1
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Chrupcala ML, Moseley JB. PP2A-B56 regulates Mid1 protein levels for proper cytokinesis in fission yeast. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.28.601230. [PMID: 38979265 PMCID: PMC11230426 DOI: 10.1101/2024.06.28.601230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Protein phosphorylation regulates many steps in the cell division process including cytokinesis. In the fission yeast S. pombe, the anillin-like protein Mid1 sets the cell division plane and is regulated by phosphorylation. Multiple protein kinases act on Mid1, but no protein phosphatases have been shown to regulate Mid1. Here, we discovered that the conserved protein phosphatase PP2A-B56 is required for proper cytokinesis by promoting Mid1 protein levels. We find that par1Δ cells lacking the primary B56 subunit divide asymmetrically due to the assembly of misplaced cytokinetic rings that slide toward cell tips. These par1Δ mutants have reduced whole-cell levels of Mid1 protein, leading to reduced Mid1 at the cytokinetic ring. Restoring proper Mid1 expression suppresses par1Δ cytokinesis defects. This work identifies a new PP2A-B56 pathway regulating cytokinesis through Mid1, with implications for control of cytokinesis in other organisms.
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Affiliation(s)
- Madeline L. Chrupcala
- Department of Biochemistry and Cell Biology, The Geisel School of Medicine at Dartmouth, Hanover NH
| | - James B. Moseley
- Department of Biochemistry and Cell Biology, The Geisel School of Medicine at Dartmouth, Hanover NH
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2
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Bradley D, Garand C, Belda H, Gagnon-Arsenault I, Treeck M, Elowe S, Landry CR. The substrate quality of CK2 target sites has a determinant role on their function and evolution. Cell Syst 2024; 15:544-562.e8. [PMID: 38861992 DOI: 10.1016/j.cels.2024.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 02/29/2024] [Accepted: 05/20/2024] [Indexed: 06/13/2024]
Abstract
Most biological processes are regulated by signaling modules that bind to short linear motifs. For protein kinases, substrates may have full or only partial matches to the kinase recognition motif, a property known as "substrate quality." However, it is not clear whether differences in substrate quality represent neutral variation or if they have functional consequences. We examine this question for the kinase CK2, which has many fundamental functions. We show that optimal CK2 sites are phosphorylated at maximal stoichiometries and found in many conditions, whereas minimal substrates are more weakly phosphorylated and have regulatory functions. Optimal CK2 sites tend to be more conserved, and substrate quality is often tuned by selection. For intermediate sites, increases or decreases in substrate quality may be deleterious, as we demonstrate for a CK2 substrate at the kinetochore. The results together suggest a strong role for substrate quality in phosphosite function and evolution. A record of this paper's transparent peer review process is included in the supplemental information.
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Affiliation(s)
- David Bradley
- Département de Biochimie, de Microbiologie et de Bio-informatique, Faculté des Sciences et de Génie, Université Laval, Québec City, QC G1V 0A6, Canada; Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec City, QC G1V 0A6, Canada; PROTEO, Le regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines, Université Laval, Québec City, QC G1V 0A6, Canada; Centre de Recherche sur les Données Massives (CRDM), Université Laval, Québec City, QC G1V 0A6, Canada; Département de Biologie, Faculté des Sciences et de Génie, Université Laval, Québec City, QC G1V 0A6, Canada.
| | - Chantal Garand
- PROTEO, Le regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines, Université Laval, Québec City, QC G1V 0A6, Canada; Axe de Reproduction, Santé de la mère et de l'enfant, CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Hugo Belda
- Signalling in Host-Pathogen Interaction Laboratory, The Francis Crick Institute, London NW11AT, UK
| | - Isabelle Gagnon-Arsenault
- Département de Biochimie, de Microbiologie et de Bio-informatique, Faculté des Sciences et de Génie, Université Laval, Québec City, QC G1V 0A6, Canada; Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec City, QC G1V 0A6, Canada; PROTEO, Le regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines, Université Laval, Québec City, QC G1V 0A6, Canada; Centre de Recherche sur les Données Massives (CRDM), Université Laval, Québec City, QC G1V 0A6, Canada; Département de Biologie, Faculté des Sciences et de Génie, Université Laval, Québec City, QC G1V 0A6, Canada
| | - Moritz Treeck
- Signalling in Host-Pathogen Interaction Laboratory, The Francis Crick Institute, London NW11AT, UK; Cell Biology of Host-Pathogen Interaction Laboratory, The Gulbenkian Institute of Science, Oeiras 2780-156, Portugal
| | - Sabine Elowe
- PROTEO, Le regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines, Université Laval, Québec City, QC G1V 0A6, Canada; Axe de Reproduction, Santé de la mère et de l'enfant, CHU de Québec, Université Laval, Québec City, QC, Canada; Department of Pediatrics, Faculty of Medicine, Université Laval, Québec City, QC, Canada; Centre de Recherche sur le Cancer, CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Christian R Landry
- Département de Biochimie, de Microbiologie et de Bio-informatique, Faculté des Sciences et de Génie, Université Laval, Québec City, QC G1V 0A6, Canada; Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec City, QC G1V 0A6, Canada; PROTEO, Le regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines, Université Laval, Québec City, QC G1V 0A6, Canada; Centre de Recherche sur les Données Massives (CRDM), Université Laval, Québec City, QC G1V 0A6, Canada; Département de Biologie, Faculté des Sciences et de Génie, Université Laval, Québec City, QC G1V 0A6, Canada.
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3
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Carceles-Cordon M, Orme JJ, Domingo-Domenech J, Rodriguez-Bravo V. The yin and yang of chromosomal instability in prostate cancer. Nat Rev Urol 2024; 21:357-372. [PMID: 38307951 PMCID: PMC11156566 DOI: 10.1038/s41585-023-00845-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2023] [Indexed: 02/04/2024]
Abstract
Metastatic prostate cancer remains an incurable lethal disease. Studies indicate that prostate cancer accumulates genomic changes during disease progression and displays the highest levels of chromosomal instability (CIN) across all types of metastatic tumours. CIN, which refers to ongoing chromosomal DNA gain or loss during mitosis, and derived aneuploidy, are known to be associated with increased tumour heterogeneity, metastasis and therapy resistance in many tumour types. Paradoxically, high CIN levels are also proposed to be detrimental to tumour cell survival, suggesting that cancer cells must develop adaptive mechanisms to ensure their survival. In the context of prostate cancer, studies indicate that CIN has a key role in disease progression and might also offer a therapeutic vulnerability that can be pharmacologically targeted. Thus, a comprehensive evaluation of the causes and consequences of CIN in prostate cancer, its contribution to aggressive advanced disease and a better understanding of the acquired CIN tolerance mechanisms can translate into new tumour classifications, biomarker development and therapeutic strategies.
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Affiliation(s)
| | - Jacob J Orme
- Department of Oncology, Mayo Clinic, Rochester, MN, USA
| | - Josep Domingo-Domenech
- Department of Urology, Mayo Clinic, Rochester, MN, USA.
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA.
| | - Veronica Rodriguez-Bravo
- Department of Urology, Mayo Clinic, Rochester, MN, USA.
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA.
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4
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Hu Y, Delviks-Frankenberry KA, Wu C, Arizaga F, Pathak VK, Xiong Y. Structural insights into PPP2R5A degradation by HIV-1 Vif. Nat Struct Mol Biol 2024:10.1038/s41594-024-01314-6. [PMID: 38789685 DOI: 10.1038/s41594-024-01314-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 04/11/2024] [Indexed: 05/26/2024]
Abstract
HIV-1 Vif recruits host cullin-RING-E3 ubiquitin ligase and CBFβ to degrade the cellular APOBEC3 antiviral proteins through diverse interactions. Recent evidence has shown that Vif also degrades the regulatory subunits PPP2R5(A-E) of cellular protein phosphatase 2A to induce G2/M cell cycle arrest. As PPP2R5 proteins bear no functional or structural resemblance to A3s, it is unclear how Vif can recognize different sets of proteins. Here we report the cryogenic-electron microscopy structure of PPP2R5A in complex with HIV-1 Vif-CBFβ-elongin B-elongin C at 3.58 Å resolution. The structure shows PPP2R5A binds across the Vif molecule, with biochemical and cellular studies confirming a distinct Vif-PPP2R5A interface that partially overlaps with those for A3s. Vif also blocks a canonical PPP2R5A substrate-binding site, indicating that it suppresses the phosphatase activities through both degradation-dependent and degradation-independent mechanisms. Our work identifies critical Vif motifs regulating the recognition of diverse A3 and PPP2R5A substrates, whereby disruption of these host-virus protein interactions could serve as potential targets for HIV-1 therapeutics.
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Affiliation(s)
- Yingxia Hu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Krista A Delviks-Frankenberry
- Viral Mutation Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, USA
| | - Chunxiang Wu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Fidel Arizaga
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Vinay K Pathak
- Viral Mutation Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, USA.
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
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5
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Lakshmi RB, Nayak P, Raz L, Sarkar A, Saroha A, Kumari P, Nair VM, Kombarakkaran DP, Sajana S, M G S, Agasti SS, Paul R, Ben-David U, Manna TK. CKAP5 stabilizes CENP-E at kinetochores by regulating microtubule-chromosome attachments. EMBO Rep 2024; 25:1909-1935. [PMID: 38424231 PMCID: PMC11014917 DOI: 10.1038/s44319-024-00106-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 02/02/2024] [Accepted: 02/12/2024] [Indexed: 03/02/2024] Open
Abstract
Stabilization of microtubule plus end-directed kinesin CENP-E at the metaphase kinetochores is important for chromosome alignment, but its mechanism remains unclear. Here, we show that CKAP5, a conserved microtubule plus tip protein, regulates CENP-E at kinetochores in human cells. Depletion of CKAP5 impairs CENP-E localization at kinetochores at the metaphase plate and results in increased kinetochore-microtubule stability and attachment errors. Erroneous attachments are also supported by computational modeling. Analysis of CKAP5 knockout cancer cells of multiple tissue origins shows that CKAP5 is preferentially essential in aneuploid, chromosomally unstable cells, and the sensitivity to CKAP5 depletion is correlated to that of CENP-E depletion. CKAP5 depletion leads to reduction in CENP-E-BubR1 interaction and the interaction is rescued by TOG4-TOG5 domain of CKAP5. The same domain can rescue CKAP5 depletion-induced CENP-E removal from the kinetochores. Interestingly, CKAP5 depletion facilitates recruitment of PP1 to the kinetochores and furthermore, a PP1 target site-specific CENP-E phospho-mimicking mutant gets stabilized at kinetochores in the CKAP5-depleted cells. Together, the results support a model in which CKAP5 controls mitotic chromosome attachment errors by stabilizing CENP-E at kinetochores and by regulating stability of the kinetochore-attached microtubules.
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Affiliation(s)
- R Bhagya Lakshmi
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, 695551, India
| | - Pinaki Nayak
- School of Mathematical and Computational Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032, India
| | - Linoy Raz
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Apurba Sarkar
- School of Mathematical and Computational Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032, India
| | - Akshay Saroha
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, Karnataka, 560064, India
| | - Pratibha Kumari
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, Karnataka, 560064, India
| | - Vishnu M Nair
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, 695551, India
| | - Delvin P Kombarakkaran
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, 695551, India
| | - S Sajana
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, 695551, India
| | - Sanusha M G
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, 695551, India
| | - Sarit S Agasti
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, Karnataka, 560064, India
| | - Raja Paul
- School of Mathematical and Computational Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032, India
| | - Uri Ben-David
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tapas K Manna
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, 695551, India.
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6
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Brewer A, Sathe G, Pflug BE, Clarke RG, Macartney TJ, Sapkota GP. Mapping the substrate landscape of protein phosphatase 2A catalytic subunit PPP2CA. iScience 2024; 27:109302. [PMID: 38450154 PMCID: PMC10915630 DOI: 10.1016/j.isci.2024.109302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/18/2023] [Accepted: 02/16/2024] [Indexed: 03/08/2024] Open
Abstract
Protein phosphatase 2A (PP2A) is an essential Ser/Thr phosphatase. The PP2A holoenzyme complex comprises a scaffolding (A), regulatory (B), and catalytic (C) subunit, with PPP2CA being the principal catalytic subunit. The full scope of PP2A substrates in cells remains to be defined. To address this, we employed dTAG proteolysis-targeting chimeras to efficiently and selectively degrade dTAG-PPP2CA in homozygous knock-in HEK293 cells. Unbiased global phospho-proteomics identified 2,204 proteins with significantly increased phosphorylation upon dTAG-PPP2CA degradation, implicating them as potential PPP2CA substrates. A vast majority of these are novel. Bioinformatic analyses revealed involvement of the potential PPP2CA substrates in spliceosome function, cell cycle, RNA transport, and ubiquitin-mediated proteolysis. We identify a pSP/pTP motif as a predominant target for PPP2CA and confirm some of our phospho-proteomic data with immunoblotting. We provide an in-depth atlas of potential PPP2CA substrates and establish targeted degradation as a robust tool to unveil phosphatase substrates in cells.
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Affiliation(s)
- Abigail Brewer
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Gajanan Sathe
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Billie E. Pflug
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Rosemary G. Clarke
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Thomas J. Macartney
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Gopal P. Sapkota
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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7
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Kruse T, Garvanska DH, Varga J, Garland W, McEwan B, Hein JB, Weisser MB, Puy IB, Chan CB, Parrila PS, Mendez BL, Arulanandam J, Schueler-Furman O, Jensen TH, Kettenbach A, Nilsson J. Substrate recognition principles for the PP2A-B55 protein phosphatase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.10.579793. [PMID: 38370611 PMCID: PMC10871369 DOI: 10.1101/2024.02.10.579793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
The PP2A-B55 phosphatase regulates a plethora of signaling pathways throughout eukaryotes. How PP2A-B55 selects its substrates presents a severe knowledge gap. By integrating AlphaFold modelling with comprehensive high resolution mutational scanning, we show that α-helices in substrates bind B55 through an evolutionary conserved mechanism. Despite a large diversity in sequence and composition, these α-helices share key amino acid determinants that engage discrete hydrophobic and electrostatic patches. Using deep learning protein design, we generate a specific and potent competitive peptide inhibitor of PP2A-B55 substrate interactions. With this inhibitor, we uncover that PP2A-B55 regulates the nuclear exosome targeting complex by binding to an α-helical recruitment module in RBM7. Collectively, our findings provide a framework for the understanding and interrogation of PP2A-B55 in health and disease.
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Affiliation(s)
- Thomas Kruse
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Dimitriya H Garvanska
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Julia Varga
- Department of Microbiology and Molecular Genetics, Institute for Biomedical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 9112001, Israel
| | - William Garland
- Department of Molecular Biology and Genetics, Universitetsbyen 81, Aarhus University, Aarhus, Denmark
| | - Brennan McEwan
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Jamin B Hein
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Current address: Amgen Research Copenhagen, Rønnegade 8, 5, 2100 Copenhagen, Denmark
| | - Melanie Bianca Weisser
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Iker Benavides Puy
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Camilla Bachman Chan
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Paula Sotelo Parrila
- Gene Center Munich, Ludwig-Maximilians- Universität München, Munich, 81377, Germany
| | - Blanca Lopez Mendez
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Jeyaprakash Arulanandam
- Gene Center Munich, Ludwig-Maximilians- Universität München, Munich, 81377, Germany
- Wellcome Centre for Cell Biology, University of Edinburg, Edinburgh, EH9 3BF, UK
| | - Ora Schueler-Furman
- Department of Microbiology and Molecular Genetics, Institute for Biomedical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 9112001, Israel
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Universitetsbyen 81, Aarhus University, Aarhus, Denmark
| | - Arminja Kettenbach
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Jakob Nilsson
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
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8
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Kapoor S, Adhikary K, Kotak S. PP2A-B55 SUR-6 promotes nuclear envelope breakdown in C. elegans embryos. Cell Rep 2023; 42:113495. [PMID: 37995185 DOI: 10.1016/j.celrep.2023.113495] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 09/25/2023] [Accepted: 11/09/2023] [Indexed: 11/25/2023] Open
Abstract
Nuclear envelope (NE) disassembly during mitosis is critical to ensure faithful segregation of the genetic material. NE disassembly is a phosphorylation-dependent process wherein mitotic kinases hyper-phosphorylate lamina and nucleoporins to initiate nuclear envelope breakdown (NEBD). In this study, we uncover an unexpected role of the PP2A phosphatase B55SUR-6 in NEBD during the first embryonic division of Caenorhabditis elegans embryo. B55SUR-6 depletion delays NE permeabilization and stabilizes lamina and nucleoporins. As a result, the merging of parental genomes and chromosome segregation is impaired. NEBD defect upon B55SUR-6 depletion is not due to delayed mitotic onset or mislocalization of mitotic kinases. Importantly, we demonstrate that microtubule-dependent mechanical forces synergize with B55SUR-6 for efficient NEBD. Finally, our data suggest that the lamin LMN-1 is likely a bona fide target of PP2A-B55SUR-6. These findings establish a model highlighting biochemical crosstalk between kinases, PP2A-B55SUR-6 phosphatase, and microtubule-generated mechanical forces in timely NE dissolution.
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Affiliation(s)
- Sukriti Kapoor
- Department of Microbiology and Cell Biology (MCB), Indian Institute of Science (IISc), Bangalore 560012, India
| | - Kuheli Adhikary
- Department of Microbiology and Cell Biology (MCB), Indian Institute of Science (IISc), Bangalore 560012, India
| | - Sachin Kotak
- Department of Microbiology and Cell Biology (MCB), Indian Institute of Science (IISc), Bangalore 560012, India.
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9
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Hein JB, Nguyen HT, Garvanska DH, Nasa I, Kruse T, Feng Y, Lopez Mendez B, Davey N, Kettenbach AN, Fordyce PM, Nilsson J. Phosphatase specificity principles uncovered by MRBLE:Dephos and global substrate identification. Mol Syst Biol 2023; 19:e11782. [PMID: 37916966 PMCID: PMC10698503 DOI: 10.15252/msb.202311782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 10/14/2023] [Accepted: 10/16/2023] [Indexed: 11/03/2023] Open
Abstract
Phosphoprotein phosphatases (PPPs) regulate major signaling pathways, but the determinants of phosphatase specificity are poorly understood. This is because methods to investigate this at scale are lacking. Here, we develop a novel in vitro assay, MRBLE:Dephos, that allows multiplexing of dephosphorylation reactions to determine phosphatase preferences. Using MRBLE:Dephos, we establish amino acid preferences of the residues surrounding the dephosphorylation site for PP1 and PP2A-B55, which reveals common and unique preferences. To compare the MRBLE:Dephos results to cellular substrates, we focused on mitotic exit that requires extensive dephosphorylation by PP1 and PP2A-B55. We use specific inhibition of PP1 and PP2A-B55 in mitotic exit lysates coupled with phosphoproteomics to identify more than 2,000 regulated sites. Importantly, the sites dephosphorylated during mitotic exit reveal key signatures that are consistent with MRBLE:Dephos. Furthermore, integration of our phosphoproteomic data with mitotic interactomes of PP1 and PP2A-B55 provides insight into how binding of phosphatases to substrates shapes dephosphorylation. Collectively, we develop novel approaches to investigate protein phosphatases that provide insight into mitotic exit regulation.
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Affiliation(s)
- Jamin B Hein
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- Department of BioengineeringStanford UniversityStanfordCAUSA
| | - Hieu T Nguyen
- Biochemistry and Cell BiologyGeisel School of Medicine at Dartmouth CollegeHanoverNHUSA
| | - Dimitriya H Garvanska
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Isha Nasa
- Department of BioengineeringStanford UniversityStanfordCAUSA
| | - Thomas Kruse
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Yinnian Feng
- Department of GeneticsStanford UniversityStanfordCAUSA
| | - Blanca Lopez Mendez
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Norman Davey
- Division of Cancer BiologyThe Institute of Cancer ResearchLondonUK
| | - Arminja N Kettenbach
- Biochemistry and Cell BiologyGeisel School of Medicine at Dartmouth CollegeHanoverNHUSA
| | - Polly M Fordyce
- Department of BioengineeringStanford UniversityStanfordCAUSA
- Department of GeneticsStanford UniversityStanfordCAUSA
- Sarafan ChEM‐HStanford UniversityStanfordCAUSA
- Chan Zuckerberg BiohubSan FranciscoCAUSA
| | - Jakob Nilsson
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
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10
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DeMarco AG, Dibble MG, Hall MC. Inducible degradation-coupled phosphoproteomics identifies PP2A Rts1 as a novel eisosome regulator. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.24.563668. [PMID: 37961087 PMCID: PMC10634780 DOI: 10.1101/2023.10.24.563668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Reversible protein phosphorylation is an abundant post-translational modification dynamically regulated by opposing kinases and phosphatases. Protein phosphorylation has been extensively studied in cell division, where waves of cyclin-dependent kinase activity, peaking in mitosis, drive the sequential stages of the cell cycle. Here we developed and employed a strategy to specifically probe kinase or phosphatase substrates at desired times or experimental conditions in the model organism Saccharomyces cerevisiae. We combined auxin-inducible degradation (AID) with mass spectrometry-based phosphoproteomics, which allowed us to arrest physiologically normal cultures in mitosis prior to rapid phosphatase degradation and phosphoproteome analysis. Our results revealed that protein phosphatase 2A coupled with its B56 regulatory subunit, Rts1 (PP2ARts1), is involved in dephosphorylation of numerous proteins in mitosis, highlighting the need for phosphatases to selectively maintain certain proteins in a hypophosphorylated state in the face of high mitotic kinase activity. Unexpectedly, we observed elevated phosphorylation at many sites on several subunits of the fungal eisosome complex following rapid Rts1 degradation. Eisosomes are dynamic polymeric assemblies that create furrows in the plasma membrane important in regulating nutrient import, lipid metabolism, and stress responses, among other things. We found that PP2ARts1-mediated dephosphorylation of eisosomes promotes their plasma membrane association and we provide evidence that this regulation impacts eisosome roles in metabolic homeostasis. The combination of rapid, inducible protein degradation with proteomic profiling offers several advantages over common protein disruption methods for characterizing substrates of regulatory enzymes involved in dynamic biological processes.
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Affiliation(s)
- Andrew G. DeMarco
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907
| | - Marcella G. Dibble
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907
| | - Mark C. Hall
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907
- Institute for Cancer Research, Purdue University, West Lafayette, IN, 47907
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11
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Wong HT, Luperchio AM, Riley S, Salamango DJ. Inhibition of ATM-directed antiviral responses by HIV-1 Vif. PLoS Pathog 2023; 19:e1011634. [PMID: 37669285 PMCID: PMC10503699 DOI: 10.1371/journal.ppat.1011634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 09/15/2023] [Accepted: 08/22/2023] [Indexed: 09/07/2023] Open
Abstract
Emerging evidence indicates that HIV-1 hijacks host DNA damage repair (DDR) pathways to facilitate multiple facets of virus replication. Canonically, HIV-1 engages proviral DDR responses through the accessory protein Vpr, which induces constitutive activation of DDR kinases ATM and ATR. However, in response to prolonged DDR signaling, ATM directly induces pro-inflammatory NF-κB signaling and activates multiple members of the TRIM family of antiviral restriction factors, several of which have been previously implicated in antagonizing retroviral and lentiviral replication. Here, we demonstrate that the HIV-1 accessory protein Vif blocks ATM-directed DNA repair processes, activation of NF-κB signaling responses, and TRIM protein phosphorylation. Vif function in ATM antagonism occurs in clinical isolates and in common HIV-1 Group M subtypes/clades circulating globally. Pharmacologic and functional studies combine to suggest that Vif blocks Vpr-directed activation of ATM but not ATR, signifying that HIV-1 utilizes discrete strategies to fine-tune DDR responses that promote virus replication while simultaneously inhibiting immune activation.
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Affiliation(s)
- Hoi Tong Wong
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, United States of America
| | - Adeline M. Luperchio
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, United States of America
| | - Sean Riley
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, United States of America
| | - Daniel J. Salamango
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, United States of America
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12
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Mariano NC, Rusin SF, Nasa I, Kettenbach AN. Inducible Protein Degradation as a Strategy to Identify Phosphoprotein Phosphatase 6 Substrates in RAS-Mutant Colorectal Cancer Cells. Mol Cell Proteomics 2023; 22:100614. [PMID: 37392812 PMCID: PMC10400926 DOI: 10.1016/j.mcpro.2023.100614] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 06/13/2023] [Accepted: 06/28/2023] [Indexed: 07/03/2023] Open
Abstract
Protein phosphorylation is an essential regulatory mechanism that controls most cellular processes, including cell cycle progression, cell division, and response to extracellular stimuli, among many others, and is deregulated in many diseases. Protein phosphorylation is coordinated by the opposing activities of protein kinases and protein phosphatases. In eukaryotic cells, most serine/threonine phosphorylation sites are dephosphorylated by members of the Phosphoprotein Phosphatase (PPP) family. However, we only know for a few phosphorylation sites which specific PPP dephosphorylates them. Although natural compounds such as calyculin A and okadaic acid inhibit PPPs at low nanomolar concentrations, no selective chemical PPP inhibitors exist. Here, we demonstrate the utility of endogenous tagging of genomic loci with an auxin-inducible degron (AID) as a strategy to investigate specific PPP signaling. Using Protein Phosphatase 6 (PP6) as an example, we demonstrate how rapidly inducible protein degradation can be employed to identify dephosphorylation sites and elucidate PP6 biology. Using genome editing, we introduce AID-tags into each allele of the PP6 catalytic subunit (PP6c) in DLD-1 cells expressing the auxin receptor Tir1. Upon rapid auxin-induced degradation of PP6c, we perform quantitative mass spectrometry-based proteomics and phosphoproteomics to identify PP6 substrates in mitosis. PP6 is an essential enzyme with conserved roles in mitosis and growth signaling. Consistently, we identify candidate PP6c-dependent dephosphorylation sites on proteins implicated in coordinating the mitotic cell cycle, cytoskeleton, gene expression, and mitogen-activated protein kinase (MAPK) and Hippo signaling. Finally, we demonstrate that PP6c opposes the activation of large tumor suppressor 1 (LATS1) by dephosphorylating Threonine 35 (T35) on Mps One Binder (MOB1), thereby blocking the interaction of MOB1 and LATS1. Our analyses highlight the utility of combining genome engineering, inducible degradation, and multiplexed phosphoproteomics to investigate signaling by individual PPPs on a global level, which is currently limited by the lack of tools for specific interrogation.
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Affiliation(s)
- Natasha C Mariano
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Scott F Rusin
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Isha Nasa
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA; Dartmouth Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA
| | - Arminja N Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA; Dartmouth Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA.
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13
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Nguyen H, Kettenbach AN. Substrate and phosphorylation site selection by phosphoprotein phosphatases. Trends Biochem Sci 2023; 48:713-725. [PMID: 37173206 PMCID: PMC10523993 DOI: 10.1016/j.tibs.2023.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 04/11/2023] [Accepted: 04/13/2023] [Indexed: 05/15/2023]
Abstract
Dynamic protein phosphorylation and dephosphorylation are essential regulatory mechanisms that ensure proper cellular signaling and biological functions. Deregulation of either reaction has been implicated in several human diseases. Here, we focus on the mechanisms that govern the specificity of the dephosphorylation reaction. Most cellular serine/threonine dephosphorylation is catalyzed by 13 highly conserved phosphoprotein phosphatase (PPP) catalytic subunits, which form hundreds of holoenzymes by binding to regulatory and scaffolding subunits. PPP holoenzymes recognize phosphorylation site consensus motifs and interact with short linear motifs (SLiMs) or structural elements distal to the phosphorylation site. We review recent advances in understanding the mechanisms of PPP site-specific dephosphorylation preference and substrate recruitment and highlight examples of their interplay in the regulation of cell division.
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Affiliation(s)
- Hieu Nguyen
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Arminja N Kettenbach
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA; Dartmouth Cancer Center, Lebanon, NH 03756, USA.
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14
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Heidari B, Nemie-Feyissa D, Lillo C. Distinct Clades of Protein Phosphatase 2A Regulatory B'/B56 Subunits Engage in Different Physiological Processes. Int J Mol Sci 2023; 24:12255. [PMID: 37569631 PMCID: PMC10418862 DOI: 10.3390/ijms241512255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/13/2023] Open
Abstract
Protein phosphatase 2A (PP2A) is a strongly conserved and major protein phosphatase in all eukaryotes. The canonical PP2A complex consists of a catalytic (C), scaffolding (A), and regulatory (B) subunit. Plants have three groups of evolutionary distinct B subunits: B55, B' (B56), and B''. Here, the Arabidopsis B' group is reviewed and compared with other eukaryotes. Members of the B'α/B'β clade are especially important for chromatid cohesion, and dephosphorylation of transcription factors that mediate brassinosteroid (BR) signaling in the nucleus. Other B' subunits interact with proteins at the cell membrane to dampen BR signaling or harness immune responses. The transition from vegetative to reproductive phase is influenced differentially by distinct B' subunits; B'α and B'β being of little importance, whereas others (B'γ, B'ζ, B'η, B'θ, B'κ) promote transition to flowering. Interestingly, the latter B' subunits have three motifs in a conserved manner, i.e., two docking sites for protein phosphatase 1 (PP1), and a POLO consensus phosphorylation site between these motifs. This supports the view that a conserved PP1-PP2A dephosphorelay is important in a variety of signaling contexts throughout eukaryotes. A profound understanding of these regulators may help in designing future crops and understand environmental issues.
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Affiliation(s)
| | | | - Cathrine Lillo
- IKBM, Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, 4036 Stavanger, Norway; (B.H.); (D.N.-F.)
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15
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Ghosh S, Isma J, Mazzeo L, Toniolo A, Simon C, Dotto GP. Nuclear lamin A/C phosphorylation by loss of Androgen Receptor is a global determinant of cancer-associated fibroblast activation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.28.546870. [PMID: 37425957 PMCID: PMC10327063 DOI: 10.1101/2023.06.28.546870] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Alterations of nuclear structure and function, and associated impact on gene transcription, are a hallmark of cancer cells. Little is known of these alterations in Cancer-Associated Fibroblasts (CAFs), a key component of the tumor stroma. Here we show that loss of androgen receptor (AR), which triggers early steps of CAF activation in human dermal fibroblasts (HDFs), leads to nuclear membrane alterations and increased micronuclei formation, which are unlinked from induction of cellular senescence. Similar alterations occur in fully established CAFs, which are overcome by restored AR function. AR associates with nuclear lamin A/C and loss of AR results in a substantially increased lamin A/C nucleoplasmic redistribution. Mechanistically, AR functions as a bridge between lamin A/C with the protein phosphatase PPP1. In parallel with a decreased lamin-PPP1 association, AR loss results in a marked increase of lamin A/C phosphorylation at Ser 301, which is also a feature of CAFs. Phosphorylated lamin A/C at Ser 301 binds to the transcription promoter regulatory region of several CAF effector genes, which are upregulated due to the loss of AR. More directly, expression of a lamin A/C Ser301 phosphomimetic mutant alone is sufficient to convert normal fibroblasts into tumor-promoting CAFs of the myofibroblast subtype, without an impact on senescence. These findings highlight the pivotal role of the AR-lamin A/C-PPP1 axis and lamin A/C phosphorylation at Ser 301 in driving CAF activation.
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Affiliation(s)
- Soumitra Ghosh
- Personalised Cancer Prevention Unit, ORL service, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
- Department of Immunobiology, University of Lausanne, Epalinges, Switzerland
| | - Jovan Isma
- Department of Immunobiology, University of Lausanne, Epalinges, Switzerland
| | - Luigi Mazzeo
- Department of Immunobiology, University of Lausanne, Epalinges, Switzerland
| | - Annagiada Toniolo
- Department of Immunobiology, University of Lausanne, Epalinges, Switzerland
| | - Christian Simon
- Personalised Cancer Prevention Unit, ORL service, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
- International Cancer Prevention Institute, Epalinges, Switzerland
| | - G. Paolo Dotto
- Personalised Cancer Prevention Unit, ORL service, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
- Department of Immunobiology, University of Lausanne, Epalinges, Switzerland
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA
- International Cancer Prevention Institute, Epalinges, Switzerland
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16
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Mariano NC, Rusin SF, Nasa I, Kettenbach AN. Inducible protein degradation as a strategy to identify Phosphoprotein Phosphatase 6 substrates in RAS-mutant colorectal cancer cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.25.534211. [PMID: 36993243 PMCID: PMC10055397 DOI: 10.1101/2023.03.25.534211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Protein phosphorylation is an essential regulatory mechanism that controls most cellular processes, including cell cycle progression, cell division, and response to extracellular stimuli, among many others, and is deregulated in many diseases. Protein phosphorylation is coordinated by the opposing activities of protein kinases and protein phosphatases. In eukaryotic cells, most serine/threonine phosphorylation sites are dephosphorylated by members of the Phosphoprotein Phosphatase (PPP) family. However, we only know for a few phosphorylation sites which specific PPP dephosphorylates them. Although natural compounds such as calyculin A and okadaic acid inhibit PPPs at low nanomolar concentrations, no selective chemical PPP inhibitors exist. Here, we demonstrate the utility of endogenous tagging of genomic loci with an auxin-inducible degron (AID) as a strategy to investigate specific PPP signaling. Using Protein Phosphatase 6 (PP6) as an example, we demonstrate how rapidly inducible protein degradation can be employed to identify dephosphorylation SITES and elucidate PP6 biology. Using genome editing, we introduce AID-tags into each allele of the PP6 catalytic subunit (PP6c) in DLD-1 cells expressing the auxin receptor Tir1. Upon rapid auxin-induced degradation of PP6c, we perform quantitative mass spectrometry-based proteomics and phosphoproteomics to identify PP6 substrates in mitosis. PP6 is an essential enzyme with conserved roles in mitosis and growth signaling. Consistently, we identify candidate PP6c-dependent phosphorylation sites on proteins implicated in coordinating the mitotic cell cycle, cytoskeleton, gene expression, and mitogen-activated protein kinase (MAPK) and Hippo signaling. Finally, we demonstrate that PP6c opposes the activation of large tumor suppressor 1 (LATS1) by dephosphorylating Threonine 35 (T35) on Mps One Binder (MOB1), thereby blocking the interaction of MOB1 and LATS1. Our analyses highlight the utility of combining genome engineering, inducible degradation, and multiplexed phosphoproteomics to investigate signaling by individual PPPs on a global level, which is currently limited by the lack of tools for specific interrogation.
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17
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Remsburg CM, Konrad KD, Song JL. RNA localization to the mitotic spindle is essential for early development and is regulated by kinesin-1 and dynein. J Cell Sci 2023; 136:jcs260528. [PMID: 36751992 PMCID: PMC10038151 DOI: 10.1242/jcs.260528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 01/27/2023] [Indexed: 02/09/2023] Open
Abstract
Mitosis is a fundamental and highly regulated process that acts to faithfully segregate chromosomes into two identical daughter cells. Localization of gene transcripts involved in mitosis to the mitotic spindle might be an evolutionarily conserved mechanism to ensure that mitosis occurs in a timely manner. We identified many RNA transcripts that encode proteins involved in mitosis localized at the mitotic spindles in dividing sea urchin embryos and mammalian cells. Disruption of microtubule polymerization, kinesin-1 or dynein results in lack of spindle localization of these transcripts in the sea urchin embryo. Furthermore, results indicate that the cytoplasmic polyadenylation element (CPE) within the 3'UTR of the Aurora B transcript, a recognition sequence for CPEB, is essential for RNA localization to the mitotic spindle in the sea urchin embryo. Blocking this sequence results in arrested development during early cleavage stages, suggesting that RNA localization to the mitotic spindle might be a regulatory mechanism of cell division that is important for early development.
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Affiliation(s)
- Carolyn M. Remsburg
- University of Delaware, Department of Biological Sciences, Newark, DE 19716, USA
| | - Kalin D. Konrad
- University of Delaware, Department of Biological Sciences, Newark, DE 19716, USA
| | - Jia L. Song
- University of Delaware, Department of Biological Sciences, Newark, DE 19716, USA
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18
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Kong N, Liu Z, Chan YW. RIF1 suppresses the formation of single-stranded ultrafine anaphase bridges via protein phosphatase 1. Cell Rep 2023; 42:112032. [PMID: 36719798 DOI: 10.1016/j.celrep.2023.112032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 11/07/2022] [Accepted: 01/09/2023] [Indexed: 01/31/2023] Open
Abstract
Resolution of ultrafine anaphase bridges (UFBs) must be completed before cytokinesis to ensure sister-chromatid disjunction. RIF1 is involved in UFB resolution by a mechanism that is not yet clear. Here, we show that RIF1 functions in mitosis to inhibit the formation of 53BP1 nuclear bodies and micronuclei. Meanwhile, RIF1 localizes on PICH-coated double-stranded UFBs but not on RPA-coated single-stranded UFBs. Depletion of RIF1 leads to an elevated level of RPA-coated UFBs, in a BLM-dependent manner. RIF1 interacts with all three isoforms of protein phosphatase 1 (PP1) at its CI domain in anaphase when CDK1 activity declines. CDK1 negatively regulates RIF1-PP1 interaction via the CIII domain of RIF1. Importantly, depletion of PP1 phenocopies RIF1 depletion, and phosphorylation-resistant mutant of PICH shows reduced interaction with the BTR complex and bypasses the need of RIF1 in preventing the formation of single-stranded UFBs. Overall, our data show that PP1 is the effector of RIF1 in UFB resolution.
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Affiliation(s)
- Nannan Kong
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Zeyuan Liu
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Ying Wai Chan
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
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19
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Yuki R, Ikeda Y, Yasutake R, Saito Y, Nakayama Y. SH2D4A promotes centrosome maturation to support spindle microtubule formation and mitotic progression. Sci Rep 2023; 13:2067. [PMID: 36739326 PMCID: PMC9899277 DOI: 10.1038/s41598-023-29362-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 02/02/2023] [Indexed: 02/06/2023] Open
Abstract
Mitotic progression requires the precise formation of spindle microtubules based on mature centrosomes. During the G2/M transition, centrosome maturation progresses, and associated microtubules bundle to form mitotic spindle fibers and capture the chromosomes for alignment at the cell equator. Mitotic kinases-induced phosphorylation signaling is necessary for these processes. Here, we identified SH2 domain-containing protein 4A (SH2D4A/PPP1R38) as a new mitotic regulator. SH2D4A knockdown delays mitotic progression. The time-lapse imaging analysis showed that SH2D4A specifically contributes to the alignment of chromosomes. The cold treatment assay and microtubule regrowth assay indicated that SH2D4A promotes microtubule nucleation to support kinetochore-microtubule attachment. This may be due to the centrosome maturation by SH2D4A via centrosomal recruitment of pericentriolar material (PCM) such as cep192, γ-tubulin, and PLK1. SH2D4A was found to be a negative regulator of PP1 phosphatase. Consistently, treatment with a PP1 inhibitor rescues SH2D4A-knockdown-induced phenotypes, including the microtubule nucleation and centrosomal recruitment of active PLK1. These results suggest that SH2D4A is involved in PCM recruitment to centrosomes and centrosome maturation through attenuation of PP1 phosphatases, accelerating the spindle formation and supporting mitotic progression.
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Affiliation(s)
- Ryuzaburo Yuki
- Department of Biochemistry & Molecular Biology, Kyoto Pharmaceutical University, 5 Misasagi-Nakauchi-cho, Yamashina-ku, Kyoto, 607-8414, Japan.
| | - Yuki Ikeda
- Department of Biochemistry & Molecular Biology, Kyoto Pharmaceutical University, 5 Misasagi-Nakauchi-cho, Yamashina-ku, Kyoto, 607-8414, Japan
| | - Ryuji Yasutake
- Department of Biochemistry & Molecular Biology, Kyoto Pharmaceutical University, 5 Misasagi-Nakauchi-cho, Yamashina-ku, Kyoto, 607-8414, Japan
| | - Youhei Saito
- Department of Biochemistry & Molecular Biology, Kyoto Pharmaceutical University, 5 Misasagi-Nakauchi-cho, Yamashina-ku, Kyoto, 607-8414, Japan
| | - Yuji Nakayama
- Department of Biochemistry & Molecular Biology, Kyoto Pharmaceutical University, 5 Misasagi-Nakauchi-cho, Yamashina-ku, Kyoto, 607-8414, Japan.
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20
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Rocha H, Simões PA, Budrewicz J, Lara-Gonzalez P, Carvalho AX, Dumont J, Desai A, Gassmann R. Nuclear-enriched protein phosphatase 4 ensures outer kinetochore assembly prior to nuclear dissolution. J Cell Biol 2023; 222:213846. [PMID: 36719399 PMCID: PMC9930252 DOI: 10.1083/jcb.202208154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 12/15/2022] [Accepted: 01/05/2023] [Indexed: 02/01/2023] Open
Abstract
A landmark event in the transition from interphase to mitosis in metazoans is nuclear envelope breakdown (NEBD). Important mitotic events occur prior to NEBD, including condensation of replicated chromosomes and assembly of kinetochores to rapidly engage spindle microtubules. Here, we show that nuclear-enriched protein phosphatase 4 (PP4) ensures robust assembly of the microtubule-coupling outer kinetochore prior to NEBD. In the absence of PP4, chromosomes exhibit extended monopolar orientation after NEBD and subsequently mis-segregate. A secondary consequence of diminished outer kinetochore assembly is defective sister chromatid resolution. After NEBD, a cytoplasmic activity compensates for PP4 loss, leading to outer kinetochore assembly and recovery of chromosomes from monopolar orientation to significant bi-orientation. The Ndc80-Ska microtubule-binding module of the outer kinetochore is required for this recovery. PP4 associates with the inner kinetochore protein CENP-C; however, disrupting the PP4-CENP-C interaction does not perturb chromosome segregation. These results establish that PP4-dependent outer kinetochore assembly prior to NEBD is critical for timely and proper engagement of chromosomes with spindle microtubules.
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Affiliation(s)
- Helder Rocha
- https://ror.org/05qpmg879Instituto de Investigação e Inovação em Saúde – i3S, Universidade do Porto, Porto, Portugal,Instituto de Biologia Molecular e Celular – IBMC, Universidade do Porto, Porto, Portugal
| | - Patrícia A. Simões
- https://ror.org/05qpmg879Instituto de Investigação e Inovação em Saúde – i3S, Universidade do Porto, Porto, Portugal,Instituto de Biologia Molecular e Celular – IBMC, Universidade do Porto, Porto, Portugal
| | - Jacqueline Budrewicz
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, USA,Division of Biological Sciences, Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Pablo Lara-Gonzalez
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, USA,Division of Biological Sciences, Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Ana Xavier Carvalho
- https://ror.org/05qpmg879Instituto de Investigação e Inovação em Saúde – i3S, Universidade do Porto, Porto, Portugal,Instituto de Biologia Molecular e Celular – IBMC, Universidade do Porto, Porto, Portugal
| | - Julien Dumont
- https://ror.org/02c5gc203Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Arshad Desai
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, USA,Division of Biological Sciences, Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Reto Gassmann
- https://ror.org/05qpmg879Instituto de Investigação e Inovação em Saúde – i3S, Universidade do Porto, Porto, Portugal,Instituto de Biologia Molecular e Celular – IBMC, Universidade do Porto, Porto, Portugal
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21
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Villarroya‐Beltri C, Martins AFB, García A, Giménez D, Zarzuela E, Novo M, del Álamo C, González‐Martínez J, Bonel‐Pérez GC, Díaz I, Guillamot M, Chiesa M, Losada A, Graña‐Castro O, Rovira M, Muñoz J, Salazar‐Roa M, Malumbres M. Mammalian CDC14 phosphatases control exit from stemness in pluripotent cells. EMBO J 2023; 42:e111251. [PMID: 36326833 PMCID: PMC9811616 DOI: 10.15252/embj.2022111251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 11/06/2022] Open
Abstract
Maintenance of stemness is tightly linked to cell cycle regulation through protein phosphorylation by cyclin-dependent kinases (CDKs). However, how this process is reversed during differentiation is unknown. We report here that exit from stemness and differentiation of pluripotent cells along the neural lineage are controlled by CDC14, a CDK-counteracting phosphatase whose function in mammals remains obscure. Lack of the two CDC14 family members, CDC14A and CDC14B, results in deficient development of the neural system in the mouse and impairs neural differentiation from embryonic stem cells (ESCs). Mechanistically, CDC14 directly dephosphorylates specific proline-directed Ser/Thr residues of undifferentiated embryonic transcription Factor 1 (UTF1) during the exit from stemness, triggering its proteasome-dependent degradation. Multiomic single-cell analysis of transcription and chromatin accessibility in differentiating ESCs suggests that increased UTF1 levels in the absence of CDC14 prevent the proper firing of bivalent promoters required for differentiation. CDC14 phosphatases are dispensable for mitotic exit, suggesting that CDC14 phosphatases have evolved to control stemness rather than cell cycle exit and establish the CDK-CDC14 axis as a critical molecular switch for linking cell cycle regulation and self-renewal.
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Affiliation(s)
| | - Ana Filipa B Martins
- Cell Division and Cancer groupSpanish National Cancer Research Centre (CNIO)MadridSpain
| | - Alejandro García
- Cell Division and Cancer groupSpanish National Cancer Research Centre (CNIO)MadridSpain
| | | | | | - Mónica Novo
- Cell Division and Cancer groupSpanish National Cancer Research Centre (CNIO)MadridSpain
| | - Cristina del Álamo
- Cell Division and Cancer groupSpanish National Cancer Research Centre (CNIO)MadridSpain
| | | | - Gloria C Bonel‐Pérez
- Cell Division and Cancer groupSpanish National Cancer Research Centre (CNIO)MadridSpain
| | - Irene Díaz
- Cell Division and Cancer groupSpanish National Cancer Research Centre (CNIO)MadridSpain
| | - María Guillamot
- Cell Division and Cancer groupSpanish National Cancer Research Centre (CNIO)MadridSpain
| | - Massimo Chiesa
- Cell Division and Cancer groupSpanish National Cancer Research Centre (CNIO)MadridSpain
| | - Ana Losada
- Chromosome Dynamics groupCNIOMadridSpain
| | - Osvaldo Graña‐Castro
- Bioinformatics UnitCNIOMadridSpain
- Present address:
Department of Basic Medical Sciences, Institute of Applied Molecular Medicine (IMMA‐Nemesio Díez), School of MedicineSan Pablo‐CEU University, CEU UniversitiesBoadilla del MonteSpain
| | - Meritxell Rovira
- Department of Physiological Science, School of Medicine, L'Hospitalet de LlobregatUniversity of Barcelona (UB)BarcelonaSpain
- Pancreas Regeneration: Pancreatic Progenitors and Their Niche Group, Regenerative Medicine Program, P‐CMR[C]Institut d'Investigació Biomèdica de Bellvitge—IDIBELL, L'Hospitalet de LlobregatBarcelonaSpain
| | | | - María Salazar‐Roa
- Cell Division and Cancer groupSpanish National Cancer Research Centre (CNIO)MadridSpain
- Present address:
Advanced Therapies and Cancer Group, Faculty of BiologyComplutense UniversityMadridSpain
| | - Marcos Malumbres
- Cell Division and Cancer groupSpanish National Cancer Research Centre (CNIO)MadridSpain
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22
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Barros-Carvalho A, Morais-de-Sá E. Balancing cell polarity PARts through dephosphorylation. J Cell Biol 2022; 221:e202208008. [PMID: 36121422 PMCID: PMC9486083 DOI: 10.1083/jcb.202208008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
How cells spatially organize their plasma membrane, cytoskeleton, and cytoplasm remains a central question for cell biologists. In this issue of JCB, Calvi et al. (2022. J. Cell Biol.https://doi.org/10.1083/jcb.202201048) identify PP1 phosphatases as key regulators of C. elegans anterior-posterior polarity, by counterbalancing aPKC-mediated phosphorylation of PAR-2.
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Affiliation(s)
- André Barros-Carvalho
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Eurico Morais-de-Sá
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
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23
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Kokot T, Köhn M. Emerging insights into serine/threonine-specific phosphoprotein phosphatase function and selectivity. J Cell Sci 2022; 135:277104. [DOI: 10.1242/jcs.259618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
ABSTRACT
Protein phosphorylation on serine and threonine residues is a widely distributed post-translational modification on proteins that acts to regulate their function. Phosphoprotein phosphatases (PPPs) contribute significantly to a plethora of cellular functions through the accurate dephosphorylation of phosphorylated residues. Most PPPs accomplish their purpose through the formation of complex holoenzymes composed of a catalytic subunit with various regulatory subunits. PPP holoenzymes then bind and dephosphorylate substrates in a highly specific manner. Despite the high prevalence of PPPs and their important role for cellular function, their mechanisms of action in the cell are still not well understood. Nevertheless, substantial experimental advancements in (phospho-)proteomics, structural and computational biology have contributed significantly to a better understanding of PPP biology in recent years. This Review focuses on recent approaches and provides an overview of substantial new insights into the complex mechanism of PPP holoenzyme regulation and substrate selectivity.
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Affiliation(s)
- Thomas Kokot
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
| | - Maja Köhn
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
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24
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Zhu K, Cai Y, Si X, Ye Z, Gao Y, Liu C, Wang R, Ma Z, Zhu H, Zhang L, Li S, Zhang H, Yue J. The phosphorylation and dephosphorylation switch of VCP/p97 regulates the architecture of centrosome and spindle. Cell Death Differ 2022; 29:2070-2088. [PMID: 35430615 PMCID: PMC9525716 DOI: 10.1038/s41418-022-01000-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/30/2022] [Accepted: 03/28/2022] [Indexed: 01/27/2023] Open
Abstract
The proper orientation of centrosome and spindle is essential for genome stability; however, the mechanism that governs these processes remains elusive. Here, we demonstrated that polo-like kinase 1 (Plk1), a key mitotic kinase, phosphorylates residue Thr76 in VCP/p97 (an AAA-ATPase), at the centrosome from prophase to anaphase. This phosphorylation process recruits VCP to the centrosome and in this way, it regulates centrosome orientation. VCP exhibits strong co-localization with Eg5 (a mitotic kinesin motor), at the mitotic spindle, and the dephosphorylation of Thr76 in VCP is required for the enrichment of both VCP and Eg5 at the spindle, thus ensuring proper spindle architecture and chromosome segregation. We also showed that the phosphatase, PTEN, is responsible for the dephosphorylation of Thr76 in VCP; when PTEN was knocked down, the normal spread of VCP from the centrosome to the spindle was abolished. Cryo-EM structures of VCPT76A and VCPT76E, which represent dephosphorylated and phosphorylated states of VCP, respectively, revealed that the Thr76 phosphorylation modulates VCP by altering the inter-domain and inter-subunit interactions, and ultimately the nucleotide-binding pocket conformation. Interestingly, the tumor growth in nude mice implanted with VCPT76A-reconstituted cancer cells was significantly slower when compared with those implanted with VCPWT-reconstituted cancer cells. Collectively, our findings demonstrate that the phosphorylation and dephosphorylation switch of VCP regulates the architecture of centrosome and spindle for faithful chromosome segregation.
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Affiliation(s)
- Kaiyuan Zhu
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Yang Cai
- Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Xiaotong Si
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Zuodong Ye
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Yuanzhu Gao
- Department of Biology, SUSTech Cryo-EM Centre, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Chuang Liu
- Department of Biology, SUSTech Cryo-EM Centre, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Rui Wang
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Zhibin Ma
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Huazhang Zhu
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Liang Zhang
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Shengjin Li
- The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
| | - Hongmin Zhang
- Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Jianbo Yue
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China.
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China.
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25
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Han KJ, Mikalayeva V, Gerber SA, Kettenbach AN, Skeberdis VA, Prekeris R. Rab40c regulates focal adhesions and PP6 activity by controlling ANKRD28 ubiquitylation. Life Sci Alliance 2022; 5:5/9/e202101346. [PMID: 35512830 PMCID: PMC9070665 DOI: 10.26508/lsa.202101346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 04/26/2022] [Accepted: 04/26/2022] [Indexed: 11/24/2022] Open
Abstract
Rab40c is a SOCS box-containing protein which binds Cullin5 to form a ubiquitin E3 ligase complex (Rab40c/CRL5) to regulate protein ubiquitylation. However, the exact functions of Rab40c remain to be determined, and what proteins are the targets of Rab40c-Cullin5-mediated ubiquitylation in mammalian cells are unknown. Here we showed that in migrating MDA-MB-231 cells Rab40c regulates focal adhesion's number, size, and distribution. Mechanistically, we found that Rab40c binds the protein phosphatase 6 (PP6) complex and ubiquitylates one of its subunits, ankyrin repeat domain 28 (ANKRD28), thus leading to its lysosomal degradation. Furthermore, we identified that phosphorylation of FAK and MOB1 is decreased in Rab40c knock-out cells, which may contribute to focal adhesion site regulation by Rab40c. Thus, we propose a model where Rab40c/CRL5 regulates ANKRD28 ubiquitylation and degradation, leading to a decrease in PP6 activity, which ultimately affects FAK and Hippo pathway signaling to alter focal adhesion dynamics.
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Affiliation(s)
- Ke-Jun Han
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Valeryia Mikalayeva
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Scott A Gerber
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA.,Norris Cotton Cancer Center, Lebanon, NH, USA
| | - Arminja N Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA.,Norris Cotton Cancer Center, Lebanon, NH, USA
| | - Vytenis A Skeberdis
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Rytis Prekeris
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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26
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Luperchio AM, Jónsson SR, Salamango DJ. Evolutionary Conservation of PP2A Antagonism and G2/M Cell Cycle Arrest in Maedi-Visna Virus Vif. Viruses 2022; 14:1701. [PMID: 36016323 PMCID: PMC9413702 DOI: 10.3390/v14081701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/29/2022] [Accepted: 07/29/2022] [Indexed: 11/18/2022] Open
Abstract
The canonical function of lentiviral Vif proteins is to counteract the mutagenic potential of APOBEC3 antiviral restriction factors. However, recent studies have discovered that Vif proteins from diverse HIV-1 and simian immunodeficiency virus (SIV) isolates degrade cellular B56 phosphoregulators to remodel the host phosphoproteome and induce G2/M cell cycle arrest. Here, we evaluate the conservation of this activity among non-primate lentiviral Vif proteins using fluorescence-based degradation assays and demonstrate that maedi-visna virus (MVV) Vif efficiently degrades all five B56 family members. Testing an extensive panel of single amino acid substitution mutants revealed that MVV Vif recognizes B56 proteins through a conserved network of electrostatic interactions. Furthermore, experiments using genetic and pharmacologic approaches demonstrate that degradation of B56 proteins requires the cellular cofactor cyclophilin A. Lastly, MVV Vif-mediated depletion of B56 proteins induces a potent G2/M cell cycle arrest phenotype. Therefore, remodeling of the cellular phosphoproteome and induction of G2/M cell cycle arrest are ancient and conserved functions of lentiviral Vif proteins, which suggests that they are advantageous for lentiviral pathogenesis.
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Affiliation(s)
- Adeline M. Luperchio
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, NY 11794, USA;
| | - Stefán R. Jónsson
- Institute for Experimental Pathology, University of Iceland, Keldur, 112 Reykjavik, Iceland;
| | - Daniel J. Salamango
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, NY 11794, USA;
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27
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Vit G, Duro J, Rajendraprasad G, Hertz EPT, Holland LKK, Weisser MB, McEwan BC, Lopez‐Mendez B, Sotelo‐Parrilla P, Jeyaprakash AA, Montoya G, Mailand N, Maeda K, Kettenbach A, Barisic M, Nilsson J. Chemogenetic profiling reveals PP2A-independent cytotoxicity of proposed PP2A activators iHAP1 and DT-061. EMBO J 2022; 41:e110611. [PMID: 35695070 PMCID: PMC9289710 DOI: 10.15252/embj.2022110611] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 05/18/2022] [Accepted: 05/19/2022] [Indexed: 01/01/2023] Open
Abstract
Protein phosphatase 2A (PP2A) is an abundant phosphoprotein phosphatase that acts as a tumor suppressor. For this reason, compounds able to activate PP2A are attractive anticancer agents. The compounds iHAP1 and DT-061 have recently been reported to selectively stabilize specific PP2A-B56 complexes to mediate cell killing. We were unable to detect direct effects of iHAP1 and DT-061 on PP2A-B56 activity in biochemical assays and composition of holoenzymes. Therefore, we undertook genome-wide CRISPR-Cas9 synthetic lethality screens to uncover biological pathways affected by these compounds. We found that knockout of mitotic regulators is synthetic lethal with iHAP1 while knockout of endoplasmic reticulum (ER) and Golgi components is synthetic lethal with DT-061. Indeed we showed that iHAP1 directly blocks microtubule assembly both in vitro and in vivo and thus acts as a microtubule poison. In contrast, DT-061 disrupts both the Golgi apparatus and the ER and lipid synthesis associated with these structures. Our work provides insight into the biological pathways perturbed by iHAP1 and DT-061 causing cellular toxicity and argues that these compounds cannot be used for dissecting PP2A-B56 biology.
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Affiliation(s)
- Gianmatteo Vit
- Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Joana Duro
- Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Girish Rajendraprasad
- Cell Division and CytoskeletonDanish Cancer Society Research CenterCopenhagenDenmark
| | - Emil P T Hertz
- Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Lya Katrine Kauffeldt Holland
- Cell Death and Metabolism UnitCenter for Autophagy, Recycling and Disease (CARD)Danish Cancer Society Research Center (DCRC)CopenhagenDenmark
| | - Melanie Bianca Weisser
- Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Brennan C McEwan
- Department of Biochemistry and Cell BiologyGeisel School of Medicine at Dartmouth CollegeHanoverNHUSA,Norris Cotton Cancer CenterLebanonNHUSA
| | - Blanca Lopez‐Mendez
- Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | | | | | - Guillermo Montoya
- Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Niels Mailand
- Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Kenji Maeda
- Cell Death and Metabolism UnitCenter for Autophagy, Recycling and Disease (CARD)Danish Cancer Society Research Center (DCRC)CopenhagenDenmark
| | - Arminja Kettenbach
- Department of Biochemistry and Cell BiologyGeisel School of Medicine at Dartmouth CollegeHanoverNHUSA
| | - Marin Barisic
- Cell Division and CytoskeletonDanish Cancer Society Research CenterCopenhagenDenmark,Department of Cellular and Molecular MedicineFaculty of Health SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Jakob Nilsson
- Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
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28
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Vukušić K, Tolić IM. Polar Chromosomes—Challenges of a Risky Path. Cells 2022; 11:cells11091531. [PMID: 35563837 PMCID: PMC9101661 DOI: 10.3390/cells11091531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/28/2022] [Accepted: 04/30/2022] [Indexed: 12/29/2022] Open
Abstract
The process of chromosome congression and alignment is at the core of mitotic fidelity. In this review, we discuss distinct spatial routes that the chromosomes take to align during prometaphase, which are characterized by distinct biomolecular requirements. Peripheral polar chromosomes are an intriguing case as their alignment depends on the activity of kinetochore motors, polar ejection forces, and a transition from lateral to end-on attachments to microtubules, all of which can result in the delayed alignment of these chromosomes. Due to their undesirable position close to and often behind the spindle pole, these chromosomes may be particularly prone to the formation of erroneous kinetochore-microtubule interactions, such as merotelic attachments. To prevent such errors, the cell employs intricate mechanisms to preposition the spindle poles with respect to chromosomes, ensure the formation of end-on attachments in restricted spindle regions, repair faulty attachments by error correction mechanisms, and delay segregation by the spindle assembly checkpoint. Despite this protective machinery, there are several ways in which polar chromosomes can fail in alignment, mis-segregate, and lead to aneuploidy. In agreement with this, polar chromosomes are present in certain tumors and may even be involved in the process of tumorigenesis.
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29
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Gillani SQ, Reshi I, Nabi N, Un Nisa M, Sarwar Z, Bhat S, Roberts TM, Higgins JMG, Andrabi S. PCTAIRE1 promotes mitotic progression and resistance against antimitotic and apoptotic signals. J Cell Sci 2022; 135:jcs258831. [PMID: 35044463 PMCID: PMC8918779 DOI: 10.1242/jcs.258831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 12/29/2021] [Indexed: 10/24/2022] Open
Abstract
PCTAIRE1 (also known as CDK16) is a serine-threonine kinase implicated in physiological processes like neuronal development, vesicle trafficking, spermatogenesis and cell proliferation. However, its exact role in cell division remains unclear. In this study, using a library screening approach, we identified PCTAIRE1 among several candidates that resisted mitotic arrest and mitotic cell death induced by polyomavirus small T (PolST) expression in mammalian cells. Our study showed that PCTAIRE1 is a mitotic kinase that localizes at centrosomes during G2 and at spindle poles as the cells enter mitosis, and then at the midbody during cytokinesis. We also report that PCTAIRE1 protein levels fluctuate through the cell cycle and reach their peak at mitosis, during which there is an increase in PCTAIRE1 phosphorylation as well. Interestingly, knockdown of PCTAIRE1 resulted in aberrant mitosis by interfering with spindle assembly and chromosome segregation. Further, we found that PCTAIRE1 promotes resistance of cancer cells to antimitotic drugs, and this underscores the significance of PCTAIRE1 as a potential drug target for overcoming chemotherapeutic resistance. Taken together, these studies establish PCTAIRE1 as a critical mediator of mitotic progression and highlight its role in chemotherapeutic resistance. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
| | - Irfana Reshi
- Department of Biotechnology, University of Kashmir, Srinagar 190006, India
| | - Nusrat Nabi
- Department of Biochemistry, University of Kashmir, Srinagar 190006, India
| | - Misbah Un Nisa
- Department of Biochemistry, University of Kashmir, Srinagar 190006, India
| | - Zarka Sarwar
- Department of Biochemistry, University of Kashmir, Srinagar 190006, India
| | - Sameer Bhat
- Department of Biotechnology, University of Kashmir, Srinagar 190006, India
| | - Thomas M. Roberts
- Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Jonathan M. G. Higgins
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University,Newcastle upon Tyne NE2 4HH, UK
| | - Shaida Andrabi
- Department of Biochemistry, University of Kashmir, Srinagar 190006, India
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30
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Song X, Conti D, Shrestha RL, Braun D, Draviam VM. Counteraction between Astrin-PP1 and Cyclin-B-CDK1 pathways protects chromosome-microtubule attachments independent of biorientation. Nat Commun 2021; 12:7010. [PMID: 34853300 PMCID: PMC8636589 DOI: 10.1038/s41467-021-27131-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 11/02/2021] [Indexed: 02/08/2023] Open
Abstract
Defects in chromosome-microtubule attachment can cause chromosomal instability (CIN), frequently associated with infertility and aggressive cancers. Chromosome-microtubule attachment is mediated by a large macromolecular structure, the kinetochore. Sister kinetochores of each chromosome are pulled by microtubules from opposing spindle-poles, a state called biorientation which prevents chromosome missegregation. Kinetochore-microtubule attachments that lack the opposing-pull are detached by Aurora-B/Ipl1. It is unclear how mono-oriented attachments that precede biorientation are spared despite the lack of opposing-pull. Using an RNAi-screen, we uncover a unique role for the Astrin-SKAP complex in protecting mono-oriented attachments. We provide evidence of domains in the microtubule-end associated protein that sense changes specific to end-on kinetochore-microtubule attachments and assemble an outer-kinetochore crescent to stabilise attachments. We find that Astrin-PP1 and Cyclin-B-CDK1 pathways counteract each other to preserve mono-oriented attachments. Thus, CIN prevention pathways are not only surveying attachment defects but also actively recognising and stabilising mature attachments independent of biorientation. Chromosome instability frequently occurs due to issues with chromosome-microtubule attachments. Here the authors show that the Astrin-PP1 and Cyclin-B-CDK1 pathways counteract each other to protect chromosome-microtubule attachments independent of biorientation.
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Affiliation(s)
- Xinhong Song
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, E1 4NS, UK
| | - Duccio Conti
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, E1 4NS, UK.,Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227, Dortmund, Germany
| | - Roshan L Shrestha
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK.,Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Dominique Braun
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK
| | - Viji M Draviam
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, E1 4NS, UK. .,Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK.
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31
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Menon DU, Kirsanov O, Geyer CB, Magnuson T. Mammalian SWI/SNF chromatin remodeler is essential for reductional meiosis in males. Nat Commun 2021; 12:6581. [PMID: 34772938 PMCID: PMC8589837 DOI: 10.1038/s41467-021-26828-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 10/22/2021] [Indexed: 11/09/2022] Open
Abstract
The mammalian SWI/SNF nucleosome remodeler is essential for spermatogenesis. Here, we identify a role for ARID2, a PBAF (Polybromo - Brg1 Associated Factor)-specific subunit, in meiotic division. Arid2cKO spermatocytes arrest at metaphase-I and are deficient in spindle assembly, kinetochore-associated Polo-like kinase1 (PLK1), and centromeric targeting of Histone H3 threonine3 phosphorylation (H3T3P) and Histone H2A threonine120 phosphorylation (H2AT120P). By determining ARID2 and BRG1 genomic associations, we show that PBAF localizes to centromeres and promoters of genes known to govern spindle assembly and nuclear division in spermatocytes. Consistent with gene ontology of target genes, we also identify a role for ARID2 in centrosome stability. Additionally, misexpression of genes such as Aurkc and Ppp1cc (Pp1γ), known to govern chromosome segregation, potentially compromises the function of the chromosome passenger complex (CPC) and deposition of H3T3P, respectively. Our data support a model where-in PBAF activates genes essential for meiotic cell division.
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Affiliation(s)
- Debashish U Menon
- Department of Genetics, and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-7264, USA
| | - Oleksandr Kirsanov
- Department of Anatomy & Cell Biology at the Brody School of Medicine, East Carolina University, Greenville, NC, 27858, USA
| | - Christopher B Geyer
- Department of Anatomy & Cell Biology at the Brody School of Medicine, East Carolina University, Greenville, NC, 27858, USA
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27858, USA
| | - Terry Magnuson
- Department of Genetics, and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-7264, USA.
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32
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Brauer BL, Wiredu K, Mitchell S, Moorhead GB, Gerber SA, Kettenbach AN. Affinity-based profiling of endogenous phosphoprotein phosphatases by mass spectrometry. Nat Protoc 2021; 16:4919-4943. [PMID: 34518704 PMCID: PMC8822503 DOI: 10.1038/s41596-021-00604-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 07/12/2021] [Indexed: 02/08/2023]
Abstract
Phosphoprotein phosphatases (PPPs) execute >90% of serine/threonine dephosphorylation in cells and tissues. While the role of PPPs in cell biology and diseases such as cancer, cardiac hypertrophy and Alzheimer's disease is well established, the molecular mechanisms governing and governed by PPPs still await discovery. Here we describe a chemical proteomic strategy, phosphatase inhibitor beads and mass spectrometry (PIB-MS), that enables the identification and quantification of PPPs and their posttranslational modifications in as little as 12 h. Using a specific but nonselective PPP inhibitor immobilized on beads, PIB-MS enables the efficient affinity-capture, identification and quantification of endogenous PPPs and associated proteins ('PPPome') from cells and tissues. PIB-MS captures functional, endogenous PPP subunit interactions and enables discovery of new binding partners. It performs PPP enrichment without exogenous expression of tagged proteins or specific antibodies. Because PPPs are among the most conserved proteins across evolution, PIB-MS can be employed in any cell line, tissue or organism.
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Affiliation(s)
- Brooke L Brauer
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Kwame Wiredu
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Sierra Mitchell
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Greg B Moorhead
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Scott A Gerber
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
- Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA
| | - Arminja N Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA.
- Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA.
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33
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Structural Insights into Protein Regulation by Phosphorylation and Substrate Recognition of Protein Kinases/Phosphatases. Life (Basel) 2021; 11:life11090957. [PMID: 34575106 PMCID: PMC8467178 DOI: 10.3390/life11090957] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 09/05/2021] [Accepted: 09/10/2021] [Indexed: 12/30/2022] Open
Abstract
Protein phosphorylation is one of the most widely observed and important post-translational modification (PTM) processes. Protein phosphorylation is regulated by protein kinases, each of which covalently attaches a phosphate group to an amino acid side chain on a serine (Ser), threonine (Thr), or tyrosine (Tyr) residue of a protein, and by protein phosphatases, each of which, conversely, removes a phosphate group from a phosphoprotein. These reversible enzyme activities provide a regulatory mechanism by activating or deactivating many diverse functions of proteins in various cellular processes. In this review, their structures and substrate recognition are described and summarized, focusing on Ser/Thr protein kinases and protein Ser/Thr phosphatases, and the regulation of protein structures by phosphorylation. The studies reviewed here and the resulting information could contribute to further structural, biochemical, and combined studies on the mechanisms of protein phosphorylation and to drug discovery approaches targeting protein kinases or protein phosphatases.
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34
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Nelson DR, Hazzouri KM, Lauersen KJ, Jaiswal A, Chaiboonchoe A, Mystikou A, Fu W, Daakour S, Dohai B, Alzahmi A, Nobles D, Hurd M, Sexton J, Preston MJ, Blanchette J, Lomas MW, Amiri KMA, Salehi-Ashtiani K. Large-scale genome sequencing reveals the driving forces of viruses in microalgal evolution. Cell Host Microbe 2021; 29:250-266.e8. [PMID: 33434515 DOI: 10.1016/j.chom.2020.12.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/08/2020] [Accepted: 11/18/2020] [Indexed: 01/08/2023]
Abstract
Being integral primary producers in diverse ecosystems, microalgal genomes could be mined for ecological insights, but representative genome sequences are lacking for many phyla. We cultured and sequenced 107 microalgae species from 11 different phyla indigenous to varied geographies and climates. This collection was used to resolve genomic differences between saltwater and freshwater microalgae. Freshwater species showed domain-centric ontology enrichment for nuclear and nuclear membrane functions, while saltwater species were enriched in organellar and cellular membrane functions. Further, marine species contained significantly more viral families in their genomes (p = 8e-4). Sequences from Chlorovirus, Coccolithovirus, Pandoravirus, Marseillevirus, Tupanvirus, and other viruses were found integrated into the genomes of algal from marine environments. These viral-origin sequences were found to be expressed and code for a wide variety of functions. Together, this study comprehensively defines the expanse of protein-coding and viral elements in microalgal genomes and posits a unified adaptive strategy for algal halotolerance.
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Affiliation(s)
- David R Nelson
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE.
| | - Khaled M Hazzouri
- Khalifa Center for Genetic Engineering and Biotechnology (KCGEB), UAE University, Al Ain, Abu Dhabi, UAE; Biology Department, College of Science, UAE University, Al Ain, Abu Dhabi, UAE
| | - Kyle J Lauersen
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Ashish Jaiswal
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi, UAE
| | | | - Alexandra Mystikou
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Weiqi Fu
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Sarah Daakour
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Bushra Dohai
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Amnah Alzahmi
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - David Nobles
- UTEX Culture Collection of Algae at the University of Texas at Austin, Austin, TX, USA
| | - Mark Hurd
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Julie Sexton
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Michael J Preston
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Joan Blanchette
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Michael W Lomas
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Khaled M A Amiri
- Khalifa Center for Genetic Engineering and Biotechnology (KCGEB), UAE University, Al Ain, Abu Dhabi, UAE; Biology Department, College of Science, UAE University, Al Ain, Abu Dhabi, UAE
| | - Kourosh Salehi-Ashtiani
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE; Division of Science and Math, New York University Abu Dhabi, Abu Dhabi, UAE.
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35
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Aurora-B phosphorylates the myosin II heavy chain to promote cytokinesis. J Biol Chem 2021; 297:101024. [PMID: 34343568 PMCID: PMC8385403 DOI: 10.1016/j.jbc.2021.101024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/21/2021] [Accepted: 07/29/2021] [Indexed: 12/22/2022] Open
Abstract
Cytokinesis, the final step of mitosis, is mediated by an actomyosin contractile ring, the formation of which is temporally and spatially regulated following anaphase onset. Aurora-B is a member of the chromosomal passenger complex, which regulates various processes during mitosis; it is not understood, however, how Aurora-B is involved in cytokinesis. Here, we show that Aurora-B and myosin-IIB form a complex in vivo during telophase. Aurora-B phosphorylates the myosin-IIB rod domain at threonine 1847 (T1847), abrogating the ability of myosin-IIB monomers to form filaments. Furthermore, phosphorylation of myosin-IIB filaments by Aurora-B also promotes filament disassembly. We show that myosin-IIB possessing a phosphomimetic mutation at T1847 was unable to rescue cytokinesis failure caused by myosin-IIB depletion. Cells expressing a phosphoresistant mutation at T1847 had significantly longer intercellular bridges, implying that Aurora-B-mediated phosphorylation of myosin-IIB is important for abscission. We propose that myosin-IIB is a substrate of Aurora-B and reveal a new mechanism of myosin-IIB regulation by Aurora-B in the late stages of mitosis.
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36
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Jang JK, Gladstein AC, Das A, Shapiro JG, Sisco ZL, McKim KS. Multiple pools of PP2A regulate spindle assembly, kinetochore attachments and cohesion in Drosophila oocytes. J Cell Sci 2021; 134:jcs254037. [PMID: 34297127 PMCID: PMC8325958 DOI: 10.1242/jcs.254037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 06/14/2021] [Indexed: 01/06/2023] Open
Abstract
Meiosis in female oocytes lacks centrosomes, the microtubule-organizing centers. In Drosophila oocytes, meiotic spindle assembly depends on the chromosomal passenger complex (CPC). To investigate the mechanisms that regulate Aurora B activity, we examined the role of protein phosphatase 2A (PP2A) in Drosophila oocyte meiosis. We found that both forms of PP2A, B55 and B56, antagonize the Aurora B spindle assembly function, suggesting that a balance between Aurora B and PP2A activity maintains the oocyte spindle during meiosis I. PP2A-B56, which has a B subunit encoded by two partially redundant paralogs, wdb and wrd, is also required for maintenance of sister chromatid cohesion, establishment of end-on microtubule attachments, and metaphase I arrest in oocytes. WDB recruitment to the centromeres depends on BUBR1, MEI-S332 and kinetochore protein SPC105R. Although BUBR1 stabilizes microtubule attachments in Drosophila oocytes, it is not required for cohesion maintenance during meiosis I. We propose at least three populations of PP2A-B56 regulate meiosis, two of which depend on SPC105R and a third that is associated with the spindle.
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Affiliation(s)
| | | | | | | | | | - Kim S. McKim
- Waksman Institute, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
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37
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Ueki Y, Hadders MA, Weisser MB, Nasa I, Sotelo‐Parrilla P, Cressey LE, Gupta T, Hertz EPT, Kruse T, Montoya G, Jeyaprakash AA, Kettenbach A, Lens SMA, Nilsson J. A highly conserved pocket on PP2A-B56 is required for hSgo1 binding and cohesion protection during mitosis. EMBO Rep 2021; 22:e52295. [PMID: 33973335 PMCID: PMC8256288 DOI: 10.15252/embr.202052295] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 04/07/2021] [Accepted: 04/13/2021] [Indexed: 01/11/2023] Open
Abstract
The shugoshin proteins are universal protectors of centromeric cohesin during mitosis and meiosis. The binding of human hSgo1 to the PP2A-B56 phosphatase through a coiled-coil (CC) region mediates cohesion protection during mitosis. Here we undertook a structure function analysis of the PP2A-B56-hSgo1 complex, revealing unanticipated aspects of complex formation and function. We establish that a highly conserved pocket on the B56 regulatory subunit is required for hSgo1 binding and cohesion protection during mitosis in human somatic cells. Consistent with this, we show that hSgo1 blocks the binding of PP2A-B56 substrates containing a canonical B56 binding motif. We find that PP2A-B56 bound to hSgo1 dephosphorylates Cdk1 sites on hSgo1 itself to modulate cohesin interactions. Collectively our work provides important insight into cohesion protection during mitosis.
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Affiliation(s)
- Yumi Ueki
- The Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Michael A Hadders
- Oncode Institute and Center for Molecular MedicineUniversity Medical Center UtrechUtrecht UniversityUtrechtThe Netherlands
| | - Melanie B Weisser
- The Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Isha Nasa
- Biochemistry and Cell BiologyGeisel School of Medicine at Dartmouth CollegeHanoverNHUSA
| | | | - Lauren E Cressey
- Biochemistry and Cell BiologyGeisel School of Medicine at Dartmouth CollegeHanoverNHUSA
| | - Tanmay Gupta
- Wellcome Center for Cell BiologyUniversity of EdinburghEdinburghUK
| | - Emil P T Hertz
- The Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Thomas Kruse
- The Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Guillermo Montoya
- The Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical ScienceUniversity of CopenhagenCopenhagenDenmark
| | | | - Arminja Kettenbach
- Biochemistry and Cell BiologyGeisel School of Medicine at Dartmouth CollegeHanoverNHUSA
| | - Susanne M A Lens
- Oncode Institute and Center for Molecular MedicineUniversity Medical Center UtrechUtrecht UniversityUtrechtThe Netherlands
| | - Jakob Nilsson
- The Novo Nordisk Foundation Center for Protein ResearchFaculty of Health and Medical ScienceUniversity of CopenhagenCopenhagenDenmark
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38
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Protein phosphatase 1 regulates atypical mitotic and meiotic division in Plasmodium sexual stages. Commun Biol 2021; 4:760. [PMID: 34145386 PMCID: PMC8213788 DOI: 10.1038/s42003-021-02273-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 05/25/2021] [Indexed: 02/05/2023] Open
Abstract
PP1 is a conserved eukaryotic serine/threonine phosphatase that regulates many aspects of mitosis and meiosis, often working in concert with other phosphatases, such as CDC14 and CDC25. The proliferative stages of the malaria parasite life cycle include sexual development within the mosquito vector, with male gamete formation characterized by an atypical rapid mitosis, consisting of three rounds of DNA synthesis, successive spindle formation with clustered kinetochores, and a meiotic stage during zygote to ookinete development following fertilization. It is unclear how PP1 is involved in these unusual processes. Using real-time live-cell and ultrastructural imaging, conditional gene knockdown, RNA-seq and proteomic approaches, we show that Plasmodium PP1 is implicated in both mitotic exit and, potentially, establishing cell polarity during zygote development in the mosquito midgut, suggesting that small molecule inhibitors of PP1 should be explored for blocking parasite transmission.
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39
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Liu SY, Ikegami K. Nuclear lamin phosphorylation: an emerging role in gene regulation and pathogenesis of laminopathies. Nucleus 2021; 11:299-314. [PMID: 33030403 PMCID: PMC7588210 DOI: 10.1080/19491034.2020.1832734] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Decades of studies have established that nuclear lamin polymers form the nuclear lamina, a protein meshwork that supports the nuclear envelope structure and tethers heterochromatin to the nuclear periphery. Much less is known about unpolymerized nuclear lamins in the nuclear interior, some of which are now known to undergo specific phosphorylation. A recent finding that phosphorylated lamins bind gene enhancer regions offers a new hypothesis that lamin phosphorylation may influence transcriptional regulation in the nuclear interior. In this review, we discuss the regulation, localization, and functions of phosphorylated lamins. We summarize kinases that phosphorylate lamins in a variety of biological contexts. Our discussion extends to laminopathies, a spectrum of degenerative disorders caused by lamin gene mutations, such as cardiomyopathies and progeria. We compare the prevailing hypothesis for laminopathy pathogenesis based on lamins’ function at the nuclear lamina with an emerging hypothesis based on phosphorylated lamins’ function in the nuclear interior.
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Affiliation(s)
- Sunny Yang Liu
- Department of Pediatrics, The University of Chicago , Chicago, Illinois, USA
| | - Kohta Ikegami
- Department of Pediatrics, The University of Chicago , Chicago, Illinois, USA.,Division of Molecular and Cardiovascular Biology, Cincinnati Children's Hospital Medical Center , Cincinnati, Ohio, USA
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40
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Hein JB, Garvanska DH, Nasa I, Kettenbach AN, Nilsson J. Coupling of Cdc20 inhibition and activation by BubR1. J Cell Biol 2021; 220:211939. [PMID: 33819340 PMCID: PMC8025235 DOI: 10.1083/jcb.202012081] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/18/2021] [Accepted: 02/25/2021] [Indexed: 12/25/2022] Open
Abstract
Tight regulation of the APC/C-Cdc20 ubiquitin ligase that targets cyclin B1 for degradation is important for mitotic fidelity. The spindle assembly checkpoint (SAC) inhibits Cdc20 through the mitotic checkpoint complex (MCC). In addition, phosphorylation of Cdc20 by cyclin B1–Cdk1 independently inhibits APC/C–Cdc20 activation. This creates a conundrum for how Cdc20 is activated before cyclin B1 degradation. Here, we show that the MCC component BubR1 harbors both Cdc20 inhibition and activation activities, allowing for cross-talk between the two Cdc20 inhibition pathways. Specifically, BubR1 acts as a substrate specifier for PP2A-B56 to enable efficient Cdc20 dephosphorylation in the MCC. A mutant Cdc20 mimicking the dephosphorylated state escapes a mitotic checkpoint arrest, arguing that restricting Cdc20 dephosphorylation to the MCC is important. Collectively, our work reveals how Cdc20 can be dephosphorylated in the presence of cyclin B1-Cdk1 activity without causing premature anaphase onset.
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Affiliation(s)
- Jamin B Hein
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Science, Copenhagen, Denmark
| | - Dimitriya H Garvanska
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Science, Copenhagen, Denmark
| | - Isha Nasa
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Arminja N Kettenbach
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Jakob Nilsson
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Science, Copenhagen, Denmark
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41
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De Jamblinne CV, Decelle B, Dehghani M, Joseph M, Sriskandarajah N, Leguay K, Rambaud B, Lemieux S, Roux PP, Hipfner DR, Carréno S. STRIPAK regulates Slik localization to control mitotic morphogenesis and epithelial integrity. J Cell Biol 2021; 219:152107. [PMID: 32960945 PMCID: PMC7594492 DOI: 10.1083/jcb.201911035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 07/17/2020] [Accepted: 08/20/2020] [Indexed: 02/01/2023] Open
Abstract
Proteins of the ezrin, radixin, and moesin (ERM) family control cell and tissue morphogenesis. We previously reported that moesin, the only ERM in Drosophila, controls mitotic morphogenesis and epithelial integrity. We also found that the Pp1-87B phosphatase dephosphorylates moesin, counteracting its activation by the Ste20-like kinase Slik. To understand how this signaling pathway is itself regulated, we conducted a genome-wide RNAi screen, looking for new regulators of moesin activity. We identified that Slik is a new member of the striatin-interacting phosphatase and kinase complex (STRIPAK). We discovered that the phosphatase activity of STRIPAK reduces Slik phosphorylation to promote its cortical association and proper activation of moesin. Consistent with this finding, inhibition of STRIPAK phosphatase activity causes cell morphology defects in mitosis and impairs epithelial tissue integrity. Our results implicate the Slik–STRIPAK complex in the control of multiple morphogenetic processes.
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Affiliation(s)
- Camille Valérie De Jamblinne
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada.,Programmes de biologie moléculaire, Université de Montréal, Montréal, Quebec, Canada
| | - Barbara Decelle
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada
| | - Mehrnoush Dehghani
- Institut de recherches cliniques de Montréal, Montréal, Quebec, Canada.,Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
| | - Mathieu Joseph
- Institut de recherches cliniques de Montréal, Montréal, Quebec, Canada.,Programmes de biologie moléculaire, Université de Montréal, Montréal, Quebec, Canada
| | - Neera Sriskandarajah
- Institut de recherches cliniques de Montréal, Montréal, Quebec, Canada.,Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
| | - Kévin Leguay
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada.,Programmes de biologie moléculaire, Université de Montréal, Montréal, Quebec, Canada
| | - Basile Rambaud
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada.,Programmes de biologie moléculaire, Université de Montréal, Montréal, Quebec, Canada
| | - Sébastien Lemieux
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada.,Département de Biochimie, Université de Montréal, Montréal, Quebec, Canada
| | - Philippe P Roux
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada.,Programmes de biologie moléculaire, Université de Montréal, Montréal, Quebec, Canada.,Département de Pathologie et de Biologie Cellulaire, Université de Montréal, Montréal, Quebec, Canada
| | - David R Hipfner
- Institut de recherches cliniques de Montréal, Montréal, Quebec, Canada.,Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada.,Programmes de biologie moléculaire, Université de Montréal, Montréal, Quebec, Canada.,Département de Médecine, Université de Montréal, Montréal, Quebec, Canada
| | - Sébastien Carréno
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada.,Programmes de biologie moléculaire, Université de Montréal, Montréal, Quebec, Canada.,Département de Pathologie et de Biologie Cellulaire, Université de Montréal, Montréal, Quebec, Canada
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42
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Lei WL, Qian WP, Sun QY. Critical Functions of PP2A-Like Protein Phosphotases in Regulating Meiotic Progression. Front Cell Dev Biol 2021; 9:638559. [PMID: 33718377 PMCID: PMC7947259 DOI: 10.3389/fcell.2021.638559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/08/2021] [Indexed: 01/31/2023] Open
Abstract
Meiosis is essential to the continuity of life in sexually-reproducing organisms through the formation of haploid gametes. Unlike somatic cells, the germ cells undergo two successive rounds of meiotic divisions after a single cycle of DNA replication, resulting in the decrease in ploidy. In humans, errors in meiotic progression can cause infertility and birth defects. Post-translational modifications, such as phosphorylation, ubiquitylation and sumoylation have emerged as important regulatory events in meiosis. There are dynamic equilibrium of protein phosphorylation and protein dephosphorylation in meiotic cell cycle process, regulated by a conservative series of protein kinases and protein phosphatases. Among these protein phosphatases, PP2A, PP4, and PP6 constitute the PP2A-like subfamily within the serine/threonine protein phosphatase family. Herein, we review recent discoveries and explore the role of PP2A-like protein phosphatases during meiotic progression.
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Affiliation(s)
- Wen-Long Lei
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen, China
| | - Wei-Ping Qian
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen, China
| | - Qing-Yuan Sun
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
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43
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Specificity determinants of phosphoprotein phosphatases controlling kinetochore functions. Essays Biochem 2021; 64:325-336. [PMID: 32501472 DOI: 10.1042/ebc20190065] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/11/2020] [Accepted: 05/14/2020] [Indexed: 12/12/2022]
Abstract
Kinetochores are instrumental for accurate chromosome segregation by binding to microtubules in order to move chromosomes and by delaying anaphase onset through the spindle assembly checkpoint (SAC). Dynamic phosphorylation of kinetochore components is key to control these activities and is tightly regulated by temporal and spatial recruitment of kinases and phosphoprotein phosphatases (PPPs). Here we focus on PP1, PP2A-B56 and PP2A-B55, three PPPs that are important regulators of mitosis. Despite the fact that these PPPs share a very similar active site, they target unique ser/thr phosphorylation sites to control kinetochore function. Specificity is in part achieved by PPPs binding to short linear motifs (SLiMs) that guide their substrate specificity. SLiMs bind to conserved pockets on PPPs and are degenerate in nature, giving rise to a range of binding affinities. These SLiMs control the assembly of numerous substrate specifying complexes and their position and binding strength allow PPPs to target specific phosphorylation sites. In addition, the activity of PPPs is regulated by mitotic kinases and inhibitors, either directly at the activity level or through affecting PPP-SLiM interactions. Here, we discuss recent progress in understanding the regulation of PPP specificity and activity and how this controls kinetochore biology.
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44
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Salamango DJ, Harris RS. Demystifying Cell Cycle Arrest by HIV-1 Vif. Trends Microbiol 2021; 29:381-384. [PMID: 33478820 DOI: 10.1016/j.tim.2021.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/28/2020] [Accepted: 01/04/2021] [Indexed: 11/26/2022]
Abstract
Although APOBEC3 degradation is the canonical function of HIV-1 Vif, this viral protein also induces potent cell cycle arrest through a newly defined mechanism. Here, we review recent advances in this area and propose that the scope of this activity may go beyond subversion of the host cell cycle.
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Affiliation(s)
- Daniel J Salamango
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Institute for Molecular Virology, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Reuben S Harris
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN 55455, USA.
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45
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Salamango DJ, Harris RS. Dual Functionality of HIV-1 Vif in APOBEC3 Counteraction and Cell Cycle Arrest. Front Microbiol 2021; 11:622012. [PMID: 33510734 PMCID: PMC7835321 DOI: 10.3389/fmicb.2020.622012] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/11/2020] [Indexed: 01/02/2023] Open
Abstract
Accessory proteins are a key feature that distinguishes primate immunodeficiency viruses such as human immunodeficiency virus type I (HIV-1) from other retroviruses. A prime example is the virion infectivity factor, Vif, which hijacks a cellular co-transcription factor (CBF-β) to recruit a ubiquitin ligase complex (CRL5) to bind and degrade antiviral APOBEC3 enzymes including APOBEC3D (A3D), APOBEC3F (A3F), APOBEC3G (A3G), and APOBEC3H (A3H). Although APOBEC3 antagonism is essential for viral pathogenesis, and a more than sufficient functional justification for Vif’s evolution, most viral proteins have evolved multiple functions. Indeed, Vif has long been known to trigger cell cycle arrest and recent studies have shed light on the underlying molecular mechanism. Vif accomplishes this function using the same CBF-β/CRL5 ubiquitin ligase complex to degrade a family of PPP2R5 phospho-regulatory proteins. These advances have helped usher in a new era of accessory protein research and fresh opportunities for drug development.
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Affiliation(s)
- Daniel J Salamango
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, United States.,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, United States
| | - Reuben S Harris
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, United States.,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, United States.,Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN, United States
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46
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Singh P, Halova L, Hagan IM. Highly Synchronous Mitotic Progression in Schizosaccharomyces pombe Upon Relief of Transient Cdc2-asM17 Inhibition. Methods Mol Biol 2021; 2329:123-142. [PMID: 34085220 DOI: 10.1007/978-1-0716-1538-6_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2024]
Abstract
Synchronized progression of a cell population through the cell division cycle supports the biochemical and functional dissection of cell cycle controls and execution. The concerted behaviour of the population reflects the attributes of each cell within that population. The reversible imposition of a block to cell cycle progression at the G2-M boundary through transient inactivation of the Cdk1-Cyclin B activating phosphatase, Cdc25, with the temperature sensitive cdc25-22 mutant, has been widely used to study fission yeast mitosis and DNA replication. However, the biology of the compromised Cdc25-22 phosphatase generates significant division abnormalities upon release from mitotic arrest. We show how reversible inhibition of Cdc2-asM17, with the ATP analog 3-BrB-PP1, generates higher levels of synchrony with timing and morphology much more reminiscent of a normal division. We also describe a version of the H1 kinase assay of Cdk1-Cyclin B activity that is widely used to monitor mitotic progression which does not require radiolabeled ATP.
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Affiliation(s)
- Pawan Singh
- Cell Division Group, CRUK Manchester Institute, The University of Manchester, Alderley Park, UK
| | - Lenka Halova
- Cell Division Group, CRUK Manchester Institute, The University of Manchester, Alderley Park, UK
| | - Iain Michael Hagan
- Cell Division Group, CRUK Manchester Institute, The University of Manchester, Alderley Park, UK.
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Salvi F, Hoermann B, Del Pino García J, Fontanillo M, Derua R, Beullens M, Bollen M, Barabas O, Köhn M. Towards Dissecting the Mechanism of Protein Phosphatase-1 Inhibition by Its C-Terminal Phosphorylation. Chembiochem 2020; 22:834-838. [PMID: 33085143 PMCID: PMC7984433 DOI: 10.1002/cbic.202000669] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/21/2020] [Indexed: 01/23/2023]
Abstract
Phosphoprotein phosphatase‐1 (PP1) is a key player in the regulation of phospho‐serine (pSer) and phospho‐threonine (pThr) dephosphorylation and is involved in a large fraction of cellular signaling pathways. Aberrant activity of PP1 has been linked to many diseases, including cancer and heart failure. Besides a well‐established activity control by regulatory proteins, an inhibitory function for phosphorylation (p) of a Thr residue in the C‐terminal intrinsically disordered tail of PP1 has been demonstrated. The associated phenotype of cell‐cycle arrest was repeatedly proposed to be due to autoinhibition of PP1 through either conformational changes or substrate competition. Here, we use PP1 variants created by mutations and protein semisynthesis to differentiate between these hypotheses. Our data support the hypothesis that pThr exerts its inhibitory function by mediating protein complex formation rather than by a direct mechanism of structural changes or substrate competition.
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Affiliation(s)
- Francesca Salvi
- Genome Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany
| | - Bernhard Hoermann
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
| | - Javier Del Pino García
- Laboratory of Biosignaling and Therapeutics Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Miriam Fontanillo
- Genome Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany
| | - Rita Derua
- Laboratory of Protein Phosphorylation and Proteomics Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, 3000, Leuven, Belgium.,SyBioMa, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Monique Beullens
- Laboratory of Biosignaling and Therapeutics Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Mathieu Bollen
- Laboratory of Biosignaling and Therapeutics Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Orsolya Barabas
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany
| | - Maja Köhn
- Genome Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
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48
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Rosendo-Pineda MJ, Vicente JJ, Vivas O, Pacheco J, Loza-Huerta A, Sampieri A, Wordeman L, Moreno C, Vaca L. Phosphorylation of NMDA receptors by cyclin B/CDK1 modulates calcium dynamics and mitosis. Commun Biol 2020; 3:665. [PMID: 33184446 PMCID: PMC7665045 DOI: 10.1038/s42003-020-01393-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/15/2020] [Indexed: 12/02/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDAR) are glutamate-gated calcium channels named after their artificial agonist. NMDAR are implicated in cell proliferation under normal and pathophysiological conditions. However, the role of NMDAR during mitosis has not yet been explored in individual cells. We found that neurotransmitter-evoked calcium entry via endogenous NMDAR in cortical astrocytes was transient during mitosis. The same occurred in HEK293 cells transfected with the NR1/NR2A subunits of NMDAR. This transient calcium entry during mitosis was due to phosphorylation of the first intracellular loop of NMDAR (S584 of NR1 and S580 of NR2A) by cyclin B/CDK1. Expression of phosphomimetic mutants resulted in transient calcium influx and enhanced NMDAR inactivation independent of the cell cycle phase. Phosphomimetic mutants increased entry of calcium in interphase and generated several alterations during mitosis: increased mitotic index, increased number of cells with lagging chromosomes and fragmentation of pericentriolar material. In summary, by controlling cytosolic calcium, NMDAR modulate mitosis and probably cell differentiation/proliferation. Our results suggest that phosphorylation of NMDAR by cyclin B/CDK1 during mitosis is required to preserve mitotic fidelity. Altering the modulation of the NMDAR by cyclin B/CDK1 may conduct to aneuploidy and cancer.
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Affiliation(s)
| | - Juan Jesus Vicente
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Oscar Vivas
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Jonathan Pacheco
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán, DF, 04510, Mexico
| | - Arlet Loza-Huerta
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán, DF, 04510, Mexico
| | - Alicia Sampieri
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán, DF, 04510, Mexico
| | - Linda Wordeman
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Claudia Moreno
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Luis Vaca
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán, DF, 04510, Mexico.
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, 98195, USA.
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BUBR1 Pseudokinase Domain Promotes Kinetochore PP2A-B56 Recruitment, Spindle Checkpoint Silencing, and Chromosome Alignment. Cell Rep 2020; 33:108397. [PMID: 33207204 DOI: 10.1016/j.celrep.2020.108397] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 10/13/2020] [Accepted: 10/26/2020] [Indexed: 12/13/2022] Open
Abstract
The balance of phospho-signaling at the outer kinetochore is critical for forming accurate attachments between kinetochores and the mitotic spindle and timely exit from mitosis. A major player in determining this balance is the PP2A-B56 phosphatase, which is recruited to the kinase attachment regulatory domain (KARD) of budding uninhibited by benzimidazole 1-related 1 (BUBR1) in a phospho-dependent manner. This unleashes a rapid, switch-like phosphatase relay that reverses mitotic phosphorylation at the kinetochore, extinguishing the checkpoint and promoting anaphase. Here, we demonstrate that the C-terminal pseudokinase domain of human BUBR1 is required to promote KARD phosphorylation. Mutation or removal of the pseudokinase domain results in decreased PP2A-B56 recruitment to the outer kinetochore attenuated checkpoint silencing and errors in chromosome alignment as a result of imbalance in Aurora B activity. Our data, therefore, elucidate a function for the BUBR1 pseudokinase domain in ensuring accurate and timely exit from mitosis.
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Functional and Structural Insights into a Vif/PPP2R5 Complex Elucidated Using Patient HIV-1 Isolates and Computational Modeling. J Virol 2020; 94:JVI.00631-20. [PMID: 32847850 DOI: 10.1128/jvi.00631-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 08/17/2020] [Indexed: 02/06/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) Vif recruits a cellular ubiquitin ligase complex to degrade antiviral APOBEC3 enzymes (APOBEC3C-H) and PP2A phosphatase regulators (PPP2R5A to PPP2R5E). While APOBEC3 antagonism is the canonical function of HIV-1 Vif, this viral accessory protein is also known to trigger G2/M cell cycle arrest. Vif initiates G2/M arrest by degrading multiple PPP2R5 family members, an activity prevalent among diverse HIV-1 and simian immunodeficiency virus (SIV) isolates. Here, computational protein-protein docking was used to delineate a Vif/CBF-β/PPP2R5 complex in which Vif is predicted to bind the same PPP2R5 surface as physiologic phosphatase targets. This model was tested using targeted mutagenesis of amino acid residues within or adjacent to the putative interface to show loss or retention, respectively, of Vif-induced PPP2R5 degradation activity. Additionally, expression of a peptide that mimics cellular targets of PPP2R5s robustly inhibited Vif-mediated degradation of PPP2R5A but not APOBEC3G. Moreover, live-cell imaging studies examining Vif-mediated degradation of PPP2R5A and APOBEC3G within the same cell revealed that PPP2R5A degradation kinetics are comparable to those of APOBEC3G with a half-life of roughly 6 h postinfection, demonstrating that Vif can concurrently mediate the degradation of distinct cellular substrates. Finally, experiments with a panel of patient-derived Vif isolates indicated that PPP2R5A degradation activity is common in patient-derived isolates. Taken together, these results support a model in which PPP2R5 degradation and global changes in the cellular phosphoproteome are likely to be advantageous for viral pathogenesis.IMPORTANCE A critical function of HIV-1 Vif is to counteract the family of APOBEC3 innate immune proteins. It is also widely accepted that Vif induces G2/M cell cycle arrest in several different cell types. Recently, it has been shown that Vif degrades multiple PPP2R5 phosphoregulators to induce the G2/M arrest phenotype. Here, computational approaches are used to test a structural model of the Vif/PPP2R5 complex. In addition, imaging studies are used to show that Vif degrades these PPP2R5 substrates in roughly the same time frame as APOBEC3 degradation and that this activity is prevalent in patient-derived Vif isolates. These studies are important by further defining PPP2R5 proteins as a bona fide substrate of HIV-1 Vif.
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