1
|
Hellmuth S, Stemmann O. Requirement of Nek2a and cyclin A2 for Wapl-dependent removal of cohesin from prophase chromatin. EMBO J 2024:10.1038/s44318-024-00228-9. [PMID: 39271794 DOI: 10.1038/s44318-024-00228-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 08/14/2024] [Accepted: 08/27/2024] [Indexed: 09/15/2024] Open
Abstract
Sister chromatid cohesion is mediated by the cohesin complex. In mitotic prophase cohesin is removed from chromosome arms in a Wapl- and phosphorylation-dependent manner. Sgo1-PP2A protects pericentromeric cohesion by dephosphorylation of cohesin and its associated Wapl antagonist sororin. However, Sgo1-PP2A relocates to inner kinetochores well before sister chromatids are separated by separase, leaving pericentromeric regions unprotected. Why deprotected cohesin is not removed by Wapl remains enigmatic. By reconstituting Wapl-dependent cohesin removal from chromatin in vitro, we discovered a requirement for Nek2a and Cdk1/2-cyclin A2. These kinases phosphorylate cohesin-bound Pds5b, thereby converting it from a sororin- to a Wapl-interactor. Replacement of endogenous Pds5b by a phosphorylation mimetic variant causes premature sister chromatid separation (PCS). Conversely, phosphorylation-resistant Pds5b impairs chromosome arm separation in prometaphase-arrested cells and suppresses PCS in the absence of Sgo1. Early mitotic degradation of Nek2a and cyclin A2 may therefore explain why only separase, but not Wapl, can trigger anaphase.
Collapse
Affiliation(s)
- Susanne Hellmuth
- Chair of Genetics, University of Bayreuth, 95440, Bayreuth, Germany.
| | - Olaf Stemmann
- Chair of Genetics, University of Bayreuth, 95440, Bayreuth, Germany
| |
Collapse
|
2
|
Zhang Y, Li R, Li H, Huang Y, Mei Y, Zheng Y, Guo Y, Zhou Z, Yong Z, Zhao Y, Dong W, Gao J, Cao X. Morpho-histological and Transcriptome Analysis Reveal the Unreduced Sperm Formation Mechanism in cdk1-Depletion Zebrafish. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2024:10.1007/s10126-024-10366-0. [PMID: 39243300 DOI: 10.1007/s10126-024-10366-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2024] [Accepted: 08/26/2024] [Indexed: 09/09/2024]
Abstract
Cyclin-dependent kinases (Cdks) are major molecules related to cell cycle regulation. Polyploidy can be caused by the production of unreduced gametes, which is often related to the abnormal cell cycle of germ cells. Here, we successfully constructed a cdk1 mutation line (cdk1+/-) in zebrafish, a commonly used model organism. It showed that cdk1 depletion resulted in the generation of both polyploid and aneuploid embryos of WT♀ × cdk1+/-♂ zebrafish. In addition to normal sperms (1N), the depletion of cdk1 in zebrafish also led to the production of some large-head 2N sperms and higher ploidy sperms. Results of bivalent analysis of testis and ultrastructure analysis of spermatogonia suggested that the production of these large-head sperms was due to spermatogonia chromosome doubling in cdk1+/- zebrafish. Transcriptome analysis revealed aberrant expressions of some cell cycle and DNA replication-related genes in the early testis of cdk1+/- zebrafish relative to WT zebrafish. Through STRING correlation analysis, we further proved that cdk1 depletion affected the mitosis process and endoduplication initiation of spermatogonia by regulating expressions of some proteins related to cell cycle (i.e., Espl1 and Pp1) and DNA replication (i.e., Orc1 and Rnaseh2b), thereby leading to the formation of unreduced sperms. This study provides important information on revealing the molecular mechanisms of unreduced gamete formation caused by cdk1 mutation. Meanwhile, it also provides an important reference for the creation of fish polyploid germplasm.
Collapse
Affiliation(s)
- Yunbang Zhang
- College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Provincial Engineering Laboratory for Pond Aquaculture, No. 1 Shizishan Street, Hongshan District, Wuhan, 430070, Hubei Province, People's Republic of China
| | - Rongyun Li
- College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hui Li
- College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yuwei Huang
- College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yihui Mei
- College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yuxuan Zheng
- College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yankun Guo
- College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zihao Zhou
- College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhonglin Yong
- College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Ying Zhao
- College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wenjing Dong
- College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jian Gao
- College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Provincial Engineering Laboratory for Pond Aquaculture, No. 1 Shizishan Street, Hongshan District, Wuhan, 430070, Hubei Province, People's Republic of China
| | - Xiaojuan Cao
- College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
- Hubei Provincial Engineering Laboratory for Pond Aquaculture, No. 1 Shizishan Street, Hongshan District, Wuhan, 430070, Hubei Province, People's Republic of China.
| |
Collapse
|
3
|
Cheng SY, Yi ZY, Zhang CH, Sun QY, Qian WP, Li J. Vinorelbine administration impedes the timely progression of meiotic maturation and induces aneuploidy in mouse oocytes. Reprod Toxicol 2024; 128:108634. [PMID: 38851359 DOI: 10.1016/j.reprotox.2024.108634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/29/2024] [Accepted: 06/05/2024] [Indexed: 06/10/2024]
Abstract
Vinorelbine is a commonly used drug to treat various malignancies, such as breast cancer, non-small cell lung cancer, and metastatic pleural mesothelioma. Its side effects include severe neutropenia, local phlebitis, gastrointestinal reactions, and neurotoxicity. In view of the scarcity of research on vinorelbine's reproductive toxicity, this study evaluated the impact of vinorelbine ditartrate, a commonly used form of vinorelbine, on oocyte maturation in vitro. Our investigation revealed that vinorelbine ditartrate had no effect on oocyte meiotic resumption. However, it did reduce the rate of first polar body extrusion, suggesting that it could significantly impede the meiotic maturation of oocytes. Vinorelbine ditartrate exposure was found to disturb the regular spindle assembly and chromosome alignment, leading to the continuous activation of the spindle assembly checkpoint (SAC) and a delayed activation of the anaphase-promoting complex/cyclosome (APC/C), ultimately causing aneuploidy in oocytes. Consequently, the administration of vinorelbine is likely to result in oocyte aneuploidy, which can be helpful in providing a drug reference and fertility guidance in a clinical context.
Collapse
Affiliation(s)
- Si-Yu Cheng
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen, China
| | - Zi-Yun Yi
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen, China
| | - Chun-Hui Zhang
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen, China
| | - Qing-Yuan Sun
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China.
| | - Wei-Ping Qian
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen, China.
| | - Jian Li
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen, China.
| |
Collapse
|
4
|
Zhu Q, Du L, Wu J, Li J, Lin Z. Walrycin B, as a novel separase inhibitor, exerts potent anticancer efficacy in a mouse xenograft model. Biochem Pharmacol 2024; 229:116502. [PMID: 39173842 DOI: 10.1016/j.bcp.2024.116502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 07/30/2024] [Accepted: 08/20/2024] [Indexed: 08/24/2024]
Abstract
Proper chromosome segregation during cell division relies on the timely dissolution of chromosome cohesion. Separase (EC3.4.22.49), a cysteine protease, plays a critical role in mitosis by cleaving the kleisin subunit of cohesin, thereby presenting a promising target for cancer therapy. However, challenges in isolating active human separase suitable for high-throughput screening have limited the identification of effective inhibitors. Here, we conducted a high-throughput screening of small-molecule inhibitors using the protease domain of Chaetomium thermophilum separase (ctSPD), which not only shares significant sequence similarity with human separase but is also readily available. After conducting a primary screening of a library containing 9,172 compounds and subsequent validation using human separase, we identified walrycin B and its analogs, toxoflavin, 3-methyltoxoflavin, and 3-phenyltoxoflavin, as potent inhibitors of human separase. Subsequent microscale thermophoresis assays and molecular dynamics simulations revealed that walrycin B binds to the active site of separase and competes with substrates for binding. Additionally, cell-based studies showed that walrycin B and its analogs effectively induce cell cycle arrest at the M phase, activate apoptosis, and ultimately lead to cell death in mitosis. Finally, in a mouse xenograft model, walrycin B exhibited significant antitumor efficacy with minimal side effects. Together, these findings highlight the therapeutic potential of walrycin B for cancer treatment and its utility as a chemical tool in future studies involving separase.
Collapse
Affiliation(s)
- Qinwei Zhu
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Liyang Du
- College of Pharmacy and Medical Technology, Putian University, Putian 351100, China
| | - Juhong Wu
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Jinyu Li
- College of Chemistry, Fuzhou University, Fuzhou 350108, China.
| | - Zhonghui Lin
- College of Chemistry, Fuzhou University, Fuzhou 350108, China.
| |
Collapse
|
5
|
Rahman MS, Shindo Y, Oka K, Ikeda W, Suzuki M. Live Cell Monitoring of Separase Activity, a Key Enzymatic Reaction for Chromosome Segregation, with Chimeric FRET-Based Molecular Sensor upon Cell Cycle Progression. BIOSENSORS 2024; 14:192. [PMID: 38667185 PMCID: PMC11048197 DOI: 10.3390/bios14040192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/29/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024]
Abstract
Separase is a key cysteine protease in the separation of sister chromatids through the digestion of the cohesin ring that inhibits chromosome segregation as a trigger of the metaphase-anaphase transition in eukaryotes. Its activity is highly regulated by binding with securin and cyclinB-CDK1 complex. These bindings prevent the proteolytic activity of separase until the onset of anaphase. Chromosome missegregation and aneuploidy are frequently observed in malignancies. However, there are some difficulties in biochemical examinations due to the instability of separase in vitro and the fact that few spatiotemporal resolution approaches exist for monitoring live separase activity throughout mitotic processes. Here, we have developed FRET-based molecular sensors, including GFP variants, with separase-cleavable sequences as donors and covalently attached fluorescent dyes as acceptor molecules. These are applicable to conventional live cell imaging and flow cytometric analysis because of efficient live cell uptake. We investigated the performance of equivalent molecular sensors, either localized or not localized inside the nucleus under cell cycle control, using flow cytometry. Synchronized cell cycle progression rendered significant separase activity detections in both molecular sensors. We obtained consistent outcomes with localized molecular sensor introduction and cell cycle control by fluorescent microscopic observations. We thus established live cell separase activity monitoring systems that can be used specifically or statistically, which could lead to the elucidation of separase properties in detail.
Collapse
Affiliation(s)
- Md. Shazadur Rahman
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan; (M.S.R.); (W.I.)
- Department of Agricultural Chemistry, Hajee Mohammad Danesh Science and Technology University, Dinajpur 5200, Bangladesh
| | - Yutaka Shindo
- Department of Bioscience and informatics, Faculty of Science and Technology, Keio University, Yokohama 223-0061, Japan; (Y.S.); (K.O.)
| | - Kotaro Oka
- Department of Bioscience and informatics, Faculty of Science and Technology, Keio University, Yokohama 223-0061, Japan; (Y.S.); (K.O.)
- School of Frontier Engineering, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara 252-0373, Japan
| | - Wataru Ikeda
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan; (M.S.R.); (W.I.)
| | - Miho Suzuki
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan; (M.S.R.); (W.I.)
| |
Collapse
|
6
|
Wang T, Zou Y, Meng H, Zheng P, Teng J, Huang N, Chen J. Securin acetylation prevents precocious separase activation and premature sister chromatid separation. Curr Biol 2024; 34:1295-1308.e5. [PMID: 38452759 DOI: 10.1016/j.cub.2024.02.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 01/08/2024] [Accepted: 02/15/2024] [Indexed: 03/09/2024]
Abstract
Lysine acetylation of non-histone proteins plays crucial roles in many cellular processes. In this study, we examine the role of lysine acetylation during sister chromatid separation in mitosis. We investigate the acetylation of securin at K21 by cell-cycle-dependent acetylome analysis and uncover its role in separase-triggered chromosome segregation during mitosis. Prior to the onset of anaphase, the acetylated securin via TIP60 prevents its degradation by the APC/CCDC20-mediated ubiquitin-proteasome system. This, in turn, restrains precocious activation of separase and premature separation of sister chromatids. Additionally, the acetylation-dependent stability of securin is also enhanced by its dephosphorylation. As anaphase approaches, HDAC1-mediated deacetylation of securin promotes its degradation, allowing released separase to cleave centromeric cohesin. Blocking securin deacetylation leads to longer anaphase duration and errors in chromosome segregation. Thus, this study illustrates the emerging role of securin acetylation dynamics in mitotic progression and genetic stability.
Collapse
Affiliation(s)
- Tianning Wang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing 100871, China; Breast Disease Diagnosis and Treatment Center/Department of Thyroid Surgery, Central Hospital Affiliated to Shandong First Medical University, Jinan 250013, China; Research Center of Translational Medicine, Central Hospital Affiliated to Shandong First Medical University, Jinan 250013, China
| | - Yuhong Zou
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing 100871, China
| | - Hui Meng
- Institute of Neuroscience, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China; Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China
| | - Pengli Zheng
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Junlin Teng
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing 100871, China.
| | - Ning Huang
- Institute of Neuroscience, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China; Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China.
| | - Jianguo Chen
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing 100871, China; Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China.
| |
Collapse
|
7
|
Pati D. Role of chromosomal cohesion and separation in aneuploidy and tumorigenesis. Cell Mol Life Sci 2024; 81:100. [PMID: 38388697 PMCID: PMC10884101 DOI: 10.1007/s00018-024-05122-5] [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: 11/13/2023] [Revised: 12/28/2023] [Accepted: 01/09/2024] [Indexed: 02/24/2024]
Abstract
Cell division is a crucial process, and one of its essential steps involves copying the genetic material, which is organized into structures called chromosomes. Before a cell can divide into two, it needs to ensure that each newly copied chromosome is paired tightly with its identical twin. This pairing is maintained by a protein complex known as cohesin, which is conserved in various organisms, from single-celled ones to humans. Cohesin essentially encircles the DNA, creating a ring-like structure to handcuff, to keep the newly synthesized sister chromosomes together in pairs. Therefore, chromosomal cohesion and separation are fundamental processes governing the attachment and segregation of sister chromatids during cell division. Metaphase-to-anaphase transition requires dissolution of cohesins by the enzyme Separase. The tight regulation of these processes is vital for safeguarding genomic stability. Dysregulation in chromosomal cohesion and separation resulting in aneuploidy, a condition characterized by an abnormal chromosome count in a cell, is strongly associated with cancer. Aneuploidy is a recurring hallmark in many cancer types, and abnormalities in chromosomal cohesion and separation have been identified as significant contributors to various cancers, such as acute myeloid leukemia, myelodysplastic syndrome, colorectal, bladder, and other solid cancers. Mutations within the cohesin complex have been associated with these cancers, as they interfere with chromosomal segregation, genome organization, and gene expression, promoting aneuploidy and contributing to the initiation of malignancy. In summary, chromosomal cohesion and separation processes play a pivotal role in preserving genomic stability, and aberrations in these mechanisms can lead to aneuploidy and cancer. Gaining a deeper understanding of the molecular intricacies of chromosomal cohesion and separation offers promising prospects for the development of innovative therapeutic approaches in the battle against cancer.
Collapse
Affiliation(s)
- Debananda Pati
- Texas Children's Cancer Center, Department of Pediatrics Hematology/Oncology, Molecular and Cellular Biology, Baylor College of Medicine, 1102 Bates Avenue, Houston, TX, 77030, USA.
| |
Collapse
|
8
|
Toyoda JH, Martino J, Speer RM, Meaza I, Lu H, Williams AR, Bolt AM, Kouokam JC, Aboueissa AEM, Wise JP. Hexavalent Chromium Targets Securin to Drive Numerical Chromosome Instability in Human Lung Cells. Int J Mol Sci 2023; 25:256. [PMID: 38203427 PMCID: PMC10778806 DOI: 10.3390/ijms25010256] [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: 11/18/2023] [Revised: 12/14/2023] [Accepted: 12/15/2023] [Indexed: 01/12/2024] Open
Abstract
Hexavalent chromium [Cr(VI)] is a known human lung carcinogen with widespread exposure in environmental and occupational settings. Despite well-known cancer risks, the molecular mechanisms of Cr(VI)-induced carcinogenesis are not well understood, but a major driver of Cr(VI) carcinogenesis is chromosome instability. Previously, we reported Cr(VI) induced numerical chromosome instability, premature centriole disengagement, centrosome amplification, premature centromere division, and spindle assembly checkpoint bypass. A key regulator of these events is securin, which acts by regulating the cleavage ability of separase. Thus, in this study we investigated securin disruption by Cr(VI) exposure. We exposed human lung cells to a particulate Cr(VI) compound, zinc chromate, for acute (24 h) and prolonged (120 h) time points. We found prolonged Cr(VI) exposure caused marked decrease in securin levels and function. After prolonged exposure at the highest concentration, securin protein levels were decreased to 15.3% of control cells, while securin mRNA quantification was 7.9% relative to control cells. Additionally, loss of securin function led to increased separase activity manifested as enhanced cleavage of separase substrates; separase, kendrin, and SCC1. These data show securin is targeted by prolonged Cr(VI) exposure in human lung cells. Thus, a new mechanistic model for Cr(VI)-induced carcinogenesis emerges with centrosome and centromere disruption as key components of numerical chromosome instability, a key driver in Cr(VI) carcinogenesis.
Collapse
Affiliation(s)
- Jennifer H. Toyoda
- Wise Laboratory for Environmental and Genetic Toxicology, University of Louisville, 500 S Preston Street, Building 55A, Room 1422, Louisville, KY 40292, USA (R.M.S.); (H.L.); (J.C.K.)
| | - Julieta Martino
- Wise Laboratory for Environmental and Genetic Toxicology, University of Louisville, 500 S Preston Street, Building 55A, Room 1422, Louisville, KY 40292, USA (R.M.S.); (H.L.); (J.C.K.)
| | - Rachel M. Speer
- Wise Laboratory for Environmental and Genetic Toxicology, University of Louisville, 500 S Preston Street, Building 55A, Room 1422, Louisville, KY 40292, USA (R.M.S.); (H.L.); (J.C.K.)
| | - Idoia Meaza
- Wise Laboratory for Environmental and Genetic Toxicology, University of Louisville, 500 S Preston Street, Building 55A, Room 1422, Louisville, KY 40292, USA (R.M.S.); (H.L.); (J.C.K.)
| | - Haiyan Lu
- Wise Laboratory for Environmental and Genetic Toxicology, University of Louisville, 500 S Preston Street, Building 55A, Room 1422, Louisville, KY 40292, USA (R.M.S.); (H.L.); (J.C.K.)
| | - Aggie R. Williams
- Wise Laboratory for Environmental and Genetic Toxicology, University of Louisville, 500 S Preston Street, Building 55A, Room 1422, Louisville, KY 40292, USA (R.M.S.); (H.L.); (J.C.K.)
| | - Alicia M. Bolt
- Department of Pharmaceutical Sciences, The University of New Mexico College of Pharmacy, Albuquerque, NM 87131, USA;
| | - Joseph Calvin Kouokam
- Wise Laboratory for Environmental and Genetic Toxicology, University of Louisville, 500 S Preston Street, Building 55A, Room 1422, Louisville, KY 40292, USA (R.M.S.); (H.L.); (J.C.K.)
| | | | - John Pierce Wise
- Wise Laboratory for Environmental and Genetic Toxicology, University of Louisville, 500 S Preston Street, Building 55A, Room 1422, Louisville, KY 40292, USA (R.M.S.); (H.L.); (J.C.K.)
| |
Collapse
|
9
|
Yu J, Morgan DO, Boland A. The molecular mechanisms of human separase regulation. Biochem Soc Trans 2023:233012. [PMID: 37140261 DOI: 10.1042/bst20221400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/11/2023] [Accepted: 04/18/2023] [Indexed: 05/05/2023]
Abstract
Sister chromatid segregation is the final irreversible step of mitosis. It is initiated by a complex regulatory system that ultimately triggers the timely activation of a conserved cysteine protease named separase. Separase cleaves the cohesin protein ring that links the sister chromatids and thus facilitates their separation and segregation to the opposite poles of the dividing cell. Due to the irreversible nature of this process, separase activity is tightly controlled in all eukaryotic cells. In this mini-review, we summarize the latest structural and functional findings on the regulation of separase, with an emphasis on the regulation of the human enzyme by two inhibitors, the universal inhibitor securin and the vertebrate-specific inhibitor CDK1-cyclin B. We discuss the two fundamentally different inhibitory mechanisms by which these inhibitors block separase activity by occluding substrate binding. We also describe conserved mechanisms that facilitate substrate recognition and point out open research questions that will guide studies of this fascinating enzyme for years to come.
Collapse
Affiliation(s)
- Jun Yu
- Department of Molecular and Cellular Biology, University of Geneva, CH-1211 Geneva, Switzerland
| | - David O Morgan
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94143, U.S.A
| | - Andreas Boland
- Department of Molecular and Cellular Biology, University of Geneva, CH-1211 Geneva, Switzerland
| |
Collapse
|
10
|
Konecna M, Abbasi Sani S, Anger M. Separase and Roads to Disengage Sister Chromatids during Anaphase. Int J Mol Sci 2023; 24:ijms24054604. [PMID: 36902034 PMCID: PMC10003635 DOI: 10.3390/ijms24054604] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/19/2023] [Accepted: 02/22/2023] [Indexed: 03/02/2023] Open
Abstract
Receiving complete and undamaged genetic information is vital for the survival of daughter cells after chromosome segregation. The most critical steps in this process are accurate DNA replication during S phase and a faithful chromosome segregation during anaphase. Any errors in DNA replication or chromosome segregation have dire consequences, since cells arising after division might have either changed or incomplete genetic information. Accurate chromosome segregation during anaphase requires a protein complex called cohesin, which holds together sister chromatids. This complex unifies sister chromatids from their synthesis during S phase, until separation in anaphase. Upon entry into mitosis, the spindle apparatus is assembled, which eventually engages kinetochores of all chromosomes. Additionally, when kinetochores of sister chromatids assume amphitelic attachment to the spindle microtubules, cells are finally ready for the separation of sister chromatids. This is achieved by the enzymatic cleavage of cohesin subunits Scc1 or Rec8 by an enzyme called Separase. After cohesin cleavage, sister chromatids remain attached to the spindle apparatus and their poleward movement on the spindle is initiated. The removal of cohesion between sister chromatids is an irreversible step and therefore it must be synchronized with assembly of the spindle apparatus, since precocious separation of sister chromatids might lead into aneuploidy and tumorigenesis. In this review, we focus on recent discoveries concerning the regulation of Separase activity during the cell cycle.
Collapse
Affiliation(s)
- Marketa Konecna
- Department of Genetics and Reproduction, Veterinary Research Institute, 621 00 Brno, Czech Republic
- Institute of Animal Physiology and Genetics, Czech Academy of Science, 277 21 Libechov, Czech Republic
- Faculty of Science, Masaryk University, 602 00 Brno, Czech Republic
| | - Soodabeh Abbasi Sani
- Department of Genetics and Reproduction, Veterinary Research Institute, 621 00 Brno, Czech Republic
- Faculty of Science, Masaryk University, 602 00 Brno, Czech Republic
| | - Martin Anger
- Department of Genetics and Reproduction, Veterinary Research Institute, 621 00 Brno, Czech Republic
- Institute of Animal Physiology and Genetics, Czech Academy of Science, 277 21 Libechov, Czech Republic
- Correspondence:
| |
Collapse
|
11
|
Shindo N, Kumada K, Iemura K, Yasuda J, Fujimori H, Mochizuki M, Tamai K, Tanaka K, Hirota T. Autocleavage of separase suppresses its premature activation by promoting binding to cyclin B1. Cell Rep 2022; 41:111723. [PMID: 36450246 DOI: 10.1016/j.celrep.2022.111723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 09/25/2022] [Accepted: 11/03/2022] [Indexed: 12/02/2022] Open
Abstract
Accurate chromosome segregation requires timely activation of separase, a protease that cleaves cohesin during the metaphase-to-anaphase transition. However, the mechanism that maintains the inactivity of separase prior to this event remains unclear. We provide evidence that separase autocleavage plays an essential role in this process. We show that the inhibition of separase autocleavage results in premature activity before the onset of anaphase, accompanied by the formation of chromosomal bridges and spindle rocking. This deregulation is attributed to the reduced binding of cyclin B1 to separase that occurs during the metaphase-to-anaphase transition. Furthermore, when separase is mutated to render the regulation by cyclin B1 irrelevant, which keeps separase in securin-binding form, the deregulation induced by autocleavage inhibition is rescued. Our results reveal a physiological role of separase autocleavage in regulating separase, which ensures faithful chromosome segregation.
Collapse
Affiliation(s)
- Norihisa Shindo
- Division of Molecular and Cellular Oncology, Miyagi Cancer Center Research Institute, Natori, Japan.
| | - Kazuki Kumada
- Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
| | - Kenji Iemura
- Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Jun Yasuda
- Division of Molecular and Cellular Oncology, Miyagi Cancer Center Research Institute, Natori, Japan
| | - Haruna Fujimori
- Division of Cancer Stem Cell, Miyagi Cancer Center Research Institute, Natori, Japan
| | - Mai Mochizuki
- Division of Cancer Stem Cell, Miyagi Cancer Center Research Institute, Natori, Japan
| | - Keiichi Tamai
- Division of Cancer Stem Cell, Miyagi Cancer Center Research Institute, Natori, Japan
| | - Kozo Tanaka
- Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Toru Hirota
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research (JFCR), Tokyo, Japan
| |
Collapse
|
12
|
Wassmann K. Separase Control and Cohesin Cleavage in Oocytes: Should I Stay or Should I Go? Cells 2022; 11:3399. [PMID: 36359795 PMCID: PMC9656630 DOI: 10.3390/cells11213399] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 10/19/2023] Open
Abstract
The key to gametogenesis is the proper execution of a specialized form of cell division named meiosis. Prior to the meiotic divisions, the recombination of maternal and paternal chromosomes creates new genetic combinations necessary for fitness and adaptation to an ever-changing environment. Two rounds of chromosome segregation -meiosis I and II- have to take place without intermediate S-phase and lead to the creation of haploid gametes harboring only half of the genetic material. Importantly, the segregation patterns of the two divisions are fundamentally different and require adaptation of the mitotic cell cycle machinery to the specificities of meiosis. Separase, the enzyme that cleaves Rec8, a subunit of the cohesin complex constituting the physical connection between sister chromatids, has to be activated twice: once in meiosis I and immediately afterwards, in meiosis II. Rec8 is cleaved on chromosome arms in meiosis I and in the centromere region in meiosis II. This step-wise cohesin removal is essential to generate gametes of the correct ploidy and thus, embryo viability. Hence, separase control and Rec8 cleavage must be perfectly controlled in time and space. Focusing on mammalian oocytes, this review lays out what we know and what we still ignore about this fascinating mechanism.
Collapse
Affiliation(s)
- Katja Wassmann
- Institut Jacques Monod, Université Paris Cité, CNRS, 75013 Paris, France
| |
Collapse
|
13
|
Boukaba A, Wu Q, Liu J, Chen C, Liang J, Li J, Strunnikov A. Mapping separase-mediated cleavage in situ. NAR Genom Bioinform 2022; 4:lqac085. [PMID: 36415827 PMCID: PMC9673495 DOI: 10.1093/nargab/lqac085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 10/13/2022] [Accepted: 10/25/2022] [Indexed: 11/21/2022] Open
Abstract
Separase is a protease that performs critical functions in the maintenance of genetic homeostasis. Among them, the cleavage of the meiotic cohesin during meiosis is a key step in producing gametes in eukaryotes. However, the exact chromosomal localization of this proteolytic cleavage was not addressed due to the lack of experimental tools. To this end, we developed a method based on monoclonal antibodies capable of recognizing the predicted neo-epitopes produced by separase-mediated proteolysis in the RAD21 and REC8 cohesin subunits. To validate the epigenomic strategy of mapping cohesin proteolysis, anti-RAD21 neo-epitopes antibodies were used in ChIP-On-ChEPseq analysis of human cells undergoing mitotic anaphase. Second, a similar analysis applied for mapping of REC8 cleavage in germline cells in Macaque showed a correlation with a subset of alpha-satellites and other repeats, directly demonstrating that the site-specific mei-cohesin proteolysis hotspots are coincident but not identical with centromeres. The sequences for the corresponding immunoglobulin genes show a convergence of antibodies with close specificity. This approach could be potentially used to investigate cohesin ring opening events in other chromosomal locations, if applied to single cells.
Collapse
Affiliation(s)
- Abdelhalim Boukaba
- Molecular Epigenetics Laboratory, Guangzhou Institutes of Biomedicine and Health , Guangzhou , Guangdong , 510530 , China
| | - Qiongfang Wu
- Molecular Epigenetics Laboratory, Guangzhou Institutes of Biomedicine and Health , Guangzhou , Guangdong , 510530 , China
| | - Jian Liu
- Molecular Epigenetics Laboratory, Guangzhou Institutes of Biomedicine and Health , Guangzhou , Guangdong , 510530 , China
| | - Cheng Chen
- Molecular Epigenetics Laboratory, Guangzhou Institutes of Biomedicine and Health , Guangzhou , Guangdong , 510530 , China
| | - Jierong Liang
- Molecular Epigenetics Laboratory, Guangzhou Institutes of Biomedicine and Health , Guangzhou , Guangdong , 510530 , China
| | - Jingjing Li
- Molecular Epigenetics Laboratory, Guangzhou Institutes of Biomedicine and Health , Guangzhou , Guangdong , 510530 , China
| | - Alexander V Strunnikov
- Molecular Epigenetics Laboratory, Guangzhou Institutes of Biomedicine and Health , Guangzhou , Guangdong , 510530 , China
| |
Collapse
|
14
|
Archambault V, Li J, Emond-Fraser V, Larouche M. Dephosphorylation in nuclear reassembly after mitosis. Front Cell Dev Biol 2022; 10:1012768. [PMID: 36268509 PMCID: PMC9576876 DOI: 10.3389/fcell.2022.1012768] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 08/31/2022] [Indexed: 11/13/2022] Open
Abstract
In most animal cell types, the interphase nucleus is largely disassembled during mitotic entry. The nuclear envelope breaks down and chromosomes are compacted into separated masses. Chromatin organization is also mostly lost and kinetochores assemble on centromeres. Mitotic protein kinases play several roles in inducing these transformations by phosphorylating multiple effector proteins. In many of these events, the mechanistic consequences of phosphorylation have been characterized. In comparison, how the nucleus reassembles at the end of mitosis is less well understood in mechanistic terms. In recent years, much progress has been made in deciphering how dephosphorylation of several effector proteins promotes nuclear envelope reassembly, chromosome decondensation, kinetochore disassembly and interphase chromatin organization. The precise roles of protein phosphatases in this process, in particular of the PP1 and PP2A groups, are emerging. Moreover, how these enzymes are temporally and spatially regulated to ensure that nuclear reassembly progresses in a coordinated manner has been partly uncovered. This review provides a global view of nuclear reassembly with a focus on the roles of dephosphorylation events. It also identifies important open questions and proposes hypotheses.
Collapse
Affiliation(s)
- Vincent Archambault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC, Canada
- *Correspondence: Vincent Archambault,
| | - Jingjing Li
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Virginie Emond-Fraser
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Myreille Larouche
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
| |
Collapse
|
15
|
Identification of a novel substrate motif of yeast separase and deciphering the recognition specificity using AlphaFold2 and molecular dynamics simulation. Biochem Biophys Res Commun 2022; 620:173-179. [DOI: 10.1016/j.bbrc.2022.06.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 06/19/2022] [Indexed: 11/19/2022]
|
16
|
Chen J, Gao C, Luo M, Zheng C, Lin X, Ning Y, Ma L, He W, Xie D, Liu K, Hong K, Han C. MicroRNA-202 safeguards meiotic progression by preventing premature SEPARASE-mediated REC8 cleavage. EMBO Rep 2022; 23:e54298. [PMID: 35712867 PMCID: PMC9346496 DOI: 10.15252/embr.202154298] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 05/23/2022] [Accepted: 05/27/2022] [Indexed: 03/26/2024] Open
Abstract
MicroRNAs (miRNAs) are believed to play important roles in mammalian spermatogenesis but the in vivo functions of single miRNAs in this highly complex developmental process remain unclear. Here, we report that miR-202, a member of the let-7 family, plays an important role in spermatogenesis by phenotypic evaluation of miR-202 knockout (KO) mice. Loss of miR-202 results in spermatocyte apoptosis and perturbation of the zygonema-to-pachynema transition. Multiple processes during meiosis prophase I including synapsis and crossover formation are disrupted, and inter-sister chromatid synapses are detected. Moreover, we demonstrate that Separase mRNA is a miR-202 direct target and provides evidence that miR-202 upregulates REC8 by repressing Separase expression. Therefore, we have identified miR-202 as a new regulating noncoding gene that acts on the established SEPARASE-REC8 axis in meiosis.
Collapse
Affiliation(s)
- Jian Chen
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
- Institute for Stem Cell and RegenerationChinese Academy of SciencesBeijingChina
- Beijing Institute for Stem Cell and Regenerative MedicineBeijingChina
| | - Chenxu Gao
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
- Institute for Stem Cell and RegenerationChinese Academy of SciencesBeijingChina
- Beijing Institute for Stem Cell and Regenerative MedicineBeijingChina
- Savaid Medical SchoolUniversity of Chinese Academy of SciencesBeijingChina
| | - Mengcheng Luo
- Department of Tissue and EmbryologyHubei Provincial Key Laboratory of Developmentally Originated DiseaseSchool of Basic Medical SciencesWuhan UniversityWuhanChina
| | - Chunwei Zheng
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
- Institute for Stem Cell and RegenerationChinese Academy of SciencesBeijingChina
- Beijing Institute for Stem Cell and Regenerative MedicineBeijingChina
| | - Xiwen Lin
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
- Institute for Stem Cell and RegenerationChinese Academy of SciencesBeijingChina
- Beijing Institute for Stem Cell and Regenerative MedicineBeijingChina
| | - Yan Ning
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
- Institute for Stem Cell and RegenerationChinese Academy of SciencesBeijingChina
- Beijing Institute for Stem Cell and Regenerative MedicineBeijingChina
- Savaid Medical SchoolUniversity of Chinese Academy of SciencesBeijingChina
| | - Longfei Ma
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
- Institute for Stem Cell and RegenerationChinese Academy of SciencesBeijingChina
- Beijing Institute for Stem Cell and Regenerative MedicineBeijingChina
- Savaid Medical SchoolUniversity of Chinese Academy of SciencesBeijingChina
| | - Wei He
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
- Institute for Stem Cell and RegenerationChinese Academy of SciencesBeijingChina
- Beijing Institute for Stem Cell and Regenerative MedicineBeijingChina
- Savaid Medical SchoolUniversity of Chinese Academy of SciencesBeijingChina
| | - Dan Xie
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
- Institute for Stem Cell and RegenerationChinese Academy of SciencesBeijingChina
- Beijing Institute for Stem Cell and Regenerative MedicineBeijingChina
- Savaid Medical SchoolUniversity of Chinese Academy of SciencesBeijingChina
| | - Kui Liu
- Shenzhen Key Laboratory of Fertility RegulationCenter of Assisted Reproduction and EmbryologyThe University of Hong Kong‐Shenzhen HospitalShenzhenChina
- Department of Obstetrics and GynecologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongChina
| | - Kai Hong
- Department of UrologyPeking University Third HospitalBeijingChina
| | - Chunsheng Han
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
- Institute for Stem Cell and RegenerationChinese Academy of SciencesBeijingChina
- Beijing Institute for Stem Cell and Regenerative MedicineBeijingChina
- Savaid Medical SchoolUniversity of Chinese Academy of SciencesBeijingChina
| |
Collapse
|
17
|
Hauf S. Two giants of cell division in an oppressive embrace. Nature 2021; 596:41-42. [PMID: 34290414 DOI: 10.1038/d41586-021-01944-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
18
|
Yu J, Raia P, Ghent CM, Raisch T, Sadian Y, Cavadini S, Sabale PM, Barford D, Raunser S, Morgan DO, Boland A. Structural basis of human separase regulation by securin and CDK1-cyclin B1. Nature 2021; 596:138-142. [PMID: 34290405 PMCID: PMC8482764 DOI: 10.1038/s41586-021-03764-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 06/23/2021] [Indexed: 02/06/2023]
Abstract
In early mitosis, the duplicated chromosomes are held together by the ring-shaped cohesin complex1. Separation of chromosomes during anaphase is triggered by separase-a large cysteine endopeptidase that cleaves the cohesin subunit SCC1 (also known as RAD212-4). Separase is activated by degradation of its inhibitors, securin5 and cyclin B6, but the molecular mechanisms of separase regulation are not clear. Here we used cryogenic electron microscopy to determine the structures of human separase in complex with either securin or CDK1-cyclin B1-CKS1. In both complexes, separase is inhibited by pseudosubstrate motifs that block substrate binding at the catalytic site and at nearby docking sites. As in Caenorhabditis elegans7 and yeast8, human securin contains its own pseudosubstrate motifs. By contrast, CDK1-cyclin B1 inhibits separase by deploying pseudosubstrate motifs from intrinsically disordered loops in separase itself. One autoinhibitory loop is oriented by CDK1-cyclin B1 to block the catalytic sites of both separase and CDK19,10. Another autoinhibitory loop blocks substrate docking in a cleft adjacent to the separase catalytic site. A third separase loop contains a phosphoserine6 that promotes complex assembly by binding to a conserved phosphate-binding pocket in cyclin B1. Our study reveals the diverse array of mechanisms by which securin and CDK1-cyclin B1 bind and inhibit separase, providing the molecular basis for the robust control of chromosome segregation.
Collapse
Affiliation(s)
- Jun Yu
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
| | - Pierre Raia
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
| | - Chloe M Ghent
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
| | - Tobias Raisch
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Yashar Sadian
- Bioimaging Center, University of Geneva, Geneva, Switzerland
| | - Simone Cavadini
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Pramod M Sabale
- Department of Organic Chemistry, NCCR Chemical Biology, University of Geneva, Geneva, Switzerland
| | | | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - David O Morgan
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
| | - Andreas Boland
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland.
| |
Collapse
|
19
|
Thomas C, Wetherall B, Levasseur MD, Harris RJ, Kerridge ST, Higgins JMG, Davies OR, Madgwick S. A prometaphase mechanism of securin destruction is essential for meiotic progression in mouse oocytes. Nat Commun 2021; 12:4322. [PMID: 34262048 PMCID: PMC8280194 DOI: 10.1038/s41467-021-24554-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 06/24/2021] [Indexed: 11/10/2022] Open
Abstract
Successful cell division relies on the timely removal of key cell cycle proteins such as securin. Securin inhibits separase, which cleaves the cohesin rings holding chromosomes together. Securin must be depleted before anaphase to ensure chromosome segregation occurs with anaphase. Here we find that in meiosis I, mouse oocytes contain an excess of securin over separase. We reveal a mechanism that promotes excess securin destruction in prometaphase I. Importantly, this mechanism relies on two phenylalanine residues within the separase-interacting segment (SIS) of securin that are only exposed when securin is not bound to separase. We suggest that these residues facilitate the removal of non-separase-bound securin ahead of metaphase, as inhibiting this period of destruction by mutating both residues causes the majority of oocytes to arrest in meiosis I. We further propose that cellular securin levels exceed the amount an oocyte is capable of removing in metaphase alone, such that the prometaphase destruction mechanism identified here is essential for correct meiotic progression in mouse oocytes.
Collapse
Affiliation(s)
- Christopher Thomas
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK. .,Max Planck Institute for Biophysical Chemistry, Gottingen, Germany.
| | - Benjamin Wetherall
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Mark D Levasseur
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Rebecca J Harris
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Scott T Kerridge
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Jonathan M G Higgins
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Owen R Davies
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.,Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, UK
| | - Suzanne Madgwick
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.
| |
Collapse
|
20
|
Jo M, Kusano Y, Hirota T. Unraveling pathologies underlying chromosomal instability in cancers. Cancer Sci 2021; 112:2975-2983. [PMID: 34032342 PMCID: PMC8353923 DOI: 10.1111/cas.14989] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/16/2021] [Accepted: 05/18/2021] [Indexed: 12/11/2022] Open
Abstract
Aneuploidy is a widespread feature of malignant tumors that arises through persistent chromosome mis‐segregation in mitosis associated with a pathological condition called chromosomal instability, or CIN. Since CIN is known to have a causal relationship with poor prognosis accompanying by multi‐drug resistance, tumor relapse, and metastasis, many research groups have endeavored to understand the mechanisms underlying CIN. In this review, we overview possible etiologies of CIN. The key processes to achieve faithful chromosome segregation include the regulation of sister chromatid cohesion, kinetochore‐microtubule attachment, bipolar spindle formation, spindle‐assembly checkpoint, and the activity of separase. Aberrant chromosome structures during DNA replication might also be a potential cause of CIN. Defective regulation in these processes can lead to chromosome mis‐segregation, manifested by lagging chromosomes, and DNA bridges in anaphase, leading to gross chromosome rearrangements. Investigation into the molecular etiologies of CIN should allow us to explore novel strategies to intervene in CIN to control cancers.
Collapse
Affiliation(s)
- Minji Jo
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research (JFCR), Tokyo, Japan
| | - Yoshiharu Kusano
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research (JFCR), Tokyo, Japan
| | - Toru Hirota
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research (JFCR), Tokyo, Japan
| |
Collapse
|
21
|
Mengoli V, Jonak K, Lyzak O, Lamb M, Lister LM, Lodge C, Rojas J, Zagoriy I, Herbert M, Zachariae W. Deprotection of centromeric cohesin at meiosis II requires APC/C activity but not kinetochore tension. EMBO J 2021; 40:e106812. [PMID: 33644894 PMCID: PMC8013787 DOI: 10.15252/embj.2020106812] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 01/03/2023] Open
Abstract
Genome haploidization involves sequential loss of cohesin from chromosome arms and centromeres during two meiotic divisions. At centromeres, cohesin's Rec8 subunit is protected from separase cleavage at meiosis I and then deprotected to allow its cleavage at meiosis II. Protection of centromeric cohesin by shugoshin-PP2A seems evolutionarily conserved. However, deprotection has been proposed to rely on spindle forces separating the Rec8 protector from cohesin at metaphase II in mammalian oocytes and on APC/C-dependent destruction of the protector at anaphase II in yeast. Here, we have activated APC/C in the absence of sister kinetochore biorientation at meiosis II in yeast and mouse oocytes, and find that bipolar spindle forces are dispensable for sister centromere separation in both systems. Furthermore, we show that at least in yeast, protection of Rec8 by shugoshin and inhibition of separase by securin are both required for the stability of centromeric cohesin at metaphase II. Our data imply that related mechanisms preserve the integrity of dyad chromosomes during the short metaphase II of yeast and the prolonged metaphase II arrest of mammalian oocytes.
Collapse
Affiliation(s)
- Valentina Mengoli
- Laboratory of Chromosome BiologyMax Planck Institute of BiochemistryMartinsriedGermany
- Present address:
Institute for Research in BiomedicineUniversità della Svizzera ItalianaBellinzonaSwitzerland
| | - Katarzyna Jonak
- Laboratory of Chromosome BiologyMax Planck Institute of BiochemistryMartinsriedGermany
| | - Oleksii Lyzak
- Laboratory of Chromosome BiologyMax Planck Institute of BiochemistryMartinsriedGermany
| | - Mahdi Lamb
- Biosciences InstituteCentre for LifeTimes SquareNewcastle UniversityNewcastle upon TyneUK
| | - Lisa M Lister
- Biosciences InstituteCentre for LifeTimes SquareNewcastle UniversityNewcastle upon TyneUK
| | - Chris Lodge
- Biosciences InstituteCentre for LifeTimes SquareNewcastle UniversityNewcastle upon TyneUK
| | - Julie Rojas
- Laboratory of Chromosome BiologyMax Planck Institute of BiochemistryMartinsriedGermany
| | - Ievgeniia Zagoriy
- Laboratory of Chromosome BiologyMax Planck Institute of BiochemistryMartinsriedGermany
- Present address:
EMBL HeidelbergHeidelbergGermany
| | - Mary Herbert
- Biosciences InstituteCentre for LifeTimes SquareNewcastle UniversityNewcastle upon TyneUK
| | - Wolfgang Zachariae
- Laboratory of Chromosome BiologyMax Planck Institute of BiochemistryMartinsriedGermany
| |
Collapse
|
22
|
Li J, Zhang HY, Wang F, Sun QY, Qian WP. The Cyclin B2/CDK1 Complex Conservatively Inhibits Separase Activity in Oocyte Meiosis II. Front Cell Dev Biol 2021; 9:648053. [PMID: 33777955 PMCID: PMC7993350 DOI: 10.3389/fcell.2021.648053] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 02/09/2021] [Indexed: 11/15/2022] Open
Abstract
Recently, we have reported that the cyclin B2/CDK1 complex regulates homologous chromosome segregation through inhibiting separase activity in oocyte meiosis I, which further elucidates the compensation of cyclin B2 on cyclin B1’s function in meiosis I. However, whether cyclin B2/CDK1 complex also negatively regulates separase activity during oocyte meiosis II remains unknown. In the present study, we investigated the function of cyclin B2 in meiosis II of oocyte. We found that stable cyclin B2 expression impeded segregation of sister chromatids after oocyte parthenogenetic activation. Consistently, stable cyclin B2 inhibited separase activation, while introduction of non-phosphorylatable separase mutant rescued chromatid separation in the stable cyclin B2-expressed oocytes. Therefore, the cyclin B2/CDK1 complex conservatively regulates separase activity via inhibitory phosphorylation of separase in both meiosis I and meiosis II of mouse oocyte.
Collapse
Affiliation(s)
- Jian Li
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Hong-Yong Zhang
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China.,State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Feng Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Qing-Yuan Sun
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Wei-Ping Qian
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China.,Guangdong Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, China
| |
Collapse
|
23
|
Abstract
Separase is a large cysteine protease in eukaryotes and has crucial roles in many cellular processes, especially chromosome segregation during mitosis and meiosis, apoptosis, DNA damage repair, centrosome disengagement and duplication, spindle stabilization and elongation. It dissolves the cohesion between sister chromatids by cleaving one of the subunits of the cohesin ring for chromosome segregation. The activity of separase is tightly controlled at many levels, through direct binding of inhibitory proteins as well as posttranslational modification. Dysregulation of separase activity is linked to cancer and genome instability, making it a target for drug discovery. One of the best-known inhibitors of separase is securin, which has been identified in yeast, plants, and animals. Securin forms a tight complex with separase and potently inhibits its catalytic activity. Recent structures of the separase-securin complex have revealed the molecular mechanism for the inhibitory activity of securin. A segment of securin is bound in the active site of separase, thereby blocking substrate binding. Securin itself is not cleaved by separase as its binding mode is not compatible with catalysis. Securin also has extensive interactions with separase outside the active site, consistent with its function as a chaperone to stabilize this enzyme.
Collapse
Affiliation(s)
- Shukun Luo
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA.
| |
Collapse
|
24
|
Holder J, Mohammed S, Barr FA. Ordered dephosphorylation initiated by the selective proteolysis of cyclin B drives mitotic exit. eLife 2020; 9:e59885. [PMID: 32869743 PMCID: PMC7529458 DOI: 10.7554/elife.59885] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/31/2020] [Indexed: 12/13/2022] Open
Abstract
APC/C-mediated proteolysis of cyclin B and securin promotes anaphase entry, inactivating CDK1 and permitting chromosome segregation, respectively. Reduction of CDK1 activity relieves inhibition of the CDK1-counteracting phosphatases PP1 and PP2A-B55, allowing wide-spread dephosphorylation of substrates. Meanwhile, continued APC/C activity promotes proteolysis of other mitotic regulators. Together, these activities orchestrate a complex series of events during mitotic exit. However, the relative importance of regulated proteolysis and dephosphorylation in dictating the order and timing of these events remains unclear. Using high temporal-resolution proteomics, we compare the relative extent of proteolysis and protein dephosphorylation. This reveals highly-selective rapid proteolysis of cyclin B, securin and geminin at the metaphase-anaphase transition, followed by slow proteolysis of other substrates. Dephosphorylation requires APC/C-dependent destruction of cyclin B and was resolved into PP1-dependent categories with unique sequence motifs. We conclude that dephosphorylation initiated by selective proteolysis of cyclin B drives the bulk of changes observed during mitotic exit.
Collapse
Affiliation(s)
- James Holder
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
| | - Shabaz Mohammed
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
| | - Francis A Barr
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
| |
Collapse
|
25
|
Antitumor effect of a WEE1 inhibitor and potentiation of olaparib sensitivity by DNA damage response modulation in triple-negative breast cancer. Sci Rep 2020; 10:9930. [PMID: 32555285 PMCID: PMC7303169 DOI: 10.1038/s41598-020-66018-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 03/06/2020] [Indexed: 01/24/2023] Open
Abstract
Due to its regulation of CDK1/2 phosphorylation, WEE1 plays essentially roles in the regulations of G2/M checkpoint and DNA damage response (DDR). WEE1 inhibition can increase genomic instability by inducing replication stress and G2/M checkpoint inactivation, which result in increased cellular sensitivity to DNA damaging agents. We considered an increase in genomic instability induced by WEE1 inhibition might be used to augment the effects of drugs targeting DNA repair protein. Typically, PARP inhibitors are effective in germline BRCA 1/2 mutated breast and ovarian cancer, but their applicabilities in triple-negative breast cancer (TNBC) are limited. This study was conducted to investigate the anti-tumor effects of the WEE1 inhibitor, AZD1775, and the mechanism responsible for its potentiation of sensitivity to olaparib (a PARP inhibitor) via the modulation of DDR in TNBC cells. Our results suggest that AZD1775 could be used to broaden the application range of olaparib in TNBC and provide a rationale for a clinical trial of combined olaparib and AZD1775 therapy.
Collapse
|
26
|
Cyclin A1 in Oocytes Prevents Chromosome Segregation And Anaphase Entry. Sci Rep 2020; 10:7455. [PMID: 32366979 PMCID: PMC7198627 DOI: 10.1038/s41598-020-64418-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 04/13/2020] [Indexed: 11/08/2022] Open
Abstract
In several species, including Xenopus, mouse and human, two members of cyclin A family were identified. Cyclin A2, which is ubiquitously expressed in dividing cells and plays role in DNA replication, entry into mitosis and spindle assembly, and cyclin A1, whose function is less clear and which is expressed in spermatocytes, leukemia cells and in postmitotic multiciliated cells. Deletion of the gene showed that cyclin A1 is essential for male meiosis, but nonessential for female meiosis. Our results revealed, that the cyclin A1 is not only dispensable in oocytes, we show here that its expression is in fact undesirable in these cells. Our data demonstrate that the APC/C and proteasome in oocytes are unable to target sufficiently cyclin A1 before anaphase, which leads into anaphase arrest and direct inhibition of separase. The cyclin A1-induced cell cycle arrest is oocyte-specific and the presence of cyclin A1 in early embryos has no effect on cell cycle progression or chromosome division. Cyclin A1 is therefore not only an important cell cycle regulator with biased expression in germline, being essential for male and damaging for female meiosis, its persistent expression during anaphase in oocytes shows fundamental differences between APC/C function in oocytes and in early embryos.
Collapse
|
27
|
Separase-triggered apoptosis enforces minimal length of mitosis. Nature 2020; 580:542-547. [PMID: 32322059 DOI: 10.1038/s41586-020-2187-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 02/10/2020] [Indexed: 01/13/2023]
Abstract
Prolonged mitosis often results in apoptosis1. Shortened mitosis causes tumorigenic aneuploidy, but it is unclear whether it also activates the apoptotic machinery2. Separase, a cysteine protease and trigger of all eukaryotic anaphases, has a caspase-like catalytic domain but has not previously been associated with cell death3,4. Here we show that human cells that enter mitosis with already active separase rapidly undergo death in mitosis owing to direct cleavage of anti-apoptotic MCL1 and BCL-XL by separase. Cleavage not only prevents MCL1 and BCL-XL from sequestering pro-apoptotic BAK, but also converts them into active promoters of death in mitosis. Our data strongly suggest that the deadliest cleavage fragment, the C-terminal half of MCL1, forms BAK/BAX-like pores in the mitochondrial outer membrane. MCL1 and BCL-XL are turned into separase substrates only upon phosphorylation by NEK2A. Early mitotic degradation of this kinase is therefore crucial for preventing apoptosis upon scheduled activation of separase in metaphase. Speeding up mitosis by abrogation of the spindle assembly checkpoint results in a temporal overlap of the enzymatic activities of NEK2A and separase and consequently in cell death. We propose that NEK2A and separase jointly check on spindle assembly checkpoint integrity and eliminate cells that are prone to chromosome missegregation owing to accelerated progression through early mitosis.
Collapse
|
28
|
Hellmuth S, Gómez-H L, Pendás AM, Stemmann O. Securin-independent regulation of separase by checkpoint-induced shugoshin-MAD2. Nature 2020; 580:536-541. [PMID: 32322060 DOI: 10.1038/s41586-020-2182-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 01/31/2020] [Indexed: 01/27/2023]
Abstract
Separation of eukaryotic sister chromatids during the cell cycle is timed by the spindle assembly checkpoint (SAC) and ultimately triggered when separase cleaves cohesion-mediating cohesin1-3. Silencing of the SAC during metaphase activates the ubiquitin ligase APC/C (anaphase-promoting complex, also known as the cyclosome) and results in the proteasomal destruction of the separase inhibitor securin1. In the absence of securin, mammalian chromosomes still segregate on schedule, but it is unclear how separase is regulated under these conditions4,5. Here we show that human shugoshin 2 (SGO2), an essential protector of meiotic cohesin with unknown functions in the soma6,7, is turned into a separase inhibitor upon association with SAC-activated MAD2. SGO2-MAD2 can functionally replace securin and sequesters most separase in securin-knockout cells. Acute loss of securin and SGO2, but not of either protein individually, resulted in separase deregulation associated with premature cohesin cleavage and cytotoxicity. Similar to securin8,9, SGO2 is a competitive inhibitor that uses a pseudo-substrate sequence to block the active site of separase. APC/C-dependent ubiquitylation and action of the AAA-ATPase TRIP13 in conjunction with the MAD2-specific adaptor p31comet liberate separase from SGO2-MAD2 in vitro. The latter mechanism facilitates a considerable degree of sister chromatid separation in securin-knockout cells that lack APC/C activity. Thus, our results identify an unexpected function of SGO2 in mitotically dividing cells and a mechanism of separase regulation that is independent of securin but still supervised by the SAC.
Collapse
Affiliation(s)
| | - Laura Gómez-H
- Molecular Mechanisms Program, Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), Salamanca, Spain
| | - Alberto M Pendás
- Molecular Mechanisms Program, Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), Salamanca, Spain
| | - Olaf Stemmann
- Chair of Genetics, University of Bayreuth, Bayreuth, Germany.
| |
Collapse
|
29
|
Li J, Dong F, Ouyang YC, Sun QY, Qian WP. Overexpression of cyclin A1 promotes meiotic resumption but induces premature chromosome separation in mouse oocyte. J Cell Physiol 2020; 235:7136-7145. [PMID: 32030765 DOI: 10.1002/jcp.29612] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 01/22/2020] [Indexed: 01/29/2023]
Abstract
Mammalian cyclin A1 is prominently expressed in testis and essential for meiosis in the male mouse, however, it shows weak expression in ovary, especially during oocyte maturation. To understand why cyclin A1 behaves in this way in the oocyte, we investigated the effect of cyclin A1 overexpression on mouse oocyte meiotic maturation. Our results revealed that cyclin A1 overexpression triggered meiotic resumption even in the presence of germinal vesicle breakdown inhibitor, milrinone. Nevertheless, the cyclin A1-overexpressed oocytes failed to extrude the first polar body but were completely arrested at metaphase I. Consequently, cyclin A1 overexpression destroyed the spindle morphology and chromosome alignment by inducing premature separation of chromosomes and sister chromatids. Therefore, cyclin A1 overexpression will prevent oocyte maturation although it can promote meiotic resumption. All these results show that decreased expression of cyclin A1 in oocytes may have an evolutional significance to keep long-lasting prophase arrest and orderly chromosome separation during oocyte meiotic maturation.
Collapse
Affiliation(s)
- Jian Li
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China.,State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Feng Dong
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Ying-Chun Ouyang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Qing-Yuan Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Wei-Ping Qian
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| |
Collapse
|
30
|
Zhang N, Sarkar AK, Li F, Demerzhan SA, Gilbertson SR, Pati D. Stability and pharmacokinetics of separase inhibitor-Sepin-1 in Sprague-Dawley rats. Biochem Pharmacol 2020; 174:113808. [PMID: 31930961 DOI: 10.1016/j.bcp.2020.113808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 01/09/2020] [Indexed: 11/29/2022]
Abstract
Separase, a sister chromatid cohesion-resolving enzyme, is an oncogene and overexpressed in many human cancers. Sepin-1 (2,2-dimethyl-5-nitro-2H-benzimidazole-1,3-dioxide) is a potent separase inhibitor that impedes cancer cell growth, cell migration, and wound healing, suggesting that Sepin-1 possesses a great potential to target separase-overexpressing tumors. As a part of the IND-enabling studies to bring Sepin-1 to clinic, herein we report the results from a 28-day repeat-dose pharmacokinetic study of Sepin-1 in rats. Sepin-1 was intravenously administered to Sprague-Dawley rats once daily for 28 days at three different (5, 10, and 20 mg/kg) doses. Blood samples were collected after administration of doses on days 1 and 28. Sepin-1 is unstable and isomerizes in basic solutions, but it is stable in acidic buffer such as citrate-buffered saline (pH 4.0). UHPLC-MS analysis indicated Sepin-1 was rapidly metabolized in vivo. One of the major metabolites was an amine adduct of 2,2-dimethyl-5-nitro-2H-benzimidazole (named Sepin-1.55). The concentration of Sepin-1.55 in blood samples was Sepin-1 dose-dependent and used for pharmacokinetic analysis of Sepin-1. Tmax was approximately 5-15 min. The data suggest that no Sepin-1 accumulation occurred from daily repeat dosing and similar exposures on the first and final day of dosing. Data also suggest a gender difference, namely that female rats have more exposure and slower clearance than male rats. The data support that Sepin-1 is a potential drug candidate that can be further developed to treat Separase-overexpressing human tumors.
Collapse
Affiliation(s)
- Nenggang Zhang
- Texas Children's Cancer Center, Departments of Pediatrics and Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Asis K Sarkar
- Texas Children's Cancer Center, Departments of Pediatrics and Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Feng Li
- Center for Drug Discovery, Departments of Pathology and Immunology, Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX, USA
| | | | | | - Debananda Pati
- Texas Children's Cancer Center, Departments of Pediatrics and Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
| |
Collapse
|
31
|
Bansal S, Tiwari S. Mechanisms for the temporal regulation of substrate ubiquitination by the anaphase-promoting complex/cyclosome. Cell Div 2019; 14:14. [PMID: 31889987 PMCID: PMC6927175 DOI: 10.1186/s13008-019-0057-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 12/04/2019] [Indexed: 12/16/2022] Open
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is a multi-subunit, multifunctional ubiquitin ligase that controls the temporal degradation of numerous cell cycle regulatory proteins to direct the unidirectional cell cycle phases. Several different mechanisms contribute to ensure the correct order of substrate modification by the APC/C complex. Recent advances in biochemical, biophysical and structural studies of APC/C have provided a deep mechanistic insight into the working of this complex ubiquitin ligase. This complex displays remarkable conformational flexibility in response to various binding partners and post-translational modifications, which together regulate substrate selection and catalysis of APC/C. Apart from this, various features and modifications of the substrates also influence their recognition and affinity to APC/C complex. Ultimately, temporal degradation of substrates depends on the kind of ubiquitin modification received, the processivity of APC/C, and other extrinsic mechanisms. This review discusses our current understanding of various intrinsic and extrinsic mechanisms responsible for 'substrate ordering' by the APC/C complex.
Collapse
Affiliation(s)
- Shivangee Bansal
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Swati Tiwari
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067 India
| |
Collapse
|
32
|
Li J, Ouyang YC, Zhang CH, Qian WP, Sun QY. The cyclin B2/CDK1 complex inhibits separase activity in mouse oocyte meiosis I. Development 2019; 146:dev.182519. [PMID: 31704793 DOI: 10.1242/dev.182519] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 11/04/2019] [Indexed: 01/26/2023]
Abstract
Chromosome segregation is driven by separase, activity of which is inhibited by binding to securin and cyclin B1/CDK1. In meiosis, premature separase activity will induce aneuploidy or abolish chromosome segregation owing to the untimely destruction of cohesin. Recently, we have proved that cyclin B2 can compensate for cyclin B1 in CDK1 activation for the oocyte meiosis G2/M transition. In the present study, we identify an interaction between cyclin B2/CDK1 and separase in mouse oocytes. We find that cyclin B2 degradation is required for separase activation during the metaphase I-anaphase I transition because the presence of stable cyclin B2 leads to failure of homologous chromosome separation and to metaphase I arrest, especially in the simultaneous absence of securin and cyclin B1. Moreover, non-phosphorylatable separase rescues the separation of homologous chromosomes in stable cyclin B2-arrested cyclin B1-null oocytes. Our results indicate that cyclin B2/CDK1 is also responsible for separase inhibition via inhibitory phosphorylation to regulate chromosome separation in oocyte meiosis, which may not occur in other cell types.
Collapse
Affiliation(s)
- Jian Li
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, 518036 Shenzhen, China.,State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, China
| | - Ying-Chun Ouyang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, China
| | - Chun-Hui Zhang
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, 518036 Shenzhen, China
| | - Wei-Ping Qian
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, 518036 Shenzhen, China
| | - Qing-Yuan Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, China .,University of Chinese Academy of Sciences, 100101 Beijing, China
| |
Collapse
|
33
|
Rosen LE, Klebba JE, Asfaha JB, Ghent CM, Campbell MG, Cheng Y, Morgan DO. Cohesin cleavage by separase is enhanced by a substrate motif distinct from the cleavage site. Nat Commun 2019; 10:5189. [PMID: 31729382 PMCID: PMC6858450 DOI: 10.1038/s41467-019-13209-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 10/28/2019] [Indexed: 11/18/2022] Open
Abstract
Chromosome segregation begins when the cysteine protease, separase, cleaves the Scc1 subunit of cohesin at the metaphase-to-anaphase transition. Separase is inhibited prior to metaphase by the tightly bound securin protein, which contains a pseudosubstrate motif that blocks the separase active site. To investigate separase substrate specificity and regulation, here we develop a system for producing recombinant, securin-free human separase. Using this enzyme, we identify an LPE motif on the Scc1 substrate that is distinct from the cleavage site and is required for rapid and specific substrate cleavage. Securin also contains a conserved LPE motif, and we provide evidence that this sequence blocks separase engagement of the Scc1 LPE motif. Our results suggest that rapid cohesin cleavage by separase requires a substrate docking interaction outside the active site. This interaction is blocked by securin, providing a second mechanism by which securin inhibits cohesin cleavage.
Collapse
Affiliation(s)
- Laura E Rosen
- Department of Physiology, University of California, San Francisco, CA, 94143, USA
| | - Joseph E Klebba
- Department of Physiology, University of California, San Francisco, CA, 94143, USA
| | - Jonathan B Asfaha
- Department of Physiology, University of California, San Francisco, CA, 94143, USA
| | - Chloe M Ghent
- Department of Physiology, University of California, San Francisco, CA, 94143, USA
| | - Melody G Campbell
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, 94143, USA
| | - Yifan Cheng
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, 94143, USA
| | - David O Morgan
- Department of Physiology, University of California, San Francisco, CA, 94143, USA.
| |
Collapse
|
34
|
Toxicity study of separase inhibitor-Sepin-1 in Sprague-Dawley rats. Pathol Res Pract 2019; 216:152730. [PMID: 31784093 DOI: 10.1016/j.prp.2019.152730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/17/2019] [Accepted: 11/10/2019] [Indexed: 01/01/2023]
Abstract
Sepin-1 is a small compound that inhibits enzymatic activity of Separase and growth of cancer cells. As part of the IND-enabling studies to develop Sepin-1 as a chemotherapeutic agent, herein we have profiled the toxicity of Sepin-1 in Sprague-Dawley rats in a good laboratory practice (GLP) setting. The maximum tolerated dose (MTD) of Sepin-1 in rats is 40 mg/kg in single dose study and 20 mg/kg in the study dosed for 7 consecutive days. The toxicity study consists of two parts-Main Study and Recovery Study. Sepin-1 with 0 (control), 5 (low dose), 10 (median dose), and 20 (high dose) mg/kg was administered by bolus intravenous injection to rats once daily for 28 consecutive days. The animals in the Main Study were euthanized on Day 29, whereas animals in the Recovery Study were allowed to recover for 28 days following the 28-day Sepin-1 dose before they were euthanized on Day 29 of the off-dose period. Although the effects of Sepin-1 at low and median doses are minimal, hematological analysis shows that high-dose Sepin-1 is associated with decrease of red blood cells and hemoglobin, and increase in the number of reticulocytes and platelets as well as mean corpuscular volume. Clinical chemistry indicates that Sepin-1 causes increase of total bilirubin and decrease of creatine kinase. Histopathology analysis indicates Sepin-1 results in minimal bone marrow erythroid hyperplasia, minimal to moderate splenic extramedullary hematopoiesis, minimal splenic lymphoid depletion, minimal to mild thymic lymphoid depletion, and minimal to mild mandibular lymph node lymphoid hyperplasia in male and female rats in the Main Study. Those abnormal changes are Sepin-1 dose-dependent and mostly reversible after a 28-day recovery period in animals from the Recovery Study. Based on our results, we conclude that Sepin-1 at pharmacologic doses (5-10 mg/kg) is well tolerable, with no significant rates of mortality or morbidity, and can further be developed as a potential new drug to treat Separase-overexpressed tumors.
Collapse
|
35
|
Holder J, Poser E, Barr FA. Getting out of mitosis: spatial and temporal control of mitotic exit and cytokinesis by PP1 and PP2A. FEBS Lett 2019; 593:2908-2924. [PMID: 31494926 DOI: 10.1002/1873-3468.13595] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 07/31/2019] [Accepted: 08/19/2019] [Indexed: 12/11/2022]
Abstract
Here, we will review the evidence showing that mitotic exit is initiated by regulated proteolysis and then driven by the PPP family of phosphoserine/threonine phosphatases. Rapid APC/CCDC20 and ubiquitin-dependent proteolysis of cyclin B and securin initiates sister chromatid separation, the first step of mitotic exit. Because proteolysis of Aurora and Polo family kinases dependent on APC/CCDH1 is relatively slow, this creates a new regulatory state, anaphase, different to G2 and M-phase. We will discuss how the CDK1-counteracting phosphatases PP1 and PP2A-B55, together with Aurora and Polo kinases, contribute to the temporal regulation and order of events in the different stages of mitotic exit from anaphase to cytokinesis. For PP2A-B55, these timing properties are created by the ENSA-dependent inhibitory pathway and differential recognition of phosphoserine and phosphothreonine. Finally, we will discuss how Aurora B and PP2A-B56 are needed for the spatial regulation of anaphase spindle formation and how APC/C-dependent destruction of PLK1 acts as a timer for abscission, the final event of cytokinesis.
Collapse
Affiliation(s)
- James Holder
- Department of Biochemistry, University of Oxford, UK
| | - Elena Poser
- Department of Biochemistry, University of Oxford, UK
| | | |
Collapse
|
36
|
Masnadi-Shirazi M, Maurya MR, Pao G, Ke E, Verma IM, Subramaniam S. Time varying causal network reconstruction of a mouse cell cycle. BMC Bioinformatics 2019; 20:294. [PMID: 31142274 PMCID: PMC6542064 DOI: 10.1186/s12859-019-2895-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 05/13/2019] [Indexed: 12/21/2022] Open
Abstract
Background Biochemical networks are often described through static or time-averaged measurements of the component macromolecules. Temporal variation in these components plays an important role in both describing the dynamical nature of the network as well as providing insights into causal mechanisms. Few methods exist, specifically for systems with many variables, for analyzing time series data to identify distinct temporal regimes and the corresponding time-varying causal networks and mechanisms. Results In this study, we use well-constructed temporal transcriptional measurements in a mammalian cell during a cell cycle, to identify dynamical networks and mechanisms describing the cell cycle. The methods we have used and developed in part deal with Granger causality, Vector Autoregression, Estimation Stability with Cross Validation and a nonparametric change point detection algorithm that enable estimating temporally evolving directed networks that provide a comprehensive picture of the crosstalk among different molecular components. We applied our approach to RNA-seq time-course data spanning nearly two cell cycles from Mouse Embryonic Fibroblast (MEF) primary cells. The change-point detection algorithm is able to extract precise information on the duration and timing of cell cycle phases. Using Least Absolute Shrinkage and Selection Operator (LASSO) and Estimation Stability with Cross Validation (ES-CV), we were able to, without any prior biological knowledge, extract information on the phase-specific causal interaction of cell cycle genes, as well as temporal interdependencies of biological mechanisms through a complete cell cycle. Conclusions The temporal dependence of cellular components we provide in our model goes beyond what is known in the literature. Furthermore, our inference of dynamic interplay of multiple intracellular mechanisms and their temporal dependence on one another can be used to predict time-varying cellular responses, and provide insight on the design of precise experiments for modulating the regulation of the cell cycle. Electronic supplementary material The online version of this article (10.1186/s12859-019-2895-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Maryam Masnadi-Shirazi
- Department of Electrical and Computer Engineering and Bioengineering, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - Mano R Maurya
- Department of Bioengineering and San Diego Supercomputer center, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - Gerald Pao
- Salk institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Eugene Ke
- Salk institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Inder M Verma
- Salk institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Shankar Subramaniam
- Department of Bioengineering, Departments of Computer Science and Engineering, Cellular and Molecular Medicine, and the Graduate Program in Bioinformatics, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA.
| |
Collapse
|
37
|
Mirkovic M, Oliveira RA. Centromeric Cohesin: Molecular Glue and Much More. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2019; 56:485-513. [PMID: 28840250 DOI: 10.1007/978-3-319-58592-5_20] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sister chromatid cohesion, mediated by the cohesin complex, is a prerequisite for faithful chromosome segregation during mitosis. Premature release of sister chromatid cohesion leads to random segregation of the genetic material and consequent aneuploidy. Multiple regulatory mechanisms ensure proper timing for cohesion establishment, concomitant with DNA replication, and cohesion release during the subsequent mitosis. Here we summarize the most important phases of the cohesin cycle and the coordination of cohesion release with the progression through mitosis. We further discuss recent evidence that has revealed additional functions for centromeric localization of cohesin in the fidelity of mitosis in metazoans. Beyond its well-established role as "molecular glue", centromeric cohesin complexes are now emerging as a scaffold for multiple fundamental processes during mitosis, including the formation of correct chromosome and kinetochore architecture, force balance with the mitotic spindle, and the association with key molecules that regulate mitotic fidelity, particularly at the chromosomal inner centromere. Centromeric chromatin may be thus seen as a dynamic place where cohesin ensures mitotic fidelity by multiple means.
Collapse
Affiliation(s)
- Mihailo Mirkovic
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 2780-156, Oeiras, Portugal
| | - Raquel A Oliveira
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 2780-156, Oeiras, Portugal.
| |
Collapse
|
38
|
Alfonso-Pérez T, Hayward D, Holder J, Gruneberg U, Barr FA. MAD1-dependent recruitment of CDK1-CCNB1 to kinetochores promotes spindle checkpoint signaling. J Cell Biol 2019; 218:1108-1117. [PMID: 30674583 PMCID: PMC6446853 DOI: 10.1083/jcb.201808015] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 11/19/2018] [Accepted: 01/07/2019] [Indexed: 12/22/2022] Open
Abstract
Cyclin B-dependent kinase (CDK1-CCNB1) promotes entry into mitosis. Additionally, it inhibits mitotic exit by activating the spindle checkpoint. This latter role is mediated through phosphorylation of the checkpoint kinase MPS1 and other spindle checkpoint proteins. We find that CDK1-CCNB1 localizes to unattached kinetochores and like MPS1 is lost from these structures upon microtubule attachment. This suggests that CDK1-CCNB1 is an integral component and not only an upstream regulator of the spindle checkpoint pathway. Complementary proteomic and cell biological analysis demonstrate that the spindle checkpoint protein MAD1 is one of the major components of CCNB1 complexes, and that CCNB1 is recruited to unattached kinetochores in an MPS1-dependent fashion through interaction with the first 100 amino acids of MAD1. This MPS1 and MAD1-dependent pool of CDK1-CCNB1 creates a positive feedback loop necessary for timely recruitment of MPS1 to kinetochores during mitotic entry and for sustained spindle checkpoint arrest. CDK1-CCNB1 is therefore an integral component of the spindle checkpoint, ensuring the fidelity of mitosis.
Collapse
Affiliation(s)
| | - Daniel Hayward
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - James Holder
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Ulrike Gruneberg
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Francis A Barr
- Department of Biochemistry, University of Oxford, Oxford, UK
| |
Collapse
|
39
|
Li Y, Wang L, Zhang L, He Z, Feng G, Sun H, Wang J, Li Z, Liu C, Han J, Mao J, Li P, Yuan X, Jiang L, Zhang Y, Zhou Q, Li W. Cyclin B3 is required for metaphase to anaphase transition in oocyte meiosis I. J Cell Biol 2019; 218:1553-1563. [PMID: 30770433 PMCID: PMC6504906 DOI: 10.1083/jcb.201808088] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/18/2018] [Accepted: 02/07/2019] [Indexed: 12/20/2022] Open
Abstract
Meiosis with a single round of DNA replication and two successive rounds of chromosome segregation requires specific cyclins associated with cyclin-dependent kinases (CDKs) to ensure its fidelity. But how cyclins control the distinctive meiosis is still largely unknown. In this study, we explored the role of cyclin B3 in female meiosis by generating Ccnb3 mutant mice via CRISPR/Cas9. Ccnb3 mutant oocytes characteristically arrested at metaphase I (MetI) with normal spindle assembly and lacked enough anaphase-promoting complex/cyclosome (APC/C) activity, which is spindle assembly checkpoint (SAC) independent, to initiate anaphase I (AnaI). Securin siRNA or CDK1 inhibitor supplements rescued the MetI arrest. Furthermore, CCNB3 directly interacts with CDK1 to exert kinase function. Besides, the MetI arrest oocytes had normal development after intracytoplasmic sperm injection (ICSI) or parthenogenetic activation (PA), along with releasing the sister chromatids, which implies that Ccnb3 exclusively functioned in meiosis I, rather than meiosis II. Our study sheds light on the specific cell cycle control of cyclins in meiosis.
Collapse
Affiliation(s)
- Yufei Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
| | - Leyun Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
| | - Linlin Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Zhengquan He
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
| | - Guihai Feng
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
| | - Hao Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jiaqiang Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
| | - Zhikun Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
| | - Chao Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jiabao Han
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Junjie Mao
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Pengcheng Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,College of Life Science, Northeast Agricultural University of China, Harbin, China
| | - Xuewei Yuan
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,College of Life Science, Northeast Agricultural University of China, Harbin, China
| | - Liyuan Jiang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,College of Life Science, Northeast Agricultural University of China, Harbin, China
| | - Ying Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China .,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
| | - Qi Zhou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China .,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Wei Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China .,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
40
|
Konishi M, Shindo N, Komiya M, Tanaka K, Itoh T, Hirota T. Quantitative analyses of the metaphase-to-anaphase transition reveal differential kinetic regulation for securin and cyclin B1. Biomed Res 2018; 39:75-85. [PMID: 29669986 DOI: 10.2220/biomedres.39.75] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Separation of sister chromatids is a drastic and irreversible step in the cell cycle. The key biochemistry behind this event is the proteolysis mediated by the ubiquitin ligase called the anaphase promoting complex, or APC/C. Securin and cyclin B1 are the two established substrates for APC/C whose degradation releases separase and inactivates cyclin B1-dependent kinase 1 (cdk1), respectively, at the metaphase-to-anaphase transition. In this study, we have combined biochemical quantifications with mathematical simulations to characterize the kinetic regulation of securin and cyclin B1, in the cytoplasmic and chromosomal compartments, and found that they are differentially distributed and degraded with different rates. Modeling their interaction with separase predicted that activation timing of separase well coincides with the decline of securin-separase concentration in the cytoplasm. Notably, it also coincides with the peak of cyclin B1-separase level on chromosomes, which appeared crucial to coordinate the timing for separase activation and cdk1 inhibition. We have also conducted phosphoproteomic analysis and identified Ki67 as a chromosomal cdk1 substrate whose dephosphorylation is facilitated by cyclin B1-separase interaction in anaphase.
Collapse
Affiliation(s)
- Makoto Konishi
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research (JFCR).,Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology
| | - Norihisa Shindo
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research (JFCR)
| | - Masataka Komiya
- Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology
| | - Kozo Tanaka
- Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University
| | - Takehiko Itoh
- Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology
| | - Toru Hirota
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research (JFCR)
| |
Collapse
|
41
|
Li F, Zhang N, Gorantla S, Gilbertson SR, Pati D. The Metabolism of Separase Inhibitor Sepin-1 in Human, Mouse, and Rat Liver Microsomes. Front Pharmacol 2018; 9:313. [PMID: 29867452 PMCID: PMC5949348 DOI: 10.3389/fphar.2018.00313] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Accepted: 03/19/2018] [Indexed: 01/02/2023] Open
Abstract
Separase, a known oncogene, is widely overexpressed in numerous human tumors of breast, bone, brain, blood, and prostate. Separase is an emerging target for cancer therapy, and separase enzymatic inhibitors such as sepin-1 are currently being developed to treat separase-overexpressed tumors. Drug metabolism plays a critical role in the efficacy and safety of drug development, as well as possible drug–drug interactions. In this study, we investigated the in vitro metabolism of sepin-1 in human, mouse, and rat liver microsomes (RLM) using metabolomic approaches. In human liver microsomes (HLM), we identified seven metabolites including one cysteine–sepin-1 adduct and one glutathione–sepin-1 adduct. All the sepin-1 metabolites in HLM were also found in both mouse and RLM. Using recombinant CYP450 isoenzymes, we demonstrated that multiple enzymes contributed to the metabolism of sepin-1, including CYP2D6 and CYP3A4 as the major metabolizing enzymes. Inhibitory effects of sepin-1 on seven major CYP450s were also evaluated using the corresponding substrates recommended by the US Food and Drug Administration. Our studies indicated that sepin-1 moderately inhibits CYP1A2, CYP2C19, and CYP3A4 with IC50 < 10 μM but weakly inhibits CYP2B6, CYP2C8/9, and CYP2D6 with IC50 > 10 μM. This information can be used to optimize the structures of sepin-1 for more suitable pharmacological properties and to predict the possible sepin-1 interactions with other chemotherapeutic drugs.
Collapse
Affiliation(s)
- Feng Li
- Center for Drug Discovery, Baylor College of Medicine, Houston, TX, United States.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States.,Advance Technology Core, Baylor College of Medicine, Houston, TX, United States
| | - Nenggang Zhang
- Texas Children's Cancer Center, Houston, TX, United States.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Siddharth Gorantla
- Texas Children's Cancer Center, Houston, TX, United States.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Scott R Gilbertson
- Department of Chemistry, University of Houston, Houston, TX, United States
| | - Debananda Pati
- Center for Drug Discovery, Baylor College of Medicine, Houston, TX, United States.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States.,Texas Children's Cancer Center, Houston, TX, United States.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| |
Collapse
|
42
|
Melesse M, Bembenek JN, Zhulin IB. Conservation of the separase regulatory domain. Biol Direct 2018; 13:7. [PMID: 29703221 PMCID: PMC5921967 DOI: 10.1186/s13062-018-0210-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 04/18/2018] [Indexed: 11/10/2022] Open
Abstract
ᅟ: We report a protein sequence analysis of the cell cycle regulatory protease, separase. The sequence and structural conservation of the C-terminal protease domain has long been recognized, whereas the N-terminal regulatory domain of separase was reported to lack detectable sequence similarity. Here we reveal significant sequence conservation of the separase regulatory domain and report a discovery of a cysteine motif (CxCxxC) conserved in major lineages of Metazoa including nematodes and vertebrates. This motif is found in a solvent exposed linker region connecting two TPR-like helical motifs. Mutation of this motif in Caenorhabditis elegans separase leads to a temperature sensitive hypomorphic protein. Conservation of this motif in organisms ranging from C. elegans to humans suggests its functional importance. REVIEWERS This article was reviewed by Lakshminarayan Iyer and Michael Galperin.
Collapse
Affiliation(s)
- Michael Melesse
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Joshua N Bembenek
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA.
| | - Igor B Zhulin
- Department of Microbiology, University of Tennessee, 1414 Cumberland Ave, Knoxville, TN, 37996, USA. .,Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
| |
Collapse
|
43
|
Zhang N, Pati D. Separase Inhibitor Sepin-1 Inhibits Foxm1 Expression and Breast Cancer Cell Growth. JOURNAL OF CANCER SCIENCE & THERAPY 2018; 10:517. [PMID: 29780443 PMCID: PMC5959057 DOI: 10.4172/1948-5956.1000517] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Sepin-1, a potent non-competitive inhibitor of separase, inhibits cancer cell growth, but the mechanisms of Sepin-1-mediated growth inhibition are not fully understood. Here we report that Sepin-1 hinders growth of breast cancer cells, cell migration, and wound healing. Inhibition of cell growth induced by Sepin-1 in vitro doesn't appear to be through apoptosis but rather due to growth inhibition. Following Sepin-1 treatment caspases 3 and 7 are not activated and Poly (ADP-ribose) polymerase (Parp) is not cleaved. The expression of Forkhead box protein M1 (FoxM1), a transcription factor, and its target genes in the cell cycle, including Plk1, Cdk1, Aurora A, and Lamin B1, are reduced in a Sepin-1-dependent manner. Expressions of Raf kinase family members A-Raf, B-Raf, and C-Raf also are inhibited following treatment with Sepin-1. Raf is an intermediator in the Raf-Mek-Erk signaling pathway that phosphorylates FoxM1. Activated FoxM1 can promote its own transcription via a positive feedback loop. Sepin-1-induced downregulation of Raf and FoxM1 may inhibit expression of cell cycle-driving genes, resulting in inhibition of cell growth.
Collapse
Affiliation(s)
- Nenggang Zhang
- Department of Pediatrics, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, Texas, USA
| | - Debananda Pati
- Department of Pediatrics, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, Texas, USA
| |
Collapse
|
44
|
Lianga N, Doré C, Kennedy EK, Yeh E, Williams EC, Fortinez CM, Wang A, Bloom KS, Rudner AD. Cdk1 phosphorylation of Esp1/Separase functions with PP2A and Slk19 to regulate pericentric Cohesin and anaphase onset. PLoS Genet 2018; 14:e1007029. [PMID: 29561844 PMCID: PMC5880407 DOI: 10.1371/journal.pgen.1007029] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 04/02/2018] [Accepted: 09/17/2017] [Indexed: 12/27/2022] Open
Abstract
Anaphase onset is an irreversible cell cycle transition that is triggered by the activation of the protease Separase. Separase cleaves the Mcd1 (also known as Scc1) subunit of Cohesin, a complex of proteins that physically links sister chromatids, triggering sister chromatid separation. Separase is regulated by the degradation of the anaphase inhibitor Securin which liberates Separase from inhibitory Securin/Separase complexes. In many organisms, Securin is not essential suggesting that Separase is regulated by additional mechanisms. In this work, we show that in budding yeast Cdk1 activates Separase (Esp1 in yeast) through phosphorylation to trigger anaphase onset. Esp1 activation is opposed by protein phosphatase 2A associated with its regulatory subunit Cdc55 (PP2ACdc55) and the spindle protein Slk19. Premature anaphase spindle elongation occurs when Securin (Pds1 in yeast) is inducibly degraded in cells that also contain phospho-mimetic mutations in ESP1, or deletion of CDC55 or SLK19. This striking phenotype is accompanied by advanced degradation of Mcd1, disruption of pericentric Cohesin organization and chromosome mis-segregation. Our findings suggest that PP2ACdc55 and Slk19 function redundantly with Pds1 to inhibit Esp1 within pericentric chromatin, and both Pds1 degradation and Cdk1-dependent phosphorylation of Esp1 act together to trigger anaphase onset.
Collapse
Affiliation(s)
- Noel Lianga
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Carole Doré
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Erin K. Kennedy
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Elaine Yeh
- University of North Carolina, Chapel Hill, Department of Biology, Chapel Hill, NC, United States of America
| | - Elizabeth C. Williams
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Camille Marie Fortinez
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Alick Wang
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Kerry S. Bloom
- University of North Carolina, Chapel Hill, Department of Biology, Chapel Hill, NC, United States of America
| | - Adam D. Rudner
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
45
|
Luo S, Tong L. Structural biology of the separase-securin complex with crucial roles in chromosome segregation. Curr Opin Struct Biol 2018; 49:114-122. [PMID: 29452922 DOI: 10.1016/j.sbi.2018.01.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 12/26/2017] [Accepted: 01/22/2018] [Indexed: 11/15/2022]
Abstract
The cysteine protease separase opens the cohesin ring by cleaving its kleisin subunit and is a pivotal cell cycle factor for the transition from metaphase to anaphase. It is inhibited by forming a complex with the chaperone securin, and in vertebrates, also by the Cdk1-cyclin B1 complex. Separase is activated upon the destruction of securin or cyclin B1 by the proteasome, after ubiquitination by the anaphase-promoting complex/cyclosome (APC/C). Here we review recent structures of the active protease segment of Chaetomium thermophilum separase in complex with a substrate-mimic inhibitor and full-length Saccharomyces cerevisiae and Caenorhabditis elegans separase in complex with securin. These structures define the mechanism for substrate recognition and catalysis by separase, and show that securin has extensive contacts with separase, consistent with its chaperone function. They confirm that securin inhibits separase by binding as a pseudo substrate.
Collapse
Affiliation(s)
- Shukun Luo
- Department of Biological Sciences Columbia University New York, NY 10027, USA
| | - Liang Tong
- Department of Biological Sciences Columbia University New York, NY 10027, USA.
| |
Collapse
|
46
|
Abstract
Separase is a highly conserved protease required for chromosome segregation. Although observations that separase also regulates membrane trafficking events have been made, it is still not clear how separase achieves this function. Here, we present an extensive ENU mutagenesis suppressor screen aimed at identifying suppressors of sep-1(e2406), a temperature-sensitive maternal effect embryonic lethal separase mutant that primarily attenuates membrane trafficking rather than chromosome segregation. We screened nearly a million haploid genomes and isolated 68 suppressed lines. We identified 14 independent intragenic sep-1(e2406) suppressed lines. These intragenic alleles map to seven SEP-1 residues within the N-terminus, compensating for the original mutation within the poorly conserved N-terminal domain. Interestingly, 47 of the suppressed lines have novel mutations throughout the entire coding region of the pph-5 phosphatase, indicating that this is an important regulator of separase. We also found that a mutation near the MEEVD motif of HSP-90, which binds and activates PPH-5, also rescues sep-1(e2406) mutants. Finally, we identified six potentially novel suppressor lines that fall into five complementation groups. These new alleles provide the opportunity to more exhaustively investigate the regulation and function of separase.
Collapse
|
47
|
Nikalayevich E, Bouftas N, Wassmann K. Detection of Separase Activity Using a Cleavage Sensor in Live Mouse Oocytes. Methods Mol Biol 2018; 1818:99-112. [PMID: 29961259 DOI: 10.1007/978-1-4939-8603-3_11] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Separase proteolytically removes cohesin complexes from sister chromatid arms in meiosis I, which is essential for chromosome segregation. Regulation of separase activity is essential for proper cell cycle progression and correct chromosome segregation. Onset of endogenous separase activity has not yet been observed in live oocytes.We describe here a method for detecting separase activity in mouse oocytes in vivo. This method utilizes a previously described cleavage sensor made up of H2B-mCherry fused with Scc1(107-268 aa)-YFP. The cleavage sensor is loaded on the chromosomes through its H2B-tag, and the signal from both mCherry and YFP is visible. Upon separase activation the Scc1 fragment is cleaved and YFP dissociates from the chromosomes. The change in the ratio between mCherry and YFP fluorescence intensity is a readout of separase activity.
Collapse
Affiliation(s)
- Elvira Nikalayevich
- Sorbonne Universités, UPMC Université Paris 06, Institut de Biologie Paris Seine (IBPS), UMR7622, Paris, France.
- CNRS, IBPS, UMR7622 Developmental Biology Lab, Paris, France.
| | - Nora Bouftas
- Sorbonne Universités, UPMC Université Paris 06, Institut de Biologie Paris Seine (IBPS), UMR7622, Paris, France
- CNRS, IBPS, UMR7622 Developmental Biology Lab, Paris, France
| | - Katja Wassmann
- Sorbonne Universités, UPMC Université Paris 06, Institut de Biologie Paris Seine (IBPS), UMR7622, Paris, France.
- CNRS, IBPS, UMR7622 Developmental Biology Lab, Paris, France.
| |
Collapse
|
48
|
Greaney J, Wei Z, Homer H. Regulation of chromosome segregation in oocytes and the cellular basis for female meiotic errors. Hum Reprod Update 2017; 24:135-161. [PMID: 29244163 DOI: 10.1093/humupd/dmx035] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 09/12/2017] [Accepted: 11/26/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Meiotic chromosome segregation in human oocytes is notoriously error-prone, especially with ageing. Such errors markedly reduce the reproductive chances of increasing numbers of women embarking on pregnancy later in life. However, understanding the basis for these errors is hampered by limited access to human oocytes. OBJECTIVE AND RATIONALE Important new discoveries have arisen from molecular analyses of human female recombination and aneuploidy along with high-resolution analyses of human oocyte maturation and mouse models. Here, we review these findings to provide a contemporary picture of the key players choreographing chromosome segregation in mammalian oocytes and the cellular basis for errors. SEARCH METHODS A search of PubMed was conducted using keywords including meiosis, oocytes, recombination, cohesion, cohesin complex, chromosome segregation, kinetochores, spindle, aneuploidy, meiotic cell cycle, spindle assembly checkpoint, anaphase-promoting complex, DNA damage, telomeres, mitochondria, female ageing and female fertility. We extracted papers focusing on mouse and human oocytes that best aligned with the themes of this review and that reported transformative and novel discoveries. OUTCOMES Meiosis incorporates two sequential rounds of chromosome segregation executed by a spindle whose component microtubules bind chromosomes via kinetochores. Cohesion mediated by the cohesin complex holds chromosomes together and should be resolved at the appropriate time, in a specific step-wise manner and in conjunction with meiotically programmed kinetochore behaviour. In women, the stage is set for meiotic error even before birth when female-specific crossover maturation inefficiency leads to the formation of at-risk recombination patterns. In adult life, multiple co-conspiring factors interact with at-risk crossovers to increase the likelihood of mis-segregation. Available evidence support that these factors include, but are not limited to, cohesion deterioration, uncoordinated sister kinetochore behaviour, erroneous microtubule attachments, spindle instability and structural chromosomal defects that impact centromeres and telomeres. Data from mice indicate that cohesin and centromere-specific histones are long-lived proteins in oocytes. Since these proteins are pivotal for chromosome segregation, but lack any obvious renewal pathway, their deterioration with age provides an appealing explanation for at least some of the problems in older oocytes. WIDER IMPLICATIONS Research in the mouse model has identified a number of candidate genes and pathways that are important for chromosome segregation in this species. However, many of these have not yet been investigated in human oocytes so it is uncertain at this stage to what extent they apply to women. The challenge for the future involves applying emerging knowledge of female meiotic molecular regulation towards improving clinical fertility management.
Collapse
Affiliation(s)
- Jessica Greaney
- Christopher Chen Oocyte Biology Research Laboratory, Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Royal Brisbane & Women's Hospital Campus, Herston QLD 4029, Australia
| | - Zhe Wei
- Christopher Chen Oocyte Biology Research Laboratory, Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Royal Brisbane & Women's Hospital Campus, Herston QLD 4029, Australia
| | - Hayden Homer
- Christopher Chen Oocyte Biology Research Laboratory, Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Royal Brisbane & Women's Hospital Campus, Herston QLD 4029, Australia
| |
Collapse
|
49
|
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.
Collapse
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
| |
Collapse
|
50
|
Bai X, Bembenek JN. Protease dead separase inhibits chromosome segregation and RAB-11 vesicle trafficking. Cell Cycle 2017; 16:1902-1917. [PMID: 28820333 PMCID: PMC5638362 DOI: 10.1080/15384101.2017.1363936] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 07/27/2017] [Accepted: 07/30/2017] [Indexed: 01/06/2023] Open
Abstract
Separase cleaves cohesin to allow chromosome segregation. Separase also regulates cortical granule exocytosis and vesicle trafficking during cytokinesis, both of which involve RAB-11. We investigated whether separase regulates exocytosis through a proteolytic or non-proteolytic mechanism. In C. elegans, protease-dead separase (SEP-1PD::GFP) is dominant negative. Consistent with its role in cohesin cleavage, SEP-1PD::GFP causes chromosome segregation defects. As expected, partial depletion of cohesin rescues this defect, confirming that SEP-1PD::GFP acts through a substrate trapping mechanism. SEP-1PD::GFP causes cytokinetic defects that are synergistically exacerbated by depletion of the t-SNARE SYX-4. Furthermore, SEP-1PD::GFP delays furrow ingression, causes an accumulation of RAB-11 vesicles at the cleavage furrow site and delays the exocytosis of cortical granules during anaphase I. Depletion of syx-4 further enhanced RAB-11::mCherry and SEP-1PD::GFP plasma membrane accumulation during cytokinesis, while depletion of cohesin had no effect. In contrast, centriole disengagement appears normal in SEP-1PD::GFP embryos, indicating that chromosome segregation and vesicle trafficking are more sensitive to inhibition by the inactive protease. These findings suggest that separase cleaves an unknown substrate to promote the exocytosis of RAB-11 vesicles and paves the way for biochemical identification of substrates.
Collapse
Affiliation(s)
- Xiaofei Bai
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, USA
| | - Joshua N. Bembenek
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, USA
| |
Collapse
|