1
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MacKenzie A, Vicory V, Lacefield S. Meiotic cells escape prolonged spindle checkpoint activity through kinetochore silencing and slippage. PLoS Genet 2023; 19:e1010707. [PMID: 37018287 PMCID: PMC10109492 DOI: 10.1371/journal.pgen.1010707] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 04/17/2023] [Accepted: 03/20/2023] [Indexed: 04/06/2023] Open
Abstract
To prevent chromosome mis-segregation, a surveillance mechanism known as the spindle checkpoint delays the cell cycle if kinetochores are not attached to spindle microtubules, allowing the cell additional time to correct improper attachments. During spindle checkpoint activation, checkpoint proteins bind the unattached kinetochore and send a diffusible signal to inhibit the anaphase promoting complex/cyclosome (APC/C). Previous work has shown that mitotic cells with depolymerized microtubules can escape prolonged spindle checkpoint activation in a process called mitotic slippage. During slippage, spindle checkpoint proteins bind unattached kinetochores, but the cells cannot maintain the checkpoint arrest. We asked if meiotic cells had as robust of a spindle checkpoint response as mitotic cells and whether they also undergo slippage after prolonged spindle checkpoint activity. We performed a direct comparison between mitotic and meiotic budding yeast cells that signal the spindle checkpoint through two different assays. We find that the spindle checkpoint delay is shorter in meiosis I or meiosis II compared to mitosis, overcoming a checkpoint arrest approximately 150 minutes earlier in meiosis than in mitosis. In addition, cells in meiosis I escape spindle checkpoint signaling using two mechanisms, silencing the checkpoint at the kinetochore and through slippage. We propose that meiotic cells undertake developmentally-regulated mechanisms to prevent persistent spindle checkpoint activity to ensure the production of gametes.
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Affiliation(s)
- Anne MacKenzie
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Victoria Vicory
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Soni Lacefield
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
- Department of Biochemistry and Cell Biology, the Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
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2
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MacKenzie A, Vicory V, Lacefield S. Meiotic Cells Escape Prolonged Spindle Checkpoint Activity Through Premature Silencing and Slippage. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.02.522494. [PMID: 36711621 PMCID: PMC9881877 DOI: 10.1101/2023.01.02.522494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
To prevent chromosome mis-segregation, a surveillance mechanism known as the spindle checkpoint delays the cell cycle if kinetochores are not attached to spindle microtubules, allowing the cell additional time to correct improper attachments. During spindle checkpoint activation, checkpoint proteins bind the unattached kinetochore and send a diffusible signal to inhibit the anaphase promoting complex/cyclosome (APC/C). Previous work has shown that mitotic cells with depolymerized microtubules can escape prolonged spindle checkpoint activation in a process called mitotic slippage. During slippage, spindle checkpoint proteins bind unattached kinetochores, but the cells cannot maintain the checkpoint arrest. We asked if meiotic cells had as robust of a spindle checkpoint response as mitotic cells and whether they also undergo slippage after prolonged spindle checkpoint activity. We performed a direct comparison between mitotic and meiotic budding yeast cells that signal the spindle checkpoint due to a lack of either kinetochore-microtubule attachments or due to a loss of tension-bearing attachments. We find that the spindle checkpoint is not as robust in meiosis I or meiosis II compared to mitosis, overcoming a checkpoint arrest approximately 150 minutes earlier in meiosis. In addition, cells in meiosis I escape spindle checkpoint signaling using two mechanisms, silencing the checkpoint at the kinetochore and through slippage. We propose that meiotic cells undertake developmentally-regulated mechanisms to prevent persistent spindle checkpoint activity to ensure the production of gametes. AUTHOR SUMMARY Mitosis and meiosis are the two major types of cell divisions. Mitosis gives rise to genetically identical daughter cells, while meiosis is a reductional division that gives rise to gametes. Cell cycle checkpoints are highly regulated surveillance mechanisms that prevent cell cycle progression when circumstances are unfavorable. The spindle checkpoint promotes faithful chromosome segregation to safeguard against aneuploidy, in which cells have too many or too few chromosomes. The spindle checkpoint is activated at the kinetochore and then diffuses to inhibit cell cycle progression. Although the checkpoint is active in both mitosis and meiosis, most studies involving checkpoint regulation have been performed in mitosis. By activating the spindle checkpoint in both mitosis and meiosis in budding yeast, we show that cells in meiosis elicit a less persistent checkpoint signal compared to cells in mitosis. Further, we show that cells use distinct mechanisms to escape the checkpoint in mitosis and meiosis I. While cells in mitosis and meiosis II undergo anaphase onset while retaining checkpoint proteins at the kinetochore, cells in meiosis I prematurely lose checkpoint protein localization at the kinetochore. If the mechanism to remove the checkpoint components from the kinetochore is disrupted, meiosis I cells can still escape checkpoint activity. Together, these results highlight that cell cycle checkpoints are differentially regulated during meiosis to avoid long delays and to allow gametogenesis.
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Affiliation(s)
- Anne MacKenzie
- Department of Biology, Indiana University, Bloomington, IN USA
| | - Victoria Vicory
- Department of Biology, Indiana University, Bloomington, IN USA
| | - Soni Lacefield
- Department of Biology, Indiana University, Bloomington, IN USA,Department of Biochemistry and Cell Biology, the Geisel School of Medicine at Dartmouth, Hanover, NH USA,To whom correspondence should be addressed to Soni Lacefield:
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3
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Coutelier H, Ilioaia O, Le Peillet J, Hamon M, D’Amours D, Teixeira MT, Xu Z. The Polo kinase Cdc5 is regulated at multiple levels in the adaptation response to telomere dysfunction. Genetics 2022; 223:6808627. [PMID: 36342193 PMCID: PMC9836022 DOI: 10.1093/genetics/iyac171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
Telomere dysfunction activates the DNA damage checkpoint to induce a cell cycle arrest. After an extended period of time, however, cells can bypass the arrest and undergo cell division despite the persistence of the initial damage, a process called adaptation to DNA damage. The Polo kinase Cdc5 in Saccharomyces cerevisiae is essential for adaptation and for many other cell cycle processes. How the regulation of Cdc5 in response to telomere dysfunction relates to adaptation is not clear. Here, we report that Cdc5 protein level decreases after telomere dysfunction in a Mec1-, Rad53- and Ndd1-dependent manner. This regulation of Cdc5 is important to maintain long-term cell cycle arrest but not for the initial checkpoint arrest. We find that both Cdc5 and the adaptation-deficient mutant protein Cdc5-ad are heavily phosphorylated and several phosphorylation sites modulate adaptation efficiency. The PP2A phosphatases are involved in Cdc5-ad phosphorylation status and contribute to adaptation mechanisms. We finally propose that Cdc5 orchestrates multiple cell cycle pathways to promote adaptation.
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Affiliation(s)
| | | | | | - Marion Hamon
- Sorbonne Université, PSL, CNRS, FR550, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Damien D’Amours
- Ottawa Institute of Systems Biology, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Maria Teresa Teixeira
- Sorbonne Université, PSL, CNRS, UMR8226, Institut de Biologie Physico-Chimique, Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, 75005 Paris, France
| | - Zhou Xu
- Corresponding author: Sorbonne Université, CNRS, UMR7238, Institut de Biologie Paris‐Seine, Laboratory of Computational and Quantitative Biology, 75005 Paris, France.
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4
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Nambu M, Kishikawa A, Yamada T, Ichikawa K, Kira Y, Itabashi Y, Honda A, Yamada K, Murakami H, Yamamoto A. Direct evaluation of cohesin-mediated sister kinetochore associations at meiosis I in fission yeast. J Cell Sci 2022; 135:jcs259102. [PMID: 34851403 DOI: 10.1242/jcs.259102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 11/16/2021] [Indexed: 11/20/2022] Open
Abstract
Kinetochores drive chromosome segregation by mediating chromosome interactions with the spindle. In higher eukaryotes, sister kinetochores are separately positioned on opposite sides of sister centromeres during mitosis, but associate with each other during meiosis I. Kinetochore association facilitates the attachment of sister chromatids to the same pole, enabling the segregation of homologous chromosomes toward opposite poles. In the fission yeast, Schizosaccharomyces pombe, Rec8-containing meiotic cohesin is suggested to establish kinetochore associations by mediating cohesion of the centromere cores. However, cohesin-mediated kinetochore associations on intact chromosomes have never been demonstrated directly. In the present study, we describe a novel method for the direct evaluation of kinetochore associations on intact chromosomes in live S. pombe cells, and demonstrate that sister kinetochores and the centromere cores are positioned separately on mitotic chromosomes but associate with each other on meiosis I chromosomes. Furthermore, we demonstrate that kinetochore association depends on meiotic cohesin and the cohesin regulators Moa1 and Mrc1, and requires mating-pheromone signaling for its establishment. These results confirm cohesin-mediated kinetochore association and its regulatory mechanisms, along with the usefulness of the developed method for its analysis. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Masashi Nambu
- Graduate School of Integrated Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Atsuki Kishikawa
- Graduate School of Integrated Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Takatomi Yamada
- Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Kento Ichikawa
- Graduate School of Integrated Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Yunosuke Kira
- Faculty of Science, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Yuta Itabashi
- Graduate School of Integrated Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Akira Honda
- Graduate School of Integrated Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Kohei Yamada
- Graduate School of Integrated Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Hiroshi Murakami
- Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Ayumu Yamamoto
- Graduate School of Integrated Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
- Faculty of Science, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
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5
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Sane A, Sridhar S, Sanyal K, Ghosh SK. Shugoshin ensures maintenance of the spindle assembly checkpoint response and efficient spindle disassembly. Mol Microbiol 2021; 116:1079-1098. [PMID: 34407255 DOI: 10.1111/mmi.14796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/07/2021] [Accepted: 08/15/2021] [Indexed: 11/27/2022]
Abstract
Shugoshin proteins are evolutionarily conserved across eukaryotes, with some species-specific cellular functions, ensuring the fidelity of chromosome segregation. They act as adaptors at various subcellular locales to mediate several protein-protein interactions in a spatio-temporal manner. Here, we characterize shugoshin (Sgo1) in the human fungal pathogen Candida albicans. We observe that Sgo1 retains its centromeric localization and performs its conserved functions of regulating the sister chromatid biorientation, centromeric condensin localization, and maintenance of chromosomal passenger complex (CPC). We identify novel roles of Sgo1 as a spindle assembly checkpoint (SAC) component with functions in maintaining a prolonged SAC response by retaining Mad2 and Bub1 at the kinetochores in response to improper kinetochore-microtubule attachments. Strikingly, we discover the in vivo localization of Sgo1 along the length of the mitotic spindle. Our results indicate that Sgo1 performs a hitherto unknown function of facilitating timely disassembly of the mitotic spindle in C. albicans. To summarize, this study unravels a unique functional adaptation of shugoshin in maintaining genomic stability.
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Affiliation(s)
- Aakanksha Sane
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Powai, India
| | - Shreyas Sridhar
- Molecular Biology & Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India.,Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Kaustuv Sanyal
- Molecular Biology & Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India.,Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Santanu K Ghosh
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Powai, India
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6
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Su XB, Wang M, Schaffner C, Nerusheva OO, Clift D, Spanos C, Kelly DA, Tatham M, Wallek A, Wu Y, Rappsilber J, Jeyaprakash AA, Storchova Z, Hay RT, Marston AL. SUMOylation stabilizes sister kinetochore biorientation to allow timely anaphase. J Cell Biol 2021; 220:e202005130. [PMID: 33929514 PMCID: PMC8094117 DOI: 10.1083/jcb.202005130] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 02/18/2021] [Accepted: 03/24/2021] [Indexed: 12/12/2022] Open
Abstract
During mitosis, sister chromatids attach to microtubules from opposite poles, called biorientation. Sister chromatid cohesion resists microtubule forces, generating tension, which provides the signal that biorientation has occurred. How tension silences the surveillance pathways that prevent cell cycle progression and correct erroneous kinetochore-microtubule attachments remains unclear. Here we show that SUMOylation dampens error correction to allow stable sister kinetochore biorientation and timely anaphase onset. The Siz1/Siz2 SUMO ligases modify the pericentromere-localized shugoshin (Sgo1) protein before its tension-dependent release from chromatin. Sgo1 SUMOylation reduces its binding to protein phosphatase 2A (PP2A), and weakening of this interaction is important for stable biorientation. Unstable biorientation in SUMO-deficient cells is associated with persistence of the chromosome passenger complex (CPC) at centromeres, and SUMOylation of CPC subunit Bir1 also contributes to timely anaphase onset. We propose that SUMOylation acts in a combinatorial manner to facilitate dismantling of the error correction machinery within pericentromeres and thereby sharpen the metaphase-anaphase transition.
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Affiliation(s)
- Xue Bessie Su
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Menglu Wang
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Claudia Schaffner
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Olga O. Nerusheva
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Dean Clift
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
- Laboratory of Molecular Biology, Medical Research Council, Cambridge, UK
| | - Christos Spanos
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - David A. Kelly
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Michael Tatham
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, UK
| | - Andreas Wallek
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Yehui Wu
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Juri Rappsilber
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
- Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - A. Arockia Jeyaprakash
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Zuzana Storchova
- Max Planck Institute of Biochemistry, Martinsried, Germany
- Technische Universität Kaiserslautern, Kaiserslautern, Germany
| | - Ronald T. Hay
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, UK
| | - Adèle L. Marston
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
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7
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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.
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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.
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8
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PP2A Functions during Mitosis and Cytokinesis in Yeasts. Int J Mol Sci 2019; 21:ijms21010264. [PMID: 31906018 PMCID: PMC6981662 DOI: 10.3390/ijms21010264] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 12/13/2022] Open
Abstract
Protein phosphorylation is a common mechanism for the regulation of cell cycle progression. The opposing functions of cell cycle kinases and phosphatases are crucial for accurate chromosome segregation and exit from mitosis. Protein phosphatases 2A are heterotrimeric complexes that play essential roles in cell growth, proliferation, and regulation of the cell cycle. Here, we review the function of the protein phosphatase 2A family as the counteracting force for the mitotic kinases. We focus on recent findings in the regulation of mitotic exit and cytokinesis by PP2A phosphatases in S. cerevisiae and other fungal species.
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9
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Sherwin D, Wang Y. The Opposing Functions of Protein Kinases and Phosphatases in Chromosome Bipolar Attachment. Int J Mol Sci 2019; 20:ijms20246182. [PMID: 31817904 PMCID: PMC6940769 DOI: 10.3390/ijms20246182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 11/22/2019] [Accepted: 12/06/2019] [Indexed: 01/17/2023] Open
Abstract
Accurate chromosome segregation during cell division is essential to maintain genome integrity in all eukaryotic cells, and chromosome missegregation leads to aneuploidy and therefore represents a hallmark of many cancers. Accurate segregation requires sister kinetochores to attach to microtubules emanating from opposite spindle poles, known as bipolar attachment or biorientation. Recent studies have uncovered several mechanisms critical to chromosome bipolar attachment. First, a mechanism exists to ensure that the conformation of sister centromeres is biased toward bipolar attachment. Second, the phosphorylation of some kinetochore proteins destabilizes kinetochore attachment to facilitate error correction, but a protein phosphatase reverses this phosphorylation. Moreover, the activity of the spindle assembly checkpoint is regulated by kinases and phosphatases at the kinetochore, and this checkpoint prevents anaphase entry in response to faulty kinetochore attachment. The fine-tuned kinase/phosphatase balance at kinetochores is crucial for faithful chromosome segregation during both mitosis and meiosis. Here, we discuss the function and regulation of protein phosphatases in the establishment of chromosome bipolar attachment with a focus on the model organism budding yeast.
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Affiliation(s)
| | - Yanchang Wang
- Correspondence: ; Tel.: +1-850-644-0402; Fax: +1-850-644-5781
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10
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Galander S, Barton RE, Kelly DA, Marston AL. Spo13 prevents premature cohesin cleavage during meiosis. Wellcome Open Res 2019; 4:29. [PMID: 30906881 PMCID: PMC6426077 DOI: 10.12688/wellcomeopenres.15066.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2019] [Indexed: 01/21/2024] Open
Abstract
Background: Meiosis produces gametes through two successive nuclear divisions, meiosis I and meiosis II. In contrast to mitosis and meiosis II, where sister chromatids are segregated, during meiosis I, homologous chromosomes are segregated. This requires the monopolar attachment of sister kinetochores and the loss of cohesion from chromosome arms, but not centromeres, during meiosis I. The establishment of both sister kinetochore mono-orientation and cohesion protection rely on the budding yeast meiosis I-specific Spo13 protein, the functional homolog of fission yeast Moa1 and mouse MEIKIN. Methods: Here we investigate the effects of loss of SPO13 on cohesion during meiosis I using a live-cell imaging approach. Results: Unlike wild type, cells lacking SPO13 fail to maintain the meiosis-specific cohesin subunit, Rec8, at centromeres and segregate sister chromatids to opposite poles during anaphase I. We show that the cohesin-destabilizing factor, Wpl1, is not primarily responsible for the loss of cohesion during meiosis I. Instead, premature loss of centromeric cohesin during anaphase I in spo13 Δ cells relies on separase-dependent cohesin cleavage. Further, cohesin loss in spo13 Δ anaphase I cells is blocked by forcibly tethering the regulatory subunit of protein phosphatase 2A, Rts1, to Rec8. Conclusions: Our findings indicate that separase-dependent cleavage of phosphorylated Rec8 causes premature cohesin loss in spo13 Δ cells.
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Affiliation(s)
- Stefan Galander
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Rachael E. Barton
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - David A. Kelly
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Adèle L. Marston
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3BF, UK
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11
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Galander S, Barton RE, Kelly DA, Marston AL. Spo13 prevents premature cohesin cleavage during meiosis. Wellcome Open Res 2019; 4:29. [PMID: 30906881 PMCID: PMC6426077 DOI: 10.12688/wellcomeopenres.15066.2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2019] [Indexed: 01/11/2023] Open
Abstract
Background: Meiosis produces gametes through two successive nuclear divisions, meiosis I and meiosis II. In contrast to mitosis and meiosis II, where sister chromatids are segregated, during meiosis I, homologous chromosomes are segregated. This requires the monopolar attachment of sister kinetochores and the loss of cohesion from chromosome arms, but not centromeres, during meiosis I. The establishment of both sister kinetochore mono-orientation and cohesion protection rely on the budding yeast meiosis I-specific Spo13 protein, the functional homolog of fission yeast Moa1 and mouse MEIKIN. Methods: Here we investigate the effects of loss of
SPO13 on cohesion during meiosis I using a live-cell imaging approach. Results: Unlike wild type, cells lacking
SPO13 fail to maintain the meiosis-specific cohesin subunit, Rec8, at centromeres and segregate sister chromatids to opposite poles during anaphase I. We show that the cohesin-destabilizing factor, Wpl1, is not primarily responsible for the loss of cohesion during meiosis I. Instead, premature loss of centromeric cohesin during anaphase I in
spo13Δ cells relies on separase-dependent cohesin cleavage. Further, cohesin loss in
spo13Δ anaphase I cells is blocked by forcibly tethering the regulatory subunit of protein phosphatase 2A, Rts1, to Rec8. Conclusions: Our findings indicate that separase-dependent cleavage of phosphorylated Rec8 causes premature cohesin loss in
spo13Δ cells.
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Affiliation(s)
- Stefan Galander
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Rachael E Barton
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - David A Kelly
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Adèle L Marston
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3BF, UK
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12
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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.
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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.
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13
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Galander S, Barton RE, Borek WE, Spanos C, Kelly DA, Robertson D, Rappsilber J, Marston AL. Reductional Meiosis I Chromosome Segregation Is Established by Coordination of Key Meiotic Kinases. Dev Cell 2019; 49:526-541.e5. [PMID: 31031198 PMCID: PMC6547162 DOI: 10.1016/j.devcel.2019.04.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 12/05/2018] [Accepted: 03/31/2019] [Indexed: 02/07/2023]
Abstract
Meiosis produces gametes through a specialized, two-step cell division, which is highly error prone in humans. Reductional meiosis I, where maternal and paternal chromosomes (homologs) segregate, is followed by equational meiosis II, where sister chromatids separate. Uniquely during meiosis I, sister kinetochores are monooriented and pericentromeric cohesin is protected. Here, we demonstrate that these key adaptations for reductional chromosome segregation are achieved through separable control of multiple kinases by the meiosis-I-specific budding yeast Spo13 protein. Recruitment of Polo kinase to kinetochores directs monoorientation, while independently, cohesin protection is achieved by containing the effects of cohesin kinases. Therefore, reductional chromosome segregation, the defining feature of meiosis, is established by multifaceted kinase control by a master regulator. The recent identification of Spo13 orthologs, fission yeast Moa1 and mouse MEIKIN, suggests that kinase coordination by a meiosis I regulator may be a general feature in the establishment of reductional chromosome segregation.
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Affiliation(s)
- Stefan Galander
- The Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Rachael E Barton
- The Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Weronika E Borek
- The Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Christos Spanos
- The Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - David A Kelly
- The Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Daniel Robertson
- The Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Juri Rappsilber
- The Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK; Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Adèle L Marston
- The Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK.
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Ariño J, Velázquez D, Casamayor A. Ser/Thr protein phosphatases in fungi: structure, regulation and function. MICROBIAL CELL 2019; 6:217-256. [PMID: 31114794 PMCID: PMC6506691 DOI: 10.15698/mic2019.05.677] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Reversible phospho-dephosphorylation of proteins is a major mechanism for the control of cellular functions. By large, Ser and Thr are the most frequently residues phosphorylated in eukar-yotes. Removal of phosphate from these amino acids is catalyzed by a large family of well-conserved enzymes, collectively called Ser/Thr protein phosphatases. The activity of these enzymes has an enormous impact on cellular functioning. In this work we pre-sent the members of this family in S. cerevisiae and other fungal species, and review the most recent findings concerning their regu-lation and the roles they play in the most diverse aspects of cell biology.
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Affiliation(s)
- Joaquín Ariño
- Departament de Bioquímica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
| | - Diego Velázquez
- Departament de Bioquímica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
| | - Antonio Casamayor
- Departament de Bioquímica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
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15
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Ramos F, Villoria MT, Alonso-Rodríguez E, Clemente-Blanco A. Role of protein phosphatases PP1, PP2A, PP4 and Cdc14 in the DNA damage response. Cell Stress 2019; 3:70-85. [PMID: 31225502 PMCID: PMC6551743 DOI: 10.15698/cst2019.03.178] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Maintenance of genome integrity is fundamental for cellular physiology. Our hereditary information encoded in the DNA is intrinsically susceptible to suffer variations, mostly due to the constant presence of endogenous and environmental genotoxic stresses. Genomic insults must be repaired to avoid loss or inappropriate transmission of the genetic information, a situation that could lead to the appearance of developmental anomalies and tumorigenesis. To safeguard our genome, cells have evolved a series of mechanisms collectively known as the DNA damage response (DDR). This surveillance system regulates multiple features of the cellular response, including the detection of the lesion, a transient cell cycle arrest and the restoration of the broken DNA molecule. While the role of multiple kinases in the DDR has been well documented over the last years, the intricate roles of protein dephosphorylation have only recently begun to be addressed. In this review, we have compiled recent information about the function of protein phosphatases PP1, PP2A, PP4 and Cdc14 in the DDR, focusing mainly on their capacity to regulate the DNA damage checkpoint and the repair mechanism encompassed in the restoration of a DNA lesion.
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Affiliation(s)
- Facundo Ramos
- Cell Cycle and Genome Stability Group. Institute of Functional Biology and Genomics (IBFG). Spanish National Research Council (CSIC), University of Salamanca (USAL), C/Zacarías González 2, Salamanca 37007, SPAIN
| | - María Teresa Villoria
- Cell Cycle and Genome Stability Group. Institute of Functional Biology and Genomics (IBFG). Spanish National Research Council (CSIC), University of Salamanca (USAL), C/Zacarías González 2, Salamanca 37007, SPAIN
| | - Esmeralda Alonso-Rodríguez
- Cell Cycle and Genome Stability Group. Institute of Functional Biology and Genomics (IBFG). Spanish National Research Council (CSIC), University of Salamanca (USAL), C/Zacarías González 2, Salamanca 37007, SPAIN
| | - Andrés Clemente-Blanco
- Cell Cycle and Genome Stability Group. Institute of Functional Biology and Genomics (IBFG). Spanish National Research Council (CSIC), University of Salamanca (USAL), C/Zacarías González 2, Salamanca 37007, SPAIN
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16
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The DNA Damage Checkpoint and the Spindle Position Checkpoint Maintain Meiotic Commitment in Saccharomyces cerevisiae. Curr Biol 2019; 29:449-460.e2. [PMID: 30686741 DOI: 10.1016/j.cub.2018.12.043] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 11/26/2018] [Accepted: 12/21/2018] [Indexed: 01/17/2023]
Abstract
During meiosis, diploid progenitor cells undergo one round of DNA replication followed by two rounds of chromosome segregation to form haploid gametes. Once cells initiate the meiotic divisions, it is imperative that they finish meiosis. A failure to maintain meiosis can result in highly aberrant polyploid cells, which could lead to oncogenesis in the germline. How cells stay committed to finishing meiosis, even in the presence of a mitosis-inducing signal, is poorly understood. We addressed this question in budding yeast, in which cells enter meiosis when starved. If nutrient-rich medium is added before a defined commitment point in mid-prometaphase I, they can return to mitosis. Cells in stages beyond the commitment point will finish meiosis, even with nutrient addition. Because checkpoints are signaling pathways known to couple cell-cycle processes with one another, we asked if checkpoints could ensure meiotic commitment. We find that two checkpoints with well-defined functions in mitosis, the DNA damage checkpoint and the spindle position checkpoint, have crucial roles in meiotic commitment. With nutrient-rich medium addition at stages beyond the commitment point, cells that are deficient in both checkpoints because they lack Rad53 and either Bub2, Bfa1, or Kin4 can return to mitotic growth and go on to form polyploid cells. The results demonstrate that the two checkpoints prevent cells from exiting meiosis in the presence of a mitosis-inducing signal. This study reveals a previously unknown function for the DNA damage checkpoint and the spindle position checkpoint in maintaining meiotic commitment.
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17
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Baro B, Játiva S, Calabria I, Vinaixa J, Bech-Serra JJ, de LaTorre C, Rodrigues J, Hernáez ML, Gil C, Barceló-Batllori S, Larsen MR, Queralt E. SILAC-based phosphoproteomics reveals new PP2A-Cdc55-regulated processes in budding yeast. Gigascience 2018; 7:4982941. [PMID: 29688323 PMCID: PMC5967524 DOI: 10.1093/gigascience/giy047] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 04/18/2018] [Indexed: 01/12/2023] Open
Abstract
Background Protein phosphatase 2A (PP2A) is a family of conserved serine/threonine phosphatases involved in several essential aspects of cell growth and proliferation. PP2ACdc55 phosphatase has been extensively related to cell cycle events in budding yeast; however, few PP2ACdc55 substrates have been identified. Here, we performed a quantitative mass spectrometry approach to reveal new substrates of PP2ACdc55 phosphatase and new PP2A-related processes in mitotic arrested cells. Results We identified 62 statistically significant PP2ACdc55 substrates involved mainly in actin-cytoskeleton organization. In addition, we validated new PP2ACdc55 substrates such as Slk19 and Lte1, involved in early and late anaphase pathways, and Zeo1, a component of the cell wall integrity pathway. Finally, we constructed docking models of Cdc55 and its substrate Mob1. We found that the predominant interface on Cdc55 is mediated by a protruding loop consisting of residues 84–90, thus highlighting the relevance of these aminoacids for substrate interaction. Conclusions We used phosphoproteomics of Cdc55-deficient cells to uncover new PP2ACdc55 substrates and functions in mitosis. As expected, several hyperphosphorylated proteins corresponded to Cdk1-dependent substrates, although other kinases’ consensus motifs were also enriched in our dataset, suggesting that PP2ACdc55 counteracts and regulates other kinases distinct from Cdk1. Indeed, Pkc1 emerged as a novel node of PP2ACdc55 regulation, highlighting a major role of PP2ACdc55 in actin cytoskeleton and cytokinesis, gene ontology terms significantly enriched in the PP2ACdc55-dependent phosphoproteome.
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Affiliation(s)
- Barbara Baro
- Cell Cycle Group, Cancer Epigenetics and Biology Program, Institut d'Investigacions Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Soraya Játiva
- Cell Cycle Group, Cancer Epigenetics and Biology Program, Institut d'Investigacions Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Inés Calabria
- Cell Cycle Group, Cancer Epigenetics and Biology Program, Institut d'Investigacions Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Judith Vinaixa
- Cell Cycle Group, Cancer Epigenetics and Biology Program, Institut d'Investigacions Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Joan-Josep Bech-Serra
- IDIBELL Proteomics Unit, Institut d'Investigacions Biomèdica de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Carolina de LaTorre
- IDIBELL Proteomics Unit, Institut d'Investigacions Biomèdica de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain
| | - João Rodrigues
- Structural Biology Department, School of Medicine, Stanford, California, USA
| | - María Luisa Hernáez
- Proteomics Unit, Parque Científico de Madrid, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Concha Gil
- Proteomics Unit, Parque Científico de Madrid, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Silvia Barceló-Batllori
- IDIBELL Proteomics Unit, Institut d'Investigacions Biomèdica de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Martin R Larsen
- Department of Biochemistry and Molecular Biology, Odense M, Denmark
| | - Ethel Queralt
- Cell Cycle Group, Cancer Epigenetics and Biology Program, Institut d'Investigacions Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
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18
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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.
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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
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19
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Botchkarev VV, Haber JE. Functions and regulation of the Polo-like kinase Cdc5 in the absence and presence of DNA damage. Curr Genet 2018; 64:87-96. [PMID: 28770345 PMCID: PMC6249032 DOI: 10.1007/s00294-017-0727-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 07/24/2017] [Accepted: 07/26/2017] [Indexed: 12/20/2022]
Abstract
Polo-like kinases are essential cell cycle regulators that are conserved from yeast to humans. Unlike higher eukaryotes, who express multiple Polo-like kinase family members that perform many important functions, budding yeast express only a single Polo-like kinase, Cdc5, which is the homolog of mammalian cell cycle master regulator Polo-like kinase 1. Cdc5 is a fascinating multifaceted protein that is programmed to target its many substrates in a timely, sequential manner to ensure proper cell cycle progression. Over the years, many lessons about Polo-like kinase 1 have been learned by studying Cdc5 in budding yeast. Cdc5 has been well documented in regulating mitotic entry, chromosome segregation, mitotic exit, and cytokinesis. Cdc5 also plays important roles during cell division after DNA damage. Here, we briefly review the many functions of Cdc5 and its regulation in the absence and presence of DNA damage.
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Affiliation(s)
- Vladimir V Botchkarev
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA, 02454, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
- Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
| | - James E Haber
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA, 02454, USA.
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20
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Seoane AI, Morgan DO. Firing of Replication Origins Frees Dbf4-Cdc7 to Target Eco1 for Destruction. Curr Biol 2017; 27:2849-2855.e2. [PMID: 28918948 DOI: 10.1016/j.cub.2017.07.070] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/12/2017] [Accepted: 07/31/2017] [Indexed: 12/14/2022]
Abstract
Robust progression through the cell-division cycle depends on the precisely ordered phosphorylation of hundreds of different proteins by cyclin-dependent kinases (CDKs) and other kinases. The order of CDK substrate phosphorylation depends on rising CDK activity, coupled with variations in substrate affinities for different CDK-cyclin complexes and the opposing phosphatases [1-4]. Here, we address the ordering of substrate phosphorylation by a second major cell-cycle kinase, Cdc7-Dbf4 or Dbf4-dependent kinase (DDK). The primary function of DDK is to initiate DNA replication by phosphorylating the Mcm2-7 replicative helicase [5-7]. DDK also phosphorylates the cohesin acetyltransferase Eco1 [8]. Sequential phosphorylations of Eco1 by CDK, DDK, and Mck1 create a phosphodegron that is recognized by the ubiquitin ligase SCFCdc4. DDK, despite being activated in early S phase, does not phosphorylate Eco1 to trigger its degradation until late S phase [8]. DDK associates with docking sites on loaded Mcm double hexamers at unfired replication origins [9, 10]. We hypothesized that these docking interactions sequester limiting amounts of DDK, delaying Eco1 phosphorylation by DDK until replication is complete. Consistent with this hypothesis, we find that overproduction of DDK leads to premature Eco1 degradation. Eco1 degradation also occurs prematurely if Mcm complex loading at origins is prevented by depletion of Cdc6, and Eco1 is stabilized if loaded Mcm complexes are prevented from firing by a Cdc45 mutant. We propose that the timing of Eco1 phosphorylation, and potentially that of other DDK substrates, is determined in part by sequestration of DDK at unfired replication origins during S phase.
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Affiliation(s)
- Agustin I Seoane
- Departments of Physiology and Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - David O Morgan
- Departments of Physiology and Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA.
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21
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Kumar R. Separase: Function Beyond Cohesion Cleavage and an Emerging Oncogene. J Cell Biochem 2017; 118:1283-1299. [PMID: 27966791 DOI: 10.1002/jcb.25835] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 12/12/2016] [Indexed: 12/22/2022]
Abstract
Proper and timely segregation of genetic endowment is necessary for survival and perpetuation of every species. Mis-segregation of chromosomes and resulting aneuploidy leads to genetic instability, which can jeopardize the survival of an individual or population as a whole. Abnormality with segregation of genetic contents has been associated with several medical consequences including cancer, sterility, mental retardation, spontaneous abortion, miscarriages, and other birth related defects. Separase, by irreversible cleavage of cohesin complex subunit, paves the way for metaphase/anaphase transition during the cell cycle. Both over or reduced expression and altered level of separase have been associated with several medical consequences including cancer, as a result separase now emerges as an important oncogene and potential molecular target for medical intervenes. Recently, separase is also found to be essential in separation and duplication of centrioles. Here, I review the role of separase in mitosis, meiosis, non-canonical roles of separase, separase regulation, as a regulator of centriole disengagement, nonproteolytic roles, diverse substrates, structural insights, and association of separase with cancer. At the ends, I proposed a model which showed that separase is active throughout the cell cycle and there is a mere increase in separase activity during metaphase contrary to the common believes that separase is inactive throughout cell cycle except for metaphase. J. Cell. Biochem. 118: 1283-1299, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Ravinder Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400 076, Maharashtra, India
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22
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Kamenz J, Hauf S. Time To Split Up: Dynamics of Chromosome Separation. Trends Cell Biol 2017; 27:42-54. [DOI: 10.1016/j.tcb.2016.07.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 07/14/2016] [Accepted: 07/29/2016] [Indexed: 11/16/2022]
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23
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Sivakumar S, Gorbsky GJ. Spatiotemporal regulation of the anaphase-promoting complex in mitosis. Nat Rev Mol Cell Biol 2015; 16:82-94. [PMID: 25604195 DOI: 10.1038/nrm3934] [Citation(s) in RCA: 198] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The appropriate timing of events that lead to chromosome segregation during mitosis and cytokinesis is essential to prevent aneuploidy, and defects in these processes can contribute to tumorigenesis. Key mitotic regulators are controlled through ubiquitylation and proteasome-mediated degradation. The APC/C (anaphase-promoting complex; also known as the cyclosome) is an E3 ubiquitin ligase that has a crucial function in the regulation of the mitotic cell cycle, particularly at the onset of anaphase and during mitotic exit. Co-activator proteins, inhibitor proteins, protein kinases and phosphatases interact with the APC/C to temporally and spatially control its activity and thus ensure accurate timing of mitotic events.
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Affiliation(s)
- Sushama Sivakumar
- Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, Oklahoma 73104, USA
| | - Gary J Gorbsky
- Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, Oklahoma 73104, USA
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Abstract
The shugoshin/Mei-S332 family are proteins that associate with the chromosomal region surrounding the centromere (the pericentromere) and that play multiple and distinct roles in ensuring the accuracy of chromosome segregation during both mitosis and meiosis. The underlying role of shugoshins appears to be to serve as pericentromeric adaptor proteins that recruit several different effectors to this region of the chromosome to regulate processes critical for chromosome segregation. Crucially, shugoshins undergo changes in their localization in response to the tension that is exerted on sister chromosomes by the forces of the spindle that will pull them apart. This has led to the idea that shugoshins provide a platform for activities required at the pericentromere only when sister chromosomes lack tension. Conversely, disassembly of the shugoshin pericentromeric platform may provide a signal that sister chromosomes are under tension. Here the functions and regulation of these important tension-sensitive pericentromeric proteins are discussed.
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25
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Lu D, Hsiao JY, Davey NE, Van Voorhis VA, Foster SA, Tang C, Morgan DO. Multiple mechanisms determine the order of APC/C substrate degradation in mitosis. ACTA ACUST UNITED AC 2014; 207:23-39. [PMID: 25287299 PMCID: PMC4195823 DOI: 10.1083/jcb.201402041] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
To ensure proper mitotic progression, robust ordering of the destruction of APC/CCdc20 substrates is driven by the integration of molecular mechanisms ranging from phosphorylation-dependent interaction with substrates to sensing of the status of the spindle assembly checkpoint. The ubiquitin protein ligase anaphase-promoting complex or cyclosome (APC/C) controls mitosis by promoting ordered degradation of securin, cyclins, and other proteins. The mechanisms underlying the timing of APC/C substrate degradation are poorly understood. We explored these mechanisms using quantitative fluorescence microscopy of GFP-tagged APC/CCdc20 substrates in living budding yeast cells. Degradation of the S cyclin, Clb5, begins early in mitosis, followed 6 min later by the degradation of securin and Dbf4. Anaphase begins when less than half of securin is degraded. The spindle assembly checkpoint delays the onset of Clb5 degradation but does not influence securin degradation. Early Clb5 degradation depends on its interaction with the Cdk1–Cks1 complex and the presence of a Cdc20-binding “ABBA motif” in its N-terminal region. The degradation of securin and Dbf4 is delayed by Cdk1-dependent phosphorylation near their Cdc20-binding sites. Thus, a remarkably diverse array of mechanisms generates robust ordering of APC/CCdc20 substrate destruction.
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Affiliation(s)
- Dan Lu
- Department of Physiology and Department of Biochemistry and Biophysics and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
| | - Jennifer Y Hsiao
- Department of Physiology and Department of Biochemistry and Biophysics and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
| | - Norman E Davey
- Department of Physiology and Department of Biochemistry and Biophysics and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
| | - Vanessa A Van Voorhis
- Department of Physiology and Department of Biochemistry and Biophysics and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
| | - Scott A Foster
- Department of Physiology and Department of Biochemistry and Biophysics and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
| | - Chao Tang
- Center for Quantitative Biology and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - David O Morgan
- Department of Physiology and Department of Biochemistry and Biophysics and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
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26
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Agircan FG, Schiebel E. Sensors at centrosomes reveal determinants of local separase activity. PLoS Genet 2014; 10:e1004672. [PMID: 25299182 PMCID: PMC4191886 DOI: 10.1371/journal.pgen.1004672] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 08/14/2014] [Indexed: 01/08/2023] Open
Abstract
Separase is best known for its function in sister chromatid separation at the metaphase-anaphase transition. It also has a role in centriole disengagement in late mitosis/G1. To gain insight into the activity of separase at centrosomes, we developed two separase activity sensors: mCherry-Scc1(142-467)-ΔNLS-eGFP-PACT and mCherry-kendrin(2059-2398)-eGFP-PACT. Both localize to the centrosomes and enabled us to monitor local separase activity at the centrosome in real time. Both centrosomal sensors were cleaved by separase before anaphase onset, earlier than the corresponding H2B-mCherry-Scc1(142-467)-eGFP sensor at chromosomes. This indicates that substrate cleavage by separase is not synchronous in the cells. Depletion of the proteins astrin or Aki1, which have been described as inhibitors of centrosomal separase, did not led to a significant activation of separase at centrosomes, emphasizing the importance of direct separase activity measurements at the centrosomes. Inhibition of polo-like kinase Plk1, on the other hand, decreased the separase activity towards the Scc1 but not the kendrin reporter. Together these findings indicate that Plk1 regulates separase activity at the level of substrate affinity at centrosomes and may explain in part the role of Plk1 in centriole disengagement.
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Affiliation(s)
- Fikret Gurkan Agircan
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Allianz, Heidelberg, Germany
| | - Elmar Schiebel
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Allianz, Heidelberg, Germany
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Eshleman HD, Morgan DO. Sgo1 recruits PP2A to chromosomes to ensure sister chromatid bi-orientation during mitosis. J Cell Sci 2014; 127:4974-83. [PMID: 25236599 DOI: 10.1242/jcs.161273] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Sister chromatid bi-orientation on the mitotic spindle is essential for proper chromosome segregation. Defects in bi-orientation are sensed and corrected to prevent chromosome mis-segregation and aneuploidy. This response depends on the adaptor protein Sgo1, which associates with pericentromeric chromatin in mitosis. The mechanisms underlying Sgo1 function and regulation are unclear. Here, we show that Sgo1 is an anaphase-promoting complex/cyclosome (APC/C) substrate in budding yeast (Saccharomyces cerevisiae), and that its mitotic destruction depends on an unusual D-box-related sequence motif near its C-terminus. We find that the removal of Sgo1 from chromosomes before anaphase is not dependent on its destruction, but rather on other mechanisms responsive to tension between sister chromatids. Additionally, we find that Sgo1 recruits the protein phosphatase 2A (PP2A) isoform containing Rts1 to the pericentromeric region prior to bi-orientation, and that artificial recruitment of Rts1 to this region of a single chromosome is sufficient to perform the function of Sgo1 on that chromosome. We conclude that in early mitosis, Sgo1 associates transiently with pericentromeric chromatin to promote bi-orientation, in large part by recruiting the Rts1 isoform of PP2A.
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Affiliation(s)
- Heather D Eshleman
- Departments of Physiology and Biochemistry and Biophysics, University of California, San Francisco, CA 94158, USA
| | - David O Morgan
- Departments of Physiology and Biochemistry and Biophysics, University of California, San Francisco, CA 94158, USA
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Nerusheva OO, Galander S, Fernius J, Kelly D, Marston AL. Tension-dependent removal of pericentromeric shugoshin is an indicator of sister chromosome biorientation. Genes Dev 2014; 28:1291-309. [PMID: 24939933 PMCID: PMC4066400 DOI: 10.1101/gad.240291.114] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 05/20/2014] [Indexed: 12/24/2022]
Abstract
During mitosis and meiosis, sister chromatid cohesion resists the pulling forces of microtubules, enabling the generation of tension at kinetochores upon chromosome biorientation. How tension is read to signal the bioriented state remains unclear. Shugoshins form a pericentromeric platform that integrates multiple functions to ensure proper chromosome biorientation. Here we show that budding yeast shugoshin Sgo1 dissociates from the pericentromere reversibly in response to tension. The antagonistic activities of the kinetochore-associated Bub1 kinase and the Sgo1-bound phosphatase protein phosphatase 2A (PP2A)-Rts1 underlie a tension-dependent circuitry that enables Sgo1 removal upon sister kinetochore biorientation. Sgo1 dissociation from the pericentromere triggers dissociation of condensin and Aurora B from the centromere, thereby stabilizing the bioriented state. Conversely, forcing sister kinetochores to be under tension during meiosis I leads to premature Sgo1 removal and precocious loss of pericentromeric cohesion. Overall, we show that the pivotal role of shugoshin is to build a platform at the pericentromere that attracts activities that respond to the absence of tension between sister kinetochores. Disassembly of this platform in response to intersister kinetochore tension signals the bioriented state. Therefore, tension sensing by shugoshin is a central mechanism by which the bioriented state is read.
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Affiliation(s)
- Olga O. Nerusheva
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom
| | - Stefan Galander
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom
| | - Josefin Fernius
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom
| | - David Kelly
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom
| | - Adele L. Marston
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom
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Sivakumar S, Daum JR, Tipton AR, Rankin S, Gorbsky GJ. The spindle and kinetochore-associated (Ska) complex enhances binding of the anaphase-promoting complex/cyclosome (APC/C) to chromosomes and promotes mitotic exit. Mol Biol Cell 2014; 25:594-605. [PMID: 24403607 PMCID: PMC3937086 DOI: 10.1091/mbc.e13-07-0421] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The spindle and kinetochore-associated (Ska) protein complex is a heterotrimeric complex required for timely anaphase onset. The major phenotypes seen after small interfering RNA-mediated depletion of Ska are transient alignment defects followed by metaphase arrest that ultimately results in cohesion fatigue. We find that cells depleted of Ska3 arrest at metaphase with only partial degradation of cyclin B1 and securin. In cells arrested with microtubule drugs, Ska3-depleted cells exhibit slower mitotic exit when the spindle checkpoint is silenced by inhibition of the checkpoint kinase, Mps1, or when cells are forced to exit mitosis downstream of checkpoint silencing by inactivation of Cdk1. These results suggest that in addition to a role in fostering kinetochore-microtubule attachment and chromosome alignment, the Ska complex has functions in promoting anaphase onset. We find that both Ska3 and microtubules promote chromosome association of the anaphase-promoting complex/cyclosome (APC/C). Chromosome-bound APC/C shows significantly stronger ubiquitylation activity than cytoplasmic APC/C. Forced localization of Ska complex to kinetochores, independent of microtubules, results in enhanced accumulation of APC/C on chromosomes and accelerated cyclin B1 degradation during induced mitotic exit. We propose that a Ska-microtubule-kinetochore association promotes APC/C localization to chromosomes, thereby enhancing anaphase onset and mitotic exit.
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Affiliation(s)
- Sushama Sivakumar
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104 Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
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30
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Marston AL. Chromosome segregation in budding yeast: sister chromatid cohesion and related mechanisms. Genetics 2014; 196:31-63. [PMID: 24395824 PMCID: PMC3872193 DOI: 10.1534/genetics.112.145144] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 09/18/2013] [Indexed: 12/28/2022] Open
Abstract
Studies on budding yeast have exposed the highly conserved mechanisms by which duplicated chromosomes are evenly distributed to daughter cells at the metaphase-anaphase transition. The establishment of proteinaceous bridges between sister chromatids, a function provided by a ring-shaped complex known as cohesin, is central to accurate segregation. It is the destruction of this cohesin that triggers the segregation of chromosomes following their proper attachment to microtubules. Since it is irreversible, this process must be tightly controlled and driven to completion. Furthermore, during meiosis, modifications must be put in place to allow the segregation of maternal and paternal chromosomes in the first division for gamete formation. Here, I review the pioneering work from budding yeast that has led to a molecular understanding of the establishment and destruction of cohesion.
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Affiliation(s)
- Adele L Marston
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom
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31
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Baro B, Rodriguez-Rodriguez JA, Calabria I, Hernáez ML, Gil C, Queralt E. Dual Regulation of the mitotic exit network (MEN) by PP2A-Cdc55 phosphatase. PLoS Genet 2013; 9:e1003966. [PMID: 24339788 PMCID: PMC3854864 DOI: 10.1371/journal.pgen.1003966] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 10/04/2013] [Indexed: 12/17/2022] Open
Abstract
Exit from mitosis in budding yeast is triggered by activation of the key mitotic phosphatase Cdc14. At anaphase onset, the protease separase and Zds1 promote the downregulation of PP2ACdc55 phosphatase, which facilitates Cdk1-dependent phosphorylation of Net1 and provides the first wave of Cdc14 activity. Once Cdk1 activity starts to decline, the mitotic exit network (MEN) is activated to achieve full Cdc14 activation. Here we describe how the PP2ACdc55 phosphatase could act as a functional link between FEAR and MEN due to its action on Bfa1 and Mob1. We demonstrate that PP2ACdc55 regulates MEN activation by facilitating Cdc5- and Cdk1-dependent phosphorylation of Bfa1 and Mob1, respectively. Downregulation of PP2ACdc55 initiates MEN activity up to Cdc15 by Bfa1 inactivation. Surprisingly, the premature Bfa1 inactivation observed does not entail premature MEN activation, since an additional Cdk1-Clb2 inhibitory signal acting towards Dbf2-Mob1 activity restrains MEN activity until anaphase. In conclusion, we propose a clear picture of how PP2ACdc55 functions affect the regulation of various MEN components, contributing to mitotic exit. Cell cycle studies over the years have tried to elucidate the molecular mechanisms behind cell division, one of the most highly regulated of all cell processes, which ensures life in all organisms. Protein phosphorylation emerged as a key regulatory mechanism in the cell cycle. The highly conserved family of cyclin-dependent kinases, the Cdks, are considered the main component of the cell cycle control system. However, it has become clear that opposing phosphatases also play a key role in determining the phosphorylation state of the proteins. Cells enter mitosis when mitotic Cdk activity increases, having its pick of activity during metaphase. To exit mitosis, cells must coordinate chromosome segregation with Cdk inactivation processes involving the activation of protein phosphatases. Here we show that the phosphatase PP2A regulates the mitotic exit network (MEN) by counteracting the phosphorylation of Bfa1 and Mob1. Our findings provide new insights into the mechanism by which PP2A-Cdc55 functions affect the regulation of various MEN components that contribute to mitotic exit. The core signalling elements of the MEN, SIN and Hippo pathways are highly conserved. Therefore, studies of MEN regulation will contribute to our understanding of MEN-related pathways in other organisms.
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Affiliation(s)
- Barbara Baro
- Cell Cycle Group, Cancer Epigenetics and Biology Program (PEBC), Institut d'Investigacions Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Jose-Antonio Rodriguez-Rodriguez
- Cell Cycle Group, Cancer Epigenetics and Biology Program (PEBC), Institut d'Investigacions Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Ines Calabria
- Cell Cycle Group, Cancer Epigenetics and Biology Program (PEBC), Institut d'Investigacions Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - María Luisa Hernáez
- Unidad de Proteómica, Parque Científico de Madrid, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Concha Gil
- Unidad de Proteómica, Parque Científico de Madrid, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Ethel Queralt
- Cell Cycle Group, Cancer Epigenetics and Biology Program (PEBC), Institut d'Investigacions Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
- * E-mail:
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32
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Qian J, Winkler C, Bollen M. 4D-networking by mitotic phosphatases. Curr Opin Cell Biol 2013; 25:697-703. [DOI: 10.1016/j.ceb.2013.06.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Revised: 06/14/2013] [Accepted: 06/18/2013] [Indexed: 01/21/2023]
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Lianga N, Williams EC, Kennedy EK, Doré C, Pilon S, Girard SL, Deneault JS, Rudner AD. A Wee1 checkpoint inhibits anaphase onset. ACTA ACUST UNITED AC 2013; 201:843-62. [PMID: 23751495 PMCID: PMC3678162 DOI: 10.1083/jcb.201212038] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The budding yeast Wee1 kinase Swe1 restrains the metaphase-to-anaphase transition by preventing the Cdk1-dependent phosphorylation and activation of APCCdc20. Cdk1 drives both mitotic entry and the metaphase-to-anaphase transition. Past work has shown that Wee1 inhibition of Cdk1 blocks mitotic entry. Here we show that the budding yeast Wee1 kinase, Swe1, also restrains the metaphase-to-anaphase transition by preventing Cdk1 phosphorylation and activation of the mitotic form of the anaphase-promoting complex/cyclosome (APCCdc20). Deletion of SWE1 or its opposing phosphatase MIH1 (the budding yeast cdc25+) altered the timing of anaphase onset, and activation of the Swe1-dependent morphogenesis checkpoint or overexpression of Swe1 blocked cells in metaphase with reduced APC activity in vivo and in vitro. The morphogenesis checkpoint also depended on Cdc55, a regulatory subunit of protein phosphatase 2A (PP2A). cdc55Δ checkpoint defects were rescued by mutating 12 Cdk1 phosphorylation sites on the APC, demonstrating that the APC is a target of this checkpoint. These data suggest a model in which stepwise activation of Cdk1 and inhibition of PP2ACdc55 triggers anaphase onset.
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Affiliation(s)
- Noel Lianga
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
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Wang P, Galan JA, Normandin K, Bonneil É, Hickson GR, Roux PP, Thibault P, Archambault V. Cell cycle regulation of Greatwall kinase nuclear localization facilitates mitotic progression. ACTA ACUST UNITED AC 2013; 202:277-93. [PMID: 23857770 PMCID: PMC3718974 DOI: 10.1083/jcb.201211141] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Greatwall kinase relocation from the nucleus to the cytoplasm is required at mitotic entry and is mediated by a phosphorylation-dependent mechanism targeting its central region. Cell division requires the coordination of critical protein kinases and phosphatases. Greatwall (Gwl) kinase activity inactivates PP2A-B55 at mitotic entry to promote the phosphorylation of cyclin B–Cdk1 substrates, but how Gwl is regulated is poorly understood. We found that the subcellular localization of Gwl changed dramatically during the cell cycle in Drosophila. Gwl translocated from the nucleus to the cytoplasm in prophase. We identified two critical nuclear localization signals in the central, poorly characterized region of Gwl, which are required for its function. The Polo kinase associated with and phosphorylated Gwl in this region, promoting its binding to 14-3-3ε and its localization to the cytoplasm in prophase. Our results suggest that cyclin B–Cdk1 phosphorylation of Gwl is also required for its nuclear exclusion by a distinct mechanism. We show that the nucleo-cytoplasmic regulation of Gwl is essential for its functions in vivo and propose that the spatial regulation of Gwl at mitotic entry contributes to the mitotic switch.
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Affiliation(s)
- Peng Wang
- Institut de recherche en immunologie et en cancérologie, Université de Montréal, Montréal, Québec H3C 3J7, Canada
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