not bound to Cdk1. Furthermore, we provide evidence that the affinity of Cyclin B1 for Cdk1 increases during the cell cycle, indicating that the assembly of the complex is a regulated step. Our work lays the groundwork for studying the kinetics of protein complex assembly and disassembly during the cell cycle in living cells.
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Affiliation(s)
- Martina Barbiero
- Cancer Biology, The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, London SW3 6JB, UK
| | - Luca Cirillo
- Cancer Biology, The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, London SW3 6JB, UK
| | - Sapthaswaran Veerapathiran
- Cancer Biology, The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, London SW3 6JB, UK
| | - Catherine Coates
- Cancer Biology, The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, London SW3 6JB, UK
| | - Camilla Ruffilli
- Cancer Biology, The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, London SW3 6JB, UK
| | - Jonathon Pines
- Cancer Biology, The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, London SW3 6JB, UK
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7
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Bury M, Le Calvé B, Ferbeyre G, Blank V, Lessard F. New Insights into CDK Regulators: Novel Opportunities for Cancer Therapy. Trends Cell Biol 2021; 31:331-344. [PMID: 33676803 DOI: 10.1016/j.tcb.2021.01.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/28/2021] [Accepted: 01/29/2021] [Indexed: 12/13/2022]
Abstract
Cyclins and their catalytic partners, the cyclin-dependent kinases (CDKs), control the transition between different phases of the cell cycle. CDK/cyclin activity is regulated by CDK inhibitors (CKIs), currently comprising the CDK-interacting protein/kinase inhibitory protein (CIP/KIP) family and the inhibitor of kinase (INK) family. Recent studies have identified a third group of CKIs, called ribosomal protein-inhibiting CDKs (RPICs). RPICs were discovered in the context of cellular senescence, a stable cell cycle arrest with tumor-suppressing abilities. RPICs accumulate in the nonribosomal fraction of senescent cells due to a decrease in rRNA biogenesis. Accordingly, RPICs are often downregulated in human cancers together with other ribosomal proteins, the tumor-suppressor functions of which are still under study. In this review, we discuss unique therapies that have been developed to target CDK activity in the context of cancer treatment or senescence-associated pathologies, providing novel tools for precision medicine.
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Affiliation(s)
- Marina Bury
- De Duve Institute, UCLouvain, 1200 Brussels, Belgium
| | | | - Gerardo Ferbeyre
- Department of Biochemistry and Molecular Medicine, University of Montreal, Montreal, QC, H3C 3J7, Canada.
| | - Volker Blank
- Lady Davis Institute for Medical Research, Departments of Medicine and Physiology, McGill University, Montreal, QC, H3T 1E2, Canada.
| | - Frédéric Lessard
- Department of Biochemistry and Molecular Medicine, University of Montreal, Montreal, QC, H3C 3J7, Canada.
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8
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Gao F, Li C, Zhao X, Xie J, Fang G, Li Y. CKS2 modulates cell-cycle progression of tongue squamous cell carcinoma cells partly via modulating the cellular distribution of DUTPase. J Oral Pathol Med 2020; 50:175-182. [PMID: 33107644 DOI: 10.1111/jop.13116] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/18/2020] [Accepted: 10/07/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND CKS2 (CDC28 Protein Kinase Regulatory Subunit 2) is a gene that encodes CKS2 protein that has been characterized as a binding partner of the catalytic subunit of the cyclin-dependent kinases. However, its expression profile and regulatory effects in tongue squamous cell carcinoma has not yet been explored. METHODS Bioinformatic analysis was conducted using bulk-seq data from The Cancer Genome Atlas and single-cell RNA-seq data from GSE103322. SCC9 and CAL27 cells were used as in vitro cell models for cellular and molecular studies. RESULTS CKS2 expression was significantly upregulated in tongue squamous cell carcinoma tissues (N = 128) compared with adjacent normal tissues (N = 13). Its upregulation was associated with significantly shorter disease-specific survival and progression-free survival. Cellular status estimation in tumor cells indicated that CKS2 expression was moderately and positively correlated with cell-cycle progression. CKS2 inhibition in SCC9 and CAL27 cells resulted in decreased proliferation, weakened colony formation capability, and cell-cycle arrest at the G2/M phase. Immunofluorescence staining and co-Immunoprecipitation (co-IP) assay confirmed co-localization and interaction between CKS2 and DUTPase. CKS2 knockdown did not alter DUTPase expression but reduced its nuclear distribution. Both CKS2 and DUT expression were moderately correlated with their gene-level copy number. CONCLUSION CKS2 expression is associated with unfavorable survival of patients with tongue squamous cell carcinoma. Inhibiting its expression could reduce tongue squamous cell carcinoma cell growth and induce G2/M arrest. CKS2 may interact with DUTPase and regulate its nuclear localization. Gene-level copy amplification might be an important mechanism of upregulated CKS2 and DUT in the tumor.
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Affiliation(s)
- Fei Gao
- Operation Room, Jinan Stomatological Hospital, Jinan, China
| | - Chong Li
- Department of Outpatient Nursing, Jinan Stomatological Hospital, Jinan, China
| | - Xiqun Zhao
- Department of Pediatric Dentistry, Jinan Stomatological Hospital, Jinan, China
| | - Jianli Xie
- Department of Prosthodontics, Jinan Stomatological Hospital, Jinan, China
| | - Guiqing Fang
- Clinical laboratory, Jinan Stomatological Hospital, Jinan, China
| | - Ying Li
- Department of Outpatient Nursing, Jinan Stomatological Hospital, Jinan, China
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9
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Yang X, Li Z, Polyakova T, Dejneka A, Zablotskii V, Zhang X. Effect of static magnetic field on DNA synthesis: The interplay between DNA chirality and magnetic field left-right asymmetry. FASEB Bioadv 2020; 2:254-263. [PMID: 32259051 PMCID: PMC7133733 DOI: 10.1096/fba.2019-00045] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 05/26/2019] [Accepted: 02/03/2020] [Indexed: 12/13/2022] Open
Abstract
Interactions between magnetic fields (MFs) and living cells may stimulate a large variety of cellular responses to a MF, while the underlying intracellular mechanisms still remain a great puzzle. On a fundamental level, the MF - cell interaction is affected by the two broken symmetries: (a) left-right (LR) asymmetry of the MF and (b) chirality of DNA molecules carrying electric charges and subjected to the Lorentz force when moving in a MF. Here we report on the chirality-driven effect of static magnetic fields (SMFs) on DNA synthesis. This newly discovered effect reveals how the interplay between two fundamental features of symmetry in living and inanimate nature-DNA chirality and the inherent features of MFs to distinguish the left and right-manifests itself in different DNA synthesis rates in the upward and downward SMFs, consequently resulting in unequal cell proliferation for the two directions of the field. The interplay between DNA chirality and MF LR asymmetry will provide fundamental knowledge for many MF-induced biological phenotypes.
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Affiliation(s)
- Xingxing Yang
- High Magnetic Field LaboratoryKey Laboratory of High Magnetic Field and Ion Beam Physical BiologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiChina
- Science Island Branch of Graduate SchoolUniversity of Science and Technology of ChinaHefeiChina
| | - Zhiyuan Li
- High Magnetic Field LaboratoryKey Laboratory of High Magnetic Field and Ion Beam Physical BiologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiChina
| | - Tatyana Polyakova
- Institute of Physics of the Czech Academy of SciencesPragueCzech Republic
| | - Alexandr Dejneka
- Institute of Physics of the Czech Academy of SciencesPragueCzech Republic
| | - Vitalii Zablotskii
- Institute of Physics of the Czech Academy of SciencesPragueCzech Republic
| | - Xin Zhang
- High Magnetic Field LaboratoryKey Laboratory of High Magnetic Field and Ion Beam Physical BiologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiChina
- Science Island Branch of Graduate SchoolUniversity of Science and Technology of ChinaHefeiChina
- Institutes of Physical Science and Information TechnologyAnhui UniversityHefeiChina
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10
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Paradoxical mitotic exit induced by a small molecule inhibitor of APC/C Cdc20. Nat Chem Biol 2020; 16:546-555. [PMID: 32152539 PMCID: PMC7289404 DOI: 10.1038/s41589-020-0495-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 02/05/2020] [Indexed: 11/09/2022]
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is a ubiquitin ligase that initiates anaphase and mitotic exit. APC/C is activated by Cdc20 and inhibited by the mitotic checkpoint complex (MCC), which delays mitotic exit when the spindle assembly checkpoint (SAC) is activated. We previously identified apcin as a small molecule ligand of Cdc20 that inhibits APC/CCdc20 and prolongs mitosis. Here we find that apcin paradoxically shortens mitosis when SAC activity is high. These opposing effects of apcin arise from targeting of a common binding site in Cdc20 required for both substrate ubiquitination and MCC-dependent APC/C inhibition. Furthermore, we found that apcin cooperates with p31comet to relieve MCC-dependent inhibition of APC/C. Apcin therefore causes either net APC/C inhibition, prolonging mitosis when SAC activity is low, or net APC/C activation, shortening mitosis when SAC activity is high, demonstrating that a small molecule can produce opposing biological effects depending on regulatory context.
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11
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Leal-Esteban LC, Fajas L. Cell cycle regulators in cancer cell metabolism. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165715. [PMID: 32035102 DOI: 10.1016/j.bbadis.2020.165715] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/09/2020] [Accepted: 01/30/2020] [Indexed: 12/31/2022]
Abstract
Cancer proliferation and progression involves altered metabolic pathways as a result of continuous demand for energy and nutrients. In the last years, cell cycle regulators have been involved in the control of metabolic processes, such as glucose and insulin pathways and lipid synthesis, in addition to their canonical function controlling cell cycle progression. Here we describe recent data demonstrating the role of cell cycle regulators in the metabolic control especially in studies performed in cancer models. Moreover, we discuss the importance of these findings in the context of current cancer therapies to provide an overview of the relevance of targeting metabolism using inhibitors of the cell cycle regulation.
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Affiliation(s)
- Lucia C Leal-Esteban
- Metabolism and Cancer Laboratory, Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Lluis Fajas
- Metabolism and Cancer Laboratory, Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland.
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12
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Jonsson M, Fjeldbo CS, Holm R, Stokke T, Kristensen GB, Lyng H. Mitochondrial Function of CKS2 Oncoprotein Links Oxidative Phosphorylation with Cell Division in Chemoradioresistant Cervical Cancer. Neoplasia 2019; 21:353-362. [PMID: 30856376 PMCID: PMC6411633 DOI: 10.1016/j.neo.2019.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/04/2019] [Accepted: 01/08/2019] [Indexed: 12/03/2022]
Abstract
CDK regulatory subunit 2 (CKS2) has a nuclear function that promotes cell division and is a candidate biomarker of chemoradioresistance in cervical cancer. The underlying mechanisms are, however, not completely understood. We investigated whether CKS2 also has a mitochondrial function that augments tumor aggressiveness. Based on global gene expression data of two cervical cancer cohorts of 150 and 135 patients, we identified a set of genes correlated with CKS2 expression. Gene set enrichment analysis showed enrichment of mitochondrial cellular compartments, and the hallmarks oxidative phosphorylation (OXPHOS) and targets of the MYC oncogene in the gene set. By in situ proximity ligation assay, we showed that CKS2 formed complex with the positively correlated MYC target, mitochondrial single-stranded DNA binding protein SSBP1, in the mitochondrion of cervix tumor samples and HeLa and SiHa cervical cancer cell lines, indicating a role in mitochondrial DNA (mtDNA) replication and thereby OXPHOS. CDK1 was found to be part of the complex. Flow cytometry analyses of HeLa cells showed cell cycle regulation of the CKS2-SSBP1 complex consistent with mtDNA replication activity. Moreover, repression of mtDNA replication and OXPHOS by acute hypoxia decreased CKS2-SSBP1 complex abundance and expression of MYC targets. By immunohistochemistry, cytoplasmic CKS2 expression was found to add to the prognostic impact of nuclear CKS2 expression in patients, suggesting that the mitochondrial function promotes tumor aggressiveness. Our study uncovers a novel link between regulation of cell division by nuclear pathways and OXPHOS in the mitochondrion that involves CKS2 and promotes chemoradioresistance of cervical cancer.
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Affiliation(s)
- Marte Jonsson
- Department of Radiation Biology, Oslo University Hospital, Oslo, Norway
| | | | - Ruth Holm
- Department of Pathology, Oslo University Hospital, Oslo, Norway
| | - Trond Stokke
- Department of Radiation Biology, Oslo University Hospital, Oslo, Norway
| | - Gunnar Balle Kristensen
- Department of Gynaecologic Oncology, Oslo University Hospital, Oslo, Norway; Institute for Cancer Genetics and Informatics, Oslo University Hospital, Oslo, Norway
| | - Heidi Lyng
- Department of Radiation Biology, Oslo University Hospital, Oslo, Norway.
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13
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Alfieri C, Zhang S, Barford D. Visualizing the complex functions and mechanisms of the anaphase promoting complex/cyclosome (APC/C). Open Biol 2017; 7:170204. [PMID: 29167309 PMCID: PMC5717348 DOI: 10.1098/rsob.170204] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 10/10/2017] [Indexed: 12/17/2022] Open
Abstract
The anaphase promoting complex or cyclosome (APC/C) is a large multi-subunit E3 ubiquitin ligase that orchestrates cell cycle progression by mediating the degradation of important cell cycle regulators. During the two decades since its discovery, much has been learnt concerning its role in recognizing and ubiquitinating specific proteins in a cell-cycle-dependent manner, the mechanisms governing substrate specificity, the catalytic process of assembling polyubiquitin chains on its target proteins, and its regulation by phosphorylation and the spindle assembly checkpoint. The past few years have witnessed significant progress in understanding the quantitative mechanisms underlying these varied APC/C functions. This review integrates the overall functions and properties of the APC/C with mechanistic insights gained from recent cryo-electron microscopy (cryo-EM) studies of reconstituted human APC/C complexes.
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Affiliation(s)
- Claudio Alfieri
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Suyang Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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Balachandran RS, Heighington CS, Starostina NG, Anderson JW, Owen DL, Vasudevan S, Kipreos ET. The ubiquitin ligase CRL2ZYG11 targets cyclin B1 for degradation in a conserved pathway that facilitates mitotic slippage. J Cell Biol 2016; 215:151-166. [PMID: 27810909 PMCID: PMC5084644 DOI: 10.1083/jcb.201601083] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 09/22/2016] [Indexed: 12/18/2022] Open
Abstract
Cells arrested in mitosis by inactivation of the APC/C complex sometimes manage to exit mitosis in a process called mitotic slippage, which helps cancer cells circumvent chemotherapy drugs. Balachandran et al. show that mitotic slippage occurs as a result of targeting of cyclin B1 for degradation by the ligase CRL2ZYG11. The anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase is known to target the degradation of cyclin B1, which is crucial for mitotic progression in animal cells. In this study, we show that the ubiquitin ligase CRL2ZYG-11 redundantly targets the degradation of cyclin B1 in Caenorhabditis elegans and human cells. In C. elegans, both CRL2ZYG-11 and APC/C are required for proper progression through meiotic divisions. In human cells, inactivation of CRL2ZYG11A/B has minimal effects on mitotic progression when APC/C is active. However, when APC/C is inactivated or cyclin B1 is overexpressed, CRL2ZYG11A/B-mediated degradation of cyclin B1 is required for normal progression through metaphase. Mitotic cells arrested by the spindle assembly checkpoint, which inactivates APC/C, often exit mitosis in a process termed “mitotic slippage,” which generates tetraploid cells and limits the effectiveness of antimitotic chemotherapy drugs. We show that ZYG11A/B subunit knockdown, or broad cullin–RING ubiquitin ligase inactivation with the small molecule MLN4924, inhibits mitotic slippage in human cells, suggesting the potential for antimitotic combination therapy.
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Affiliation(s)
| | | | | | - James W Anderson
- Department of Cellular Biology, University of Georgia, Athens, GA 30602
| | - David L Owen
- Department of Cellular Biology, University of Georgia, Athens, GA 30602
| | | | - Edward T Kipreos
- Department of Cellular Biology, University of Georgia, Athens, GA 30602
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Zhang S, Chang L, Alfieri C, Zhang Z, Yang J, Maslen S, Skehel M, Barford D. Molecular mechanism of APC/C activation by mitotic phosphorylation. Nature 2016; 533:260-264. [PMID: 27120157 PMCID: PMC4878669 DOI: 10.1038/nature17973] [Citation(s) in RCA: 136] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 04/06/2016] [Indexed: 12/11/2022]
Abstract
In eukaryotes, the anaphase-promoting complex (APC/C, also known as the cyclosome) regulates the ubiquitin-dependent proteolysis of specific cell-cycle proteins to coordinate chromosome segregation in mitosis and entry into the G1 phase. The catalytic activity of the APC/C and its ability to specify the destruction of particular proteins at different phases of the cell cycle are controlled by its interaction with two structurally related coactivator subunits, Cdc20 and Cdh1. Coactivators recognize substrate degrons, and enhance the affinity of the APC/C for its cognate E2 (refs 4-6). During mitosis, cyclin-dependent kinase (Cdk) and polo-like kinase (Plk) control Cdc20- and Cdh1-mediated activation of the APC/C. Hyperphosphorylation of APC/C subunits, notably Apc1 and Apc3, is required for Cdc20 to activate the APC/C, whereas phosphorylation of Cdh1 prevents its association with the APC/C. Since both coactivators associate with the APC/C through their common C-box and Ile-Arg tail motifs, the mechanism underlying this differential regulation is unclear, as is the role of specific APC/C phosphorylation sites. Here, using cryo-electron microscopy and biochemical analysis, we define the molecular basis of how phosphorylation of human APC/C allows for its control by Cdc20. An auto-inhibitory segment of Apc1 acts as a molecular switch that in apo unphosphorylated APC/C interacts with the C-box binding site and obstructs engagement of Cdc20. Phosphorylation of the auto-inhibitory segment displaces it from the C-box-binding site. Efficient phosphorylation of the auto-inhibitory segment, and thus relief of auto-inhibition, requires the recruitment of Cdk-cyclin in complex with a Cdk regulatory subunit (Cks) to a hyperphosphorylated loop of Apc3. We also find that the small-molecule inhibitor, tosyl-l-arginine methyl ester, preferentially suppresses APC/C(Cdc20) rather than APC/C(Cdh1), and interacts with the binding sites of both the C-box and Ile-Arg tail motifs. Our results reveal the mechanism for the regulation of mitotic APC/C by phosphorylation and provide a rationale for the development of selective inhibitors of this state.
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Affiliation(s)
- Suyang Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Leifu Chang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Claudio Alfieri
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Ziguo Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Jing Yang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Sarah Maslen
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Mark Skehel
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
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16
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Kamenz J, Mihaljev T, Kubis A, Legewie S, Hauf S. Robust Ordering of Anaphase Events by Adaptive Thresholds and Competing Degradation Pathways. Mol Cell 2015; 60:446-59. [PMID: 26527280 DOI: 10.1016/j.molcel.2015.09.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 08/08/2015] [Accepted: 09/24/2015] [Indexed: 11/26/2022]
Abstract
The splitting of chromosomes in anaphase and their delivery into the daughter cells needs to be accurately executed to maintain genome stability. Chromosome splitting requires the degradation of securin, whereas the distribution of the chromosomes into the daughter cells requires the degradation of cyclin B. We show that cells encounter and tolerate variations in the abundance of securin or cyclin B. This makes the concurrent onset of securin and cyclin B degradation insufficient to guarantee that early anaphase events occur in the correct order. We uncover that the timing of chromosome splitting is not determined by reaching a fixed securin level, but that this level adapts to the securin degradation kinetics. In conjunction with securin and cyclin B competing for degradation during anaphase, this provides robustness to the temporal order of anaphase events. Our work reveals how parallel cell-cycle pathways can be temporally coordinated despite variability in protein concentrations.
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Affiliation(s)
- Julia Kamenz
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA; Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, USA; Friedrich Miescher Laboratory of the Max Planck Society, 72076 Tuebingen, Germany
| | | | - Armin Kubis
- Friedrich Miescher Laboratory of the Max Planck Society, 72076 Tuebingen, Germany
| | - Stefan Legewie
- Institute of Molecular Biology (IMB), 55128 Mainz, Germany.
| | - Silke Hauf
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA; Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, USA; Friedrich Miescher Laboratory of the Max Planck Society, 72076 Tuebingen, Germany.
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17
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Cronin NB, Yang J, Zhang Z, Kulkarni K, Chang L, Yamano H, Barford D. Atomic-Resolution Structures of the APC/C Subunits Apc4 and the Apc5 N-Terminal Domain. J Mol Biol 2015; 427:3300-3315. [PMID: 26343760 PMCID: PMC4590430 DOI: 10.1016/j.jmb.2015.08.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 08/19/2015] [Accepted: 08/26/2015] [Indexed: 10/25/2022]
Abstract
Many essential biological processes are mediated by complex molecular machines comprising multiple subunits. Knowledge on the architecture of individual subunits and their positions within the overall multimeric complex is key to understanding the molecular mechanisms of macromolecular assemblies. The anaphase-promoting complex/cyclosome (APC/C) is a large multisubunit complex that regulates cell cycle progression by ubiquitinating cell cycle proteins for proteolysis by the proteasome. The holo-complex is composed of 15 different proteins that assemble to generate a complex of 20 subunits. Here, we describe the crystal structures of Apc4 and the N-terminal domain of Apc5 (Apc5(N)). Apc4 comprises a WD40 domain split by a long α-helical domain, whereas Apc5(N) has an α-helical fold. In a separate study, we had fitted these atomic models to a 3.6-Å-resolution cryo-electron microscopy map of the APC/C. We describe how, in the context of the APC/C, regions of Apc4 disordered in the crystal assume order through contacts to Apc5, whereas Apc5(N) shows small conformational changes relative to its crystal structure. We discuss the complementary approaches of high-resolution electron microscopy and protein crystallography to the structure determination of subunits of multimeric complexes.
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Affiliation(s)
- Nora B Cronin
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom
| | - Jing Yang
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Ziguo Zhang
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Kiran Kulkarni
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; Division of Biochemical Sciences, Council of Scientific and Industrial Research National Chemical Laboratory, Pune 411008, India
| | - Leifu Chang
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Hiroyuki Yamano
- Cancer Institute, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6BT, United Kingdom
| | - David Barford
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom.
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18
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Clijsters L, van Zon W, Riet BT, Voets E, Boekhout M, Ogink J, Rumpf-Kienzl C, Wolthuis RMF. Inefficient degradation of cyclin B1 re-activates the spindle checkpoint right after sister chromatid disjunction. Cell Cycle 2015; 13:2370-8. [PMID: 25483188 DOI: 10.4161/cc.29336] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Sister chromatid separation creates a sudden loss of tension on kinetochores, which could, in principle, re-activate the spindle checkpoint in anaphase. This so-called "anaphase problem" is probably avoided by timely inactivation of cyclin B1-Cdk1, which may prevent the spindle tension sensing Aurora B kinase from destabilizing kinetochore-microtubule interactions as they lose tension in anaphase. However, exactly how spindle checkpoint re-activation is prevented remains unclear. Here, we investigated how different degrees of cyclin B1 stabilization affected the spindle checkpoint in metaphase and anaphase. Cells expressing a strongly stabilized (R42A) mutant of cyclin B1 degraded APC/C(Cdc20) substrates normally, showing that checkpoint release was not inhibited by high cyclin B1-Cdk1 activity. However, after this initial wave of APC/C(Cdc20) activity, the spindle checkpoint returned in cells with uncohesed sister chromatids. Expression of a lysine mutant of cyclin B1 that is degraded only slightly inefficiently allowed a normal metaphase-to-anaphase transition. Strikingly, however, the spindle checkpoint returned in cells that had not degraded the cyclin B1 mutant 10-15 min after anaphase onset. When cyclin B1 remained in late anaphase, cytokinesis stalled, and translocation of INCENP from separated sister chromatids to the spindle midzone was blocked. This late anaphase arrest required the activity of Aurora B and Mps1. In conclusion, our results reveal that complete removal of cyclin B1 is essential to prevent the return of the spindle checkpoint following sister chromatid disjunction. Speculatively, increasing activity of APC/C(Cdc20) in late anaphase helps to keep cyclin B1 levels low.
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Affiliation(s)
- Linda Clijsters
- a Division of Cell Biology I (B5) and Division of Molecular Carcinogenesis (B7); The Netherlands Cancer Institute (NKI-AvL); Amsterdam, The Netherlands
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19
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Shang ZF, Tan W, Liu XD, Yu L, Li B, Li M, Song M, Wang Y, Xiao BB, Zhong CG, Guan H, Zhou PK. DNA-PKcs Negatively Regulates Cyclin B1 Protein Stability through Facilitating Its Ubiquitination Mediated by Cdh1-APC/C Pathway. Int J Biol Sci 2015. [PMID: 26221070 PMCID: PMC4515814 DOI: 10.7150/ijbs.12443] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is a critical component of the non-homologous end-joining pathway of DNA double-stranded break repair. DNA-PKcs has also been shown recently functioning in mitotic regulation. Here, we report that DNA-PKcs negatively regulates the stability of Cyclin B1 protein through facilitating its ubiquitination mediated by Cdh1 / E 3 ubiquitin ligase APC/C pathway. Loss of DNA-PKcs causes abnormal accumulation of Cyclin B1 protein. Cyclin B1 degradation is delayed in DNA-PKcs-deficient cells as result of attenuated ubiquitination. The impact of DNA-PKcs on Cyclin B1 stability relies on its kinase activity. Our study further reveals that DNA-PKcs interacts with APC/C core component APC2 and its co-activator Cdh1. The destruction of Cdh1 is accelerated in the absence of DNA-PKcs. Moreover, overexpression of exogenous Cdh1 can reverse the increase of Cyclin B1 protein in DNA-PKcs-deficient cells. Thus, DNA-PKcs, in addition to its direct role in DNA damage repair, functions in mitotic progression at least partially through regulating the stability of Cyclin B1 protein.
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Affiliation(s)
- Zeng-Fu Shang
- 1. School of Radiation Medicine and Protection, Medical College of Soochow University; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, P. R. China ; 2. Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology (BKLRB), Beijing Institute of Radiation Medicine, Beijing 100850, P. R. China
| | - Wei Tan
- 2. Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology (BKLRB), Beijing Institute of Radiation Medicine, Beijing 100850, P. R. China ; 3. School of Public Heath, Central South University, Changsha, Hunan Province, Changsha, Hunan 410078, P. R. China
| | - Xiao-Dan Liu
- 2. Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology (BKLRB), Beijing Institute of Radiation Medicine, Beijing 100850, P. R. China
| | - Lan Yu
- 4. Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA
| | - Bing Li
- 2. Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology (BKLRB), Beijing Institute of Radiation Medicine, Beijing 100850, P. R. China
| | - Ming Li
- 1. School of Radiation Medicine and Protection, Medical College of Soochow University; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, P. R. China
| | - Man Song
- 1. School of Radiation Medicine and Protection, Medical College of Soochow University; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, P. R. China ; 2. Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology (BKLRB), Beijing Institute of Radiation Medicine, Beijing 100850, P. R. China
| | - Yu Wang
- 2. Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology (BKLRB), Beijing Institute of Radiation Medicine, Beijing 100850, P. R. China
| | - Bei-Bei Xiao
- 1. School of Radiation Medicine and Protection, Medical College of Soochow University; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, P. R. China
| | - Cai-Gao Zhong
- 3. School of Public Heath, Central South University, Changsha, Hunan Province, Changsha, Hunan 410078, P. R. China
| | - Hua Guan
- 2. Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology (BKLRB), Beijing Institute of Radiation Medicine, Beijing 100850, P. R. China
| | - Ping-Kun Zhou
- 1. School of Radiation Medicine and Protection, Medical College of Soochow University; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, P. R. China ; 2. Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology (BKLRB), Beijing Institute of Radiation Medicine, Beijing 100850, P. R. China
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20
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Voets E, Wolthuis R. MASTL promotes cyclin B1 destruction by enforcing Cdc20-independent binding of cyclin B1 to the APC/C. Biol Open 2015; 4:484-95. [PMID: 25750436 PMCID: PMC4400591 DOI: 10.1242/bio.201410793] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
When cells enter mitosis, the anaphase-promoting complex/cyclosome (APC/C) is activated by phosphorylation and binding of Cdc20. The RXXL destruction box (D-box) of cyclin B1 only binds Cdc20 after release of the spindle checkpoint in metaphase, initiating cyclin B1 ubiquitination upon chromosome bi-orientation. However, we found that cyclin B1, through Cdk1 and Cks, is targeted to the phosphorylated APC/CCdc20 at the start of prometaphase, when the spindle checkpoint is still active. Here, we show that MASTL is essential for cyclin B1 recruitment to the mitotic APC/C and that this occurs entirely independently of Cdc20. Importantly, MASTL-directed binding of cyclin B1 to spindle checkpoint-inhibited APC/CCdc20 critically supports efficient cyclin B1 destruction after checkpoint release. A high incidence of anaphase bridges observed in response to MASTL RNAi may result from cyclin B1 remaining after securin destruction, which is insufficient to keep MASTL-depleted cells in mitosis but delays the activation of separase.
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Affiliation(s)
- Erik Voets
- Division of Cell Biology I (B5) and Division of Molecular Carcinogenesis (B7), The Netherlands Cancer Institute (NKI-AvL), Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Rob Wolthuis
- Division of Cell Biology I (B5) and Division of Molecular Carcinogenesis (B7), The Netherlands Cancer Institute (NKI-AvL), Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands Section of Oncogenetics, Department of Clinical Genetics and CCA/V-ICI Research Program Oncogenesis, VUmc Medical Faculty, van de Boechorststraat 7, 1081 BT Amsterdam, The Netherlands
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21
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Yuan K, O'Farrell PH. Cyclin B3 is a mitotic cyclin that promotes the metaphase-anaphase transition. Curr Biol 2015; 25:811-816. [PMID: 25754637 DOI: 10.1016/j.cub.2015.01.053] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 01/07/2015] [Accepted: 01/22/2015] [Indexed: 10/23/2022]
Abstract
The timing mechanism for mitotic progression is still poorly understood. The spindle assembly checkpoint (SAC), whose reversal upon chromosome alignment is thought to time anaphase [1-3], is functional during the rapid mitotic cycles of the Drosophila embryo; but its genetic inactivation had no consequence on the timing of the early mitoses. Mitotic cyclins-Cyclin A, Cyclin B, and Cyclin B3-influence mitotic progression and are degraded in a stereotyped sequence [4-11]. RNAi knockdown of Cyclins A and B resulted in a Cyclin B3-only mitosis in which anaphase initiated prior to chromosome alignment. Furthermore, in such a Cyclin B3-only mitosis, colchicine-induced SAC activation failed to block Cyclin B3 destruction, chromosome decondensation, or nuclear membrane re-assembly. Injection of Cyclin B proteins restored the ability of SAC to prevent Cyclin B3 destruction. Thus, SAC function depends on particular cyclin types. Changing Cyclin B3 levels showed that it accelerated progress to anaphase, even in the absence of SAC function. The impact of Cyclin B3 on anaphase initiation appeared to decline with developmental progress. Our results show that different cyclin types affect anaphase timing differently in the early embryonic divisions. The early-destroyed cyclins-Cyclins A and B-restrain anaphase-promoting complex/cyclosome (APC/C) function, whereas the late-destroyed cyclin, Cyclin B3, stimulates function. We propose that the destruction schedule of cyclin types guides mitotic exit by affecting both Cdk1 and APC/C, whose activities change as each cyclin type is lost.
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Affiliation(s)
- Kai Yuan
- Department of Biochemistry, University of California, San Francisco, San Francisco, CA 94158-2517, USA
| | - Patrick H O'Farrell
- Department of Biochemistry, University of California, San Francisco, San Francisco, CA 94158-2517, USA.
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22
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Boekhout M, Wolthuis R. Nek2A destruction marks APC/C activation at the prophase-to-prometaphase transition by spindle-checkpoint restricted Cdc20. J Cell Sci 2015; 128:1639-53. [DOI: 10.1242/jcs.163279] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 02/06/2015] [Indexed: 12/31/2022] Open
Abstract
Nek2A is a presumed APC/CCdc20 substrate, which, like cyclin A, is degraded in mitosis while the spindle checkpoint is active. Cyclin A prevents spindle checkpoint proteins from binding to Cdc20 and is recruited to the APC/C in prometaphase. We found that Nek2A and cyclin A avoid stabilization by the spindle checkpoint in different ways. First, enhancing mitotic checkpoint complex (MCC) formation by nocodazole treatment inhibited the degradation of geminin and cyclin A while Nek2A disappeared at normal rate. Secondly, depleting Cdc20 effectively stabilized cyclin A but not Nek2A. Nevertheless, Nek2A destruction critically depended on Cdc20 binding to the APC/C. Thirdly, in contrast to cyclin A, Nek2A was recruited to the APC/C before the start of mitosis. Interestingly, the spindle checkpoint very effectively stabilized an APC/C-binding mutant of Nek2A, which required the Nek2A KEN box. Apparently, in cells, the spindle checkpoint primarily prevents Cdc20 from binding destruction motifs. Nek2A disappearance marks the prophase-to-prometaphase transition, when Cdc20, regardless of the spindle checkpoint, activates the APC/C. However, Mad2 depletion accelerated Nek2A destruction, showing that spindle checkpoint release further increases APC/CCdc20 catalytic activity.
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Lu D, Hsiao JY, Davey NE, Van Voorhis VA, Foster SA, Tang C, Morgan DO. Multiple mechanisms determine the order of APC/C substrate degradation in mitosis. ACTA ACUST UNITED AC 2014; 207:23-39. [PMID: 25287299 PMCID: PMC4195823 DOI: 10.1083/jcb.201402041] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
To ensure proper mitotic progression, robust ordering of the destruction of APC/CCdc20 substrates is driven by the integration of molecular mechanisms ranging from phosphorylation-dependent interaction with substrates to sensing of the status of the spindle assembly checkpoint. The ubiquitin protein ligase anaphase-promoting complex or cyclosome (APC/C) controls mitosis by promoting ordered degradation of securin, cyclins, and other proteins. The mechanisms underlying the timing of APC/C substrate degradation are poorly understood. We explored these mechanisms using quantitative fluorescence microscopy of GFP-tagged APC/CCdc20 substrates in living budding yeast cells. Degradation of the S cyclin, Clb5, begins early in mitosis, followed 6 min later by the degradation of securin and Dbf4. Anaphase begins when less than half of securin is degraded. The spindle assembly checkpoint delays the onset of Clb5 degradation but does not influence securin degradation. Early Clb5 degradation depends on its interaction with the Cdk1–Cks1 complex and the presence of a Cdc20-binding “ABBA motif” in its N-terminal region. The degradation of securin and Dbf4 is delayed by Cdk1-dependent phosphorylation near their Cdc20-binding sites. Thus, a remarkably diverse array of mechanisms generates robust ordering of APC/CCdc20 substrate destruction.
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Affiliation(s)
- Dan Lu
- Department of Physiology and Department of Biochemistry and Biophysics and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
| | - Jennifer Y Hsiao
- Department of Physiology and Department of Biochemistry and Biophysics and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
| | - Norman E Davey
- Department of Physiology and Department of Biochemistry and Biophysics and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
| | - Vanessa A Van Voorhis
- Department of Physiology and Department of Biochemistry and Biophysics and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
| | - Scott A Foster
- Department of Physiology and Department of Biochemistry and Biophysics and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
| | - Chao Tang
- Center for Quantitative Biology and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - David O Morgan
- Department of Physiology and Department of Biochemistry and Biophysics and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
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24
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Matsusaka T, Enquist-Newman M, Morgan DO, Pines J. Co-activator independent differences in how the metaphase and anaphase APC/C recognise the same substrate. Biol Open 2014; 3:904-12. [PMID: 25217616 PMCID: PMC4197439 DOI: 10.1242/bio.20149415] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 08/13/2014] [Indexed: 12/20/2022] Open
Abstract
The Anaphase Promoting Complex or Cyclosome (APC/C) is critical to the control of mitosis. The APC/C is an ubiquitin ligase that targets specific mitotic regulators for proteolysis at distinct times in mitosis, but how this is achieved is not well understood. We have addressed this question by determining whether the same substrate, cyclin B1, is recognised in the same way by the APC/C at different times in mitosis. Unexpectedly, we find that distinct but overlapping motifs in cyclin B1 are recognised by the APC/C in metaphase compared with anaphase, and this does not depend on the exchange of Cdc20 for Cdh1. Thus, changes in APC/C substrate specificity in mitosis can potentially be conferred by altering interaction sites in addition to exchanging Cdc20 for Cdh1.
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Affiliation(s)
- Takahiro Matsusaka
- The Gurdon Institute, Tennis Court Road, Cambridge CB2 1QN, UK Department of Zoology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Maria Enquist-Newman
- Department of Physiology, University of California in San Francisco (UCSF), 600 16th Street, San Francisco, CA 94158, USA
| | - David O Morgan
- Department of Physiology, University of California in San Francisco (UCSF), 600 16th Street, San Francisco, CA 94158, USA
| | - Jonathon Pines
- The Gurdon Institute, Tennis Court Road, Cambridge CB2 1QN, UK Department of Zoology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
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Synergistic blockade of mitotic exit by two chemical inhibitors of the APC/C. Nature 2014; 514:646-9. [PMID: 25156254 DOI: 10.1038/nature13660] [Citation(s) in RCA: 190] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 07/04/2014] [Indexed: 02/07/2023]
Abstract
Protein machines are multi-subunit protein complexes that orchestrate highly regulated biochemical tasks. An example is the anaphase-promoting complex/cyclosome (APC/C), a 13-subunit ubiquitin ligase that initiates the metaphase-anaphase transition and mitotic exit by targeting proteins such as securin and cyclin B1 for ubiquitin-dependent destruction by the proteasome. Because blocking mitotic exit is an effective approach for inducing tumour cell death, the APC/C represents a potential novel target for cancer therapy. APC/C activation in mitosis requires binding of Cdc20 (ref. 5), which forms a co-receptor with the APC/C to recognize substrates containing a destruction box (D-box). Here we demonstrate that we can synergistically inhibit APC/C-dependent proteolysis and mitotic exit by simultaneously disrupting two protein-protein interactions within the APC/C-Cdc20-substrate ternary complex. We identify a small molecule, called apcin (APC inhibitor), which binds to Cdc20 and competitively inhibits the ubiquitylation of D-box-containing substrates. Analysis of the crystal structure of the apcin-Cdc20 complex suggests that apcin occupies the D-box-binding pocket on the side face of the WD40-domain. The ability of apcin to block mitotic exit is synergistically amplified by co-addition of tosyl-l-arginine methyl ester, a small molecule that blocks the APC/C-Cdc20 interaction. This work suggests that simultaneous disruption of multiple, weak protein-protein interactions is an effective approach for inactivating a protein machine.
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Clijsters L, Wolthuis R. PIP-box-mediated degradation prohibits re-accumulation of Cdc6 during S phase. J Cell Sci 2014; 127:1336-45. [PMID: 24434580 DOI: 10.1242/jcs.145862] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Cdc6 and Cdt1 initiate DNA replication licensing when cells exit mitosis. In cycling cells, Cdc6 is efficiently degraded from anaphase onwards as a result of APC/C-Cdh1 activity. When APC/C-Cdh1 is switched off again, at the end of G1 phase, Cdc6 could thus re-accumulate, risking the re-licensing of DNA as long as Cdt1 is present. Here, we carefully investigated the dynamics of Cdt1 and Cdc6 in cycling cells. We reveal a novel APC/C-Cdh1-independent degradation pathway that prevents nuclear Cdc6 re-accumulation at the G1-S transition and during S phase. Similar to Cdt1, nuclear clearance of Cdc6 depends on an N-terminal PIP-box and the Cdt2-containing CRL4 complex. When cells reach G2 phase, Cdc6 rapidly re-accumulates but, at this time, Cdt1 is mostly absent and expression of Cdc6 is limited to the cytoplasm. We propose that Cdk1 contributes to the nuclear export of Cdc6 at the S-to-G2 transition. In summary, our results show that different control mechanisms of Cdc6 restrain erroneous licensing of DNA replication during G1, S and G2 phase.
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Affiliation(s)
- Linda Clijsters
- Division of Cell Biology (B5) and Division of Molecular Carcinogenesis (B7), The Netherlands Cancer Institute (NKI-AVL), Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
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Yang CH, Kuo WT, Chuang YT, Chen CY, Lin CC. Cyclin B1 destruction box-mediated protein instability: the enhanced sensitivity of fluorescent-protein-based reporter gene system. BIOMED RESEARCH INTERNATIONAL 2013; 2013:732307. [PMID: 24416725 PMCID: PMC3876668 DOI: 10.1155/2013/732307] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 11/19/2013] [Indexed: 12/26/2022]
Abstract
The periodic expression and destruction of several cyclins are the most important steps for the exact regulation of cell cycle. Cyclins are degraded by the ubiquitin-proteasome system during cell cycle. Besides, a short sequence near the N-terminal of cyclin B called the destruction box (D-box; CDB) is also required. Fluorescent-protein-based reporter gene system is insensitive to analysis because of the overly stable fluorescent proteins. Therefore, in this study, we use human CDB fused with both enhanced green fluorescent protein (EGFP) at C-terminus and red fluorescent protein (RFP, DsRed) at N-terminus in the transfected human melanoma cells to examine the effects of CDB on different fluorescent proteins. Our results indicated that CDB-fused fluorescent protein can be used to examine the slight gene regulations in the reporter gene system and have the potential to be the system for screening of functional compounds in the future.
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Affiliation(s)
- Chao-Hsun Yang
- Department of Cosmetic Science, Providence University, No. 200, Section 7, Taiwan Boulevard, Shalu District, Taichung 43301, Taiwan
| | - Wan-Ting Kuo
- Department of Cosmetic Science, Providence University, No. 200, Section 7, Taiwan Boulevard, Shalu District, Taichung 43301, Taiwan
| | - Yun-Ting Chuang
- Department of Cosmetic Science, Providence University, No. 200, Section 7, Taiwan Boulevard, Shalu District, Taichung 43301, Taiwan
| | - Cheng-Yu Chen
- Department of Cosmetic Science, Providence University, No. 200, Section 7, Taiwan Boulevard, Shalu District, Taichung 43301, Taiwan
- Graduate Institute of Biotechnology, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan
| | - Chih-Chien Lin
- Department of Cosmetic Science, Providence University, No. 200, Section 7, Taiwan Boulevard, Shalu District, Taichung 43301, Taiwan
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Kikuchi R, Ohata H, Ohoka N, Kawabata A, Naito M. APOLLON protein promotes early mitotic CYCLIN A degradation independent of the spindle assembly checkpoint. J Biol Chem 2013; 289:3457-67. [PMID: 24302728 DOI: 10.1074/jbc.m113.514430] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the mammalian cell cycle, both CYCLIN A and CYCLIN B are required for entry into mitosis, and their elimination is also essential to complete the process. During mitosis, CYCLIN A and CYCLIN B are ubiquitylated by the anaphase-promoting complex/cyclosome (APC/C) and then subjected to proteasomal degradation. However, CYCLIN A, but not CYCLIN B, begins to be degraded in the prometaphase when APC/C is inactivated by the spindle assembly checkpoint (SAC). Here, we show that APOLLON (also known as BRUCE or BIRC6) plays a role in SAC-independent degradation of CYCLIN A in early mitosis. APPOLON interacts with CYCLIN A that is not associated with cyclin-dependent kinases. APPOLON also interacts with APC/C, and it facilitates CYCLIN A ubiquitylation. In APPOLON-deficient cells, mitotic degradation of CYCLIN A is delayed, and the total, but not the cyclin-dependent kinase-bound, CYCLIN A level was increased. We propose APPOLON to be a novel regulator of mitotic CYCLIN A degradation independent of SAC.
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Affiliation(s)
- Ryo Kikuchi
- From the Institute of Molecular and Cellular Biosciences
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Lee YC, Que J, Chen YC, Lin JT, Liou YC, Liao PC, Liu YP, Lee KH, Lin LC, Hsiao M, Hung LY, Huang CY, Lu PJ. Pin1 acts as a negative regulator of the G2/M transition by interacting with the Aurora-A-Bora complex. J Cell Sci 2013; 126:4862-72. [PMID: 23970419 DOI: 10.1242/jcs.121368] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Pin1 was the first prolyl isomerase identified that is involved in cell division. The mechanism by which Pin1 acts as a negative regulator of mitotic activity in G2 phase remains unclear. Here, we found that Aurora A can interact with and phosphorylate Pin1 at Ser16, which suppresses the G2/M function of Pin1 by disrupting its binding ability and mitotic entry. Our results also show that phosphorylation of Bora at Ser274 and Ser278 is crucial for binding of Pin1. Through the interaction, Pin1 can alter the cytoplasmic translocation of Bora and promote premature degradation by β-TrCP, which results in a delay in mitotic entry. Together with the results that Pin1 protein levels do not significantly fluctuate during cell-cycle progression and Aurora A suppresses Pin1 G2/M function, our data demonstrate that a gain of Pin1 function can override the Aurora-A-mediated functional suppression of Pin1. Collectively, these results highlight the physiological significance of Aurora-A-mediated Pin1 Ser16 phosphorylation for mitotic entry and the suppression of Pin1 is functionally linked to the regulation of mitotic entry through the Aurora-A-Bora complex.
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Affiliation(s)
- Yu-Cheng Lee
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 704, Taiwan
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Clijsters L, Ogink J, Wolthuis R. The spindle checkpoint, APC/C(Cdc20), and APC/C(Cdh1) play distinct roles in connecting mitosis to S phase. ACTA ACUST UNITED AC 2013; 201:1013-26. [PMID: 23775192 PMCID: PMC3691463 DOI: 10.1083/jcb.201211019] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The spindle checkpoint, APC/C-Cdc20, and APC/C-Cdh1 act successively to connect disappearance of geminin and cyclin B1 to a peak of Cdt1 and Cdc6. DNA replication depends on a preceding licensing event by Cdt1 and Cdc6. In animal cells, relicensing after S phase but before mitosis is prevented by the Cdt1 inhibitor geminin and mitotic cyclin activity. Here, we show that geminin, like cyclin B1 and securin, is a bona fide target of the spindle checkpoint and APC/CCdc20. Cyclin B1 and geminin are degraded simultaneously during metaphase, which directs Cdt1 accumulation on segregating sister chromatids. Subsequent activation of APC/CCdh1 leads to degradation of Cdc6 well before Cdt1 becomes unstable in a replication-coupled manner. In mitosis, the spindle checkpoint supports Cdt1 accumulation, which promotes S phase onset. We conclude that the spindle checkpoint, APC/CCdc20, and APC/CCdh1 act successively to ensure that the disappearance of licensing inhibitors coincides exactly with a peak of Cdt1 and Cdc6. Whereas cell cycle entry from quiescence requires Cdc6 resynthesis, our results indicate that proliferating cells use a window of time in mitosis, before Cdc6 is degraded, as an earlier opportunity to direct S phase.
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Affiliation(s)
- Linda Clijsters
- Division of Cell Biology I (B5), The Netherlands Cancer Institute (NKI-AvL), 1066 CX Amsterdam, Netherlands.
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Abstract
The anaphase-promoting complex or cyclosome (APC/C) is a conserved, multisubunit E3 ubiquitin (Ub) ligase that is active both in dividing and in postmitotic cells. Its contributions to life are especially well studied in the domain of cell division, in which the APC/C lies at the epicenter of a regulatory network that controls the directionality and timing of cell cycle events. Biochemical and structural work is shedding light on the overall organization of APC/C subunits and on the mechanism of substrate recognition and Ub chain initiation and extension as well as on the molecular mechanisms of a checkpoint that seizes control of APC/C activity during mitosis. Here, we review how these recent advancements are modifying our understanding of the APC/C.
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Affiliation(s)
- Ivana Primorac
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
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Omolo B, Carson C, Chu H, Zhou Y, Simpson DA, Hesse JE, Paules RS, Nyhan KC, Ibrahim JG, Kaufmann WK. A prognostic signature of G(2) checkpoint function in melanoma cell lines. Cell Cycle 2013; 12:1071-82. [PMID: 23454897 PMCID: PMC3646863 DOI: 10.4161/cc.24067] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 02/21/2013] [Indexed: 12/31/2022] Open
Abstract
As DNA damage checkpoints are barriers to carcinogenesis, G(2) checkpoint function was quantified to test for override of this checkpoint during melanomagenesis. Primary melanocytes displayed an effective G(2) checkpoint response to ionizing radiation (IR)-induced DNA damage. Thirty-seven percent of melanoma cell lines displayed a significant defect in G(2) checkpoint function. Checkpoint function was melanoma subtype-specific with "epithelial-like" melanoma lines, with wild type NRAS and BRAF displaying an effective checkpoint, while lines with mutant NRAS and BRAF displayed defective checkpoint function. Expression of oncogenic B-Raf in a checkpoint-effective melanoma attenuated G(2) checkpoint function significantly but modestly. Other alterations must be needed to produce the severe attenuation of G(2) checkpoint function seen in some BRAF-mutant melanoma lines. Quantitative trait analysis tools identified mRNA species whose expression was correlated with G(2) checkpoint function in the melanoma lines. A 165 gene signature was identified with a high correlation with checkpoint function (p < 0.004) and low false discovery rate (≤ 0.077). The G(2) checkpoint gene signature predicted G(2) checkpoint function with 77-94% accuracy. The signature was enriched in lysosomal genes and contained numerous genes that are associated with regulation of chromatin structure and cell cycle progression. The core machinery of the cell cycle was not altered in checkpoint-defective lines but rather numerous mediators of core machinery function were. When applied to an independent series of primary melanomas, the predictive G(2) checkpoint signature was prognostic of distant metastasis-free survival. These results emphasize the value of expression profiling of primary melanomas for understanding melanoma biology and disease prognosis.
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Affiliation(s)
- Bernard Omolo
- Division of Mathematics and Computer Science; University of South Carolina Upstate; Spartanburg, SC USA
| | - Craig Carson
- Department of Dermatology; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Haitao Chu
- Division of Biostatistics; University of Minnesota, Minneapolis, MN USA
| | - Yingchun Zhou
- Pathology and Laboratory Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Dennis A. Simpson
- Pathology and Laboratory Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Jill E. Hesse
- Environmental Stress and Cancer Group; National Institute of Environmental Health Sciences; Research Triangle Park, NC USA
| | - Richard S. Paules
- Environmental Stress and Cancer Group; National Institute of Environmental Health Sciences; Research Triangle Park, NC USA
| | - Kristine C. Nyhan
- Department of Radiation Oncology; University of California-San Francisco; San Francisco, CA USA
| | - Joseph G. Ibrahim
- Departments of Biostatistics; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
- Center for Environmental Health and Susceptibility; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
- Lineberger Comprehensive Cancer Center; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - William K. Kaufmann
- Pathology and Laboratory Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
- Center for Environmental Health and Susceptibility; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
- Lineberger Comprehensive Cancer Center; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
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The CDK subunit CKS2 counteracts CKS1 to control cyclin A/CDK2 activity in maintaining replicative fidelity and neurodevelopment. Dev Cell 2012; 23:356-70. [PMID: 22898779 PMCID: PMC3898080 DOI: 10.1016/j.devcel.2012.06.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 05/16/2012] [Accepted: 06/28/2012] [Indexed: 01/09/2023]
Abstract
CKS proteins are evolutionarily conserved cyclin-dependent kinase (CDK) subunits whose functions are incompletely understood. Mammals have two CKS proteins. CKS1 acts as a cofactor to the ubiquitin ligase complex SCFSKP2 to promote degradation of CDK inhibitors, such as p27. Little is known about the role of the closely related CKS2. Using a Cks2−/− knockout mouse model, we show that CKS2 counteracts CKS1 and stabilizes p27. Unopposed CKS1 activity in Cks2−/− cells leads to loss of p27. The resulting unrestricted cyclin A/CDK2 activity is accompanied by shortening of the cell cycle, increased replication fork velocity, and DNA damage. In vivo, Cks2−/− cortical progenitor cells are limited in their capacity to differentiate into mature neurons, a phenotype akin to animals lacking p27. We propose that the balance between CKS2 and CKS1 modulates p27 degradation, and with it cyclin A/CDK2 activity, to safeguard replicative fidelity and control neuronal differentiation.
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Min M, Lindon C. Substrate targeting by the ubiquitin-proteasome system in mitosis. Semin Cell Dev Biol 2012; 23:482-91. [PMID: 22326960 DOI: 10.1016/j.semcdb.2012.01.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 01/11/2012] [Accepted: 01/23/2012] [Indexed: 12/15/2022]
Abstract
Both cell cycle progression and the ubiquitin-proteasome system (UPS) that drives it are precisely regulated. Enzymatically, many ubiquitylation and degradation reactions have been characterized in in vitro systems, providing insights into the fundamental mechanisms of the UPS. Biologically, a range of degradation events depending on a ubiquitin ligase called the Anaphase-Promoting Complex (APC/C), have been shown to control mitotic progression through removal of key substrates with extreme temporal precision. However we are only just beginning to understand how the different enzymatic activities of the UPS act collectively - and in cooperation with other cellular factors - for accurate temporal and spatial control of mitotic substrate levels in vivo.
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Affiliation(s)
- Mingwei Min
- University of Cambridge, Department of Genetics, Downing St., Cambridge CB2 3EH, UK
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Apostolidis PA, Lindsey S, Miller WM, Papoutsakis ET. Proposed megakaryocytic regulon of p53: the genes engaged to control cell cycle and apoptosis during megakaryocytic differentiation. Physiol Genomics 2012; 44:638-50. [PMID: 22548738 DOI: 10.1152/physiolgenomics.00028.2012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
During endomitosis, megakaryocytes undergo several rounds of DNA synthesis without division leading to polyploidization. In primary megakaryocytes and in the megakaryocytic cell line CHRF, loss or knock-down of p53 enhances cell cycling and inhibits apoptosis, leading to increased polyploidization. To support the hypothesis that p53 suppresses megakaryocytic polyploidization, we show that stable expression of wild-type p53 in K562 cells (a p53-null cell line) attenuates the cells' ability to undergo polyploidization during megakaryocytic differentiation due to diminished DNA synthesis and greater apoptosis. This suggested that p53's effects during megakaryopoiesis are mediated through cell cycle- and apoptosis-related target genes, possibly by arresting DNA synthesis and promoting apoptosis. To identify candidate genes through which p53 mediates these effects, gene expression was compared between p53 knock-down (p53-KD) and control CHRF cells induced to undergo terminal megakaryocytic differentiation using microarray analysis. Among substantially downregulated p53 targets in p53-KD megakaryocytes were cell cycle regulators CDKN1A (p21) and PLK2, proapoptotic FAS, TNFRSF10B, CASP8, NOTCH1, TP53INP1, TP53I3, DRAM1, ZMAT3 and PHLDA3, DNA-damage-related RRM2B and SESN1, and actin component ACTA2, while antiapoptotic CKS1B, BCL2, GTSE1, and p53 family member TP63 were upregulated in p53-KD cells. Additionally, a number of cell cycle-related, proapoptotic, and cytoskeleton-related genes with known functions in megakaryocytes but not known to carry p53-responsive elements were differentially expressed between p53-KD and control CHRF cells. Our data support a model whereby p53 expression during megakaryopoiesis serves to control polyploidization and the transition from endomitosis to apoptosis by impeding cell cycling and promoting apoptosis. Furthermore, we identify a putative p53 regulon that is proposed to orchestrate these effects.
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Affiliation(s)
- Pani A Apostolidis
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA.
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Marteil G, Gagné JP, Borsuk E, Richard-Parpaillon L, Poirier GG, Kubiak JZ. Proteomics reveals a switch in CDK1-associated proteins upon M-phase exit during the Xenopus laevis oocyte to embryo transition. Int J Biochem Cell Biol 2011; 44:53-64. [PMID: 21959252 DOI: 10.1016/j.biocel.2011.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 09/09/2011] [Accepted: 09/14/2011] [Indexed: 02/04/2023]
Abstract
Cyclin-dependent kinase 1 (CDK1) is a major M-phase kinase which requires the binding to a regulatory protein, Cyclin B, to be active. CDK1/Cyclin B complex is called M-phase promoting factor (MPF) for its key role in controlling both meiotic and mitotic M-phase of the cell cycle. CDK1 inactivation is necessary for oocyte activation and initiation of embryo development. This complex process requires both Cyclin B polyubiquitination and proteosomal degradation via the ubiquitin-conjugation pathway, followed by the dephosphorylation of the monomeric CDK1 on Thr161. Previous proteomic analyses revealed a number of CDK1-associated proteins in human HeLa cells. It is, however, unknown whether specific partners are involved in CDK1 inactivation upon M-phase exit. To better understand CDK1 regulation during MII-arrest and oocyte activation, we immunoprecipitated (IPed) CDK1 together with its associated proteins from M-phase-arrested and M-phase-exiting Xenopus laevis oocytes. A mass spectrometry (MS) analysis revealed a number of new putative CDK1 partners. Most importantly, the composition of the CDK1-associated complex changed rapidly during M-phase exit. Additionally, an analysis of CDK1 complexes precipitated with beads covered with p9 protein, a fission yeast suc1 homologue well known for its high affinity for CDKs, was performed to identify the most abundant proteins associated with CDK1. The screen was auto-validated by identification of: (i) two forms of CDK1: Cdc2A and B, (ii) a set of Cyclins B with clearly diminishing number of peptides identified upon M-phase exit, (iii) a number of known CDK1 substrates (e.g. peroxiredoxine) and partners (e.g. HSPA8, a member of the HSP70 family) both in IP and in p9 precipitated pellets. In IP samples we also identified chaperones, which can modulate CDK1 three-dimensional structure, as well as calcineurin, a protein necessary for successful oocyte activation. These results shed a new light on CDK1 regulation via a dynamic change in the composition of the protein complex upon M-phase exit and the oocyte to embryo transition.
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Affiliation(s)
- Gaëlle Marteil
- CNRS, UMR 6061, Institute of Genetics and Development of Rennes, Rennes, France
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Kevei Z, Baloban M, Da Ines O, Tiricz H, Kroll A, Regulski K, Mergaert P, Kondorosi E. Conserved CDC20 cell cycle functions are carried out by two of the five isoforms in Arabidopsis thaliana. PLoS One 2011; 6:e20618. [PMID: 21687678 PMCID: PMC3110789 DOI: 10.1371/journal.pone.0020618] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 05/09/2011] [Indexed: 12/21/2022] Open
Abstract
Background The CDC20 and Cdh1/CCS52 proteins are substrate determinants and activators of the Anaphase Promoting Complex/Cyclosome (APC/C) E3 ubiquitin ligase and as such they control the mitotic cell cycle by targeting the degradation of various cell cycle regulators. In yeasts and animals the main CDC20 function is the destruction of securin and mitotic cyclins. Plants have multiple CDC20 gene copies whose functions have not been explored yet. In Arabidopsis thaliana there are five CDC20 isoforms and here we aimed at defining their contribution to cell cycle regulation, substrate selectivity and plant development. Methodology/Principal Findings Studying the gene structure and phylogeny of plant CDC20s, the expression of the five AtCDC20 gene copies and their interactions with the APC/C subunit APC10, the CCS52 proteins, components of the mitotic checkpoint complex (MCC) and mitotic cyclin substrates, conserved CDC20 functions could be assigned for AtCDC20.1 and AtCDC20.2. The other three intron-less genes were silent and specific for Arabidopsis. We show that AtCDC20.1 and AtCDC20.2 are components of the MCC and interact with mitotic cyclins with unexpected specificity. AtCDC20.1 and AtCDC20.2 are expressed in meristems, organ primordia and AtCDC20.1 also in pollen grains and developing seeds. Knocking down both genes simultaneously by RNAi resulted in severe delay in plant development and male sterility. In these lines, the meristem size was reduced while the cell size and ploidy levels were unaffected indicating that the lower cell number and likely slowdown of the cell cycle are the cause of reduced plant growth. Conclusions/Significance The intron-containing CDC20 gene copies provide conserved and redundant functions for cell cycle progression in plants and are required for meristem maintenance, plant growth and male gametophyte formation. The Arabidopsis-specific intron-less genes are possibly “retrogenes” and have hitherto undefined functions or are pseudogenes.
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Affiliation(s)
- Zoltán Kevei
- Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2355, Gif-sur-Yvette, France
- Institute for Plant Genomics, Human Biotechnology and Bioenergy, Bay Zoltan Foundation for Applied Research, Szeged, Hungary
| | - Mikhail Baloban
- Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2355, Gif-sur-Yvette, France
| | - Olivier Da Ines
- Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2355, Gif-sur-Yvette, France
| | - Hilda Tiricz
- Institute for Plant Genomics, Human Biotechnology and Bioenergy, Bay Zoltan Foundation for Applied Research, Szeged, Hungary
| | - Alexandra Kroll
- Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2355, Gif-sur-Yvette, France
| | - Krzysztof Regulski
- Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2355, Gif-sur-Yvette, France
| | - Peter Mergaert
- Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2355, Gif-sur-Yvette, France
| | - Eva Kondorosi
- Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2355, Gif-sur-Yvette, France
- Institute for Plant Genomics, Human Biotechnology and Bioenergy, Bay Zoltan Foundation for Applied Research, Szeged, Hungary
- * E-mail:
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Regulated inactivation of the spindle assembly checkpoint without functional mitotic spindles. EMBO J 2011; 30:2648-61. [PMID: 21642954 DOI: 10.1038/emboj.2011.176] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Accepted: 05/09/2011] [Indexed: 12/13/2022] Open
Abstract
The spindle assembly checkpoint (SAC) arrests mitosis until bipolar attachment of spindle microtubules to all chromosomes is accomplished. However, when spindle formation is prevented and the SAC cannot be satisfied, mammalian cells can eventually overcome the mitotic arrest while the checkpoint is still activated. We find that Aspergillus nidulans cells, which are unable to satisfy the SAC, inactivate the checkpoint after a defined period of mitotic arrest. Such SAC inactivation allows normal nuclear reassembly and mitotic exit without DNA segregation. We demonstrate that the mechanisms, which govern such SAC inactivation, require protein synthesis and can occur independently of inactivation of the major mitotic regulator Cdk1/Cyclin B or mitotic exit. Moreover, in the continued absence of spindle function cells transit multiple cell cycles in which the SAC is reactivated each mitosis before again being inactivated. Such cyclic activation and inactivation of the SAC suggests that it is subject to cell-cycle regulation that is independent of bipolar spindle function.
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Taneichi D, Iijima K, Doi A, Koyama T, Minemoto Y, Tokunaga K, Shimura M, Kano S, Ishizaka Y. Identification of SNF2h, a chromatin-remodeling factor, as a novel binding protein of Vpr of human immunodeficiency virus type 1. J Neuroimmune Pharmacol 2011; 6:177-87. [PMID: 21519849 DOI: 10.1007/s11481-011-9276-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 03/16/2011] [Indexed: 12/24/2022]
Abstract
Vpr, an accessory gene of human immunodeficiency virus type 1, encodes a virion-associated nuclear protein that plays an important role in the primary viral infection of resting macrophages. It has a variety of biological functions, including roles in a cell cycle abnormality at G(2)/M phase, apoptosis, nuclear transfer of preintegration complex, and DNA double-strand breaks (DSBs), some of which depend on its association with the chromatin of the host cells. Given that DSB signals are postulated to be a positive factor in the viral infection, understanding the mode of chromatin recruitment of Vpr is important. Here, we identified SNF2h, a chromatin-remodeling factor, as a novel binding partner of Vpr involved in its chromatin recruitment. When endogenous SNF2h protein was extensively downregulated by SNF2h small interfering RNA (siRNA), the amount of Vpr loaded on chromatin decreased to about 30% of the control level. Biochemical analysis using a mutant Vpr suggested that Vpr binds SNF2h via HFRIG (amino acids 71-75 depicted by single letters) and the Vpr mutant lacking this motif lost the activity to induce DSB-dependent signals. Consistently, Vpr-induced DSBs were attenuated by extensive downregulaion of endogenous SNF2h. Based on these data, we discuss the role of DSB and DSB signals in the viral infection.
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Affiliation(s)
- Daiki Taneichi
- Department of Intractable Diseases, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku, Tokyo 162-8655, Japan
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Meyer HJ, Rape M. Processive ubiquitin chain formation by the anaphase-promoting complex. Semin Cell Dev Biol 2011; 22:544-50. [PMID: 21477659 DOI: 10.1016/j.semcdb.2011.03.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 03/16/2011] [Indexed: 12/11/2022]
Abstract
Progression through mitosis requires the sequential ubiquitination of cell cycle regulators by the anaphase-promoting complex, resulting in their proteasomal degradation. Although several mechanisms contribute to APC/C regulation during mitosis, the APC/C is able to discriminate between its many substrates by exploiting differences in the processivity of ubiquitin chain assembly. Here, we discuss how the APC/C achieves processive ubiquitin chain formation to trigger the sequential degradation of cell cycle regulators during mitosis.
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Affiliation(s)
- Hermann-Josef Meyer
- University of California at Berkeley, Department of Molecular and Cell Biology, Berkeley, CA 94720-3202, United States
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41
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Izawa D, Pines J. How APC/C-Cdc20 changes its substrate specificity in mitosis. Nat Cell Biol 2011; 13:223-33. [PMID: 21336306 PMCID: PMC3059483 DOI: 10.1038/ncb2165] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Accepted: 11/26/2010] [Indexed: 01/26/2023]
Abstract
Progress through mitosis requires that the right protein be degraded at the right time. One ubiquitin ligase, the anaphase-promoting complex or cyclosome (APC/C) targets most of the crucial mitotic regulators by changing its substrate specificity throughout mitosis. The spindle assembly checkpoint (SAC) acts on the APC/C co-activator, Cdc20 (cell division cycle 20), to block the degradation of metaphase substrates (for example, cyclin B1 and securin), but not others (for example, cyclin A). How this is achieved is unclear. Here we show that Cdc20 binds to different sites on the APC/C depending on the SAC. Cdc20 requires APC3 and APC8 to bind and activate the APC/C when the SAC is satisfied, but requires only APC8 to bind the APC/C when the SAC is active. Moreover, APC10 is crucial for the destruction of cyclin B1 and securin, but not cyclin A. We conclude that the SAC causes Cdc20 to bind to different sites on the APC/C and this alters APC/C substrate specificity.
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Affiliation(s)
- Daisuke Izawa
- Gurdon Institute and Department of Zoology, Tennis Court Road,Cambridge CB2 1QN, UK
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42
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McLean JR, Chaix D, Ohi MD, Gould KL. State of the APC/C: organization, function, and structure. Crit Rev Biochem Mol Biol 2011; 46:118-36. [PMID: 21261459 DOI: 10.3109/10409238.2010.541420] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The ubiquitin-proteasome protein degradation system is involved in many essential cellular processes including cell cycle regulation, cell differentiation, and the unfolded protein response. The anaphase-promoting complex/cyclosome (APC/C), an evolutionarily conserved E3 ubiquitin ligase, was discovered 15 years ago because of its pivotal role in cyclin degradation and mitotic progression. Since then, we have learned that the APC/C is a very large, complex E3 ligase composed of 13 subunits, yielding a molecular machine of approximately 1 MDa. The intricate regulation of the APC/C is mediated by the Cdc20 family of activators, pseudosubstrate inhibitors, protein kinases and phosphatases and the spindle assembly checkpoint. The large size, complexity, and dynamic nature of the APC/C represent significant obstacles toward high-resolution structural techniques; however, over the last decade, there have been a number of lower resolution APC/C structures determined using single particle electron microscopy. These structures, when combined with data generated from numerous genetic and biochemical studies, have begun to shed light on how APC/C activity is regulated. Here, we discuss the most recent developments in the APC/C field concerning structure, substrate recognition, and catalysis.
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Affiliation(s)
- Janel R McLean
- Howard Hughes Medical Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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43
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Song L, Rape M. Substrate-specific regulation of ubiquitination by the anaphase-promoting complex. Cell Cycle 2011; 10:52-6. [PMID: 21191176 DOI: 10.4161/cc.10.1.14387] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
By orchestrating the sequential degradation of a large number of cell cycle regulators, the ubiquitin ligase anaphase-promoting complex (APC/C) is essential for proliferation in all eukaryotes. The correct timing of APC/C-dependent substrate degradation, a critical feature of progression through mitosis, was long known to be controlled by mechanisms targeting the core APC/C-machinery. Recent experiments, however, have revealed an important contribution of substrate-specific regulation of the APC/C to achieve accurate cell division. In this perspective, we describe different mechanisms of substrate-specific APC/C-regulation and discuss their importance for cell division.
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Affiliation(s)
- Ling Song
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
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Abstract
Cyclin A outcompetes inhibitory spindle assembly checkpoint proteins for binding to the APC/C ubiquitin ligase coactivator Cdc20 to promote its self-destruction even when the checkpoint is active (see also a paper from van Zon et al., in this issue). The anaphase-promoting complex/cyclosome (APC/C) is the ubiquitin ligase essential to mitosis, which ensures that specific proteins are degraded at specific times to control the order of mitotic events. The APC/C coactivator, Cdc20, is targeted by the spindle assembly checkpoint (SAC) to restrict APC/C activity until metaphase, yet early substrates, such as cyclin A, are degraded in the presence of the active checkpoint. Cdc20 and the cyclin-dependent kinase cofactor, Cks, are required for cyclin A destruction, but how they enable checkpoint-resistant destruction has not been elucidated. In this study, we answer this problem: we show that the N terminus of cyclin A binds directly to Cdc20 and with sufficient affinity that it can outcompete the SAC proteins. Subsequently, the Cks protein is necessary and sufficient to promote cyclin A degradation in the presence of an active checkpoint by binding cyclin A–Cdc20 to the APC/C.
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Affiliation(s)
- Barbara Di Fiore
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, England, UK
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