1
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Padi SKR, Vos MR, Godek RJ, Fuller JR, Kruse T, Hein JB, Nilsson J, Kelker MS, Page R, Peti W. Cryo-EM structures of PP2A:B55-FAM122A and PP2A:B55-ARPP19. Nature 2024; 625:195-203. [PMID: 38123684 PMCID: PMC10765524 DOI: 10.1038/s41586-023-06870-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 11/15/2023] [Indexed: 12/23/2023]
Abstract
Progression through the cell cycle is controlled by regulated and abrupt changes in phosphorylation1. Mitotic entry is initiated by increased phosphorylation of mitotic proteins, a process driven by kinases2, whereas mitotic exit is achieved by counteracting dephosphorylation, a process driven by phosphatases, especially PP2A:B553. Although the role of kinases in mitotic entry is well established, recent data have shown that mitosis is only successfully initiated when the counterbalancing phosphatases are also inhibited4. Inhibition of PP2A:B55 is achieved by the intrinsically disordered proteins ARPP195,6 and FAM122A7. Despite their critical roles in mitosis, the mechanisms by which they achieve PP2A:B55 inhibition is unknown. Here, we report the single-particle cryo-electron microscopy structures of PP2A:B55 bound to phosphorylated ARPP19 and FAM122A. Consistent with our complementary NMR spectroscopy studies, both intrinsically disordered proteins bind PP2A:B55, but do so in highly distinct manners, leveraging multiple distinct binding sites on B55. Our extensive structural, biophysical and biochemical data explain how substrates and inhibitors are recruited to PP2A:B55 and provide a molecular roadmap for the development of therapeutic interventions for PP2A:B55-related diseases.
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Affiliation(s)
- Sathish K R Padi
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, USA
| | - Margaret R Vos
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
| | - Rachel J Godek
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
| | | | - Thomas Kruse
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Jamin B Hein
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Jakob Nilsson
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | | | - Rebecca Page
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA.
| | - Wolfgang Peti
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, USA.
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2
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Padi SK, Vos MR, Godek RJ, Fuller JR, Kruse T, Hein JB, Nilsson J, Kelker MS, Page R, Peti W. Cryo-EM structures of PP2A:B55-FAM122A and PP2A:B55-ARPP19. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.31.555365. [PMID: 37693408 PMCID: PMC10491220 DOI: 10.1101/2023.08.31.555365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Progression through the cell cycle is controlled by regulated and abrupt changes in phosphorylation.1 Mitotic entry is initiated by increased phosphorylation of mitotic proteins, a process driven by kinases,2 while mitotic exit is achieved by counteracting dephosphorylation, a process driven by phosphatases, especially PP2A:B55.3 While the role of kinases in mitotic entry is well-established, recent data have shown that mitosis is only successfully initiated when the counterbalancing phosphatases are also inhibited.4 For PP2A:B55, inhibition is achieved by the two intrinsically disordered proteins (IDPs), ARPP19 (phosphorylation-dependent)6,7 and FAM122A5 (inhibition is phosphorylation-independent). Despite their critical roles in mitosis, the mechanisms by which they achieve PP2A:B55 inhibition is unknown. Here, we report the cryo-electron microscopy structures of PP2A:B55 bound to phosphorylated ARPP19 and FAM122A. Consistent with our complementary NMR spectroscopy studies both IDPs bind PP2A:B55, but do so in highly distinct manners, unexpectedly leveraging multiple distinct binding sites on B55. Our extensive structural, biophysical and biochemical data explain how substrates and inhibitors are recruited to PP2A:B55 and provides a molecular roadmap for the development of therapeutic interventions for PP2A:B55 related diseases.
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Affiliation(s)
- Sathish K.R. Padi
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, USA
| | - Margaret R. Vos
- Department of Cell Biology, University of Connecticut Health Center, Farmington, USA
| | - Rachel J. Godek
- Department of Cell Biology, University of Connecticut Health Center, Farmington, USA
| | | | - Thomas Kruse
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Jamin B. Hein
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Jakob Nilsson
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | | | - Rebecca Page
- Department of Cell Biology, University of Connecticut Health Center, Farmington, USA
| | - Wolfgang Peti
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, USA
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3
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Gu W, Zheng H, Canessa CM. Phosphatases maintain low catalytic activity of SGK1: DNA damage resets the balance in favor of phosphorylation. J Biol Chem 2023; 299:104941. [PMID: 37343701 PMCID: PMC10372406 DOI: 10.1016/j.jbc.2023.104941] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/23/2023] Open
Abstract
The serum- and glucocorticoid-induced kinase 1 (SGK1) promotes cell survival under stress conditions and facilitates the emergence of drug resistance in cancer. The underlying mechanisms of these observations are not fully understood. In this study, we found that SGK1 activity is suppressed by the action of the S/T phosphatases PP5 and PP2A, which constantly dephosphorylate SGK1. Using newly developed anti-phospho SGK1 antibodies and inhibitors of phosphatases, we determined that the high degree of dephosphorylation is caused by two factors: the tendency of SGK1 to unfold, which makes it dependent on Hsp90 chaperone complexes composed of four proteins, Hsp90/CDC37/PP5/SGK1, and where the phosphatase PP5 persistently dephosphorylates SGK1 within the complex. SGK1 binding to PP2A regulatory subunits B55γ and B55δ brings PP2A catalytic subunit close to exposed SGK1 phosphoresidues. A further association of phosphorylated pS37-FAM122A-an endogenous inhibitor of PP2A-to the holoenzyme diminishes dephosphorylation of SGK1 mediated by PP2A. Our study also reveals that genotoxic stress can reverse the dominant impact of phosphatases over kinases by activating the DNA-dependent protein kinase, which enhances mTORC2 activity directed to SGK1. Thus, our results provide insight into a molecular pathway that enables SGK1 to gain phosphorylation and catalytic activity and promote cell survival, potentially diminishing the efficacy of cancer treatments. As the DNA damage response operates in many cancer cells and is further induced by chemotherapies, the findings of this study could have significant implications for the development of novel cancer therapies targeting SGK1.
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Affiliation(s)
- Wenxue Gu
- School of Medicine, Tsinghua University, Beijing, China
| | - Hongyan Zheng
- School of Medicine, Tsinghua University, Beijing, China
| | - Cecilia M Canessa
- School of Medicine, Tsinghua University, Beijing, China; Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, USA.
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4
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Gupta A, Dagar G, Chauhan R, Sadida HQ, Almarzooqi SK, Hashem S, Uddin S, Macha MA, Akil ASAS, Pandita TK, Bhat AA, Singh M. Cyclin-dependent kinases in cancer: Role, regulation, and therapeutic targeting. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 135:21-55. [PMID: 37061333 DOI: 10.1016/bs.apcsb.2023.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Regulated cell division is one of the fundamental phenomena which is the basis of all life on earth. Even a single base pair mutation in DNA leads to the production of the dysregulated protein that can have catastrophic consequences. Cell division is tightly controlled and orchestrated by proteins called cyclins and cyclin-dependent kinase (CDKs), which serve as licensing factors during different phases of cell division. Dysregulated cell division is one of the most important hallmarks of cancer and is commonly associated with a mutation in cyclins and CDKs along with tumor suppressor proteins. Therefore, targeting the component of the cell cycle which leads to these characteristics would be an effective strategy for treating cancers. Specifically, Cyclin-dependent kinases (CDKs) involved in cell cycle regulation have been identified to be overexpressed in many cancers. Many studies indicate that oncogenesis occurs in cancerous cells by the overactivity of different CDKs, which impact cell cycle progression and checkpoint dysregulation which is responsible for development of tumor. The development of CDK inhibitors has emerged as a promising and novel approach for cancer treatment in both solid and hematological malignancies. Some of the novel CDK inhibitors have shown remarkable results in clinical trials, such as-Ribociclib®, Palbociclib® and Abemaciclib®, which are CDK4/6 inhibitors and have received FDA approval for the treatment of breast cancer. In this chapter, we discuss the molecular mechanism through which cyclins and CDKs regulate cell cycle progression and the emergence of cyclins and CDKs as rational targets in cancer. We also discuss recent advances in developing CDK inhibitors, which have emerged as a novel class of inhibitors, and their associated toxicities in recent years.
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Affiliation(s)
- Ashna Gupta
- Department of Medical Oncology, Dr B.R Ambedkar Institute Rotary Cancer Hospital All India Institute of Medical Sciences, New Delhi, India
| | - Gunjan Dagar
- Department of Medical Oncology, Dr B.R Ambedkar Institute Rotary Cancer Hospital All India Institute of Medical Sciences, New Delhi, India
| | - Ravi Chauhan
- Department of Medical Oncology, Dr B.R Ambedkar Institute Rotary Cancer Hospital All India Institute of Medical Sciences, New Delhi, India
| | - Hana Q Sadida
- Department of Human Genetics-Precision Medicine in Diabetes, Obesity and Cancer Research Program, Sidra Medicine, Doha, Qatar
| | - Sara K Almarzooqi
- Department of Human Genetics-Precision Medicine in Diabetes, Obesity and Cancer Research Program, Sidra Medicine, Doha, Qatar
| | - Sheema Hashem
- Department of Human Genetics, Sidra Medicine, Doha, Qatar
| | - Shahab Uddin
- Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | - Muzafar A Macha
- Watson-Crick Centre for Molecular Medicine, Islamic University of Science and Technology, Awantipora, Jammu and Kashmir, India
| | - Ammira S Al-Shabeeb Akil
- Department of Human Genetics-Precision Medicine in Diabetes, Obesity and Cancer Research Program, Sidra Medicine, Doha, Qatar
| | - Tej K Pandita
- Center for Genomics and Precision Medicine, Texas A&M College of Medicine, Houston, TX, United States
| | - Ajaz A Bhat
- Department of Human Genetics-Precision Medicine in Diabetes, Obesity and Cancer Research Program, Sidra Medicine, Doha, Qatar.
| | - Mayank Singh
- Department of Medical Oncology, Dr B.R Ambedkar Institute Rotary Cancer Hospital All India Institute of Medical Sciences, New Delhi, India.
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5
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The Role of NO/sGC/cGMP/PKG Signaling Pathway in Regulation of Platelet Function. Cells 2022; 11:cells11223704. [PMID: 36429131 PMCID: PMC9688146 DOI: 10.3390/cells11223704] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
Abstract
Circulating blood platelets are controlled by stimulatory and inhibitory factors, and a tightly regulated equilibrium between these two opposing processes is essential for normal platelet and vascular function. NO/cGMP/ Protein Kinase G (PKG) pathways play a highly significant role in platelet inhibition, which is supported by a large body of studies and data. This review focused on inconsistent and controversial data of NO/sGC/cGMP/PKG signaling in platelets including sources of NO that activate sGC in platelets, the role of sGC/PKG in platelet inhibition/activation, and the complexity of the regulation of platelet inhibitory mechanisms by cGMP/PKG pathways. In conclusion, we suggest that the recently developed quantitative phosphoproteomic method will be a powerful tool for the analysis of PKG-mediated effects. Analysis of phosphoproteins in PKG-activated platelets will reveal many new PKG substrates. A future detailed analysis of these substrates and their involvement in different platelet inhibitory pathways could be a basis for the development of new antiplatelet drugs that may target only specific aspects of platelet functions.
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6
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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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7
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Schwein PA, Ge Y, Yang B, D’Souza A, Mody A, Shen D, Woo CM. Writing and Erasing O-GlcNAc on Casein Kinase 2 Alpha Alters the Phosphoproteome. ACS Chem Biol 2022; 17:1111-1121. [PMID: 35467332 DOI: 10.1021/acschembio.1c00987] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
O-GlcNAc is an essential carbohydrate modification that intersects with phosphorylation signaling pathways via crosstalk on protein substrates or by direct modification of the kinases that write the phosphate modification. Casein kinase 2 alpha (CK2α), the catalytic subunit of the ubiquitously expressed and constitutively active kinase CK2, is modified by O-GlcNAc, but the effect of this modification on the phosphoproteome in cells is unknown. Here, we apply complementary targeted O-GlcNAc editors, nanobody-OGT and -splitOGA, to selectively write and erase O-GlcNAc from a tagged CK2α to measure the effects on the phosphoproteome in cells. These tools effectively and selectively edit the Ser347 glycosite on CK2α. Using quantitative phosphoproteomics, we report 51 phosphoproteins whose enrichment changes as a function of editing O-GlcNAc on CK2α, including HDAC1, HDAC2, ENSA, SMARCAD1, and PABPN1. Specific phosphosites on HDAC1 Ser393 and HDAC2 Ser394, both reported CK2 substrates, are significantly enhanced by O-GlcNAcylation of CK2α. These data will propel future studies on the crosstalk between O-GlcNAc and phosphorylation.
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Affiliation(s)
- Paul A. Schwein
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, Massachusetts 02138, United States
| | - Yun Ge
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, Massachusetts 02138, United States
| | - Bo Yang
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, Massachusetts 02138, United States
| | - Alexandria D’Souza
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, Massachusetts 02138, United States
| | - Alison Mody
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, Massachusetts 02138, United States
| | - Dacheng Shen
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, Massachusetts 02138, United States
| | - Christina M. Woo
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, Massachusetts 02138, United States
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8
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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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9
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A modular approach for modeling the cell cycle based on functional response curves. PLoS Comput Biol 2021; 17:e1009008. [PMID: 34379640 PMCID: PMC8382204 DOI: 10.1371/journal.pcbi.1009008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 08/23/2021] [Accepted: 07/19/2021] [Indexed: 12/02/2022] Open
Abstract
Modeling biochemical reactions by means of differential equations often results in systems with a large number of variables and parameters. As this might complicate the interpretation and generalization of the obtained results, it is often desirable to reduce the complexity of the model. One way to accomplish this is by replacing the detailed reaction mechanisms of certain modules in the model by a mathematical expression that qualitatively describes the dynamical behavior of these modules. Such an approach has been widely adopted for ultrasensitive responses, for which underlying reaction mechanisms are often replaced by a single Hill function. Also time delays are usually accounted for by using an explicit delay in delay differential equations. In contrast, however, S-shaped response curves, which by definition have multiple output values for certain input values and are often encountered in bistable systems, are not easily modeled in such an explicit way. Here, we extend the classical Hill function into a mathematical expression that can be used to describe both ultrasensitive and S-shaped responses. We show how three ubiquitous modules (ultrasensitive responses, S-shaped responses and time delays) can be combined in different configurations and explore the dynamics of these systems. As an example, we apply our strategy to set up a model of the cell cycle consisting of multiple bistable switches, which can incorporate events such as DNA damage and coupling to the circadian clock in a phenomenological way. Bistability plays an important role in many biochemical processes and typically emerges from complex interaction patterns such as positive and double negative feedback loops. Here, we propose to theoretically study the effect of bistability in a larger interaction network. We explicitly incorporate a functional expression describing an S-shaped input-output curve in the model equations, without the need for considering the underlying biochemical events. This expression can be converted into a functional module for an ultrasensitive response, and a time delay is easily included as well. Exploiting the fact that several of these modules can easily be combined in larger networks, we construct a cell cycle model consisting of multiple bistable switches and show how this approach can account for a number of known properties of the cell cycle.
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10
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Larouche M, Kachaner D, Wang P, Normandin K, Garrido D, Yao C, Cormier M, Johansen KM, Johansen J, Archambault V. Spatiotemporal coordination of Greatwall-Endos-PP2A promotes mitotic progression. J Cell Biol 2021; 220:211965. [PMID: 33836042 PMCID: PMC8042607 DOI: 10.1083/jcb.202008145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 02/17/2021] [Accepted: 03/08/2021] [Indexed: 12/31/2022] Open
Abstract
Mitotic entry involves inhibition of protein phosphatase 2A bound to its B55/Tws regulatory subunit (PP2A-B55/Tws), which dephosphorylates substrates of mitotic kinases. This inhibition is induced when Greatwall phosphorylates Endos, turning it into an inhibitor of PP2A-Tws. How this mechanism operates spatiotemporally in the cell is incompletely understood. We previously reported that the nuclear export of Greatwall in prophase promotes mitotic progression. Here, we examine the importance of the localized activities of PP2A-Tws and Endos for mitotic regulation. We find that Tws shuttles through the nucleus via a conserved nuclear localization signal (NLS), but expression of Tws in the cytoplasm and not in the nucleus rescues the development of tws mutants. Moreover, we show that Endos must be in the cytoplasm before nuclear envelope breakdown (NEBD) to be efficiently phosphorylated by Greatwall and to bind and inhibit PP2A-Tws. Disrupting the cytoplasmic function of Endos before NEBD results in subsequent mitotic defects. Evidence suggests that this spatiotemporal regulation is conserved in humans.
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Affiliation(s)
- Myreille Larouche
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada.,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - David Kachaner
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada.,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Peng Wang
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada.,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Karine Normandin
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada
| | - Damien Garrido
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada.,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Changfu Yao
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA
| | - Maxime Cormier
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada
| | - Kristen M Johansen
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA
| | - Jørgen Johansen
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA
| | - Vincent Archambault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada.,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montreal, Quebec, Canada
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11
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Jin L, Chen Y, Yan C, Guo X, Jiang T, Guli A, Song X, Wan Q, Shu Q, Ding S. Phosphoproteome Profiling Revealed the Importance of mTOR Inhibition on CDK1 Activation to Further Regulate Cell Cycle Progression. J Proteome Res 2021; 20:2329-2339. [PMID: 33797919 DOI: 10.1021/acs.jproteome.0c00848] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The mammalian target of rapamycin (mTOR) functions as a critical regulator of cell cycle progression. However, the underlying mechanism by which mTOR regulates cell cycle progression remains elusive. In this study, we used stable isotope labeling of amino acids in cell culture with a two-step strategy for phosphopeptide enrichment and high-throughput quantitative mass spectrometry to perform a global phosphoproteome analysis of mTOR inhibition by rapamycin. By monitoring the phosphoproteome alterations upon rapamycin treatment, downregulation of mTOR signaling pathway was detected and enriched. Further functional analysis of phosphoproteome revealed the involvement of cell cycle events. Specifically, the elevated profile of cell cycle-related substrates was observed, and the activation of CDK1, MAPK1, and MAPK3 kinases was determined. Second, pathway interrogation using kinase inhibitor treatment confirmed that CDK1 activation operated downstream from mTOR inhibition to further regulate cell cycle progression. Third, we found that the activation of CDK1 following 4-12 h of mTOR inhibition was accompanied by the activation of the Greatwall-endosulfine complex. In conclusion, we presented a high-confidence phosphoproteome map inside the cells upon mTOR inhibition by rapamycin. Our data implied that mTOR inhibition could contribute to CDK1 activation for further regulating cell cycle progression, which was mediated by the Greatwall-endosulfine complex.
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Affiliation(s)
- Luqi Jin
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China
| | - Yu Chen
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China
| | - Chunlan Yan
- Department of Biophysics, Key Laboratory of Medical Neurobiology, Ministry of Health of China, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China
| | - Xiaoyuan Guo
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China
| | - Tingting Jiang
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China
| | - Ayiding Guli
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China
| | - Xinghui Song
- The Core Facilities, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China
| | - Qun Wan
- Department of Urinary Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China
| | - Qiang Shu
- Department of Cell Biology and Department of Cardiovascular Surgery, National Clinical Research Center For Child Health, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China
| | - Shiping Ding
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China.,Department of Cell Biology and Department of Cardiovascular Surgery, National Clinical Research Center For Child Health, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China
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12
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Kamenz J, Gelens L, Ferrell JE. Bistable, Biphasic Regulation of PP2A-B55 Accounts for the Dynamics of Mitotic Substrate Phosphorylation. Curr Biol 2020; 31:794-808.e6. [PMID: 33357450 PMCID: PMC7904671 DOI: 10.1016/j.cub.2020.11.058] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 10/20/2020] [Accepted: 11/23/2020] [Indexed: 12/12/2022]
Abstract
The phosphorylation of mitotic proteins is bistable, which contributes to the decisiveness of the transitions into and out of M phase. The bistability in substrate phosphorylation has been attributed to bistability in the activation of the cyclin-dependent kinase Cdk1. However, more recently it has been suggested that bistability also arises from positive feedback in the regulation of the Cdk1-counteracting phosphatase PP2A-B55. Here, we demonstrate biochemically using Xenopus laevis egg extracts that the Cdk1-counter-acting phosphatase PP2A-B55 functions as a bistable switch, even when the bistability of Cdk1 activation is suppressed. In addition, Cdk1 regulates PP2A-B55 in a biphasic manner; low concentrations of Cdk1 activate PP2A-B55 and high concentrations inactivate it. As a consequence of this incoherent feedforward regulation, PP2A-B55 activity rises concurrently with Cdk1 activity during interphase and suppresses substrate phosphorylation. PP2A-B55 activity is then sharply downregulated at the onset of mitosis. During mitotic exit, Cdk1 activity initially falls with no obvious change in substrate phosphorylation; dephosphorylation then commences once PP2A-B55 spikes in activity. These findings suggest that changes in Cdk1 activity are permissive for mitotic entry and exit but that the changes in PP2A-B55 activity are the ultimate trigger. Mitotic transitions are accompanied by drastic changes in the phosphorylation state of proteins. Kamenz et al. demonstrate biochemically that the major mitotic phosphatase PP2A-B55 is regulated by incoherent feedforward and double-negative feedback loops to promote rapid and switch-like mitotic entry and exit.
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Affiliation(s)
- Julia Kamenz
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305-5174, USA.
| | - Lendert Gelens
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305-5174, USA; Laboratory of Dynamics in Biological Systems, KU Leuven, Department of Cellular and Molecular Medicine, University of Leuven, B-3000 Leuven, Belgium
| | - James E Ferrell
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305-5174, USA; Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305-5307, USA.
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13
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The Cell Cycle Checkpoint System MAST(L)-ENSA/ARPP19-PP2A is Targeted by cAMP/PKA and cGMP/PKG in Anucleate Human Platelets. Cells 2020; 9:cells9020472. [PMID: 32085646 PMCID: PMC7072724 DOI: 10.3390/cells9020472] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/14/2020] [Accepted: 02/14/2020] [Indexed: 12/13/2022] Open
Abstract
The cell cycle is controlled by microtubule-associated serine/threonine kinase-like (MASTL), which phosphorylates the cAMP-regulated phosphoproteins 19 (ARPP19) at S62 and 19e/α-endosulfine (ENSA) at S67and converts them into protein phosphatase 2A (PP2A) inhibitors. Based on initial proteomic data, we hypothesized that the MASTL-ENSA/ARPP19-PP2A pathway, unknown until now in platelets, is regulated and functional in these anucleate cells. We detected ENSA, ARPP19 and various PP2A subunits (including seven different PP2A B-subunits) in proteomic studies of human platelets. ENSA-S109/ARPP19–S104 were efficiently phosphorylated in platelets treated with cAMP- (iloprost) and cGMP-elevating (NO donors/riociguat) agents. ENSA-S67/ARPP19-S62 phosphorylations increased following PP2A inhibition by okadaic acid (OA) in intact and lysed platelets indicating the presence of MASTL or a related protein kinase in human platelets. These data were validated with recombinant ENSA/ARPP19 and phospho-mutants using recombinant MASTL, protein kinase A and G. Both ARPP19 phosphorylation sites S62/S104 were dephosphorylated by platelet PP2A, but only S62-phosphorylated ARPP19 acted as PP2A inhibitor. Low-dose OA treatment of platelets caused PP2A inhibition, diminished thrombin-stimulated platelet aggregation and increased phosphorylation of distinct sites of VASP, Akt, p38 and ERK1/2 MAP kinases. In summary, our data establish the entire MASTL(like)–ENSA/ARPP19–PP2A pathway in human platelets and important interactions with the PKA, MAPK and PI3K/Akt systems.
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14
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Biola-Clier M, Gaillard JC, Rabilloud T, Armengaud J, Carriere M. Titanium Dioxide Nanoparticles Alter the Cellular Phosphoproteome in A549 Cells. NANOMATERIALS 2020; 10:nano10020185. [PMID: 31973118 PMCID: PMC7074930 DOI: 10.3390/nano10020185] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/11/2020] [Accepted: 01/16/2020] [Indexed: 12/02/2022]
Abstract
TiO2 nanoparticles (NPs) are one of the most produced NPs worldwide and are used in many consumer products. Their impact on human health, especially through inhalation, has been studied for more than two decades. TiO2 is known for its strong affinity towards phosphates, and consequently interaction with cellular phosphates may be one of the mechanisms driving its toxicity. In the present study, we used a phosphoproteomics approach to document the interaction of TiO2-NP with phosphoproteins from A549 human pulmonary alveolar epithelial cells. Cells were exposed to 21 nm anatase/rutile TiO2-NPs, then their phosphopeptides were extracted and analyzed using shotgun proteomics. By comparing the phosphoprotein content, phosphorylation status and phosphorylation sites of exposed cells with that of control cells, our results show that by affecting the phosphoproteome, TiO2-NPs affect cellular processes such as apoptosis, linked with cell cycle and the DNA damage response, TP53 being central to these pathways. Other pathways including inflammation and molecular transport are also affected. These molecular mechanisms of TiO2-NP toxicity have been reported previously, our study shows for the first time that they may derive from phosphoproteome modulation, which could be one of their upstream regulators.
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Affiliation(s)
| | - Jean-Charles Gaillard
- Laboratoire Innovations technologiques pour la Détection et le Diagnostic (Li2D), Service de Pharmacologie et Immunoanalyse (SPI), CEA, INRA, F-30207 Bagnols-sur-Cèze, France;
| | - Thierry Rabilloud
- Chemistry and Biology of Metals, Univ. Grenoble Alpes, CNRS UMR5249, CEA, IRIG-DIESE-LCBM-ProMD, F-38054 Grenoble, France;
| | - Jean Armengaud
- Laboratoire Innovations technologiques pour la Détection et le Diagnostic (Li2D), Service de Pharmacologie et Immunoanalyse (SPI), CEA, INRA, F-30207 Bagnols-sur-Cèze, France;
- Correspondence: (J.A.); (M.C.)
| | - Marie Carriere
- Univ. Grenoble-Alpes, IRIG, SyMMES, CIBEST, F-38000 Grenoble, France;
- Correspondence: (J.A.); (M.C.)
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15
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Interplay between Phosphatases and the Anaphase-Promoting Complex/Cyclosome in Mitosis. Cells 2019; 8:cells8080814. [PMID: 31382469 PMCID: PMC6721574 DOI: 10.3390/cells8080814] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 07/25/2019] [Accepted: 08/01/2019] [Indexed: 12/14/2022] Open
Abstract
Accurate division of cells into two daughters is a process that is vital to propagation of life. Protein phosphorylation and selective degradation have emerged as two important mechanisms safeguarding the delicate choreography of mitosis. Protein phosphatases catalyze dephosphorylation of thousands of sites on proteins, steering the cells through establishment of the mitotic phase and exit from it. A large E3 ubiquitin ligase, the anaphase-promoting complex/cyclosome (APC/C) becomes active during latter stages of mitosis through G1 and marks hundreds of proteins for destruction. Recent studies have revealed the complex interregulation between these two classes of enzymes. In this review, we highlight the direct and indirect mechanisms by which phosphatases and the APC/C mutually influence each other to ensure accurate spatiotemporal and orderly progression through mitosis, with a particular focus on recent insights and conceptual advances.
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16
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Aono S, Haruna Y, Watanabe YH, Mochida S, Takeda K. The fission yeast Greatwall-Endosulfine pathway is required for proper quiescence/G 0 phase entry and maintenance. Genes Cells 2019; 24:172-186. [PMID: 30584685 DOI: 10.1111/gtc.12665] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 12/14/2018] [Accepted: 12/19/2018] [Indexed: 12/30/2022]
Abstract
Cell proliferation and cellular quiescence/G0 phase must be regulated in response to intra-/extracellular environments, and such regulation is achieved by the orchestration of protein kinases and protein phosphatases. Here, we investigated fission yeast potential orthologs (Cek1, Ppk18 and Ppk31) of the metazoan Greatwall kinase (Gwl), which inhibits type-2A protein phosphatase with B55 subunit (PP2AB55 ) by phosphorylating and activating the PP2AB55 inhibitors, α-endosulfine/ARPP-19 (Ensa/ARPP-19). Gwl and Ensa/ARPP-19 regulate mitosis; however, we found Ppk18, Cek1 and Mug134/Igo1, the counterpart of Ensa/ARPP-19, are not essential for normal mitosis but regulate nitrogen starvation (-N)-induced proper G0 entry and maintenance. Genetic and biochemical analyses indicated that the conserved Gwl site (serine 64) was phosphorylated in the G0 phase in a Ppk18-dependent manner, and the phosphorylated Mug134/Igo1 inhibited PP2AB55 in vitro. The alanine substitution of the serine 64 caused defects in G0 entry and maintenance as well as the mug134/igo1+ deletion. These results indicate that PP2AB55 activity must be regulated properly to establish the G0 phase. Consistently, simultaneous deletion of the B55 gene with mug134/igo1+ partially rescued the Mug134/Igo1 mutant phenotype. We suggest that in fission yeast, PP2AB55 regulation by the Ppk18-Mug134/Igo1 pathway is required for G0 entry and establishment of robust viability during the G0 phase.
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Affiliation(s)
- Soma Aono
- Department of Biology, Faculty of Science and Engineering, Konan Uiversity, Kobe, Japan
| | - Yui Haruna
- Department of Biology, Faculty of Science and Engineering, Konan Uiversity, Kobe, Japan
| | - Yo-Hei Watanabe
- Department of Biology, Faculty of Science and Engineering, Konan Uiversity, Kobe, Japan.,Institute for Integrative Neurobiology, Konan University, Kobe, Japan
| | - Satoru Mochida
- Priority Organization for Innovation and Excellence, Kumamoto University, Kumamoto, Japan.,PRESTO Program, Japan Science and Technology Agency
| | - Kojiro Takeda
- Department of Biology, Faculty of Science and Engineering, Konan Uiversity, Kobe, Japan.,Institute for Integrative Neurobiology, Konan University, Kobe, Japan
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17
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Hached K, Goguet P, Charrasse S, Vigneron S, Sacristan MP, Lorca T, Castro A. ENSA and ARPP19 differentially control cell cycle progression and development. J Cell Biol 2019; 218:541-558. [PMID: 30626720 PMCID: PMC6363464 DOI: 10.1083/jcb.201708105] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 10/05/2018] [Accepted: 11/21/2018] [Indexed: 12/25/2022] Open
Abstract
The Greatwall kinase substrates ARPP19 and ENSA have been shown to inhibit PP2A-B55 by an identical mechanism. Hached et al. show that, surprisingly, the ARPP19 and ENSA paralogs display specific functions during mouse embryogenesis and differentially control cell cycle progression. Greatwall (GWL) is an essential kinase that indirectly controls PP2A-B55, the phosphatase counterbalancing cyclin B/CDK1 activity during mitosis. In Xenopus laevis egg extracts, GWL-mediated phosphorylation of overexpressed ARPP19 and ENSA turns them into potent PP2A-B55 inhibitors. It has been shown that the GWL/ENSA/PP2A-B55 axis contributes to the control of DNA replication, but little is known about the role of ARPP19 in cell division. By using conditional knockout mouse models, we investigated the specific roles of ARPP19 and ENSA in cell division. We found that Arpp19, but not Ensa, is essential for mouse embryogenesis. Moreover, Arpp19 ablation dramatically decreased mouse embryonic fibroblast (MEF) viability by perturbing the temporal pattern of protein dephosphorylation during mitotic progression, possibly by a drop of PP2A-B55 activity inhibition. We show that these alterations are not prevented by ENSA, which is still expressed in Arpp19Δ/Δ MEFs, suggesting that ARPP19 is essential for mitotic division. Strikingly, we demonstrate that unlike ARPP19, ENSA is not required for early embryonic development. Arpp19 knockout did not perturb the S phase, unlike Ensa gene ablation. We conclude that, during mouse embryogenesis, the Arpp19 and Ensa paralog genes display specific functions by differentially controlling cell cycle progression.
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Affiliation(s)
- Khaled Hached
- Centre de Recherche de Biologie Cellulaire de Montpellier, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5237, Université de Montpellier, Montpellier, France
| | - Perrine Goguet
- Centre de Recherche de Biologie Cellulaire de Montpellier, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5237, Université de Montpellier, Montpellier, France
| | - Sophie Charrasse
- Centre de Recherche de Biologie Cellulaire de Montpellier, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5237, Université de Montpellier, Montpellier, France
| | - Suzanne Vigneron
- Centre de Recherche de Biologie Cellulaire de Montpellier, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5237, Université de Montpellier, Montpellier, France
| | - Maria P Sacristan
- Instituto de Biología Molecular y Celular del Cáncer, Universidad de Salamanca/Consejo Superior de Investigaciones Cientificas, Salamanca, Spain
| | - Thierry Lorca
- Centre de Recherche de Biologie Cellulaire de Montpellier, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5237, Université de Montpellier, Montpellier, France
| | - Anna Castro
- Centre de Recherche de Biologie Cellulaire de Montpellier, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5237, Université de Montpellier, Montpellier, France
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18
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Marzec K, Burgess A. The Oncogenic Functions of MASTL Kinase. Front Cell Dev Biol 2018; 6:162. [PMID: 30555827 PMCID: PMC6282046 DOI: 10.3389/fcell.2018.00162] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 11/08/2018] [Indexed: 01/14/2023] Open
Abstract
MASTL kinase is a master regulator of mitosis, essential for ensuring that mitotic substrate phosphorylation is correctly maintained. It achieves this through the phosphorylation of alpha-endosulfine and subsequent inhibition of the tumor suppressor PP2A-B55 phosphatase. In recent years MASTL has also emerged as a novel oncogenic kinase that is upregulated in a number of cancer types, correlating with chromosome instability and poor patient survival. While the chromosome instability is likely directly linked to MASTL's control of mitotic phosphorylation, several new studies indicated that MASTL has additional effects outside of mitosis and beyond regulation of PP2A-B55. These include control of normal DNA replication timing, and regulation of AKT/mTOR and Wnt/β-catenin oncogenic kinase signaling. In this review, we will examine the phenotypes and mechanisms for how MASTL, ENSA, and PP2A-B55 deregulation drives tumor progression and metastasis. Finally, we will explore the rationale for the future development of MASTL inhibitors as new cancer therapeutics.
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Affiliation(s)
- Kamila Marzec
- ANZAC Research Institute, University of Sydney, Sydney, NSW, Australia
| | - Andrew Burgess
- ANZAC Research Institute, University of Sydney, Sydney, NSW, Australia.,Faculty of Medicine and Health, Concord Clinical School, University of Sydney, Sydney, NSW, Australia
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19
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Nilsson J. Protein phosphatases in the regulation of mitosis. J Cell Biol 2018; 218:395-409. [PMID: 30446607 PMCID: PMC6363451 DOI: 10.1083/jcb.201809138] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 10/29/2018] [Accepted: 10/29/2018] [Indexed: 12/15/2022] Open
Abstract
The accurate segregation of genetic material to daughter cells during mitosis depends on the precise coordination and regulation of hundreds of proteins by dynamic phosphorylation. Mitotic kinases are major regulators of protein function, but equally important are protein phosphatases that balance their actions, their coordinated activity being essential for accurate chromosome segregation. Phosphoprotein phosphatases (PPPs) that dephosphorylate phosphoserine and phosphothreonine residues are increasingly understood as essential regulators of mitosis. In contrast to kinases, the lack of a pronounced peptide-binding cleft on the catalytic subunit of PPPs suggests that these enzymes are unlikely to be specific. However, recent exciting insights into how mitotic PPPs recognize specific substrates have revealed that they are as specific as kinases. Furthermore, the activities of PPPs are tightly controlled at many levels to ensure that they are active only at the proper time and place. Here, I will discuss substrate selection and regulation of mitotic PPPs focusing mainly on animal cells and explore how these actions control mitosis, as well as important unanswered questions.
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Affiliation(s)
- Jakob Nilsson
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
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20
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Nasa I, Kettenbach AN. Coordination of Protein Kinase and Phosphoprotein Phosphatase Activities in Mitosis. Front Cell Dev Biol 2018; 6:30. [PMID: 29623276 PMCID: PMC5874294 DOI: 10.3389/fcell.2018.00030] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 03/08/2018] [Indexed: 01/09/2023] Open
Abstract
Dynamic changes in protein phosphorylation govern the transitions between different phases of the cell division cycle. A "tug of war" between highly conserved protein kinases and the family of phosphoprotein phosphatases (PPP) establishes the phosphorylation state of proteins, which controls their function. More than three-quarters of all proteins are phosphorylated at one or more sites in human cells, with the highest occupancy of phosphorylation sites seen in mitosis. Spatial and temporal regulation of opposing kinase and PPP activities is crucial for accurate execution of the mitotic program. The role of mitotic kinases has been the focus of many studies, while the contribution of PPPs was for a long time underappreciated and is just emerging. Misconceptions regarding the specificity and activity of protein phosphatases led to the belief that protein kinases are the primary determinants of mitotic regulation, leaving PPPs out of the limelight. Recent studies have shown that protein phosphatases are specific and selective enzymes, and that their activity is tightly regulated. In this review, we discuss the emerging roles of PPPs in mitosis and their regulation of and by mitotic kinases, as well as mechanisms that determine PPP substrate recognition and specificity.
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Affiliation(s)
- Isha Nasa
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States.,Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH, United States
| | - Arminja N Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States.,Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH, United States
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21
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Makhoul S, Walter E, Pagel O, Walter U, Sickmann A, Gambaryan S, Smolenski A, Zahedi RP, Jurk K. Effects of the NO/soluble guanylate cyclase/cGMP system on the functions of human platelets. Nitric Oxide 2018; 76:71-80. [PMID: 29550521 DOI: 10.1016/j.niox.2018.03.008] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 03/03/2018] [Accepted: 03/12/2018] [Indexed: 02/07/2023]
Abstract
Platelets are circulating sentinels of vascular integrity and are activated, inhibited, or modulated by multiple hormones, vasoactive substances or drugs. Endothelium- or drug-derived NO strongly inhibits platelet activation via activation of the soluble guanylate cyclase (sGC) and cGMP elevation, often in synergy with cAMP-elevation by prostacyclin. However, the molecular mechanisms and diversity of cGMP effects in platelets are poorly understood and sometimes controversial. Recently, we established the quantitative human platelet proteome, the iloprost/prostacyclin/cAMP/protein kinase A (PKA)-regulated phosphoproteome, and the interactions of the ADP- and iloprost/prostacyclin-affected phosphoproteome. We also showed that the sGC stimulator riociguat is in vitro a highly specific inhibitor, via cGMP, of various functions of human platelets. Here, we review the regulatory role of the cGMP/protein kinase G (PKG) system in human platelet function, and our current approaches to establish and analyze the phosphoproteome after selective stimulation of the sGC/cGMP pathway by NO donors and riociguat. Present data indicate an extensive and diverse NO/riociguat/cGMP phosphoproteome, which has to be compared with the cAMP phosphoproteome. In particular, sGC/cGMP-regulated phosphorylation of many membrane proteins, G-proteins and their regulators, signaling molecules, protein kinases, and proteins involved in Ca2+ regulation, suggests that the sGC/cGMP system targets multiple signaling networks rather than a limited number of PKG substrate proteins.
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Affiliation(s)
- Stephanie Makhoul
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany
| | - Elena Walter
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany
| | - Oliver Pagel
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e. V., Dortmund, Germany
| | - Ulrich Walter
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany
| | - Albert Sickmann
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e. V., Dortmund, Germany; Ruhr Universität Bochum, Medizinisches Proteom Center, Medizinische Fakultät, Bochum, Germany; Department of Chemistry, College of Physical Sciences, University of Aberdeen, Aberdeen, UK
| | - Stepan Gambaryan
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany; Russian Academy of Sciences, Sechenov Institute of Evolutionary Physiology and Biochemistry, St. Petersburg, Russia; St. Petersburg State University, Department of Cytology and Histology, St. Petersburg, Russia
| | - Albert Smolenski
- Conway Institute of Biomolecular & Biomedical Research, Univ. College Dublin, Dublin, Ireland; Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - René P Zahedi
- Gerald Bronfman Department of Oncology, Jewish General Hospital, McGill University , Montreal, Quebec H4A 3T2, Canada; Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University , Montreal, Quebec H3T 1E2, Canada
| | - Kerstin Jurk
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany.
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22
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Rogers S, McCloy R, Watkins DN, Burgess A. Mechanisms regulating phosphatase specificity and the removal of individual phosphorylation sites during mitotic exit. Bioessays 2017; 38 Suppl 1:S24-32. [PMID: 27417119 DOI: 10.1002/bies.201670905] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 09/15/2015] [Accepted: 09/17/2015] [Indexed: 12/22/2022]
Abstract
Entry into mitosis is driven by the activity of kinases, which phosphorylate over 7000 proteins on multiple sites. For cells to exit mitosis and segregate their genome correctly, these phosphorylations must be removed in a specific temporal order. This raises a critical and important question: how are specific phosphorylation sites on an individual protein removed? Traditionally, the temporal order of dephosphorylation was attributed to decreasing kinase activity. However, recent evidence in human cells has identified unique patterns of dephosphorylation during mammalian mitotic exit that cannot be fully explained by the loss of kinase activity. This suggests that specificity is determined in part by phosphatases. In this review, we explore how the physicochemical properties of an individual phosphosite and its surrounding amino acids can affect interactions with a phosphatase. These positive and negative interactions in turn help determine the specific pattern of dephosphorylation required for correct mitotic exit.
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Affiliation(s)
- Samuel Rogers
- The Kinghorn Cancer Center, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia
| | - Rachael McCloy
- The Kinghorn Cancer Center, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia
| | - D Neil Watkins
- The Kinghorn Cancer Center, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia.,St. Vincent's Clinical School, Faculty of Medicine, UNSW, Darlinghurst, NSW, Australia.,Department of Thoracic Medicine, St Vincent's Hospital, Darlinghurst, NSW, 2010, Australia
| | - Andrew Burgess
- The Kinghorn Cancer Center, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia.,St. Vincent's Clinical School, Faculty of Medicine, UNSW, Darlinghurst, NSW, Australia
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23
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Dupré AI, Haccard O, Jessus C. The greatwall kinase is dominant over PKA in controlling the antagonistic function of ARPP19 in Xenopus oocytes. Cell Cycle 2017; 16:1440-1452. [PMID: 28722544 DOI: 10.1080/15384101.2017.1338985] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The small protein ARPP19 plays a dual role during oocyte meiosis resumption. In Xenopus, ARPP19 phosphorylation at S109 by PKA is necessary for maintaining oocytes arrested in prophase of the first meiotic division. Progesterone downregulates PKA, leading to the dephosphorylation of ARPP19 at S109. This initiates a transduction pathway ending with the activation of the universal inducer of M-phase, the kinase Cdk1. This last step depends on ARPP19 phosphorylation at S67 by the kinase Greatwall. Hence, phosphorylated by PKA at S109, ARPP19 restrains Cdk1 activation while when phosphorylated by Greatwall at S67, ARPP19 becomes an inducer of Cdk1 activation. Here, we investigate the functional interplay between S109 and S67-phosphorylations of ARPP19. We show that both PKA and Gwl phosphorylate ARPP19 independently of each other and that Cdk1 is not directly involved in regulating the biological activity of ARPP19. We also show that the phosphorylation of ARPP19 at S67 that activates Cdk1, is dominant over the inhibitory S109 phosphorylation. Therefore our results highlight the importance of timely synchronizing ARPP19 phosphorylations at S109 and S67 to fully activate Cdk1.
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Affiliation(s)
- Aude-Isabelle Dupré
- a Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie du développement - Institut de Biologie Paris Seine (LBD - IBPS) , Paris , France
| | - Olivier Haccard
- a Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie du développement - Institut de Biologie Paris Seine (LBD - IBPS) , Paris , France
| | - Catherine Jessus
- a Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie du développement - Institut de Biologie Paris Seine (LBD - IBPS) , Paris , France
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24
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Musante V, Li L, Kanyo J, Lam TT, Colangelo CM, Cheng SK, Brody AH, Greengard P, Le Novère N, Nairn AC. Reciprocal regulation of ARPP-16 by PKA and MAST3 kinases provides a cAMP-regulated switch in protein phosphatase 2A inhibition. eLife 2017; 6. [PMID: 28613156 PMCID: PMC5515580 DOI: 10.7554/elife.24998] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 06/13/2017] [Indexed: 12/17/2022] Open
Abstract
ARPP-16, ARPP-19, and ENSA are inhibitors of protein phosphatase PP2A. ARPP-19 and ENSA phosphorylated by Greatwall kinase inhibit PP2A during mitosis. ARPP-16 is expressed in striatal neurons where basal phosphorylation by MAST3 kinase inhibits PP2A and regulates key components of striatal signaling. The ARPP-16/19 proteins were discovered as substrates for PKA, but the function of PKA phosphorylation is unknown. We find that phosphorylation by PKA or MAST3 mutually suppresses the ability of the other kinase to act on ARPP-16. Phosphorylation by PKA also acts to prevent inhibition of PP2A by ARPP-16 phosphorylated by MAST3. Moreover, PKA phosphorylates MAST3 at multiple sites resulting in its inhibition. Mathematical modeling highlights the role of these three regulatory interactions to create a switch-like response to cAMP. Together, the results suggest a complex antagonistic interplay between the control of ARPP-16 by MAST3 and PKA that creates a mechanism whereby cAMP mediates PP2A disinhibition. DOI:http://dx.doi.org/10.7554/eLife.24998.001
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Affiliation(s)
- Veronica Musante
- Department of Psychiatry, Yale University School of Medicine, New Haven, United States
| | - Lu Li
- The Babraham Institute, Cambridge, United Kingdom
| | - Jean Kanyo
- W.M. Keck Biotechnology Resource Laboratory, Yale University School Medicine, New Haven, United states
| | - Tukiet T Lam
- W.M. Keck Biotechnology Resource Laboratory, Yale University School Medicine, New Haven, United states
| | - Christopher M Colangelo
- W.M. Keck Biotechnology Resource Laboratory, Yale University School Medicine, New Haven, United states
| | - Shuk Kei Cheng
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, United States
| | - A Harrison Brody
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, United States
| | - Paul Greengard
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, United States
| | | | - Angus C Nairn
- Department of Psychiatry, Yale University School of Medicine, New Haven, United States
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25
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Filter JJ, Williams BC, Eto M, Shalloway D, Goldberg ML. Unfair competition governs the interaction of pCPI-17 with myosin phosphatase (PP1-MYPT1). eLife 2017; 6. [PMID: 28387646 PMCID: PMC5441869 DOI: 10.7554/elife.24665] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 03/31/2017] [Indexed: 11/30/2022] Open
Abstract
The small phosphoprotein pCPI-17 inhibits myosin light-chain phosphatase (MLCP). Current models postulate that during muscle relaxation, phosphatases other than MLCP dephosphorylate and inactivate pCPI-17 to restore MLCP activity. We show here that such hypotheses are insufficient to account for the observed rapidity of pCPI-17 inactivation in mammalian smooth muscles. Instead, MLCP itself is the critical enzyme for pCPI-17 dephosphorylation. We call the mutual sequestration mechanism through which pCPI-17 and MLCP interact inhibition by unfair competition: MLCP protects pCPI-17 from other phosphatases, while pCPI-17 blocks other substrates from MLCP’s active site. MLCP dephosphorylates pCPI-17 at a slow rate that is, nonetheless, both sufficient and necessary to explain the speed of pCPI-17 dephosphorylation and the consequent MLCP activation during muscle relaxation. DOI:http://dx.doi.org/10.7554/eLife.24665.001
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Affiliation(s)
- Joshua J Filter
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Byron C Williams
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Masumi Eto
- Department of Molecular Physiology and Biophysics, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, United States
| | - David Shalloway
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Michael L Goldberg
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
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26
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Heim A, Rymarczyk B, Mayer TU. Regulation of Cell Division. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 953:83-116. [PMID: 27975271 DOI: 10.1007/978-3-319-46095-6_3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The challenging task of mitotic cell divisions is to generate two genetically identical daughter cells from a single precursor cell. To accomplish this task, a complex regulatory network evolved, which ensures that all events critical for the duplication of cellular contents and their subsequent segregation occur in the correct order, at specific intervals and with the highest possible fidelity. Transitions between cell cycle stages are triggered by changes in the phosphorylation state and levels of components of the cell cycle machinery. Entry into S-phase and M-phase are mediated by cyclin-dependent kinases (Cdks), serine-threonine kinases that require a regulatory cyclin subunit for their activity. Resetting the system to the interphase state is mediated by protein phosphatases (PPs) that counteract Cdks by dephosphorylating their substrates. To avoid futile cycles of phosphorylation and dephosphorylation, Cdks and PPs must be regulated in a manner such that their activities are mutually exclusive.
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Affiliation(s)
- Andreas Heim
- Department of Biology and Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Universitätsstr. 10, 78457, Konstanz, Germany
| | - Beata Rymarczyk
- Department of Biology and Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Universitätsstr. 10, 78457, Konstanz, Germany
| | - Thomas U Mayer
- Department of Biology and Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Universitätsstr. 10, 78457, Konstanz, Germany.
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27
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Dormán G, Nakamura H, Pulsipher A, Prestwich GD. The Life of Pi Star: Exploring the Exciting and Forbidden Worlds of the Benzophenone Photophore. Chem Rev 2016; 116:15284-15398. [PMID: 27983805 DOI: 10.1021/acs.chemrev.6b00342] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The widespread applications of benzophenone (BP) photochemistry in biological chemistry, bioorganic chemistry, and material science have been prominent in both academic and industrial research. BP photophores have unique photochemical properties: upon n-π* excitation at 365 nm, a biradicaloid triplet state is formed reversibly, which can abstract a hydrogen atom from accessible C-H bonds; the radicals subsequently recombine, creating a stable covalent C-C bond. This light-directed covalent attachment process is exploited in many different ways: (i) binding/contact site mapping of ligand (or protein)-protein interactions; (ii) identification of molecular targets and interactome mapping; (iii) proteome profiling; (iv) bioconjugation and site-directed modification of biopolymers; (v) surface grafting and immobilization. BP photochemistry also has many practical advantages, including low reactivity toward water, stability in ambient light, and the convenient excitation at 365 nm. In addition, several BP-containing building blocks and reagents are commercially available. In this review, we explore the "forbidden" (transitions) and excitation-activated world of photoinduced covalent attachment of BP photophores by touring a colorful palette of recent examples. In this exploration, we will see the pros and cons of using BP photophores, and we hope that both novice and expert photolabelers will enjoy and be inspired by the breadth and depth of possibilities.
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Affiliation(s)
- György Dormán
- Targetex llc , Dunakeszi H-2120, Hungary.,Faculty of Pharmacy, University of Szeged , Szeged H-6720, Hungary
| | - Hiroyuki Nakamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology , Yokohama 226-8503, Japan
| | - Abigail Pulsipher
- GlycoMira Therapeutics, Inc. , Salt Lake City, Utah 84108, United States.,Division of Head and Neck Surgery, Rhinology - Sinus and Skull Base Surgery, Department of Surgery, University of Utah School of Medicine , Salt Lake City, Utah 84108, United States
| | - Glenn D Prestwich
- Division of Head and Neck Surgery, Rhinology - Sinus and Skull Base Surgery, Department of Surgery, University of Utah School of Medicine , Salt Lake City, Utah 84108, United States
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28
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Two Bistable Switches Govern M Phase Entry. Curr Biol 2016; 26:3361-3367. [PMID: 27889260 PMCID: PMC5196020 DOI: 10.1016/j.cub.2016.10.022] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 09/27/2016] [Accepted: 10/12/2016] [Indexed: 02/02/2023]
Abstract
The abrupt and irreversible transition from interphase to M phase is essential to separate DNA replication from chromosome segregation. This transition requires the switch-like phosphorylation of hundreds of proteins by the cyclin-dependent kinase 1 (Cdk1):cyclin B (CycB) complex. Previous studies have ascribed these switch-like phosphorylations to the auto-activation of Cdk1:CycB through the removal of inhibitory phosphorylations on Cdk1-Tyr15 [1, 2]. The positive feedback in Cdk1 activation creates a bistable switch that makes mitotic commitment irreversible [2, 3, 4]. Here, we surprisingly find that Cdk1 auto-activation is dispensable for irreversible, switch-like mitotic entry due to a second mechanism, whereby Cdk1:CycB inhibits its counteracting phosphatase (PP2A:B55). We show that the PP2A:B55-inhibiting Greatwall (Gwl)-endosulfine (ENSA) pathway is both necessary and sufficient for switch-like phosphorylations of mitotic substrates. Using purified components of the Gwl-ENSA pathway in a reconstituted system, we found a sharp Cdk1 threshold for phosphorylation of a luminescent mitotic substrate. The Cdk1 threshold to induce mitotic phosphorylation is distinctly higher than the Cdk1 threshold required to maintain these phosphorylations—evidence for bistability. A combination of mathematical modeling and biochemical reconstitution show that the bistable behavior of the Gwl-ENSA pathway emerges from its mutual antagonism with PP2A:B55. Our results demonstrate that two interlinked bistable mechanisms provide a robust solution for irreversible and switch-like mitotic entry. Cdk1 auto-activation loop is dispensable for switch-like mitotic entry PP2A:B55 auto-regulation creates a bistable switch Two bistable switches provide a robust solution for mitotic entry
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29
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Cundell MJ, Hutter LH, Nunes Bastos R, Poser E, Holder J, Mohammed S, Novak B, Barr FA. A PP2A-B55 recognition signal controls substrate dephosphorylation kinetics during mitotic exit. J Cell Biol 2016; 214:539-54. [PMID: 27551054 PMCID: PMC5004449 DOI: 10.1083/jcb.201606033] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 07/13/2016] [Indexed: 11/22/2022] Open
Abstract
PP2A-B55 is one of the major phosphatases regulating cell division. Despite its importance for temporal control during mitotic exit, how B55 substrates are recognized and differentially dephosphorylated is unclear. Using phosphoproteomics combined with kinetic modeling to extract B55-dependent rate constants, we have systematically identified B55 substrates and assigned their temporal order in mitotic exit. These substrates share a bipartite polybasic recognition determinant (BPR) flanking a Cdk1 phosphorylation site. Experiments and modeling show that dephosphorylation rate is encoded into B55 substrates, including its inhibitor ENSA, by cooperative action of basic residues within the BPR. A complementary acidic surface on B55 decodes this signal, supporting a cooperative electrostatic mechanism for substrate selection. A further level of specificity is encoded into B55 substrates because B55 displays selectivity for phosphothreonine. These simple biochemical properties, combined with feedback control of B55 activity by the phosphoserine-containing substrate/inhibitor ENSA, can help explain the temporal sequence of events during exit from mitosis.
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Affiliation(s)
- Michael J Cundell
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, England, UK
| | - Lukas H Hutter
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, England, UK
| | | | - Elena Poser
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, England, UK
| | - James Holder
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, England, UK
| | - Shabaz Mohammed
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, England, UK Department of Chemistry, University of Oxford, Oxford OX1 3TA, England, UK
| | - Bela Novak
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, England, UK
| | - Francis A Barr
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, England, UK
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30
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Hégarat N, Rata S, Hochegger H. Bistability of mitotic entry and exit switches during open mitosis in mammalian cells. Bioessays 2016; 38:627-43. [PMID: 27231150 DOI: 10.1002/bies.201600057] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Mitotic entry and exit are switch-like transitions that are driven by the activation and inactivation of Cdk1 and mitotic cyclins. This simple on/off reaction turns out to be a complex interplay of various reversible reactions, feedback loops, and thresholds that involve both the direct regulators of Cdk1 and its counteracting phosphatases. In this review, we summarize the interplay of the major components of the system and discuss how they work together to generate robustness, bistability, and irreversibility. We propose that it may be beneficial to regard the entry and exit reactions as two separate reversible switches that are distinguished by differences in the state of phosphatase activity, mitotic proteolysis, and a dramatic rearrangement of cellular components after nuclear envelope breakdown, and discuss how the major Cdk1 activity thresholds could be determined for these transitions.
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Affiliation(s)
- Nadia Hégarat
- Genome Damage and Stability Centre, University of Sussex, Brighton, UK
| | - Scott Rata
- Department of Biochemistry, Oxford Centre for Integrative Systems Biology, University of Oxford, Oxford, UK
| | - Helfrid Hochegger
- Genome Damage and Stability Centre, University of Sussex, Brighton, UK
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31
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Wang P, Larouche M, Normandin K, Kachaner D, Mehsen H, Emery G, Archambault V. Spatial regulation of greatwall by Cdk1 and PP2A-Tws in the cell cycle. Cell Cycle 2016; 15:528-39. [PMID: 26761639 PMCID: PMC5056603 DOI: 10.1080/15384101.2015.1127476] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 11/18/2015] [Accepted: 11/27/2015] [Indexed: 12/20/2022] Open
Abstract
Entry into mitosis requires the phosphorylation of multiple substrates by cyclin B-Cdk1, while exit from mitosis requires their dephosphorylation, which depends largely on the phosphatase PP2A in complex with its B55 regulatory subunit (Tws in Drosophila). At mitotic entry, cyclin B-Cdk1 activates the Greatwall kinase, which phosphorylates Endosulfine proteins, thereby activating their ability to inhibit PP2A-B55 competitively. The inhibition of PP2A-B55 at mitotic entry facilitates the accumulation of phosphorylated Cdk1 substrates. The coordination of these enzymes involves major changes in their localization. In interphase, Gwl is nuclear while PP2A-B55 is cytoplasmic. We recently showed that Gwl suddenly relocalizes from the nucleus to the cytoplasm in prophase, before nuclear envelope breakdown and that this controlled localization of Gwl is required for its function. We and others have shown that phosphorylation of Gwl by cyclin B-Cdk1 at multiple sites is required for its nuclear exclusion, but the precise mechanisms remained unclear. In addition, how Gwl returns to its nuclear localization was not explored. Here we show that cyclin B-Cdk1 directly inactivates a Nuclear Localization Signal in the central region of Gwl. This phosphorylation facilitates the cytoplasmic retention of Gwl, which is exported to the cytoplasm in a Crm1-dependent manner. In addition, we show that PP2A-Tws promotes the return of Gwl to its nuclear localization during cytokinesis. Our results indicate that the cyclic changes in Gwl localization at mitotic entry and exit are directly regulated by the antagonistic cyclin B-Cdk1 and PP2A-Tws enzymes.
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Affiliation(s)
- Peng Wang
- Département de biochimie et médecine moléculaire; Université de Montréal; Québec, Canada
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec, Canada
| | - Myreille Larouche
- Département de biochimie et médecine moléculaire; Université de Montréal; Québec, Canada
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec, Canada
| | - Karine Normandin
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec, Canada
| | - David Kachaner
- Département de biochimie et médecine moléculaire; Université de Montréal; Québec, Canada
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec, Canada
| | - Haytham Mehsen
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec, Canada
| | - Gregory Emery
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec, Canada
- Département de pathologie et biologie cellulaire, Université de Montréal, Montréal, Québec, Canada
| | - Vincent Archambault
- Département de biochimie et médecine moléculaire; Université de Montréal; Québec, Canada
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec, Canada
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32
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Kishimoto T. Entry into mitosis: a solution to the decades-long enigma of MPF. Chromosoma 2015; 124:417-28. [PMID: 25712366 PMCID: PMC4666901 DOI: 10.1007/s00412-015-0508-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 01/29/2015] [Accepted: 01/30/2015] [Indexed: 01/21/2023]
Abstract
Maturation or M phase-promoting factor (MPF) is the universal inducer of M phase common to eukaryotic cells. MPF was originally defined as a transferable activity that can induce the G2/M phase transition in recipient cells. Today, however, MPF is assumed to describe an activity that exhibits its effect in donor cells, and furthermore, MPF is consistently equated with the kinase cyclin B-Cdk1. In some conditions, however, MPF, as originally defined, is undetectable even though cyclin B-Cdk1 is fully active. For over three decades, this inconsistency has remained a long-standing puzzle. The enigma is now resolved through the elucidation that MPF, defined as an activity that exhibits its effect in recipient cells, consists of at least two separate kinases, cyclin B-Cdk1 and Greatwall (Gwl). Involvement of Gwl in MPF can be explained by its contribution to the autoregulatory activation of cyclin B-Cdk1 and by its stabilization of phosphorylations on cyclin B-Cdk1 substrates, both of which are essential when MPF induces the G2/M phase transition in recipient cells. To accomplish these tasks, Gwl helps cyclin B-Cdk1 by suppressing protein phosphatase 2A (PP2A)-B55 that counteracts cyclin B-Cdk1. MPF, as originally defined, is thus not synonymous with cyclin B-Cdk1, but is instead a system consisting of both cyclin B-Cdk1 that directs mitotic entry and Gwl that suppresses the anti-cyclin B-Cdk1 phosphatase. The current view that MPF is a synonym for cyclin B-Cdk1 in donor cells is thus imprecise; instead, MPF is best regarded as the entire pathway involved in the autoregulatory activation of cyclin B-Cdk1, with specifics depending on the experimental system.
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Affiliation(s)
- Takeo Kishimoto
- Laboratory of Cell and Developmental Biology, Graduate School of Bioscience, Tokyo Institute of Technology, Yokohama, 226-8501, Japan.
- Science and Education Center, Ochanomizu University, Ootsuka 2-1-1, Bunkyo-ku, Tokyo, 112-8610, Japan.
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33
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Hino H, Takaki K, Mochida S. Inhibitor-1 and -2 of PP2A have preference between PP2A complexes. Biochem Biophys Res Commun 2015; 467:297-302. [DOI: 10.1016/j.bbrc.2015.09.168] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 09/30/2015] [Indexed: 11/30/2022]
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34
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Labandera AM, Vahab AR, Chaudhuri S, Kerk D, Moorhead GBG. The mitotic PP2A regulator ENSA/ARPP-19 is remarkably conserved across plants and most eukaryotes. Biochem Biophys Res Commun 2015; 458:739-44. [PMID: 25666948 DOI: 10.1016/j.bbrc.2015.01.123] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 01/25/2015] [Indexed: 11/25/2022]
Abstract
Protein phosphatase 2A (PP2A) is a major serine/threonine phosphatase of eukaryotes. PP2A containing the B55 subunit is a key regulator of mitosis and must be inhibited by phosphorylated α-endosulfine (ENSA) or cyclic AMP-regulated 19 kDa phosphoprotein (ARPP-19) to allow passage through mitosis. Exit from mitosis then requires dephosphorylation of ENSA/ARPP-19 to relieve inhibition of PP2A/B55. ENSA/ARPP-19 has been characterized in several vertebrates and budding yeast, but little is known about its presence in plants and the majority of other eukaryotes. Here we show that three isoforms of ENSA/ARPP-19 are present in the Arabidopsis thaliana genome with distinct expression profiles across various plant tissues. The ENSA/ARPP-19 proteins, and in particular their key inhibitory sequence FDSGDY (FDSADW in plants), is remarkably conserved across plants and most eukaryotes suggesting an ancient origin and conserved function to control PP2A activity.
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Affiliation(s)
- Anne-Marie Labandera
- Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Ahmad R Vahab
- Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Sibapriya Chaudhuri
- Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - David Kerk
- Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Greg B G Moorhead
- Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada.
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35
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Haesen D, Sents W, Lemaire K, Hoorne Y, Janssens V. The Basic Biology of PP2A in Hematologic Cells and Malignancies. Front Oncol 2014; 4:347. [PMID: 25566494 PMCID: PMC4263090 DOI: 10.3389/fonc.2014.00347] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 11/20/2014] [Indexed: 12/30/2022] Open
Abstract
Reversible protein phosphorylation plays a crucial role in regulating cell signaling. In normal cells, phosphoregulation is tightly controlled by a network of protein kinases counterbalanced by several protein phosphatases. Deregulation of this delicate balance is widely recognized as a central mechanism by which cells escape external and internal self-limiting signals, eventually resulting in malignant transformation. A large fraction of hematologic malignancies is characterized by constitutive or unrestrained activation of oncogenic kinases. This is in part achieved by activating mutations, chromosomal rearrangements, or constitutive activation of upstream kinase regulators, in part by inactivation of their anti-oncogenic phosphatase counterparts. Protein phosphatase 2A (PP2A) represents a large family of cellular serine/threonine phosphatases with suspected tumor suppressive functions. In this review, we highlight our current knowledge about the complex structure and biology of these phosphatases in hematologic cells, thereby providing the rationale behind their diverse signaling functions. Eventually, this basic knowledge is a key to truly understand the tumor suppressive role of PP2A in leukemogenesis and to allow further rational development of therapeutic strategies targeting PP2A.
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Affiliation(s)
- Dorien Haesen
- Laboratory of Protein Phosphorylation and Proteomics, Department Cellular and Molecular Medicine, University of Leuven , Leuven , Belgium
| | - Ward Sents
- Laboratory of Protein Phosphorylation and Proteomics, Department Cellular and Molecular Medicine, University of Leuven , Leuven , Belgium
| | - Katleen Lemaire
- Gene Expression Unit, Department Cellular and Molecular Medicine, University of Leuven , Leuven , Belgium
| | - Yana Hoorne
- Laboratory of Protein Phosphorylation and Proteomics, Department Cellular and Molecular Medicine, University of Leuven , Leuven , Belgium
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation and Proteomics, Department Cellular and Molecular Medicine, University of Leuven , Leuven , Belgium
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36
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Williams BC, Filter JJ, Blake-Hodek KA, Wadzinski BE, Fuda NJ, Shalloway D, Goldberg ML. Greatwall-phosphorylated Endosulfine is both an inhibitor and a substrate of PP2A-B55 heterotrimers. eLife 2014; 3:e01695. [PMID: 24618897 PMCID: PMC3949306 DOI: 10.7554/elife.01695] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 01/30/2014] [Indexed: 11/13/2022] Open
Abstract
During M phase, Endosulfine (Endos) family proteins are phosphorylated by Greatwall kinase (Gwl), and the resultant pEndos inhibits the phosphatase PP2A-B55, which would otherwise prematurely reverse many CDK-driven phosphorylations. We show here that PP2A-B55 is the enzyme responsible for dephosphorylating pEndos during M phase exit. The kinetic parameters for PP2A-B55's action on pEndos are orders of magnitude lower than those for CDK-phosphorylated substrates, suggesting a simple model for PP2A-B55 regulation that we call inhibition by unfair competition. As the name suggests, during M phase PP2A-B55's attention is diverted to pEndos, which binds much more avidly and is dephosphorylated more slowly than other substrates. When Gwl is inactivated during the M phase-to-interphase transition, the dynamic balance changes: pEndos dephosphorylated by PP2A-B55 cannot be replaced, so the phosphatase can refocus its attention on CDK-phosphorylated substrates. This mechanism explains simultaneously how PP2A-B55 and Gwl together regulate pEndos, and how pEndos controls PP2A-B55. DOI: http://dx.doi.org/10.7554/eLife.01695.001.
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Affiliation(s)
- Byron C Williams
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Joshua J Filter
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | | | - Brian E Wadzinski
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, United States
| | - Nicholas J Fuda
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - David Shalloway
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Michael L Goldberg
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
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