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Bradley D, Garand C, Belda H, Gagnon-Arsenault I, Treeck M, Elowe S, Landry CR. The substrate quality of CK2 target sites has a determinant role on their function and evolution. Cell Syst 2024; 15:544-562.e8. [PMID: 38861992 DOI: 10.1016/j.cels.2024.05.005] [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: 07/03/2023] [Revised: 02/29/2024] [Accepted: 05/20/2024] [Indexed: 06/13/2024]
Abstract
Most biological processes are regulated by signaling modules that bind to short linear motifs. For protein kinases, substrates may have full or only partial matches to the kinase recognition motif, a property known as "substrate quality." However, it is not clear whether differences in substrate quality represent neutral variation or if they have functional consequences. We examine this question for the kinase CK2, which has many fundamental functions. We show that optimal CK2 sites are phosphorylated at maximal stoichiometries and found in many conditions, whereas minimal substrates are more weakly phosphorylated and have regulatory functions. Optimal CK2 sites tend to be more conserved, and substrate quality is often tuned by selection. For intermediate sites, increases or decreases in substrate quality may be deleterious, as we demonstrate for a CK2 substrate at the kinetochore. The results together suggest a strong role for substrate quality in phosphosite function and evolution. A record of this paper's transparent peer review process is included in the supplemental information.
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Affiliation(s)
- David Bradley
- Département de Biochimie, de Microbiologie et de Bio-informatique, Faculté des Sciences et de Génie, Université Laval, Québec City, QC G1V 0A6, Canada; Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec City, QC G1V 0A6, Canada; PROTEO, Le regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines, Université Laval, Québec City, QC G1V 0A6, Canada; Centre de Recherche sur les Données Massives (CRDM), Université Laval, Québec City, QC G1V 0A6, Canada; Département de Biologie, Faculté des Sciences et de Génie, Université Laval, Québec City, QC G1V 0A6, Canada.
| | - Chantal Garand
- PROTEO, Le regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines, Université Laval, Québec City, QC G1V 0A6, Canada; Axe de Reproduction, Santé de la mère et de l'enfant, CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Hugo Belda
- Signalling in Host-Pathogen Interaction Laboratory, The Francis Crick Institute, London NW11AT, UK
| | - Isabelle Gagnon-Arsenault
- Département de Biochimie, de Microbiologie et de Bio-informatique, Faculté des Sciences et de Génie, Université Laval, Québec City, QC G1V 0A6, Canada; Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec City, QC G1V 0A6, Canada; PROTEO, Le regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines, Université Laval, Québec City, QC G1V 0A6, Canada; Centre de Recherche sur les Données Massives (CRDM), Université Laval, Québec City, QC G1V 0A6, Canada; Département de Biologie, Faculté des Sciences et de Génie, Université Laval, Québec City, QC G1V 0A6, Canada
| | - Moritz Treeck
- Signalling in Host-Pathogen Interaction Laboratory, The Francis Crick Institute, London NW11AT, UK; Cell Biology of Host-Pathogen Interaction Laboratory, The Gulbenkian Institute of Science, Oeiras 2780-156, Portugal
| | - Sabine Elowe
- PROTEO, Le regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines, Université Laval, Québec City, QC G1V 0A6, Canada; Axe de Reproduction, Santé de la mère et de l'enfant, CHU de Québec, Université Laval, Québec City, QC, Canada; Department of Pediatrics, Faculty of Medicine, Université Laval, Québec City, QC, Canada; Centre de Recherche sur le Cancer, CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Christian R Landry
- Département de Biochimie, de Microbiologie et de Bio-informatique, Faculté des Sciences et de Génie, Université Laval, Québec City, QC G1V 0A6, Canada; Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec City, QC G1V 0A6, Canada; PROTEO, Le regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines, Université Laval, Québec City, QC G1V 0A6, Canada; Centre de Recherche sur les Données Massives (CRDM), Université Laval, Québec City, QC G1V 0A6, Canada; Département de Biologie, Faculté des Sciences et de Génie, Université Laval, Québec City, QC G1V 0A6, Canada.
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2
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Chia KH, Takaki H, Fujimitsu K, Darling S, Zou J, Rappsilber J, Yamano H. CDK1-PP2A-B55 interplay ensures cell cycle oscillation via Apc1-loop 300. Cell Rep 2024; 43:114155. [PMID: 38678563 DOI: 10.1016/j.celrep.2024.114155] [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: 10/16/2023] [Revised: 03/12/2024] [Accepted: 04/10/2024] [Indexed: 05/01/2024] Open
Abstract
Cell cycle control relies on a delicate balance of phosphorylation with CDK1 and phosphatases like PP1 and PP2A-B55. Yet, identifying the primary substrate responsible for cell cycle oscillations remains a challenge. We uncover the pivotal role of phospho-regulation in the anaphase-promoting complex/cyclosome (APC/C), particularly through the Apc1-loop300 domain (Apc1-300L), orchestrated by CDK1 and PP2A-B55. Premature activation of PP2A-B55 during mitosis, induced by Greatwall kinase depletion, leads to Apc1-300L dephosphorylation, stalling APC/C activity and delaying Cyclin B degradation. This effect can be counteracted using the B55-specific inhibitor pEnsa or by removing Apc1-300L. We also show Cdc20's dynamic APC/C interaction across cell cycle stages, but dephosphorylation of Apc1-300L specifically inhibits further Cdc20 recruitment. Our study underscores APC/C's central role in cell cycle oscillation, identifying it as a primary substrate regulated by the CDK-PP2A partnership.
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Affiliation(s)
- Kim Hou Chia
- Cell Cycle Control Group, University College London (UCL) Cancer Institute, London WC1E 6DD, UK
| | - Hiroko Takaki
- Cell Cycle Control Group, University College London (UCL) Cancer Institute, London WC1E 6DD, UK
| | - Kazuyuki Fujimitsu
- Cell Cycle Control Group, University College London (UCL) Cancer Institute, London WC1E 6DD, UK
| | - Sarah Darling
- Cell Cycle Control Group, University College London (UCL) Cancer Institute, London WC1E 6DD, UK
| | - Juan Zou
- University of Edinburgh, Wellcome Centre for Cell Biology, Edinburgh EH9 3BF, UK
| | - Juri Rappsilber
- University of Edinburgh, Wellcome Centre for Cell Biology, Edinburgh EH9 3BF, UK; Technische Universität Berlin, Chair of Bioanalytics, 10623 Berlin, Germany
| | - Hiroyuki Yamano
- Cell Cycle Control Group, University College London (UCL) Cancer Institute, London WC1E 6DD, UK.
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3
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Celebic D, Polat I, Legros V, Chevreux G, Wassmann K, Touati SA. Qualitative rather than quantitative phosphoregulation shapes the end of meiosis I in budding yeast. EMBO J 2024; 43:1325-1350. [PMID: 38321267 PMCID: PMC10987528 DOI: 10.1038/s44318-024-00032-5] [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: 08/28/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 02/08/2024] Open
Abstract
Exit from mitosis is brought about by dramatic changes in the phosphoproteome landscape. A drop in Cyclin-dependent kinase (Cdk) activity, the master regulatory kinase, and activation of counteracting phosphatases such as Cdc14 in budding yeast, results in ordered substrate dephosphorylation, allowing entry into a new cell cycle and replication licensing. In meiosis however, two cell divisions have to be executed without intermediate DNA replication, implying that global phosphorylation and dephosphorylation have to be adapted to the challenges of meiosis. Using a global time-resolved phosphoproteomics approach in budding yeast, we compared the phosphoproteome landscape between mitotic exit and the transition from meiosis I to meiosis II. We found that unlike exit from mitosis, Cdk phosphomotifs remain mostly stably phosphorylated at the end of meiosis I, whereas a majority of Cdk-unrelated motifs are reset by dephosphorylation. However, inducing an artificial drop of Cdk at metaphase of meiosis I leads to ordered substrate dephosphorylation, comparable to mitosis, indicating that phosphoregulation of substrates at the end of meiosis I is thus mainly qualitatively rather than quantitatively ordered.
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Affiliation(s)
- Dunja Celebic
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013, Paris, France
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, IBPS, UMR7622, Paris, France
| | - Irem Polat
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013, Paris, France
| | - Véronique Legros
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013, Paris, France
| | - Guillaume Chevreux
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013, Paris, France
| | - Katja Wassmann
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013, Paris, France
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, IBPS, UMR7622, Paris, France
| | - Sandra A Touati
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013, Paris, France.
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, IBPS, UMR7622, Paris, France.
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4
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Ng HY, Adly AN, Whelpley DH, Suhandynata RT, Zhou H, Morgan DO. Phosphate-binding pocket on cyclin B governs CDK substrate phosphorylation and mitotic timing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.28.582599. [PMID: 38464173 PMCID: PMC10925351 DOI: 10.1101/2024.02.28.582599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Cell cycle progression is governed by complexes of the cyclin-dependent kinases (CDKs) and their regulatory subunits cyclin and Cks1. CDKs phosphorylate hundreds of substrates, often at multiple sites. Multisite phosphorylation depends on Cks1, which binds initial priming phosphorylation sites to promote secondary phosphorylation at other sites. Here, we describe a similar role for a recently discovered phosphate-binding pocket (PP) on B-type cyclins. Mutation of the PP in Clb2, the major mitotic cyclin of budding yeast, alters bud morphology and delays the onset of anaphase. Using phosphoproteomics in vivo and kinase reactions in vitro, we find that mutation of the PP reduces phosphorylation of several CDK substrates, including the Bud6 subunit of the polarisome and the Cdc16 and Cdc27 subunits of the anaphase-promoting complex/cyclosome. We conclude that the cyclin PP, like Cks1, controls the timing of multisite phosphorylation on CDK substrates, thereby helping to establish the robust timing of cell-cycle events.
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Affiliation(s)
- Henry Y. Ng
- Department of Physiology, University of California San Francisco, San Francisco CA
| | - Armin N. Adly
- Department of Physiology, University of California San Francisco, San Francisco CA
| | - Devon H. Whelpley
- Department of Physiology, University of California San Francisco, San Francisco CA
| | - Raymond T. Suhandynata
- School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla CA
- Department of Pathology, University of California San Diego, La Jolla CA
| | - Huilin Zhou
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla CA
| | - David O. Morgan
- Department of Physiology, University of California San Francisco, San Francisco CA
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5
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Kruse T, Garvanska DH, Varga J, Garland W, McEwan B, Hein JB, Weisser MB, Puy IB, Chan CB, Parrila PS, Mendez BL, Arulanandam J, Schueler-Furman O, Jensen TH, Kettenbach A, Nilsson J. Substrate recognition principles for the PP2A-B55 protein phosphatase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.10.579793. [PMID: 38370611 PMCID: PMC10871369 DOI: 10.1101/2024.02.10.579793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
The PP2A-B55 phosphatase regulates a plethora of signaling pathways throughout eukaryotes. How PP2A-B55 selects its substrates presents a severe knowledge gap. By integrating AlphaFold modelling with comprehensive high resolution mutational scanning, we show that α-helices in substrates bind B55 through an evolutionary conserved mechanism. Despite a large diversity in sequence and composition, these α-helices share key amino acid determinants that engage discrete hydrophobic and electrostatic patches. Using deep learning protein design, we generate a specific and potent competitive peptide inhibitor of PP2A-B55 substrate interactions. With this inhibitor, we uncover that PP2A-B55 regulates the nuclear exosome targeting complex by binding to an α-helical recruitment module in RBM7. Collectively, our findings provide a framework for the understanding and interrogation of PP2A-B55 in health and disease.
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Affiliation(s)
- Thomas Kruse
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Dimitriya H Garvanska
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Julia Varga
- Department of Microbiology and Molecular Genetics, Institute for Biomedical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 9112001, Israel
| | - William Garland
- Department of Molecular Biology and Genetics, Universitetsbyen 81, Aarhus University, Aarhus, Denmark
| | - Brennan McEwan
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Jamin B Hein
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Current address: Amgen Research Copenhagen, Rønnegade 8, 5, 2100 Copenhagen, Denmark
| | - Melanie Bianca Weisser
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Iker Benavides Puy
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Camilla Bachman Chan
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Paula Sotelo Parrila
- Gene Center Munich, Ludwig-Maximilians- Universität München, Munich, 81377, Germany
| | - Blanca Lopez Mendez
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Jeyaprakash Arulanandam
- Gene Center Munich, Ludwig-Maximilians- Universität München, Munich, 81377, Germany
- Wellcome Centre for Cell Biology, University of Edinburg, Edinburgh, EH9 3BF, UK
| | - Ora Schueler-Furman
- Department of Microbiology and Molecular Genetics, Institute for Biomedical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 9112001, Israel
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Universitetsbyen 81, Aarhus University, Aarhus, Denmark
| | - Arminja Kettenbach
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Jakob Nilsson
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
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6
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Kommer DC, Stamatiou K, Vagnarelli P. Cell Cycle-Specific Protein Phosphatase 1 (PP1) Substrates Identification Using Genetically Modified Cell Lines. Methods Mol Biol 2024; 2740:37-61. [PMID: 38393468 DOI: 10.1007/978-1-0716-3557-5_3] [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] [Indexed: 02/25/2024]
Abstract
The identification of protein phosphatase 1 (PP1) holoenzyme substrates has proven to be a challenging task. PP1 can form different holoenzyme complexes with a variety of regulatory subunits, and many of those are cell cycle regulated. Although several methods have been used to identify PP1 substrates, their cell cycle specificity is still an unmet need. Here, we present a new strategy to investigate PP1 substrates throughout the cell cycle using clustered regularly interspersed short palindromic repeats (CRISPR)-Cas9 genome editing and generate cell lines with endogenously tagged PP1 regulatory subunit (regulatory interactor of protein phosphatase one, RIPPO). RIPPOs are tagged with the auxin-inducible degron (AID) or ascorbate peroxidase 2 (APEX2) modules, and PP1 substrate identification is conducted by SILAC proteomic-based approaches. Proteins in close proximity to RIPPOs are first identified through mass spectrometry (MS) analyses using the APEX2 system; then a list of differentially phosphorylated proteins upon RIPPOs rapid degradation (achieved via the AID system) is compiled via SILAC phospho-mass spectrometry. The "in silico" overlap between the two proteomes will be enriched for PP1 putative substrates. Several methods including fluorescence resonance energy transfer (FRET), proximity ligation assays (PLA), and in vitro assays can be used as substrate validations approaches.
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Affiliation(s)
- Dorothee C Kommer
- College of Health, Medicine and Life Science, Brunel University London, London, UK
| | | | - Paola Vagnarelli
- College of Health, Medicine and Life Science, Brunel University London, London, UK.
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7
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DeMarco AG, Dibble MG, Hall MC. Inducible degradation-coupled phosphoproteomics identifies PP2A Rts1 as a novel eisosome regulator. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.24.563668. [PMID: 37961087 PMCID: PMC10634780 DOI: 10.1101/2023.10.24.563668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Reversible protein phosphorylation is an abundant post-translational modification dynamically regulated by opposing kinases and phosphatases. Protein phosphorylation has been extensively studied in cell division, where waves of cyclin-dependent kinase activity, peaking in mitosis, drive the sequential stages of the cell cycle. Here we developed and employed a strategy to specifically probe kinase or phosphatase substrates at desired times or experimental conditions in the model organism Saccharomyces cerevisiae. We combined auxin-inducible degradation (AID) with mass spectrometry-based phosphoproteomics, which allowed us to arrest physiologically normal cultures in mitosis prior to rapid phosphatase degradation and phosphoproteome analysis. Our results revealed that protein phosphatase 2A coupled with its B56 regulatory subunit, Rts1 (PP2ARts1), is involved in dephosphorylation of numerous proteins in mitosis, highlighting the need for phosphatases to selectively maintain certain proteins in a hypophosphorylated state in the face of high mitotic kinase activity. Unexpectedly, we observed elevated phosphorylation at many sites on several subunits of the fungal eisosome complex following rapid Rts1 degradation. Eisosomes are dynamic polymeric assemblies that create furrows in the plasma membrane important in regulating nutrient import, lipid metabolism, and stress responses, among other things. We found that PP2ARts1-mediated dephosphorylation of eisosomes promotes their plasma membrane association and we provide evidence that this regulation impacts eisosome roles in metabolic homeostasis. The combination of rapid, inducible protein degradation with proteomic profiling offers several advantages over common protein disruption methods for characterizing substrates of regulatory enzymes involved in dynamic biological processes.
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Affiliation(s)
- Andrew G. DeMarco
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907
| | - Marcella G. Dibble
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907
| | - Mark C. Hall
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907
- Institute for Cancer Research, Purdue University, West Lafayette, IN, 47907
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8
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Nguyen H, Kettenbach AN. Substrate and phosphorylation site selection by phosphoprotein phosphatases. Trends Biochem Sci 2023; 48:713-725. [PMID: 37173206 PMCID: PMC10523993 DOI: 10.1016/j.tibs.2023.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 04/11/2023] [Accepted: 04/13/2023] [Indexed: 05/15/2023]
Abstract
Dynamic protein phosphorylation and dephosphorylation are essential regulatory mechanisms that ensure proper cellular signaling and biological functions. Deregulation of either reaction has been implicated in several human diseases. Here, we focus on the mechanisms that govern the specificity of the dephosphorylation reaction. Most cellular serine/threonine dephosphorylation is catalyzed by 13 highly conserved phosphoprotein phosphatase (PPP) catalytic subunits, which form hundreds of holoenzymes by binding to regulatory and scaffolding subunits. PPP holoenzymes recognize phosphorylation site consensus motifs and interact with short linear motifs (SLiMs) or structural elements distal to the phosphorylation site. We review recent advances in understanding the mechanisms of PPP site-specific dephosphorylation preference and substrate recruitment and highlight examples of their interplay in the regulation of cell division.
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Affiliation(s)
- Hieu Nguyen
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Arminja N Kettenbach
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA; Dartmouth Cancer Center, Lebanon, NH 03756, USA.
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9
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Emond-Fraser V, Larouche M, Kubiniok P, Bonneil É, Li J, Bourouh M, Frizzi L, Thibault P, Archambault V. Identification of PP2A-B55 targets uncovers regulation of emerin during nuclear envelope reassembly in Drosophila. Open Biol 2023; 13:230104. [PMID: 37463656 PMCID: PMC10353892 DOI: 10.1098/rsob.230104] [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: 04/18/2023] [Accepted: 06/21/2023] [Indexed: 07/20/2023] Open
Abstract
Mitotic exit requires the dephosphorylation of many proteins whose phosphorylation was needed for mitosis. Protein phosphatase 2A with its B55 regulatory subunit (PP2A-B55) promotes this transition. However, the events and substrates that it regulates are incompletely understood. We used proteomic approaches in Drosophila to identify proteins that interact with and are dephosphorylated by PP2A-B55. Among several candidates, we identified emerin (otefin in Drosophila). Emerin resides in the inner nuclear membrane and interacts with the DNA-binding protein barrier-to-autointegration factor (BAF) via a LEM domain. We found that the phosphorylation of emerin at Ser50 and Ser54 near its LEM domain negatively regulates its association with BAF, lamin and additional emerin in mitosis. We show that dephosphorylation of emerin at these sites by PP2A-B55 determines the timing of nuclear envelope reformation. Genetic experiments indicate that this regulation is required during embryonic development. Phosphoregulation of the emerin-BAF complex formation by PP2A-B55 appears as a key event of mitotic exit that is likely conserved across species.
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Affiliation(s)
- Virginie Emond-Fraser
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
| | - Myreille Larouche
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
| | - Peter Kubiniok
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
| | - Éric Bonneil
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
| | - Jingjing Li
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
| | - Mohammed Bourouh
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
| | - Laura Frizzi
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
| | - Pierre Thibault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
- Département de chimie, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
| | - Vincent Archambault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, H3T 1J4, Quebec, Canada
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10
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Al-Rawi A, Kaye E, Korolchuk S, Endicott JA, Ly T. Cyclin A and Cks1 promote kinase consensus switching to non-proline-directed CDK1 phosphorylation. Cell Rep 2023; 42:112139. [PMID: 36840943 DOI: 10.1016/j.celrep.2023.112139] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 11/17/2022] [Accepted: 02/02/2023] [Indexed: 02/26/2023] Open
Abstract
Ordered protein phosphorylation by CDKs is a key mechanism for regulating the cell cycle. How temporal order is enforced in mammalian cells remains unclear. Using a fixed cell kinase assay and phosphoproteomics, we show how CDK1 activity and non-catalytic CDK1 subunits contribute to the choice of substrate and site of phosphorylation. Increases in CDK1 activity alter substrate choice, with intermediate- and low-sensitivity CDK1 substrates enriched in DNA replication and mitotic functions, respectively. This activity dependence is shared between Cyclin A- and Cyclin B-CDK1. Cks1 has a proteome-wide role as an enhancer of multisite CDK1 phosphorylation. Contrary to the model of CDK1 as an exclusively proline-directed kinase, we show that Cyclin A and Cks1 enhance non-proline-directed phosphorylation, preferably on sites with a +3 lysine residue. Indeed, 70% of cell-cycle-regulated phosphorylations, where the kinase carrying out this modification has not been identified, are non-proline-directed CDK1 sites.
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Affiliation(s)
- Aymen Al-Rawi
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK; Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Edward Kaye
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | | | - Jane A Endicott
- Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Tony Ly
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK; 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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Su B, Lim D, Qi C, Zhang Z, Wang J, Zhang F, Dong C, Feng Z. VPA mediates bidirectional regulation of cell cycle progression through the PPP2R2A-Chk1 signaling axis in response to HU. Cell Death Dis 2023; 14:114. [PMID: 36781846 PMCID: PMC9925808 DOI: 10.1038/s41419-023-05649-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/15/2023]
Abstract
Cell cycle checkpoint kinases play a pivotal role in protecting against replicative stress. In this study, valproic acid (VPA), a histone deacetylase inhibitor (HDACi), was found to promote breast cancer MCF-7 cells to traverse into G2/M phase for catastrophic injury by promoting PPP2R2A (the B-regulatory subunit of Phosphatase PP2A) to facilitate the dephosphorylation of Chk1 at Ser317 and Ser345. By contrast, VPA protected normal 16HBE cells from HU toxicity through decreasing PPP2R2A expression and increasing Chk1 phosphorylation. The effect of VPA on PPP2R2A was at the post-transcription level through HDAC1/2. The in vitro results were affirmed in vivo. Patients with lower PPP2R2A expression and higher pChk1 expression showed significantly worse survival. PPP2R2A D197 and N181 are essential for PPP2R2A-Chk1 signaling and VPA-mediated bidirectional effect on augmenting HU-induced tumor cell death and protecting normal cells.
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Affiliation(s)
- Benyu Su
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - David Lim
- Translational Health Research Institute, School of Health Sciences, Western Sydney University, Campbelltown, NSW, Australia
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Chenyang Qi
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Zhongwei Zhang
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Junxiao Wang
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Fengmei Zhang
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Chao Dong
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China.
| | - Zhihui Feng
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China.
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12
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Dephosphorylation of the pre-initiation complex is critical for origin firing. Mol Cell 2023; 83:12-25.e10. [PMID: 36543171 DOI: 10.1016/j.molcel.2022.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 08/13/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022]
Abstract
In eukaryotes, cyclin-dependent kinase (CDK) ensures that the genome is duplicated exactly once by inhibiting helicase loading factors before activating origin firing. CDK activates origin firing by phosphorylating two substrates, Sld2 and Sld3, forming a transient and limiting intermediate-the pre-initiation complex (pre-IC). Here, we show in the budding yeast Saccharomyces cerevisiae that the CDK phosphorylations of Sld3 and Sld2 are rapidly turned over during S phase by the PP2A and PP4 phosphatases. PP2ARts1 targets Sld3 specifically through an Rts1-interaction motif, and this targeted dephosphorylation is important for origin firing genome-wide, for formation of the pre-IC at origins and for ensuring that Sld3 is dephosphorylated in G1 phase. PP2ARts1 promotes replication in vitro, and we show that targeted Sld3 dephosphorylation is critical for viability. Together, these studies demonstrate that phosphatases enforce the correct ordering of replication factor phosphorylation and in addition to kinases are also key drivers of replication initiation.
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13
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Vit G, Hirth A, Neugebauer N, Kraft BN, Sigismondo G, Cazzola A, Tessmer C, Duro J, Krijgsveld J, Hofmann I, Berger M, Klüter H, Niehrs C, Nilsson J, Krämer A. Human SLFN5 and its Xenopus Laevis ortholog regulate entry into mitosis and oocyte meiotic resumption. Cell Death Dis 2022; 8:484. [PMID: 36477080 PMCID: PMC9729291 DOI: 10.1038/s41420-022-01274-0] [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: 08/24/2022] [Revised: 11/22/2022] [Accepted: 11/24/2022] [Indexed: 12/12/2022]
Abstract
The Schlafen gene family was first described in mice as a regulator of thymocyte development. Further studies showed involvement of human orthologs in different processes related with viral replication, cellular proliferation, and differentiation. In recent years, a new role for human Slfn11 in DNA replication and chromatin remodeling was described. As commonly observed in many gene families, Slfn paralogs show a tissue-specific expression. This made it difficult to reach conclusions which can be valid in different biological models regarding the function of the different Schlafen proteins. In the present study, we investigate the involvement of SLFN5 in cell-cycle regulation and cell proliferation. A careful analysis of SLFN5 expression revealed that SLFN5 is highly expressed in proliferating tissues and that the protein is ubiquitously present in all the tissues and cell line models we analyzed. Very interestingly, SLFN5 expression oscillates during cell cycle, peaking during S phase. The fact that SLFN5 interacts with protein phosphatase 2A and that SLFN5 depletion causes cell cycle arrest and cellular apoptosis, suggests a direct involvement of this human paralog in cell cycle progression and cellular proliferation. We substantiated our in vitro and in cellulo results using Xenopus laevis oocytes to show that mRNA depletion of the unique Slfn gene present in Xenopus, whose protein sequence shares 80% of homology with SLFN5, recapitulates the phenotype observed in human cells preventing the resumption of meiosis during oocyte development.
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Affiliation(s)
- Gianmatteo Vit
- grid.7700.00000 0001 2190 4373Clinical Cooperation Unit Molecular Hematology/Oncology, German Cancer Research Center (DKFZ) and Department of Internal Medicine V, University of Heidelberg, Heidelberg, Germany ,grid.7700.00000 0001 2190 4373Medical Faculty Mannheim, Institute for Transfusion Medicine and Immunology, Ruprecht-Karls University of Heidelberg, Mannheim, Germany ,grid.5254.60000 0001 0674 042XThe Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Alexander Hirth
- grid.424631.60000 0004 1794 1771Division of Molecular Embryology, DKFZ-ZMBH Alliance, Deutsches Krebsforschungszentrum (DKFZ), 69120 Heidelberg, Germany, and Institute of Molecular Biology (IMB), Mainz, Germany
| | - Nicolas Neugebauer
- grid.7700.00000 0001 2190 4373Clinical Cooperation Unit Molecular Hematology/Oncology, German Cancer Research Center (DKFZ) and Department of Internal Medicine V, University of Heidelberg, Heidelberg, Germany
| | - Bianca N. Kraft
- grid.7700.00000 0001 2190 4373Clinical Cooperation Unit Molecular Hematology/Oncology, German Cancer Research Center (DKFZ) and Department of Internal Medicine V, University of Heidelberg, Heidelberg, Germany
| | - Gianluca Sigismondo
- grid.7497.d0000 0004 0492 0584Division of Proteomics of Stem Cells and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Anna Cazzola
- grid.7700.00000 0001 2190 4373Clinical Cooperation Unit Molecular Hematology/Oncology, German Cancer Research Center (DKFZ) and Department of Internal Medicine V, University of Heidelberg, Heidelberg, Germany
| | - Claudia Tessmer
- grid.7497.d0000 0004 0492 0584Genomics and Proteomics Core Facility, Unit Antibodies, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Joana Duro
- grid.5254.60000 0001 0674 042XThe Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jeroen Krijgsveld
- grid.7497.d0000 0004 0492 0584Division of Proteomics of Stem Cells and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ilse Hofmann
- grid.7497.d0000 0004 0492 0584Genomics and Proteomics Core Facility, Unit Antibodies, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Berger
- grid.9619.70000 0004 1937 0538The Lautenberg Center for General and Tumor Immunology, The Hebrew University of Jerusalem, Hadassah Medical School, Jerusalem, Israel
| | - Harald Klüter
- grid.7700.00000 0001 2190 4373Medical Faculty Mannheim, Institute for Transfusion Medicine and Immunology, Ruprecht-Karls University of Heidelberg, Mannheim, Germany
| | - Christof Niehrs
- grid.424631.60000 0004 1794 1771Division of Molecular Embryology, DKFZ-ZMBH Alliance, Deutsches Krebsforschungszentrum (DKFZ), 69120 Heidelberg, Germany, and Institute of Molecular Biology (IMB), Mainz, Germany
| | - Jakob Nilsson
- grid.5254.60000 0001 0674 042XThe Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Alwin Krämer
- grid.7700.00000 0001 2190 4373Clinical Cooperation Unit Molecular Hematology/Oncology, German Cancer Research Center (DKFZ) and Department of Internal Medicine V, University of Heidelberg, Heidelberg, Germany
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14
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Sampadi B, Vermeulen S, Mišovic B, Boei JJ, Batth TS, Chang JG, Paulsen MT, Magnuson B, Schimmel J, Kool H, Olie CS, Everts B, Vertegaal ACO, Olsen JV, Ljungman M, Jeggo PA, Mullenders LHF, Vrieling H. Divergent Molecular and Cellular Responses to Low and High-Dose Ionizing Radiation. Cells 2022; 11:cells11233794. [PMID: 36497055 PMCID: PMC9739411 DOI: 10.3390/cells11233794] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/21/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022] Open
Abstract
Cancer risk after ionizing radiation (IR) is assumed to be linear with the dose; however, for low doses, definite evidence is lacking. Here, using temporal multi-omic systems analyses after a low (LD; 0.1 Gy) or a high (HD; 1 Gy) dose of X-rays, we show that, although the DNA damage response (DDR) displayed dose proportionality, many other molecular and cellular responses did not. Phosphoproteomics uncovered a novel mode of phospho-signaling via S12-PPP1R7, and large-scale dephosphorylation events that regulate mitotic exit control in undamaged cells and the G2/M checkpoint upon IR in a dose-dependent manner. The phosphoproteomics of irradiated DNA double-strand breaks (DSBs) repair-deficient cells unveiled extended phospho-signaling duration in either a dose-dependent (DDR signaling) or independent (mTOR-ERK-MAPK signaling) manner without affecting signal magnitude. Nascent transcriptomics revealed the transcriptional activation of genes involved in NRF2-regulated antioxidant defense, redox-sensitive ERK-MAPK signaling, glycolysis and mitochondrial function after LD, suggesting a prominent role for reactive oxygen species (ROS) in molecular and cellular responses to LD exposure, whereas DDR genes were prominently activated after HD. However, how and to what extent the observed dose-dependent differences in molecular and cellular responses may impact cancer development remain unclear, as the induction of chromosomal damage was found to be dose-proportional (10-200 mGy).
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Affiliation(s)
- Bharath Sampadi
- Department of Human Genetics, Leiden University Medical Center, 2333ZC Leiden, The Netherlands
- Correspondence: (B.S.); (H.V.)
| | - Sylvia Vermeulen
- Department of Human Genetics, Leiden University Medical Center, 2333ZC Leiden, The Netherlands
| | - Branislav Mišovic
- Department of Human Genetics, Leiden University Medical Center, 2333ZC Leiden, The Netherlands
| | - Jan J. Boei
- Department of Human Genetics, Leiden University Medical Center, 2333ZC Leiden, The Netherlands
| | - Tanveer S. Batth
- Proteomics Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Science, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Jer-Gung Chang
- Department of Cell and Chemical Biology, Leiden University Medical Center, 2333ZC Leiden, The Netherlands
| | - Michelle T. Paulsen
- Department of Radiation Oncology, Rogel Cancer Center and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Brian Magnuson
- Department of Radiation Oncology, Rogel Cancer Center and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Joost Schimmel
- Department of Human Genetics, Leiden University Medical Center, 2333ZC Leiden, The Netherlands
| | - Hanneke Kool
- Department of Human Genetics, Leiden University Medical Center, 2333ZC Leiden, The Netherlands
| | - Cyriel S. Olie
- Department of Human Genetics, Leiden University Medical Center, 2333ZC Leiden, The Netherlands
| | - Bart Everts
- Department of Parasitology, Leiden University Medical Center, 2333ZA Leiden, The Netherlands
| | - Alfred C. O. Vertegaal
- Department of Cell and Chemical Biology, Leiden University Medical Center, 2333ZC Leiden, The Netherlands
| | - Jesper V. Olsen
- Proteomics Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Science, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Mats Ljungman
- Department of Radiation Oncology, Rogel Cancer Center and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Penny A. Jeggo
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RQ, UK
| | - Leon H. F. Mullenders
- Department of Human Genetics, Leiden University Medical Center, 2333ZC Leiden, The Netherlands
- Department of Genetics, Research Institute of Environmental Medicine (RIeM), Nagoya University, Nagoya 464-8601, Japan
| | - Harry Vrieling
- Department of Human Genetics, Leiden University Medical Center, 2333ZC Leiden, The Netherlands
- Correspondence: (B.S.); (H.V.)
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15
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Kokot T, Köhn M. Emerging insights into serine/threonine-specific phosphoprotein phosphatase function and selectivity. J Cell Sci 2022; 135:277104. [DOI: 10.1242/jcs.259618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
ABSTRACT
Protein phosphorylation on serine and threonine residues is a widely distributed post-translational modification on proteins that acts to regulate their function. Phosphoprotein phosphatases (PPPs) contribute significantly to a plethora of cellular functions through the accurate dephosphorylation of phosphorylated residues. Most PPPs accomplish their purpose through the formation of complex holoenzymes composed of a catalytic subunit with various regulatory subunits. PPP holoenzymes then bind and dephosphorylate substrates in a highly specific manner. Despite the high prevalence of PPPs and their important role for cellular function, their mechanisms of action in the cell are still not well understood. Nevertheless, substantial experimental advancements in (phospho-)proteomics, structural and computational biology have contributed significantly to a better understanding of PPP biology in recent years. This Review focuses on recent approaches and provides an overview of substantial new insights into the complex mechanism of PPP holoenzyme regulation and substrate selectivity.
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Affiliation(s)
- Thomas Kokot
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
| | - Maja Köhn
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
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16
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Lacroix B, Lorca T, Castro A. Structural, enzymatic and spatiotemporal regulation of PP2A-B55 phosphatase in the control of mitosis. Front Cell Dev Biol 2022; 10:967909. [PMID: 36105360 PMCID: PMC9465306 DOI: 10.3389/fcell.2022.967909] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/04/2022] [Indexed: 11/18/2022] Open
Abstract
Cells require major physical changes to induce a proper repartition of the DNA. Nuclear envelope breakdown, DNA condensation and spindle formation are promoted at mitotic entry by massive protein phosphorylation and reversed at mitotic exit by the timely and ordered dephosphorylation of mitotic substrates. This phosphorylation results from the balance between the activity of kinases and phosphatases. The role of kinases in the control of mitosis has been largely studied, however, the impact of phosphatases has long been underestimated. Recent data have now established that the regulation of phosphatases is crucial to confer timely and ordered cellular events required for cell division. One major phosphatase involved in this process is the phosphatase holoenzyme PP2A-B55. This review will be focused in the latest structural, biochemical and enzymatic insights provided for PP2A-B55 phosphatase as well as its regulators and mechanisms of action.
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Affiliation(s)
- Benjamin Lacroix
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), CNRS UMR5237, Université de Montpellier, CNRS UMR5237Montpellier, France
- Équipe Labellisée “Ligue Nationale Contre le Cancer”, Paris, France
| | - Thierry Lorca
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), CNRS UMR5237, Université de Montpellier, CNRS UMR5237Montpellier, France
- Équipe Labellisée “Ligue Nationale Contre le Cancer”, Paris, France
| | - Anna Castro
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), CNRS UMR5237, Université de Montpellier, CNRS UMR5237Montpellier, France
- Équipe Labellisée “Ligue Nationale Contre le Cancer”, Paris, France
- *Correspondence: Anna Castro,
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17
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Faustova I, Örd M, Kiselev V, Fedorenko D, Borovko I, Macs D, Pääbo K, Lõoke M, Loog M. A synthetic biology approach reveals diverse and dynamic CDK response profiles via multisite phosphorylation of NLS-NES modules. SCIENCE ADVANCES 2022; 8:eabp8992. [PMID: 35977012 PMCID: PMC9385143 DOI: 10.1126/sciadv.abp8992] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
The complexity of multisite phosphorylation mechanisms in regulating nuclear localization signals (NLSs) and nuclear export signals (NESs) is not understood, and its potential has not been used in synthetic biology. The nucleocytoplasmic shuttling of many proteins is regulated by cyclin-dependent kinases (CDKs) that rely on multisite phosphorylation patterns and short linear motifs (SLiMs) to dynamically control proteins in the cell cycle. We studied the role of motif patterns in nucleocytoplasmic shuttling using sensors based on the CDK targets Dna2, Psy4, and Mcm2/3 of Saccharomyces cerevisiae. We designed multisite phosphorylation modules by rearranging phosphorylation sites, cyclin-specific SLiMs, phospho-priming, phosphatase specificity, and NLS/NES phospho-regulation and obtained very different substrate localization dynamics. These included ultrasensitive responses with and without a delay, graded responses, and different homeostatic plateaus. Thus, CDK can do much more than trigger sequential switches during the cell cycle as it can drive complex patterns of protein localization and activity by using multisite phosphorylation networks.
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18
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JENKINSON F, ZEGERMAN P. Roles of phosphatases in eukaryotic DNA replication initiation control. DNA Repair (Amst) 2022; 118:103384. [DOI: 10.1016/j.dnarep.2022.103384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/28/2022] [Accepted: 07/30/2022] [Indexed: 11/03/2022]
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19
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Moyano-Rodríguez Y, Vaquero D, Vilalta-Castany O, Foltman M, Sanchez-Diaz A, Queralt E. PP2A-Cdc55 phosphatase regulates actomyosin ring contraction and septum formation during cytokinesis. Cell Mol Life Sci 2022; 79:165. [PMID: 35230542 PMCID: PMC8888506 DOI: 10.1007/s00018-022-04209-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 02/11/2022] [Accepted: 02/13/2022] [Indexed: 11/03/2022]
Abstract
Eukaryotic cells divide and separate all their components after chromosome segregation by a process called cytokinesis to complete cell division. Cytokinesis is highly regulated by the recruitment of the components to the division site and through post-translational modifications such as phosphorylations. The budding yeast mitotic kinases Cdc28-Clb2, Cdc5, and Dbf2-Mob1 phosphorylate several cytokinetic proteins contributing to the regulation of cytokinesis. The PP2A-Cdc55 phosphatase regulates mitosis counteracting Cdk1- and Cdc5-dependent phosphorylation. This prompted us to propose that PP2A-Cdc55 could also be counteracting the mitotic kinases during cytokinesis. Here we show that in the absence of Cdc55, AMR contraction and the primary septum formation occur asymmetrically to one side of the bud neck supporting a role for PP2A-Cdc55 in cytokinesis regulation. In addition, by in vivo and in vitro assays, we show that PP2A-Cdc55 dephosphorylates the chitin synthase II (Chs2 in budding yeast) a component of the Ingression Progression Complexes (IPCs) involved in cytokinesis. Interestingly, the non-phosphorylable version of Chs2 rescues the asymmetric AMR contraction and the defective septa formation observed in cdc55∆ mutant cells. Therefore, timely dephosphorylation of the Chs2 by PP2A-Cdc55 is crucial for proper actomyosin ring contraction. These findings reveal a new mechanism of cytokinesis regulation by the PP2A-Cdc55 phosphatase and extend our knowledge of the involvement of multiple phosphatases during cytokinesis.
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Affiliation(s)
- Yolanda Moyano-Rodríguez
- Cell Cycle Group, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Av. Gran Via de L'Hospitalet 199-203, L'Hospitalet de Llobregat, Barcelona, Spain
| | - David Vaquero
- Cell Cycle Group, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Av. Gran Via de L'Hospitalet 199-203, L'Hospitalet de Llobregat, Barcelona, Spain.,Instituto de Biomedicina de Valencia (IBV-CSIC), C/ Jaume Roig 11, Valencia, Spain
| | - Odena Vilalta-Castany
- Cell Cycle Group, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Av. Gran Via de L'Hospitalet 199-203, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Magdalena Foltman
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain.,Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain
| | - Alberto Sanchez-Diaz
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain.,Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain
| | - Ethel Queralt
- Cell Cycle Group, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Av. Gran Via de L'Hospitalet 199-203, L'Hospitalet de Llobregat, Barcelona, Spain. .,Instituto de Biomedicina de Valencia (IBV-CSIC), C/ Jaume Roig 11, Valencia, Spain.
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20
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Philip J, Örd M, Silva A, Singh S, Diffley JFX, Remus D, Loog M, Ikui AE. Cdc6 is sequentially regulated by PP2A-Cdc55, Cdc14, and Sic1 for origin licensing in S. cerevisiae. eLife 2022; 11:e74437. [PMID: 35142288 PMCID: PMC8830886 DOI: 10.7554/elife.74437] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/15/2021] [Indexed: 01/31/2023] Open
Abstract
Cdc6, a subunit of the pre-replicative complex (pre-RC), contains multiple regulatory cyclin-dependent kinase (Cdk1) consensus sites, SP or TP motifs. In Saccharomyces cerevisiae, Cdk1 phosphorylates Cdc6-T7 to recruit Cks1, the Cdk1 phospho-adaptor in S phase, for subsequent multisite phosphorylation and protein degradation. Cdc6 accumulates in mitosis and is tightly bound by Clb2 through N-terminal phosphorylation in order to prevent premature origin licensing and degradation. It has been extensively studied how Cdc6 phosphorylation is regulated by the cyclin-Cdk1 complex. However, a detailed mechanism on how Cdc6 phosphorylation is reversed by phosphatases has not been elucidated. Here, we show that PP2ACdc55 dephosphorylates Cdc6 N-terminal sites to release Clb2. Cdc14 dephosphorylates the C-terminal phospho-degron, leading to Cdc6 stabilization in mitosis. In addition, Cdk1 inhibitor Sic1 releases Clb2·Cdk1·Cks1 from Cdc6 to load Mcm2-7 on the chromatin upon mitotic exit. Thus, pre-RC assembly and origin licensing are promoted by phosphatases through the attenuation of distinct Cdk1-dependent Cdc6 inhibitory mechanisms.
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Affiliation(s)
- Jasmin Philip
- The PhD Program in Biochemistry, The Graduate Center, CUNYBrooklynUnited States
- Brooklyn CollegeBrooklynUnited States
| | | | - Andriele Silva
- The PhD Program in Biochemistry, The Graduate Center, CUNYBrooklynUnited States
- Brooklyn CollegeBrooklynUnited States
| | - Shaneen Singh
- The PhD Program in Biochemistry, The Graduate Center, CUNYBrooklynUnited States
- Brooklyn CollegeBrooklynUnited States
| | | | - Dirk Remus
- Memorial Sloan-Kettering Cancer CenterNew YorkUnited States
| | | | - Amy E Ikui
- The PhD Program in Biochemistry, The Graduate Center, CUNYBrooklynUnited States
- Brooklyn CollegeBrooklynUnited States
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21
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PP2A-B55: substrates and regulators in the control of cellular functions. Oncogene 2022; 41:1-14. [PMID: 34686773 DOI: 10.1038/s41388-021-02068-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/29/2021] [Accepted: 10/06/2021] [Indexed: 12/17/2022]
Abstract
PP2A is a major serine/threonine phosphatase class involved in the regulation of cell signaling through the removal of protein phosphorylation. This class of phosphatases is comprised of different heterotrimeric complexes displaying distinct substrate specificities. The present review will focus on one specific heterocomplex, the phosphatase PP2A-B55. Herein, we will report the direct substrates of this phosphatase identified to date, and its impact on different cell signaling cascades. We will additionally describe its negative regulation by its inhibitors Arpp19 and ENSA and their upstream kinase Greatwall. Finally, we will describe the essential molecular features defining PP2A-B55 substrate specificity that confer the correct temporal pattern of substrate dephosphorylation. The main objective of this review is to provide the reader with a unique source compiling all the knowledge of this particular holoenzyme that has evolved as a key enzyme for cell homeostasis and cancer development.
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22
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Phosphoproteomic responses of TORC1 target kinases reveal discrete and convergent mechanisms that orchestrate the quiescence program in yeast. Cell Rep 2021; 37:110149. [PMID: 34965436 DOI: 10.1016/j.celrep.2021.110149] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 10/19/2021] [Accepted: 11/30/2021] [Indexed: 01/18/2023] Open
Abstract
The eukaryotic TORC1 kinase assimilates diverse environmental cues, including growth factors and nutrients, to control growth by tuning anabolic and catabolic processes. In yeast, TORC1 stimulates protein synthesis in response to abundant nutrients primarily through its proximal effector kinase Sch9. Conversely, TORC1 inhibition following nutrient limitation unlocks various distally controlled kinases (e.g., Atg1, Gcn2, Npr1, Rim15, Slt2/Mpk1, and Yak1), which cooperate through poorly defined circuits to orchestrate the quiescence program. To better define the signaling landscape of the latter kinases, we use in vivo quantitative phosphoproteomics. Through pinpointing known and uncharted Npr1, Rim15, Slt2/Mpk1, and Yak1 effectors, our study examines the architecture of the distally controlled TORC1 kinase network. Accordingly, this is built on a combination of discrete, convergent, and multilayered feedback regulatory mechanisms, which likely ensure homeostatic control of and/or robust responses by TORC1 and its effector kinases under fluctuating nutritional conditions.
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23
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The CWI Pathway: A Versatile Toolbox to Arrest Cell-Cycle Progression. J Fungi (Basel) 2021; 7:jof7121041. [PMID: 34947023 PMCID: PMC8704918 DOI: 10.3390/jof7121041] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 11/29/2021] [Accepted: 12/02/2021] [Indexed: 02/02/2023] Open
Abstract
Cell-signaling pathways are essential for cells to respond and adapt to changes in their environmental conditions. The cell-wall integrity (CWI) pathway of Saccharomyces cerevisiae is activated by environmental stresses, compounds, and morphogenetic processes that compromise the cell wall, orchestrating the appropriate cellular response to cope with these adverse conditions. During cell-cycle progression, the CWI pathway is activated in periods of polarized growth, such as budding or cytokinesis, regulating cell-wall biosynthesis and the actin cytoskeleton. Importantly, accumulated evidence has indicated a reciprocal regulation of the cell-cycle regulatory system by the CWI pathway. In this paper, we describe how the CWI pathway regulates the main cell-cycle transitions in response to cell-surface perturbance to delay cell-cycle progression. In particular, it affects the Start transcriptional program and the initiation of DNA replication at the G1/S transition, and entry and progression through mitosis. We also describe the involvement of the CWI pathway in the response to genotoxic stress and its connection with the DNA integrity checkpoint, the mechanism that ensures the correct transmission of genetic material and cell survival. Thus, the CWI pathway emerges as a master brake that stops cell-cycle progression when cells are coping with distinct unfavorable conditions.
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24
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Haluska C, Jin F, Wang Y. Protein phosphatase 2A (PP2A) promotes anaphase entry after DNA replication stress in budding yeast. Mol Biol Cell 2021; 32:ar36. [PMID: 34668760 PMCID: PMC8694091 DOI: 10.1091/mbc.e21-04-0222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 10/01/2021] [Accepted: 10/05/2021] [Indexed: 12/31/2022] Open
Abstract
DNA replication stress activates the S-phase checkpoint that arrests the cell cycle, but it is poorly understood how cells recover from this arrest. Cyclin-dependent kinase (CDK) and protein phosphatase 2A (PP2A) are key cell cycle regulators, and Cdc55 is a regulatory subunit of PP2A in budding yeast. We found that yeast cells lacking functional PP2ACdc55 showed slow growth in the presence of hydroxyurea (HU), a DNA synthesis inhibitor, without obvious viability loss. Moreover, PP2A mutants exhibited delayed anaphase entry and sustained levels of anaphase inhibitor Pds1 after HU treatment. A DNA damage checkpoint Chk1 phosphorylates and stabilizes Pds1. We show that chk1Δ and mutation of the Chk1 phosphorylation sites in Pds1 largely restored efficient anaphase entry in PP2A mutants after HU treatment. In addition, deletion of SWE1, which encodes the inhibitory kinase for CDK or mutation of the Swe1 phosphorylation site in CDK (cdc28F19), also suppressed the anaphase entry delay in PP2A mutants after HU treatment. Our genetic data suggest that Swe1/CDK acts upstream of Pds1. Surprisingly, cdc55Δ showed significant suppression to the viability loss of S-phase checkpoint mutants during DNA synthesis block. Together, our results uncover a PP2A-Swe1-CDK-Chk1-Pds1 axis that promotes recovery from DNA replication stress.
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Affiliation(s)
- Cory Haluska
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306-4300
| | - Fengzhi Jin
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306-4300
| | - Yanchang Wang
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306-4300
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25
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Hollenstein DM, Gérecová G, Romanov N, Ferrari J, Veis J, Janschitz M, Beyer R, Schüller C, Ogris E, Hartl M, Ammerer G, Reiter W. A phosphatase-centric mechanism drives stress signaling response. EMBO Rep 2021; 22:e52476. [PMID: 34558777 PMCID: PMC8567219 DOI: 10.15252/embr.202152476] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 08/27/2021] [Accepted: 09/03/2021] [Indexed: 12/14/2022] Open
Abstract
Changing environmental cues lead to the adjustment of cellular physiology by phosphorylation signaling networks that typically center around kinases as active effectors and phosphatases as antagonistic elements. Here, we report a signaling mechanism that reverses this principle. Using the hyperosmotic stress response in Saccharomyces cerevisiae as a model system, we find that a phosphatase-driven mechanism causes induction of phosphorylation. The key activating step that triggers this phospho-proteomic response is the Endosulfine-mediated inhibition of protein phosphatase 2A-Cdc55 (PP2ACdc55 ), while we do not observe concurrent kinase activation. In fact, many of the stress-induced phosphorylation sites appear to be direct substrates of the phosphatase, rendering PP2ACdc55 the main downstream effector of a signaling response that operates in parallel and independent of the well-established kinase-centric stress signaling pathways. This response affects multiple cellular processes and is required for stress survival. Our results demonstrate how a phosphatase can assume the role of active downstream effectors during signaling and allow re-evaluating the impact of phosphatases on shaping the phosphorylome.
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Affiliation(s)
- David Maria Hollenstein
- Department of Biochemistry and Cell BiologyMax Perutz LabsVienna BioCenter (VBC)University of ViennaViennaAustria
| | - Gabriela Gérecová
- Department of Biochemistry and Cell BiologyMax Perutz LabsVienna BioCenter (VBC)University of ViennaViennaAustria
| | | | - Jessica Ferrari
- Department of Biochemistry and Cell BiologyMax Perutz LabsVienna BioCenter (VBC)University of ViennaViennaAustria
| | - Jiri Veis
- Department of Biochemistry and Cell BiologyMax Perutz LabsVienna BioCenter (VBC)University of ViennaViennaAustria
- Center for Medical BiochemistryMax Perutz Labs, Vienna BioCenterMedical University of ViennaViennaAustria
| | - Marion Janschitz
- Department of Biochemistry and Cell BiologyMax Perutz LabsVienna BioCenter (VBC)University of ViennaViennaAustria
| | - Reinhard Beyer
- Department of Applied Genetics and Cell Biology (DAGZ)University of Natural Resources and Life Sciences (BOKU)ViennaAustria
- Research Platform Bioactive Microbial Metabolites (BiMM)Tulln a.d. DonauAustria
| | - Christoph Schüller
- Department of Applied Genetics and Cell Biology (DAGZ)University of Natural Resources and Life Sciences (BOKU)ViennaAustria
- Research Platform Bioactive Microbial Metabolites (BiMM)Tulln a.d. DonauAustria
| | - Egon Ogris
- Center for Medical BiochemistryMax Perutz Labs, Vienna BioCenterMedical University of ViennaViennaAustria
| | - Markus Hartl
- Department of Biochemistry and Cell BiologyMax Perutz LabsVienna BioCenter (VBC)University of ViennaViennaAustria
- Mass Spectrometry FacilityMax Perutz Labs, Vienna BioCenterUniversity of ViennaViennaAustria
| | - Gustav Ammerer
- Department of Biochemistry and Cell BiologyMax Perutz LabsVienna BioCenter (VBC)University of ViennaViennaAustria
| | - Wolfgang Reiter
- Department of Biochemistry and Cell BiologyMax Perutz LabsVienna BioCenter (VBC)University of ViennaViennaAustria
- Mass Spectrometry FacilityMax Perutz Labs, Vienna BioCenterUniversity of ViennaViennaAustria
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26
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Docking to a Basic Helix Promotes Specific Phosphorylation by G1-Cdk1. Int J Mol Sci 2021; 22:ijms22179514. [PMID: 34502421 PMCID: PMC8431026 DOI: 10.3390/ijms22179514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/02/2021] [Accepted: 08/30/2021] [Indexed: 11/20/2022] Open
Abstract
Cyclins are the activators of cyclin-dependent kinase (CDK) complex, but they also act as docking scaffolds for different short linear motifs (SLiMs) in CDK substrates and inhibitors. According to the unified model of CDK function, the cell cycle is coordinated by CDK both via general CDK activity thresholds and cyclin-specific substrate docking. Recently, it was found that the G1-cyclins of S. cerevisiae have a specific function in promoting polarization and growth of the buds, making the G1 cyclins essential for cell survival. Thus, while a uniform CDK specificity of a single cyclin can be sufficient to drive the cell cycle in some cells, such as in fission yeast, cyclin specificity can be essential in other organisms. However, the known G1-CDK specific LP docking motif, was not responsible for this essential function, indicating that G1-CDKs use yet other unknown docking mechanisms. Here we report a discovery of a G1 cyclin-specific (Cln1,2) lysine-arginine-rich helical docking motif (the K/R motif) in G1-CDK targets involved in the mating pathway (Ste7), transcription (Xbp1), bud morphogenesis (Bud2) and spindle pole body (Spc29, Spc42, Spc110, Sli15) function of S. cerevisiae. We also show that the docking efficiency of K/R motif can be regulated by basophilic kinases such as protein kinase A. Our results further widen the list of cyclin specificity mechanisms and may explain the recently demonstrated unique essential function of G1 cyclins in budding yeast.
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27
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Quantitative model of eukaryotic Cdk control through the Forkhead CONTROLLER. NPJ Syst Biol Appl 2021; 7:28. [PMID: 34117265 PMCID: PMC8196193 DOI: 10.1038/s41540-021-00187-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 05/07/2021] [Indexed: 12/20/2022] Open
Abstract
In budding yeast, synchronization of waves of mitotic cyclins that activate the Cdk1 kinase occur through Forkhead transcription factors. These molecules act as controllers of their sequential order and may account for the separation in time of incompatible processes. Here, a Forkhead-mediated design principle underlying the quantitative model of Cdk control is proposed for budding yeast. This design rationalizes timing of cell division, through progressive and coordinated cyclin/Cdk-mediated phosphorylation of Forkhead, and autonomous cyclin/Cdk oscillations. A “clock unit” incorporating this design that regulates timing of cell division is proposed for both yeast and mammals, and has a DRIVER operating the incompatible processes that is instructed by multiple CLOCKS. TIMERS determine whether the clocks are active, whereas CONTROLLERS determine how quickly the clocks shall function depending on external MODULATORS. This “clock unit” may coordinate temporal waves of cyclin/Cdk concentration/activity in the eukaryotic cell cycle making the driver operate the incompatible processes, at separate times.
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28
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Patterson JO, Basu S, Rees P, Nurse P. CDK control pathways integrate cell size and ploidy information to control cell division. eLife 2021; 10:64592. [PMID: 34114564 PMCID: PMC8248981 DOI: 10.7554/elife.64592] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 05/24/2021] [Indexed: 12/27/2022] Open
Abstract
Maintenance of cell size homeostasis is a property that is conserved throughout eukaryotes. Cell size homeostasis is brought about by the co-ordination of cell division with cell growth and requires restriction of smaller cells from undergoing mitosis and cell division, whilst allowing larger cells to do so. Cyclin-CDK is the fundamental driver of mitosis and therefore ultimately ensures size homeostasis. Here we dissect determinants of CDK activity in vivo to investigate how cell size information is processed by the cell cycle network in fission yeast. We develop a high-throughput single-cell assay system of CDK activity in vivo and show that inhibitory tyrosine phosphorylation of CDK encodes cell size information, with the phosphatase PP2A aiding to set a size threshold for division. CDK inhibitory phosphorylation works synergistically with PP2A to prevent mitosis in smaller cells. Finally, we find that diploid cells of equivalent size to haploid cells exhibit lower CDK activity in response to equal cyclin-CDK enzyme concentrations, suggesting that CDK activity is reduced by increased DNA levels. Therefore, scaling of cyclin-CDK levels with cell size, CDK inhibitory phosphorylation, PP2A, and DNA-dependent inhibition of CDK activity, all inform the cell cycle network of cell size, thus contributing to cell size homeostasis.
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Affiliation(s)
- James Oliver Patterson
- Cell Cycle Laboratory, The Francis Crick Institute, London, United Kingdom.,College of Engineering, Swansea University, Swansea, United Kingdom
| | - Souradeep Basu
- Cell Cycle Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Paul Rees
- College of Engineering, Swansea University, Swansea, United Kingdom.,Imaging Platform, Broad Institute of Harvard and MIT, Cambridge, United States
| | - Paul Nurse
- Cell Cycle Laboratory, The Francis Crick Institute, London, United Kingdom.,Laboratory of Yeast Genetics and Cell Biology, Rockefeller University, New York, United States
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29
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Evolutionary crossroads of cell signaling: PP1 and PP2A substrate sites in intrinsically disordered regions. Biochem Soc Trans 2021; 49:1065-1074. [PMID: 34100859 PMCID: PMC8286827 DOI: 10.1042/bst20200175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/07/2021] [Accepted: 05/10/2021] [Indexed: 02/07/2023]
Abstract
Phosphorylation of the hydroxyl group of the amino acids serine and threonine is among the most prevalent post-translational modifications in mammalian cells. Phospho-serine (pSer) and -threonine (pThr) represent a central cornerstone in the cell's toolbox for adaptation to signal input. The true power for the fast modulation of the regulatory pSer/pThr sites arises from the timely attachment, binding and removal of the phosphate. The phosphorylation of serine and threonine by kinases and the binding of pSer/pThr by phosphorylation-dependent scaffold proteins is largely determined by the sequence motif surrounding the phosphorylation site (p-site). The removal of the phosphate is regulated by pSer/pThr-specific phosphatases with the two most prominent ones being PP1 and PP2A. For this family, recent advances brought forward a more complex mechanism for p-site selection. The interaction of regulatory proteins with the substrate protein constitutes a first layer for substrate recognition, but also interactions of the catalytic subunit with the amino acids in close proximity to pSer/pThr contribute to p-site selection. Here, we review the current pieces of evidence for this multi-layered, complex mechanism and hypothesize that, depending on the degree of higher structure surrounding the substrate site, recognition is more strongly influenced by regulatory subunits away from the active site for structured substrate regions, whereas the motif context is of strong relevance with p-sites in disordered regions. The latter makes these amino acid sequences crossroads for signaling and motif strength between kinases, pSer/pThr-binding proteins and phosphatases.
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30
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Pirincci Ercan D, Chrétien F, Chakravarty P, Flynn HR, Snijders AP, Uhlmann F. Budding yeast relies on G 1 cyclin specificity to couple cell cycle progression with morphogenetic development. SCIENCE ADVANCES 2021; 7:eabg0007. [PMID: 34088668 PMCID: PMC8177710 DOI: 10.1126/sciadv.abg0007] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 04/19/2021] [Indexed: 05/04/2023]
Abstract
Two models have been put forward for cyclin-dependent kinase (Cdk) control of the cell cycle. In the qualitative model, cell cycle events are ordered by distinct substrate specificities of successive cyclin waves. Alternatively, in the quantitative model, the gradual rise of Cdk activity from G1 phase to mitosis leads to ordered substrate phosphorylation at sequential thresholds. Here, we study the relative contributions of qualitative and quantitative Cdk control in Saccharomyces cerevisiae All S phase and mitotic cyclins can be replaced by a single mitotic cyclin, albeit at the cost of reduced fitness. A single cyclin can also replace all G1 cyclins to support ordered cell cycle progression, fulfilling key predictions of the quantitative model. However, single-cyclin cells fail to polarize or grow buds and thus cannot survive. Our results suggest that budding yeast has become dependent on G1 cyclin specificity to couple cell cycle progression to essential morphogenetic events.
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Affiliation(s)
| | - Florine Chrétien
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK
| | - Probir Chakravarty
- Bioinformatics and Biostatistics Science Technology Platform, The Francis Crick Institute, London, UK
| | - Helen R Flynn
- Proteomics Science Technology Platform, The Francis Crick Institute, London, UK
| | | | - Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK.
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31
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Hein JB, Garvanska DH, Nasa I, Kettenbach AN, Nilsson J. Coupling of Cdc20 inhibition and activation by BubR1. J Cell Biol 2021; 220:211939. [PMID: 33819340 PMCID: PMC8025235 DOI: 10.1083/jcb.202012081] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/18/2021] [Accepted: 02/25/2021] [Indexed: 12/25/2022] Open
Abstract
Tight regulation of the APC/C-Cdc20 ubiquitin ligase that targets cyclin B1 for degradation is important for mitotic fidelity. The spindle assembly checkpoint (SAC) inhibits Cdc20 through the mitotic checkpoint complex (MCC). In addition, phosphorylation of Cdc20 by cyclin B1–Cdk1 independently inhibits APC/C–Cdc20 activation. This creates a conundrum for how Cdc20 is activated before cyclin B1 degradation. Here, we show that the MCC component BubR1 harbors both Cdc20 inhibition and activation activities, allowing for cross-talk between the two Cdc20 inhibition pathways. Specifically, BubR1 acts as a substrate specifier for PP2A-B56 to enable efficient Cdc20 dephosphorylation in the MCC. A mutant Cdc20 mimicking the dephosphorylated state escapes a mitotic checkpoint arrest, arguing that restricting Cdc20 dephosphorylation to the MCC is important. Collectively, our work reveals how Cdc20 can be dephosphorylated in the presence of cyclin B1-Cdk1 activity without causing premature anaphase onset.
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Affiliation(s)
- Jamin B Hein
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Science, Copenhagen, Denmark
| | - Dimitriya H Garvanska
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Science, Copenhagen, Denmark
| | - Isha Nasa
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Arminja N Kettenbach
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Jakob Nilsson
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Science, Copenhagen, Denmark
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32
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Specificity determinants of phosphoprotein phosphatases controlling kinetochore functions. Essays Biochem 2021; 64:325-336. [PMID: 32501472 DOI: 10.1042/ebc20190065] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/11/2020] [Accepted: 05/14/2020] [Indexed: 12/12/2022]
Abstract
Kinetochores are instrumental for accurate chromosome segregation by binding to microtubules in order to move chromosomes and by delaying anaphase onset through the spindle assembly checkpoint (SAC). Dynamic phosphorylation of kinetochore components is key to control these activities and is tightly regulated by temporal and spatial recruitment of kinases and phosphoprotein phosphatases (PPPs). Here we focus on PP1, PP2A-B56 and PP2A-B55, three PPPs that are important regulators of mitosis. Despite the fact that these PPPs share a very similar active site, they target unique ser/thr phosphorylation sites to control kinetochore function. Specificity is in part achieved by PPPs binding to short linear motifs (SLiMs) that guide their substrate specificity. SLiMs bind to conserved pockets on PPPs and are degenerate in nature, giving rise to a range of binding affinities. These SLiMs control the assembly of numerous substrate specifying complexes and their position and binding strength allow PPPs to target specific phosphorylation sites. In addition, the activity of PPPs is regulated by mitotic kinases and inhibitors, either directly at the activity level or through affecting PPP-SLiM interactions. Here, we discuss recent progress in understanding the regulation of PPP specificity and activity and how this controls kinetochore biology.
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33
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Cordeiro MH, Smith RJ, Saurin AT. Kinetochore phosphatases suppress autonomous Polo-like kinase 1 activity to control the mitotic checkpoint. J Cell Biol 2020; 219:e202002020. [PMID: 33125045 PMCID: PMC7608062 DOI: 10.1083/jcb.202002020] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 08/20/2020] [Accepted: 10/12/2020] [Indexed: 01/04/2023] Open
Abstract
Local phosphatase regulation is needed at kinetochores to silence the mitotic checkpoint (a.k.a. spindle assembly checkpoint [SAC]). A key event in this regard is the dephosphorylation of MELT repeats on KNL1, which removes SAC proteins from the kinetochore, including the BUB complex. We show here that PP1 and PP2A-B56 phosphatases are primarily required to remove Polo-like kinase 1 (PLK1) from the BUB complex, which can otherwise maintain MELT phosphorylation in an autocatalytic manner. This appears to be their principal role in the SAC because both phosphatases become redundant if PLK1 is inhibited or BUB-PLK1 interaction is prevented. Surprisingly, MELT dephosphorylation can occur normally under these conditions even when the levels or activities of PP1 and PP2A are strongly inhibited at kinetochores. Therefore, these data imply that kinetochore phosphatase regulation is critical for the SAC, but primarily to restrain and extinguish autonomous PLK1 activity. This is likely a conserved feature of the metazoan SAC, since the relevant PLK1 and PP2A-B56 binding motifs have coevolved in the same region on MADBUB homologues.
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Affiliation(s)
| | | | - Adrian T. Saurin
- Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, UK
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34
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Plank M, Berti M, Loewith R. Phosphoproteomic Effects of Acute Depletion of PP2A Regulatory Subunit Cdc55. Proteomics 2020; 21:e2000166. [PMID: 32970932 DOI: 10.1002/pmic.202000166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 09/15/2020] [Indexed: 11/08/2022]
Abstract
Protein phosphatase regulatory subunits are increasingly recognized as promising drug targets. In the absence of an existing drug, inducible degradation provides a means of predicting candidate targets. Here auxin-inducible degradation of Saccharomyces cerevisiae PP2A regulatory subunit Cdc55 in combination with quantitative phosphoproteomics is employed. A prevalence of hyperphosphorylated phosphopeptides indicates that the approach successfully identified direct PP2ACdc55 targets. PRM follow up of data-dependent acquisition results confirmed that vacuolar amino acid transporters are among the proteins most strongly affected by Cdc55 depletion.
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Affiliation(s)
- Michael Plank
- Department of Molecular Biology, University of Geneva, Geneva, CH-1211, Switzerland.,National Centre of Competence in Research-Chemical Biology, University of Geneva, Geneva, CH-1211, Switzerland
| | - Marina Berti
- Department of Molecular Biology, University of Geneva, Geneva, CH-1211, Switzerland
| | - Robbie Loewith
- Department of Molecular Biology, University of Geneva, Geneva, CH-1211, Switzerland.,National Centre of Competence in Research-Chemical Biology, University of Geneva, Geneva, CH-1211, Switzerland
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35
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Bancroft J, Holder J, Geraghty Z, Alfonso-Pérez T, Murphy D, Barr FA, Gruneberg U. PP1 promotes cyclin B destruction and the metaphase-anaphase transition by dephosphorylating CDC20. Mol Biol Cell 2020; 31:2315-2330. [PMID: 32755477 PMCID: PMC7851957 DOI: 10.1091/mbc.e20-04-0252] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/22/2020] [Accepted: 07/29/2020] [Indexed: 12/30/2022] Open
Abstract
Ubiquitin-dependent proteolysis of cyclin B and securin initiates sister chromatid segregation and anaphase. The anaphase-promoting complex/cyclosome and its coactivator CDC20 (APC/CCDC20) form the main ubiquitin E3 ligase for these two proteins. APC/CCDC20 is regulated by CDK1-cyclin B and counteracting PP1 and PP2A family phosphatases through modulation of both activating and inhibitory phosphorylation. Here, we report that PP1 promotes cyclin B destruction at the onset of anaphase by removing specific inhibitory phosphorylation in the N-terminus of CDC20. Depletion or chemical inhibition of PP1 stabilizes cyclin B and results in a pronounced delay at the metaphase-to-anaphase transition after chromosome alignment. This requirement for PP1 is lost in cells expressing CDK1 phosphorylation-defective CDC206A mutants. These CDC206A cells show a normal spindle checkpoint response and rapidly destroy cyclin B once all chromosomes have aligned and enter into anaphase in the absence of PP1 activity. PP1 therefore facilitates the metaphase-to-anaphase transition by promoting APC/CCDC20-dependent destruction of cyclin B in human cells.
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Affiliation(s)
- James Bancroft
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - James Holder
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Zoë Geraghty
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | | | - Daniel Murphy
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Francis A. Barr
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Ulrike Gruneberg
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
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36
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The Greatwall kinase safeguards the genome integrity by affecting the kinome activity in mitosis. Oncogene 2020; 39:6816-6840. [PMID: 32978522 PMCID: PMC7605441 DOI: 10.1038/s41388-020-01470-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/21/2020] [Accepted: 09/10/2020] [Indexed: 12/19/2022]
Abstract
Progression through mitosis is balanced by the timely regulation of phosphorylation and dephosphorylation events ensuring the correct segregation of chromosomes before cytokinesis. This balance is regulated by the opposing actions of CDK1 and PP2A, as well as the Greatwall kinase/MASTL. MASTL is commonly overexpressed in cancer, which makes it a potential therapeutic anticancer target. Loss of Mastl induces multiple chromosomal errors that lead to the accumulation of micronuclei and multilobulated cells in mitosis. Our analyses revealed that loss of Mastl leads to chromosome breaks and abnormalities impairing correct segregation. Phospho-proteomic data for Mastl knockout cells revealed alterations in proteins implicated in multiple processes during mitosis including double-strand DNA damage repair. In silico prediction of the kinases with affected activity unveiled NEK2 to be regulated in the absence of Mastl. We uncovered that, RAD51AP1, involved in regulation of homologous recombination, is phosphorylated by NEK2 and CDK1 but also efficiently dephosphorylated by PP2A/B55. Our results suggest that MastlKO disturbs the equilibrium of the mitotic phosphoproteome that leads to the disruption of DNA damage repair and triggers an accumulation of chromosome breaks even in noncancerous cells.
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37
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Touati SA, Hofbauer L, Jones AW, Snijders AP, Kelly G, Uhlmann F. Cdc14 and PP2A Phosphatases Cooperate to Shape Phosphoproteome Dynamics during Mitotic Exit. Cell Rep 2020; 29:2105-2119.e4. [PMID: 31722221 PMCID: PMC6857435 DOI: 10.1016/j.celrep.2019.10.041] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 09/27/2019] [Accepted: 10/10/2019] [Indexed: 12/22/2022] Open
Abstract
Temporal control over protein phosphorylation and dephosphorylation is crucial for accurate chromosome segregation and for completion of the cell division cycle during exit from mitosis. In budding yeast, the Cdc14 phosphatase is thought to be a major regulator at this time, while in higher eukaryotes PP2A phosphatases take a dominant role. Here, we use time-resolved phosphoproteome analysis in budding yeast to evaluate the respective contributions of Cdc14, PP2ACdc55, and PP2ARts1. This reveals an overlapping requirement for all three phosphatases during mitotic progression. Our time-resolved phosphoproteome resource reveals how Cdc14 instructs the sequential pattern of phosphorylation changes, in part through preferential recognition of serine-based cyclin-dependent kinase (Cdk) substrates. PP2ACdc55 and PP2ARts1 in turn exhibit a broad substrate spectrum with some selectivity for phosphothreonines and a role for PP2ARts1 in sustaining Aurora kinase activity. These results illustrate synergy and coordination between phosphatases as they orchestrate phosphoproteome dynamics during mitotic progression. Cdc14, PP2ACdc55, and PP2ARts1 phosphatases cooperate during budding yeast mitosis Cdc14 targets serine Cdk motifs for rapid dephosphorylation PP2ACdc55 dephosphorylates Cdk and Plk substrates on threonine residues PP2ARts1 displays regulatory crosstalk with Aurora kinase
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Affiliation(s)
- Sandra A Touati
- Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK.
| | - Lorena Hofbauer
- Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Andrew W Jones
- Mass Spectrometry Proteomics Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Ambrosius P Snijders
- Mass Spectrometry Proteomics Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Gavin Kelly
- Bioinformatics & Biostatistics Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK.
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38
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Keshri R, Rajeevan A, Kotak S. PP2A--B55γ counteracts Cdk1 and regulates proper spindle orientation through the cortical dynein adaptor NuMA. J Cell Sci 2020; 133:jcs243857. [PMID: 32591484 PMCID: PMC7406356 DOI: 10.1242/jcs.243857] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 06/16/2020] [Indexed: 12/20/2022] Open
Abstract
Proper orientation of the mitotic spindle is critical for accurate development and morphogenesis. In human cells, spindle orientation is regulated by the evolutionarily conserved protein NuMA, which interacts with dynein and enriches it at the cell cortex. Pulling forces generated by cortical dynein orient the mitotic spindle. Cdk1-mediated phosphorylation of NuMA at threonine 2055 (T2055) negatively regulates its cortical localization. Thus, only NuMA not phosphorylated at T2055 localizes at the cell cortex. However, the identity and the mechanism of action of the phosphatase complex involved in T2055 dephosphorylation remains elusive. Here, we characterized the PPP2CA-B55γ (PPP2R2C)-PPP2R1B complex that counteracts Cdk1 to orchestrate cortical NuMA for proper spindle orientation. In vitro reconstitution experiments revealed that this complex is sufficient for T2055 dephosphorylation. Importantly, we identified polybasic residues in NuMA that are critical for T2055 dephosphorylation, and for maintaining appropriate cortical NuMA levels for accurate spindle elongation. Furthermore, we found that Cdk1-mediated phosphorylation and PP2A-B55γ-mediated dephosphorylation at T2055 are reversible events. Altogether, this study uncovers a novel mechanism by which Cdk1 and its counteracting PP2A-B55γ complex orchestrate spatiotemporal levels of cortical force generators for flawless mitosis.
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Affiliation(s)
- Riya Keshri
- Department of Microbiology and Cell Biology, Indian Institute of Science, 560012 Bangalore, India
| | - Ashwathi Rajeevan
- Department of Microbiology and Cell Biology, Indian Institute of Science, 560012 Bangalore, India
| | - Sachin Kotak
- Department of Microbiology and Cell Biology, Indian Institute of Science, 560012 Bangalore, India
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39
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Khondker S, Kajjo S, Chandler-Brown D, Skotheim J, Rudner A, Ikui AE. PP2A Cdc55 dephosphorylates Pds1 and inhibits spindle elongation in S. cerevisiae. J Cell Sci 2020; 133:jcs243766. [PMID: 32591482 PMCID: PMC7406319 DOI: 10.1242/jcs.243766] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 06/11/2020] [Indexed: 11/20/2022] Open
Abstract
PP2ACdc55 (the form of protein phosphatase 2A containing Cdc55) regulates cell cycle progression by reversing cyclin-dependent kinase (CDK)- and polo-like kinase (Cdc5)-dependent phosphorylation events. In S. cerevisiae, Cdk1 phosphorylates securin (Pds1), which facilitates Pds1 binding and inhibits separase (Esp1). During anaphase, Esp1 cleaves the cohesin subunit Scc1 and promotes spindle elongation. Here, we show that PP2ACdc55 directly dephosphorylates Pds1 both in vivo and in vitro Pds1 hyperphosphorylation in a cdc55 deletion mutant enhanced the Pds1-Esp1 interaction, which played a positive role in Pds1 nuclear accumulation and in spindle elongation. We also show that nuclear PP2ACdc55 plays a role during replication stress to inhibit spindle elongation. This pathway acted independently of the known Mec1, Swe1 or spindle assembly checkpoint (SAC) checkpoint pathways. We propose a model where Pds1 dephosphorylation by PP2ACdc55 disrupts the Pds1-Esp1 protein interaction and inhibits Pds1 nuclear accumulation, which prevents spindle elongation, a process that is elevated during replication stress.
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Affiliation(s)
- Shoily Khondker
- Biology Department, Brooklyn College, The City University of New York, Brooklyn, NY 11238, USA
- Biology Program, CUNY Graduate Center, New York, NY 10016, USA
| | - Sam Kajjo
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | | | - Jan Skotheim
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Adam Rudner
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Amy E. Ikui
- Biology Department, Brooklyn College, The City University of New York, Brooklyn, NY 11238, USA
- Biology Program, CUNY Graduate Center, New York, NY 10016, USA
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40
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Dissecting the sequence determinants for dephosphorylation by the catalytic subunits of phosphatases PP1 and PP2A. Nat Commun 2020; 11:3583. [PMID: 32681005 PMCID: PMC7367873 DOI: 10.1038/s41467-020-17334-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 06/22/2020] [Indexed: 12/16/2022] Open
Abstract
The phosphatases PP1 and PP2A are responsible for the majority of dephosphorylation reactions on phosphoserine (pSer) and phosphothreonine (pThr), and are involved in virtually all cellular processes and numerous diseases. The catalytic subunits exist in cells in form of holoenzymes, which impart substrate specificity. The contribution of the catalytic subunits to the recognition of substrates is unclear. By developing a phosphopeptide library approach and a phosphoproteomic assay, we demonstrate that the specificity of PP1 and PP2A holoenzymes towards pThr and of PP1 for basic motifs adjacent to the phosphorylation site are due to intrinsic properties of the catalytic subunits. Thus, we dissect this amino acid specificity of the catalytic subunits from the contribution of regulatory proteins. Furthermore, our approach enables discovering a role for PP1 as regulator of the GRB-associated-binding protein 2 (GAB2)/14-3-3 complex. Beyond this, we expect that this approach is broadly applicable to detect enzyme-substrate recognition preferences. The substrate specificity of phosphoprotein phosphatases PP1 and PP2A depends on their catalytic and regulatory subunits. Using proteomics approaches, the authors here provide insights into the sequence specificity of the catalytic subunits and their distinct contributions to PP1 and PP2A selectivity.
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41
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Jones AW, Flynn HR, Uhlmann F, Snijders AP, Touati SA. Assessing Budding Yeast Phosphoproteome Dynamics in a Time-Resolved Manner using TMT10plex Mass Tag Labeling. STAR Protoc 2020; 1:100022. [PMID: 32685930 PMCID: PMC7357674 DOI: 10.1016/j.xpro.2020.100022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Amine-reactive Tandem Mass Tag 10plex (TMT10plex) labeling permits multiplexed protein identification and quantitative analysis by tandem mass spectrometry (MS/MS). We have used this technology to label 20 Saccharomyces cerevisiae samples collected in a time-resolved manner from a wild-type and phosphatase mutant background to characterize phosphoproteome dynamics. Here, we provide a detailed protocol for biological and mass spectrometry sample preparation and analysis. For complete details on the use and execution of this protocol, please refer to Touati et al. (2019). Characterization of the phosphoproteome in a time-resolved manner TMT10plex Mass Tag labelling of budding yeast extracts Mass spectrometry sample preparation and analysis
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Affiliation(s)
- Andrew W Jones
- Mass Spectrometry Proteomics Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK.,Cell Cycle Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Helen R Flynn
- Mass Spectrometry Proteomics Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Ambrosius P Snijders
- Mass Spectrometry Proteomics Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Sandra A Touati
- Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK.,Institut de Biologie Paris Seine, CNRS UMR7622, Sorbonne Université, Paris, France
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42
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Stonyte V, Martín R, Segura-Peña D, Sekulić N, Lopez-Aviles S. Requirement of PP2A-B56 Par1 for the Stabilization of the CDK Inhibitor Rum1 and Activation of APC/C Ste9 during Pre-Start G1 in S. pombe. iScience 2020; 23:101063. [PMID: 32361273 PMCID: PMC7195536 DOI: 10.1016/j.isci.2020.101063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 03/15/2020] [Accepted: 04/09/2020] [Indexed: 11/30/2022] Open
Abstract
Exit from the cell cycle during the establishment of quiescence and upon cell differentiation requires the sustained inactivation of CDK complexes. Fission yeast cells deprived of nitrogen halt cell cycle progression in pre-Start G1, before becoming quiescent or undergoing sexual differentiation. The CDK inhibitor Rum1 and the APC/C activator Ste9 are fundamental for this arrest, but both are down-regulated by CDK complexes. Here, we show that PP2A-B56Par1 is instrumental for Rum1 stabilization and Ste9 activation. In the absence of PP2A-B56Par1, cells fail to accumulate Rum1, and this results in persistent CDK activity, Ste9 inactivation, retention of the mitotic cyclin Cdc13, and impaired withdrawal from the cell cycle during nitrogen starvation. Importantly, mutation of a putative B56 interacting motif in Rum1 recapitulates these defects. These results underscore the relevance of CDK-counteracting phosphatases in cell differentiation, establishment of the quiescent state, and escape from it in cancer cells. PP2A-B56Par1 is required for cell-cycle arrest and mating upon nitrogen deprivation Loss of Par1 impairs degradation of Cdc13 under nitrogen starvation Absence of Par1 impedes proper dephosphorylation of Ste9 and accumulation of Rum1 Mutation of a Rum1 putative PP2A-B56 SLiM depicts similar defects as the loss Par1
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Affiliation(s)
- Vilte Stonyte
- Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, Oslo, Norway
| | - Ruth Martín
- Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, Oslo, Norway.
| | - Dario Segura-Peña
- Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, Oslo, Norway
| | - Nikolina Sekulić
- Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, Oslo, Norway; Department of Chemistry, University of Oslo, Oslo, Norway
| | - Sandra Lopez-Aviles
- Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, Oslo, Norway; Department of Biosciences, University of Oslo, Oslo, Norway.
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43
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Kruse T, Gnosa SP, Nasa I, Garvanska DH, Hein JB, Nguyen H, Samsøe-Petersen J, Lopez-Mendez B, Hertz EPT, Schwarz J, Pena HS, Nikodemus D, Kveiborg M, Kettenbach AN, Nilsson J. Mechanisms of site-specific dephosphorylation and kinase opposition imposed by PP2A regulatory subunits. EMBO J 2020; 39:e103695. [PMID: 32400009 PMCID: PMC7327492 DOI: 10.15252/embj.2019103695] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 04/03/2020] [Accepted: 04/21/2020] [Indexed: 12/11/2022] Open
Abstract
PP2A is an essential protein phosphatase that regulates most cellular processes through the formation of holoenzymes containing distinct regulatory B‐subunits. Only a limited number of PP2A‐regulated phosphorylation sites are known. This hampers our understanding of the mechanisms of site‐specific dephosphorylation and of its tumor suppressor functions. Here, we develop phosphoproteomic strategies for global substrate identification of PP2A‐B56 and PP2A‐B55 holoenzymes. Strikingly, we find that B‐subunits directly affect the dephosphorylation site preference of the PP2A catalytic subunit, resulting in unique patterns of kinase opposition. For PP2A‐B56, these patterns are further modulated by affinity and position of B56 binding motifs. Our screens identify phosphorylation sites in the cancer target ADAM17 that are regulated through a conserved B56 binding site. Binding of PP2A‐B56 to ADAM17 protease decreases growth factor signaling and tumor development in mice. This work provides a roadmap for the identification of phosphatase substrates and reveals unexpected mechanisms governing PP2A dephosphorylation site specificity and tumor suppressor function.
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Affiliation(s)
- Thomas Kruse
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sebastian Peter Gnosa
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Isha Nasa
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA.,Norris Cotton Cancer Center, Lebanon, NH, USA
| | - Dimitriya Hristoforova Garvanska
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jamin B Hein
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hieu Nguyen
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA.,Norris Cotton Cancer Center, Lebanon, NH, USA
| | - Jacob Samsøe-Petersen
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Blanca Lopez-Mendez
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emil Peter Thrane Hertz
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jeanette Schwarz
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Hanna Sofia Pena
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Denise Nikodemus
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Marie Kveiborg
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Arminja N Kettenbach
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA.,Norris Cotton Cancer Center, Lebanon, NH, USA
| | - Jakob Nilsson
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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44
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Sampadi B, Pines A, Munk S, Mišovic B, de Groot AJ, van de Water B, Olsen JV, Mullenders LHF, Vrieling H. Quantitative phosphoproteomics to unravel the cellular response to chemical stressors with different modes of action. Arch Toxicol 2020; 94:1655-1671. [PMID: 32189037 PMCID: PMC7261734 DOI: 10.1007/s00204-020-02712-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 03/09/2020] [Indexed: 12/02/2022]
Abstract
Damage to cellular macromolecules and organelles by chemical exposure evokes activation of various stress response pathways. To what extent different chemical stressors activate common and stressor-specific pathways is largely unknown. Here, we used quantitative phosphoproteomics to compare the signaling events induced by four stressors with different modes of action: the DNA damaging agent: cisplatin (CDDP), the topoisomerase II inhibitor: etoposide (ETO), the pro-oxidant: diethyl maleate (DEM) and the immunosuppressant: cyclosporine A (CsA) administered at an equitoxic dose to mouse embryonic stem cells. We observed major differences between the stressors in the number and identity of responsive phosphosites and the amplitude of phosphorylation. Kinase motif and pathway analyses indicated that the DNA damage response (DDR) activation by CDDP occurs predominantly through the replication-stress-related Atr kinase, whereas ETO triggers the DDR through Atr as well as the DNA double-strand-break-associated Atm kinase. CsA shares with ETO activation of CK2 kinase. Congruent with their known modes of action, CsA-mediated signaling is related to down-regulation of pathways that control hematopoietic differentiation and immunity, whereas oxidative stress is the most prominent initiator of DEM-modulated stress signaling. This study shows that even at equitoxic doses, different stressors induce distinctive and complex phosphorylation signaling cascades.
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Affiliation(s)
- Bharath Sampadi
- Department of Human Genetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | - Alex Pines
- Department of Human Genetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | - Stephanie Munk
- Novo Nordisk Foundation Center for Protein Research, Proteomics Program, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, 2200, Copenhagen, Denmark
| | - Branislav Mišovic
- Department of Human Genetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | - Anton J de Groot
- Department of Human Genetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | - Bob van de Water
- Division of Drug Discovery and Safety, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Jesper V Olsen
- Novo Nordisk Foundation Center for Protein Research, Proteomics Program, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, 2200, Copenhagen, Denmark
| | - Leon H F Mullenders
- Department of Human Genetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
- Department of Genetics, Research Institute of Environmental Medicine (RIeM), Nagoya University, Nagoya, Japan
| | - Harry Vrieling
- Department of Human Genetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.
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45
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Understanding MAPK Signaling Pathways in Apoptosis. Int J Mol Sci 2020; 21:ijms21072346. [PMID: 32231094 PMCID: PMC7177758 DOI: 10.3390/ijms21072346] [Citation(s) in RCA: 555] [Impact Index Per Article: 138.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 03/10/2020] [Accepted: 03/25/2020] [Indexed: 02/07/2023] Open
Abstract
MAPK (mitogen-activated protein kinase) signaling pathways regulate a variety of biological processes through multiple cellular mechanisms. In most of these processes, such as apoptosis, MAPKs have a dual role since they can act as activators or inhibitors, depending on the cell type and the stimulus. In this review, we present the main pro- and anti-apoptotic mechanisms regulated by MAPKs, as well as the crosstalk observed between some MAPKs. We also describe the basic signaling properties of MAPKs (ultrasensitivity, hysteresis, digital response), and the presence of different positive feedback loops in apoptosis. We provide a simple guide to predict MAPKs’ behavior, based on the intensity and duration of the stimulus. Finally, we consider the role of MAPKs in osmostress-induced apoptosis by using Xenopus oocytes as a cell model. As we will see, apoptosis is plagued with multiple positive feedback loops. We hope this review will help to understand how MAPK signaling pathways engage irreversible cellular decisions.
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46
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Keating L, Touati SA, Wassmann K. A PP2A-B56-Centered View on Metaphase-to-Anaphase Transition in Mouse Oocyte Meiosis I. Cells 2020; 9:E390. [PMID: 32046180 PMCID: PMC7072534 DOI: 10.3390/cells9020390] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/04/2020] [Accepted: 02/05/2020] [Indexed: 12/12/2022] Open
Abstract
Meiosis is required to reduce to haploid the diploid genome content of a cell, generating gametes-oocytes and sperm-with the correct number of chromosomes. To achieve this goal, two specialized cell divisions without intermediate S-phase are executed in a time-controlled manner. In mammalian female meiosis, these divisions are error-prone. Human oocytes have an exceptionally high error rate that further increases with age, with significant consequences for human fertility. To understand why errors in chromosome segregation occur at such high rates in oocytes, it is essential to understand the molecular players at work controlling these divisions. In this review, we look at the interplay of kinase and phosphatase activities at the transition from metaphase-to-anaphase for correct segregation of chromosomes. We focus on the activity of PP2A-B56, a key phosphatase for anaphase onset in both mitosis and meiosis. We start by introducing multiple roles PP2A-B56 occupies for progression through mitosis, before laying out whether or not the same principles may apply to the first meiotic division in oocytes, and describing the known meiosis-specific roles of PP2A-B56 and discrepancies with mitotic cell cycle regulation.
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Affiliation(s)
- Leonor Keating
- Mammalian Oocyte Meiosis (MOM) UMR7622, Institut de Biologie Paris Seine, Sorbonne Université, 75005 Paris, France; (L.K.); (S.A.T.)
- CNRS UMR7622 Developmental Biology Lab, Sorbonne Université, 75005 Paris, France
| | - Sandra A. Touati
- Mammalian Oocyte Meiosis (MOM) UMR7622, Institut de Biologie Paris Seine, Sorbonne Université, 75005 Paris, France; (L.K.); (S.A.T.)
- CNRS UMR7622 Developmental Biology Lab, Sorbonne Université, 75005 Paris, France
| | - Katja Wassmann
- Mammalian Oocyte Meiosis (MOM) UMR7622, Institut de Biologie Paris Seine, Sorbonne Université, 75005 Paris, France; (L.K.); (S.A.T.)
- CNRS UMR7622 Developmental Biology Lab, Sorbonne Université, 75005 Paris, France
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47
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Warren NJH, Eastman A. Comparison of the different mechanisms of cytotoxicity induced by checkpoint kinase I inhibitors when used as single agents or in combination with DNA damage. Oncogene 2020; 39:1389-1401. [PMID: 31659257 PMCID: PMC7023985 DOI: 10.1038/s41388-019-1079-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 10/14/2019] [Accepted: 10/15/2019] [Indexed: 12/31/2022]
Abstract
Inhibition of the DNA damage response is an emerging strategy to treat cancer. Understanding how DNA damage response inhibitors cause cytotoxicity in cancer cells is crucial to their further clinical development. This review focuses on three different mechanisms of cell killing by checkpoint kinase I inhibitors (CHK1i). DNA damage induced by chemotherapy drugs, such as topoisomerase I inhibitors, results in S and G2 phase arrest. Addition of CHK1i promotes cell cycle progression before repair is completed resulting in mitotic catastrophe. Ribonucleotide reductase inhibitors such as gemcitabine also arrest cells in S phase by preventing dNTP synthesis. Addition of CHK1i re-activates the DNA helicase to unwind DNA, but in the absence of dNTPs, this leads to excessive single-strand DNA that exceeds the protective capacity of the single-strand-binding protein RPA. Unprotected DNA is subjected to nuclease cleavage, resulting in replication catastrophe. CHK1i alone also kills a subset of cell lines through MRE11 and MUS81-mediated DNA cleavage in S phase cells. The choice of mechanism depends on the activation state of CDK2. Low level activation of CDK2 mediates helicase activation, cell cycle progression, and both replication and mitotic catastrophe. In contrast, high CDK2 activity is required for sensitivity to CHK1i as monotherapy. This high CDK2 activity threshold usually occurs late in the cell cycle to prepare for mitosis, but in CHK1i-sensitive cells, high activity can be attained in early S phase, resulting in DNA cleavage and cell death. This sensitivity to CHK1i has previously been associated with endogenous replication stress, but the dependence on high CDK2 activity, as well as MRE11, contradicts this hypothesis. The major unresolved question is why some cell lines fail to restrain their high CDK2 activity and hence succumb to CHK1i in S phase. Resolving this question will facilitate stratification of patients for treatment with CHK1i as monotherapy.
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Affiliation(s)
- Nicholas J H Warren
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Lebanon, NH, 03756, USA
| | - Alan Eastman
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Lebanon, NH, 03756, USA.
- Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH, 03756, USA.
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48
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Protein Phosphatases in G1 Regulation. Int J Mol Sci 2020; 21:ijms21020395. [PMID: 31936296 PMCID: PMC7013402 DOI: 10.3390/ijms21020395] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/29/2019] [Accepted: 12/31/2019] [Indexed: 01/15/2023] Open
Abstract
Eukaryotic cells make the decision to proliferate, to differentiate or to cease dividing during G1, before passage through the restriction point or Start. Keeping cyclin-dependent kinase (CDK) activity low during this period restricts commitment to a new cell cycle and is essential to provide the adequate timeframe for the sensing of environmental signals. Here, we review the role of protein phosphatases in the modulation of CDK activity and as the counteracting force for CDK-dependent substrate phosphorylation, in budding and fission yeast. Moreover, we discuss recent findings that place protein phosphatases in the interface between nutritional signalling pathways and the cell cycle machinery.
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49
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Zhang L, Winkler S, Schlottmann FP, Kohlbacher O, Elias JE, Skotheim JM, Ewald JC. Multiple Layers of Phospho-Regulation Coordinate Metabolism and the Cell Cycle in Budding Yeast. Front Cell Dev Biol 2019; 7:338. [PMID: 31921850 PMCID: PMC6927922 DOI: 10.3389/fcell.2019.00338] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 11/29/2019] [Indexed: 01/20/2023] Open
Abstract
The coordination of metabolism and growth with cell division is crucial for proliferation. While it has long been known that cell metabolism regulates the cell division cycle, it is becoming increasingly clear that the cell division cycle also regulates metabolism. In budding yeast, we previously showed that over half of all measured metabolites change concentration through the cell cycle indicating that metabolic fluxes are extensively regulated during cell cycle progression. However, how this regulation is achieved still remains poorly understood. Since both the cell cycle and metabolism are regulated to a large extent by protein phosphorylation, we here decided to measure the phosphoproteome through the budding yeast cell cycle. Specifically, we chose a cell cycle synchronization strategy that avoids stress and nutrient-related perturbations of metabolism, and we grew the yeast on ethanol minimal medium to force cells to utilize their full biosynthetic repertoire. Using a tandem-mass-tagging approach, we found over 200 sites on metabolic enzymes and transporters to be phospho-regulated. These sites were distributed among many pathways including carbohydrate catabolism, lipid metabolism, and amino acid synthesis and therefore likely contribute to changing metabolic fluxes through the cell cycle. Among all one thousand sites whose phosphorylation increases through the cell cycle, the CDK consensus motif and an arginine-directed motif were highly enriched. This arginine-directed R-R-x-S motif is associated with protein-kinase A, which regulates metabolism and promotes growth. Finally, we also found over one thousand sites that are dephosphorylated through the G1/S transition. We speculate that the phosphatase Glc7/PP1, known to regulate both the cell cycle and carbon metabolism, may play an important role because its regulatory subunits are phospho-regulated in our data. In summary, our results identify extensive cell cycle dependent phosphorylation and dephosphorylation of metabolic enzymes and suggest multiple mechanisms through which the cell division cycle regulates metabolic signaling pathways to temporally coordinate biosynthesis with distinct phases of the cell division cycle.
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Affiliation(s)
- Lichao Zhang
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA, United States
| | - Sebastian Winkler
- Applied Bioinformatics, Department of Computer Science, University of Tübingen, Tübingen, Germany
| | - Fabian P. Schlottmann
- Molecular Cell Biology, Interfaculty Institute of Cell Biology, University of Tübingen, Tübingen, Germany
| | - Oliver Kohlbacher
- Applied Bioinformatics, Department of Computer Science, University of Tübingen, Tübingen, Germany
- Institute for Translational Bioinformatics, University Hospital Tübingen, Tübingen, Germany
- Institute for Bioinformatics and Medical Informatics, University of Tübingen, Tübingen, Germany
- Quantitative Biology Center, University of Tübingen, Tübingen, Germany
- Biomolecular Interactions, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Josh E. Elias
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA, United States
| | - Jan M. Skotheim
- Department of Biology, Stanford University, Stanford, CA, United States
| | - Jennifer C. Ewald
- Molecular Cell Biology, Interfaculty Institute of Cell Biology, University of Tübingen, Tübingen, Germany
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García-Blanco N, Vázquez-Bolado A, Moreno S. Greatwall-Endosulfine: A Molecular Switch that Regulates PP2A/B55 Protein Phosphatase Activity in Dividing and Quiescent Cells. Int J Mol Sci 2019; 20:ijms20246228. [PMID: 31835586 PMCID: PMC6941129 DOI: 10.3390/ijms20246228] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/02/2019] [Accepted: 12/05/2019] [Indexed: 12/13/2022] Open
Abstract
During the cell cycle, hundreds of proteins become phosphorylated and dephosphorylated, indicating that protein kinases and protein phosphatases play a central role in its regulation. It has been widely recognized that oscillation in cyclin-dependent kinase (CDK) activity promotes DNA replication, during S-phase, and chromosome segregation, during mitosis. Each CDK substrate phosphorylation status is defined by the balance between CDKs and CDK-counteracting phosphatases. In fission yeast and animal cells, PP2A/B55 is the main protein phosphatase that counteracts CDK activity. PP2A/B55 plays a key role in mitotic entry and mitotic exit, and it is regulated by the Greatwall-Endosulfine (ENSA) molecular switch that inactivates PP2A/B55 at the onset of mitosis, allowing maximal CDK activity at metaphase. The Greatwall-ENSA-PP2A/B55 pathway is highly conserved from yeast to animal cells. In yeasts, Greatwall is negatively regulated by nutrients through TORC1 and S6 kinase, and couples cell growth, regulated by TORC1, to cell cycle progression, driven by CDK activity. In animal cells, Greatwall is phosphorylated and activated by Cdk1 at G2/M, generating a bistable molecular switch that results in full activation of Cdk1/CyclinB. Here we review the current knowledge of the Greatwall-ENSA-PP2A/B55 pathway and discuss its role in cell cycle progression and as an integrator of nutritional cues.
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