1
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Bracci N, Baer A, Flor R, Petraccione K, Stocker T, Zhou W, Ammosova T, Dinglasan RR, Nekhai S, Kehn-Hall K. CK1 and PP1 regulate Rift Valley fever virus genome replication through L protein phosphorylation. Antiviral Res 2024:105895. [PMID: 38679165 DOI: 10.1016/j.antiviral.2024.105895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 04/15/2024] [Accepted: 04/22/2024] [Indexed: 05/01/2024]
Abstract
Rift Valley fever virus (RVFV) is an arbovirus in the Phenuiviridae family identified initially by the large 'abortion storms' observed among ruminants; RVFV can also infect humans. In humans, there is a wide variation of clinical symptoms ranging from subclinical to mild febrile illness to hepatitis, retinitis, delayed-onset encephalitis, or even hemorrhagic fever. The RVFV is a tri-segmented negative-sense RNA virus consisting of S, M, and L segments. The L segment encodes the RNA-dependent RNA polymerase (RdRp), termed the L protein, which is responsible for both viral mRNA synthesis and genome replication. Phosphorylation of viral RdRps is known to regulate viral replication. This study shows that RVFV L protein is serine phosphorylated and identified Casein Kinase 1 alpha (CK1α) and protein phosphatase 1 alpha (PP1α) as L protein binding partners. Inhibition of CK1 and PP1 through small molecule inhibitor treatment, D4476 and 1E7-03, respectively, caused a change in the phosphorylated status of the L protein. Inhibition of PP1α resulted in increased L protein phosphorylation whereas inhibition of CK1α decreased L protein phosphorylation. It was also found that in RVFV infected cells, PP1α localized to the cytoplasmic compartment. Treatment of RVFV infected cells with CK1 inhibitors reduced virus production in both mammalian and mosquito cells. Lastly, inhibition of either CK1 or PP1 reduced viral genomic RNA levels. These data indicate that L protein is phosphorylated and that CK1 and PP1 play a crucial role in regulating the L protein phosphorylation cycle, which is critical to viral RNA production and viral replication.
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Affiliation(s)
- Nicole Bracci
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Virginia, USA; Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Virginia, USA
| | - Alan Baer
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, USA
| | - Rafaela Flor
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Virginia, USA; Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Virginia, USA
| | - Kaylee Petraccione
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Virginia, USA; Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Virginia, USA
| | - Timothy Stocker
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Virginia, USA; Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Virginia, USA
| | - Weidong Zhou
- Center for Applied Proteomics and Molecular Medicine, School of Systems Biology, George Mason University, Manassas, Virginia, USA
| | - Tatiana Ammosova
- Center for Sickle Cell Disease, Department of Medicine, Howard University, Washington D.C., USA
| | - Rhoel R Dinglasan
- Emerging Pathogens Institute, University of Florida, Florida, USA; Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Florida, USA
| | - Sergei Nekhai
- Center for Sickle Cell Disease, Department of Medicine, Howard University, Washington D.C., USA
| | - Kylene Kehn-Hall
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Virginia, USA; Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Virginia, USA.
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2
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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3
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Xiong C, Deng J, Wang X, Hou Q, Zhuang S. Pharmacological inhibition of Src family kinases attenuates hyperuricemic nephropathy. Front Pharmacol 2024; 15:1352730. [PMID: 38576481 PMCID: PMC10991786 DOI: 10.3389/fphar.2024.1352730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 03/06/2024] [Indexed: 04/06/2024] Open
Abstract
Hyperuricemia is an independent risk factor for chronic kidney disease and contributes to renal fibrosis. This study aims to investigate the effect of Src family kinase (SFK) inhibition on the development of hyperuricemic nephropathy (HN) and the mechanisms involved. In a rat model of HN, feeding rats a mixture of adenine and potassium oxonate increased Src phosphorylation, severe glomerular sclerosis, and renal interstitial fibrosis, accompanied by renal dysfunction and increased urine microalbumin excretion. Administration of PP1, a highly selective SFK inhibitor, prevented renal dysfunction, reduced urine microalbumin, and inhibited activation of renal interstitial fibroblasts and expression of extracellular proteins. PP1 treatment also inhibited hyperuricemia-induced activation of the TGF-β1/Smad3, STAT3, ERK1/2, and NF-κB signaling pathways and expression of multiple profibrogenic cytokines/chemokines in the kidney. Furthermore, PP1 treatment significantly reduced serum uric acid levels and xanthine oxidase activity. Thus, blocking Src can attenuate development of HN via a mechanism associated with the suppression of TGF-β1 signaling, inflammation, and uric acid production. The results suggest that Src inhibition might be a promising therapeutic strategy for HN.
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Affiliation(s)
- Chongxiang Xiong
- Department of Nephrology, The First Affiliated Hospital of Dongguan, Guangdong Medical University, Dongguan, Guangdong, China
| | - Jin Deng
- Department of Nephrology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Xin Wang
- Department of Nephrology, The First Affiliated Hospital of Dongguan, Guangdong Medical University, Dongguan, Guangdong, China
| | - Qidi Hou
- Department of Nephrology, The First Affiliated Hospital of Dongguan, Guangdong Medical University, Dongguan, Guangdong, China
| | - Shougang Zhuang
- Department of Medicine, Rhode Island Hospital and Brown University School of Medicine, Providence, RI, United States
- Department of Nephrology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
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Gergs U, Wackerhagen S, Fuhrmann T, Schäfer I, Neumann J. Further investigations on the influence of protein phosphatases on the signaling of muscarinic receptors in the atria of mouse hearts. Naunyn Schmiedebergs Arch Pharmacol 2024:10.1007/s00210-024-02973-4. [PMID: 38308688 DOI: 10.1007/s00210-024-02973-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 01/21/2024] [Indexed: 02/05/2024]
Abstract
The vagal regulation of cardiac function involves acetylcholine (ACh) receptor activation followed by negative chronotropic and negative as well as positive inotropic effects. The resulting signaling pathways may include Gi/o protein-coupled reduction in adenylyl cyclase (AC) activity, direct Gi/o protein-coupled activation of ACh-activated potassium current (IKACh), inhibition of L-type calcium ion channels, and/or the activation of protein phosphatases. Here, we studied the role of the protein phosphatases 1 (PP1) and 2A (PP2A) for muscarinic receptor signaling in isolated atrial preparations of transgenic mice with cardiomyocyte-specific overexpression of either the catalytic subunit of PP2A (PP2A-TG) or the inhibitor-2 (I2) of PP1 (I2-TG) or in double transgenic mice overexpressing both PP2A and I2 (DT). In mouse left atrial preparations, carbachol (CCh), cumulatively applied (1 nM-10 µM), exerted at low concentrations a negative inotropic effect followed by a positive inotropic effect at higher concentrations. This biphasic effect was noted with CCh alone as well as when CCh was added after β-adrenergic pre-stimulation with isoprenaline (1 µM). Whereas the response to stimulation of β-adrenoceptors or adenosine receptors (used as controls) was changed in PP2A-TG, the response to CCh was unaffected in atrial preparations from all transgenic models studied here. Therefore, the present data tentatively indicate that neither PP2A nor PP1, but possibly other protein phosphatases, is involved in the muscarinic receptor-induced inotropic and chronotropic effects in the mouse heart.
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Affiliation(s)
- Ulrich Gergs
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany.
| | - Silke Wackerhagen
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany
| | - Tobias Fuhrmann
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany
| | - Inka Schäfer
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany
| | - Joachim Neumann
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany
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5
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Fatalska A, Hodgson G, Freund SMV, Maslen SL, Morgan T, Thorkelsson SR, van Slegtenhorst M, Lorenz S, Andreeva A, Kaat LD, Bertolotti A. Recruitment of trimeric eIF2 by phosphatase non-catalytic subunit P PP1R15B. Mol Cell 2024; 84:506-521.e11. [PMID: 38159565 PMCID: PMC7615683 DOI: 10.1016/j.molcel.2023.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 09/06/2023] [Accepted: 12/08/2023] [Indexed: 01/03/2024]
Abstract
Regulated protein phosphorylation controls most cellular processes. The protein phosphatase PP1 is the catalytic subunit of many holoenzymes that dephosphorylate serine/threonine residues. How these enzymes recruit their substrates is largely unknown. Here, we integrated diverse approaches to elucidate how the PP1 non-catalytic subunit PPP1R15B (R15B) captures its full trimeric eIF2 substrate. We found that the substrate-recruitment module of R15B is largely disordered with three short helical elements, H1, H2, and H3. H1 and H2 form a clamp that grasps the substrate in a region remote from the phosphorylated residue. A homozygous N423D variant, adjacent to H1, reducing substrate binding and dephosphorylation was discovered in a rare syndrome with microcephaly, developmental delay, and intellectual disability. These findings explain how R15B captures its 125 kDa substrate by binding the far end of the complex relative to the phosphosite to present it for dephosphorylation by PP1, a paradigm of broad relevance.
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Affiliation(s)
- Agnieszka Fatalska
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - George Hodgson
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Stefan M V Freund
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Sarah L Maslen
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Tomos Morgan
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Sigurdur R Thorkelsson
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Marjon van Slegtenhorst
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Sonja Lorenz
- Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany
| | - Antonina Andreeva
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Laura Donker Kaat
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Anne Bertolotti
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom.
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6
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Wu D, Van der Hoeven G, Claes Z, Van Eynde A, Bollen M. DNA damage-induced allosteric activation of protein phosphatase PP1:NIPP1 through Src kinase-induced circularization of NIPP1. FEBS J 2024. [PMID: 38303113 DOI: 10.1111/febs.17064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 12/06/2023] [Accepted: 12/28/2023] [Indexed: 02/03/2024]
Abstract
Protein phosphatase-1 (PP1) complexed to nuclear inhibitor of PP1 (NIPP1) limits DNA repair through dephosphorylation of NIPP1-recruited substrates. However, the PP1:NIPP1 holoenzyme is completely inactive under basal conditions, hinting at a DNA damage-regulated activation mechanism. Here, we report that DNA damage caused the activation of PP1:NIPP1 after a time delay of several hours through phosphorylation of NIPP1 at the C-terminal tyrosine 335 (Y335) by a Src-family kinase. PP1:NIPP1 activation partially resulted from the dissociation of the C terminus of NIPP1 from the active site of PP1. In addition, the released Y335-phosphorylated C terminus interacted with the N terminus of NIPP1 to enhance substrate recruitment by the flanking forkhead-associated (FHA) domain. Constitutive activation of PP1:NIPP1 by knock-in of a phospho-mimicking (Y335E) NIPP1 mutant led to the hypo-phosphorylation of FHA ligands and an accumulation of DNA double-strand breaks. Our data indicate that PP1:NIPP1 activation through circularization of NIPP1 is a late response to DNA damage that contributes to the timely recovery from damage repair.
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Affiliation(s)
- Dan Wu
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
| | - Gerd Van der Hoeven
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
| | - Zander Claes
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
| | - Aleyde Van Eynde
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
| | - Mathieu Bollen
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
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Claes Z, Bollen M. A split-luciferase lysate-based approach to identify small-molecule modulators of phosphatase subunit interactions. Cell Chem Biol 2023; 30:1666-1679.e6. [PMID: 37625414 DOI: 10.1016/j.chembiol.2023.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 05/31/2023] [Accepted: 07/30/2023] [Indexed: 08/27/2023]
Abstract
An emerging strategy for the therapeutic targeting of protein phosphatases involves the use of compounds that interfere with the binding of regulatory subunits or substrates. However, high-throughput screening strategies for such interfering molecules are scarce. Here, we report on the conversion of the NanoBiT split-luciferase system into a robust assay for the quantification of phosphatase subunit and substrate interactions in cell lysates. The assay is suitable to screen small-molecule libraries for interfering compounds. We designed and validated split-luciferase sensors for a broad range of PP1 and PP2A holoenzymes, including sensors that selectively report on weak interaction sites. To facilitate efficient hit triaging in large-scale screening campaigns, deselection procedures were developed to eliminate assay-interfering molecules with high fidelity. As a proof-of-principle, we successfully applied the split-luciferase screening tool to identify small-molecule disruptors of the interaction between the C-terminus of PP1β and the ankyrin-repeat domain of the myosin-phosphatase targeting subunit MYPT1.
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Affiliation(s)
- Zander Claes
- Laboratory of Biosignaling and Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, 3000 Leuven, Belgium
| | - Mathieu Bollen
- Laboratory of Biosignaling and Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, 3000 Leuven, Belgium.
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Hicks D, Giresh K, Wrischnik LA, Weiser DC. The P PP1R15 Family of eIF2-alpha Phosphatase Targeting Subunits (GADD34 and CReP). Int J Mol Sci 2023; 24:17321. [PMID: 38139150 PMCID: PMC10743859 DOI: 10.3390/ijms242417321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 12/01/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
The vertebrate PPP1R15 family consists of the proteins GADD34 (growth arrest and DNA damage-inducible protein 34, the product of the PPP1R15A gene) and CReP (constitutive repressor of eIF2α phosphorylation, the product of the PPP1R15B gene), both of which function as targeting/regulatory subunits for protein phosphatase 1 (PP1) by regulating subcellular localization, modulating substrate specificity and assembling complexes with target proteins. The primary cellular function of these proteins is to facilitate the dephosphorylation of eukaryotic initiation factor 2-alpha (eIF2α) by PP1 during cell stress. In this review, we will provide a comprehensive overview of the cellular function, biochemistry and pharmacology of GADD34 and CReP, starting with a brief introduction of eIF2α phosphorylation via the integrated protein response (ISR). We discuss the roles GADD34 and CReP play as feedback inhibitors of the unfolded protein response (UPR) and highlight the critical function they serve as inhibitors of the PERK-dependent branch, which is particularly important since it can mediate cell survival or cell death, depending on how long the stressful stimuli lasts, and GADD34 and CReP play key roles in fine-tuning this cellular decision. We briefly discuss the roles of GADD34 and CReP homologs in model systems and then focus on what we have learned about their function from knockout mice and human patients, followed by a brief review of several diseases in which GADD34 and CReP have been implicated, including cancer, diabetes and especially neurodegenerative disease. Because of the potential importance of GADD34 and CReP in aspects of human health and disease, we will discuss several pharmacological inhibitors of GADD34 and/or CReP that show promise as treatments and the controversies as to their mechanism of action. This review will finish with a discussion of the biochemical properties of GADD34 and CReP, their regulation and the additional interacting partners that may provide insight into the roles these proteins may play in other cellular pathways. We will conclude with a brief outline of critical areas for future study.
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Affiliation(s)
- Danielle Hicks
- Department of Science, Mathematics and Engineering, Modesto Junior College, Modesto, CA 95350, USA
- Department of Biological Sciences, University of the Pacific, Stockton, CA 95211, USA
| | - Krithika Giresh
- Department of Biological Sciences, University of the Pacific, Stockton, CA 95211, USA
| | - Lisa A. Wrischnik
- Department of Biological Sciences, University of the Pacific, Stockton, CA 95211, USA
| | - Douglas C. Weiser
- Department of Biological Sciences, University of the Pacific, Stockton, CA 95211, USA
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Kirkbride JA, Nilsson GY, Kim JI, Takeya K, Tanaka Y, Tokumitsu H, Suizu F, Eto M. PHI-1, an Endogenous Inhibitor Protein for Protein Phosphatase-1 and a Pan-Cancer Marker, Regulates Raf-1 Proteostasis. Biomolecules 2023; 13:1741. [PMID: 38136612 PMCID: PMC10741526 DOI: 10.3390/biom13121741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 11/30/2023] [Accepted: 11/30/2023] [Indexed: 12/24/2023] Open
Abstract
Raf-1, a multifunctional kinase, regulates various cellular processes, including cell proliferation, apoptosis, and migration, by phosphorylating MAPK/ERK kinase and interacting with specific kinases. Cellular Raf-1 activity is intricately regulated through pathways involving the binding of regulatory proteins, direct phosphorylation, and the ubiquitin-proteasome axis. In this study, we demonstrate that PHI-1, an endogenous inhibitor of protein phosphatase-1 (PP1), plays a pivotal role in modulating Raf-1 proteostasis within cells. Knocking down endogenous PHI-1 in HEK293 cells using siRNA resulted in increased cell proliferation and reduced apoptosis. This heightened cell proliferation was accompanied by a 15-fold increase in ERK1/2 phosphorylation. Importantly, the observed ERK1/2 hyperphosphorylation was attributable to an upregulation of Raf-1 expression, rather than an increase in Ras levels, Raf-1 Ser338 phosphorylation, or B-Raf levels. The elevated Raf-1 expression, stemming from PHI-1 knockdown, enhanced EGF-induced ERK1/2 phosphorylation through MEK. Moreover, PHI-1 knockdown significantly contributed to Raf-1 protein stability without affecting Raf-1 mRNA levels. Conversely, ectopic PHI-1 expression suppressed Raf-1 protein levels in a manner that correlated with PHI-1's inhibitory potency. Inhibiting PP1 to mimic PHI-1's function using tautomycin led to a reduction in Raf-1 expression. In summary, our findings highlight that the PHI-1-PP1 signaling axis selectively governs Raf-1 proteostasis and cell survival signals.
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Affiliation(s)
- Jason A. Kirkbride
- Department of Molecular Physiology and Biophysics, and Kimmel Cancer Center, Jefferson Medical College, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Garbo Young Nilsson
- Department of Molecular Physiology and Biophysics, and Kimmel Cancer Center, Jefferson Medical College, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Jee In Kim
- Department of Molecular Physiology and Biophysics, and Kimmel Cancer Center, Jefferson Medical College, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
- Department of Molecular Medicine, Keimyung University School of Medicine, Daegu 42601, Republic of Korea
| | - Kosuke Takeya
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, Okayama University of Science, Imabari 794-8555, Ehime, Japan (Y.T.)
| | - Yoshinori Tanaka
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, Okayama University of Science, Imabari 794-8555, Ehime, Japan (Y.T.)
| | - Hiroshi Tokumitsu
- Applied Cell Biology, Graduate School of Interdisciplinary Science & Engineering in Health Systems, Okayama University, Okayama 700-8530, Okayama, Japan
| | - Futoshi Suizu
- Oncology Pathology, Department of Pathology and Host-Defense, Faculty of Medicine, Kagawa University, Kita-gun 761-0793, Kagawa, Japan;
| | - Masumi Eto
- Department of Molecular Physiology and Biophysics, and Kimmel Cancer Center, Jefferson Medical College, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, Okayama University of Science, Imabari 794-8555, Ehime, Japan (Y.T.)
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10
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Shen Y, Peng X, Ji H, Gong W, Zhu H, Wang J. Dapagliflozin protects heart function against type-4 cardiorenal syndrome through activation of PKM2/ PP1/FUNDC1-dependent mitophagy. Int J Biol Macromol 2023; 250:126116. [PMID: 37541471 DOI: 10.1016/j.ijbiomac.2023.126116] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/01/2023] [Accepted: 08/01/2023] [Indexed: 08/06/2023]
Abstract
Dapagliflozin (DAPA) confers significant protection against heart and kidney diseases. However, whether DAPA can alleviate type 4 cardiorenal syndrome (CRS-4)-related cardiomyopathy remains unclear. We tested the hypothesis that DAPA attenuates CRS-4-related myocardial damage through pyruvate kinase isozyme M2 (PKM2) induction and FUN14 domain containing 1 (FUNDC1)-related mitophagy. Cardiomyocyte-specific PKM2 knockout (PKM2CKO) and FUNDC1 knockout (FUNDC1CKO) mice were subjected to subtotal (5/6) nephrectomy to establish a CRS-4 model in vivo. DAPA enhanced PKM2 expression and improved myocardial function and structure in vivo, and this effect was abrogated by PKM2 knockdown. A significant improvement in mitochondrial function was observed in HL-1 cells exposed to sera from DAPA-treated mice, as featured by increased ATP production, decreased mtROS production, improved mitochondrial membrane potential, preserved mitochondrial complex activity, and reduced mitochondrial apoptosis. DAPA restored FUNDC1-dependent mitophagy through post-transcriptional dephosphorylation in a manner dependent on PKM2 whereas ablation of FUNDC1 abolished the defensive actions of DAPA on myocardium and mitochondria under CRS-4. Co-IP and molecular docking assays indicated that PKM2 directly interacted with protein phosphatase 1 (PP1) and FUNDC1, leading to PP1-mediated FUNDC1 dephosphorylation. These results suggest that DAPA attenuates CRS-4-related cardiomyopathy through activating the PKM2/PP1/FUNDC1-mitophagy pathway.
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Affiliation(s)
- Yang Shen
- Department of Cardiology, School of Medicine, South China University of Technology, Guangzhou, 510006; Department of Cardiology, The Sixth Medical Center of People's Liberation Army General Hospital, Beijing, China
| | - Xiaojie Peng
- Department of Gastroenterology, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China; The Third School of Clinical Medicine, Southern Medical University, Shenzhen, Guangdong, China; Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou city, Guangdong province, China
| | - Haizhe Ji
- Faculty of medicine, Dalian university of technology, Dalian, China
| | - Wei Gong
- Department of Gastroenterology, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China; The Third School of Clinical Medicine, Southern Medical University, Shenzhen, Guangdong, China.
| | - Hang Zhu
- Department of Cardiology, School of Medicine, South China University of Technology, Guangzhou, 510006; Department of Cardiology, The Sixth Medical Center of People's Liberation Army General Hospital, Beijing, China.
| | - Jin Wang
- Department of Vascular Medicine, Peking University Shougang Hospital, Beijing 100144, China.
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11
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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12
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Camlin NJ, Venkatachalam I, Evans JP. Oscillations in PP1 activity are essential for accurate progression through mammalian oocyte meiosis. Cell Cycle 2023:1-23. [PMID: 37340734 PMCID: PMC10361142 DOI: 10.1080/15384101.2023.2225924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2023] Open
Abstract
Tightly controlled fluctuations in kinase and phosphatase activity play important roles in regulating M-phase transitions. Protein Phosphatase 1 (PP1) is one of these phosphatases, with oscillations in PP1 activity driving mitotic M-phase. Evidence from a variety of experimental systems also points to roles in meiosis. Here, we report that PP1 is important for M-phase transitions through mouse oocyte meiosis. We employed a unique small-molecule approach to inhibit or activate PP1 at distinct phases of mouse oocyte meiosis. These studies show that temporal control of PP1 activity is essential for the G2/M transition, metaphase I/anaphase I transition, and the formation of a normal metaphase II oocyte. Our data also reveal that inappropriate activation of PP1 is more deleterious at the G2/M transition than at prometaphase I-to-metaphase I, and that an active pool of PP1 during prometaphase is vital for metaphase I/anaphase I transition and metaphase II chromosome alignment. Taken together, these results establish that loss of oscillations in PP1 activity causes a range of severe meiotic defects, pointing to essential roles for PP1 in female fertility, and more broadly, M-phase regulation.
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Affiliation(s)
- Nicole J Camlin
- Department of Biological Sciences, Purdue University, West Lafayette, IN United States
| | - Ilakkiya Venkatachalam
- Department of Biological Sciences, Purdue University, West Lafayette, IN United States
- Department of Human Genetics, University of Michigan, Ann Arbor, MI United States
| | - Janice P Evans
- Department of Biological Sciences, Purdue University, West Lafayette, IN United States
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13
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Stonyte V, Mastrangelopoulou M, Timmer R, Lindbergsengen L, Vietri M, Campsteijn C, Grallert B. The GCN2/eIF2αK stress kinase regulates PP1 to ensure mitotic fidelity. EMBO Rep 2023:e56100. [PMID: 37291955 PMCID: PMC10398673 DOI: 10.15252/embr.202256100] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 06/10/2023] Open
Abstract
GCN2/eIF2αK4 is exclusively seen as an eIF2α kinase, which regulates reprogramming of protein translation in response to stress. Here, we show that GCN2 has an unexpected role in unstressed cells as a regulator of mitosis. This function is not through its canonical role in translation reprogramming, but through the regulation of two previously unidentified substrates, PP1α and γ. In the absence of GCN2 function, timing and levels of phosphorylation of key mitotic players are altered, leading to aberrant chromosome alignment, missegregating chromosomes, elevated number of tripolar spindles, and a delay in progression through mitosis. Pharmacological inhibition of GCN2 results in similar effects and is synergistic with Aurora A inhibition in causing more severe mitotic errors and cell death. We suggest that GCN2-dependent phosphorylation of PP1α and γ restrains their activity and this is important to ensure the timely regulation of phosphorylation of several PP1 substrates during early mitosis. These findings highlight a druggable PP1 inhibitor and open new avenues of research on the therapeutic potential of GCN2 inhibitors.
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Affiliation(s)
- Vilte Stonyte
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Maria Mastrangelopoulou
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Romy Timmer
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Lilian Lindbergsengen
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Marina Vietri
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Coen Campsteijn
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Beáta Grallert
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
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14
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Bogush D, Schramm J, Ding Y, He B, Singh C, Sharma A, Tukaramrao DB, Iyer S, Desai D, Nalesnik G, Hengst J, Bhalodia R, Gowda C, Dovat S. Signaling pathways and regulation of gene expression in hematopoietic cells. Adv Biol Regul 2023; 88:100942. [PMID: 36621151 DOI: 10.1016/j.jbior.2022.100942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/06/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
Cellular functions are regulated by signal transduction pathway networks consisting of protein-modifying enzymes that control the activity of many downstream proteins. Protein kinases and phosphatases regulate gene expression by reversible phosphorylation of transcriptional factors, which are their direct substrates. Casein kinase II (CK2) is a serine/threonine kinase that phosphorylates a large number of proteins that have critical roles in cellular proliferation, metabolism and survival. Altered function of CK2 has been associated with malignant transformation, immunological disorders and other types of diseases. Protein phosphatase 1 (PP1) is a serine/threonine phosphatase, which regulates the phosphorylation status of many proteins that are essential for cellular functions. IKAROS is a DNA-binding protein, which functions as a regulator of gene transcription in hematopoietic cells. CK2 directly phosphorylates IKAROS at multiple phosphosites which determines IKAROS activity as a regulator of gene expression. PP1 binds to IKAROS via the PP1-consensus recognition site and dephosphorylates serine/threonine residues that are phosphorylated by CK2. Thus, the interplay between CK2 and PP1 signaling pathways have opposing effects on the phosphorylation status of their mutual substrate - IKAROS. This review summarizes the effects of CK2 and PP1 on IKAROS role in regulation of gene expression and its function as a tumor suppressor in leukemia.
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Affiliation(s)
- Daniel Bogush
- Pennsylvania State University College of Medicine, Hershey, PA, 1703, USA
| | - Joseph Schramm
- Pennsylvania State University College of Medicine, Hershey, PA, 1703, USA
| | - Yali Ding
- Pennsylvania State University College of Medicine, Hershey, PA, 1703, USA
| | - Bing He
- Pennsylvania State University College of Medicine, Hershey, PA, 1703, USA
| | - Chingakham Singh
- Pennsylvania State University College of Medicine, Hershey, PA, 1703, USA
| | - Arati Sharma
- Pennsylvania State University College of Medicine, Hershey, PA, 1703, USA
| | | | - Soumya Iyer
- University of Chicago, Chicago, IL, 60637, USA
| | - Dhimant Desai
- Pennsylvania State University College of Medicine, Hershey, PA, 1703, USA
| | - Gregory Nalesnik
- Pennsylvania State University College of Medicine, Hershey, PA, 1703, USA
| | - Jeremy Hengst
- Pennsylvania State University College of Medicine, Hershey, PA, 1703, USA
| | - Riya Bhalodia
- Pennsylvania State University College of Medicine, Hershey, PA, 1703, USA
| | - Chandrika Gowda
- Pennsylvania State University College of Medicine, Hershey, PA, 1703, USA.
| | - Sinisa Dovat
- Pennsylvania State University College of Medicine, Hershey, PA, 1703, USA.
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15
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Kastian RF, Baba K, Kaewkascholkul N, Sasaki H, Watanabe R, Toriyama M, Inagaki N. Dephosphorylation of neural wiring protein shootin1 by PP1 phosphatase regulates netrin-1-induced axon guidance. J Biol Chem 2023; 299:104687. [PMID: 37044214 DOI: 10.1016/j.jbc.2023.104687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 04/14/2023] Open
Abstract
Axon pathfinding is an essential step in neuronal network formation. Shootin1a is a clutch-linker molecule that is mechanically involved in axon outgrowth and guidance. It was previously shown that concentration gradients of axon guidance molecule netrin-1 in the extracellular environment elicit asymmetrically localized Pak1 kinase-mediated phosphorylation of shootin1a within axonal growth cones, which is higher on the netrin-1 source side. This asymmetric phosphorylation promotes shootin1a-mediated local actin-adhesion coupling within growth cones, thereby generating directional forces for turning the growth cone toward the netrin-1 source. However, how the spatial differences in netrin-1 concentration are transduced into the asymmetrically localized signaling within growth cones remains unclear. Moreover, the protein phosphatases that dephosphorylate shootin1a remain unidentified. Here, we report that protein phosphatase-1 (PP1) dephosphorylates shootin1a in growth cones. We found that PP1 overexpression abolished the netrin-1-induced asymmetric localization of phosphorylated-shootin1a as well as axon turning. In addition, we show PP1 inhibition reversed the asymmetrically localized shootin1a phosphorylation within growth cones under netrin-1 gradient, thereby changing the netrin-1-induced growth cone turning from attraction to repulsion. These data indicate that PP1-mediated shootin1a dephosphorylation plays a key role in organizing asymmetrically-localized phosphorylated shootin1a within growth cones, which regulates netrin-1-induced axon guidance.
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Affiliation(s)
- Ria Fajarwati Kastian
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan; Mammalian Cell Engineering and Signal Transduction Research Group, Research Center for Genetic Engineering, National Research and Innovation Agency, KST Soekarno, Jl. Raya Bogor, KM. 46, Cibinong, Bogor, West Java, 16911, Indonesia
| | - Kentarou Baba
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Napol Kaewkascholkul
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Hisashi Sasaki
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Rikiya Watanabe
- Molecular Physiology Laboratory, Cluster for Pioneering Research, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Michinori Toriyama
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Naoyuki Inagaki
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
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16
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Alba Posse EJ, González C, Carriquiriborde P, Nadra A, Gasulla J. Optimization and validation of a protein phosphatase inhibition assay for accessible microcystin detection. Talanta 2023; 255:124174. [PMID: 36608426 DOI: 10.1016/j.talanta.2022.124174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/28/2022] [Accepted: 12/04/2022] [Indexed: 12/27/2022]
Abstract
The presence of cyanobacterial toxins in freshwater constitutes an increasing public health concern, especially affecting developing countries where the high cost of available methods makes monitoring programs difficult. The phosphatase inhibition assay (PPIA) is a sensitive method with low instrument requirements that allows the quantification of the most frequent cyanotoxins, microcystins (MCs). In this work, we implemented a PPIA, starting from Protein Phosphatase 1 (PP1) expression up to the validation with samples of algal blooms from Argentina. To do this, we optimized the expression and lyophilization of PP1, and the assay conditions. Also, we included robustness and possible interference analysis. We evaluated the most widely used cyanobacterial lysis methods and determined that heating for 15 min at 95 °C is simple and adequate for this assay. Then, we performed MC spikes recovery assays on water samples from three dams from Argentina, resulting in a recovery ranging from 77 to 115%. The limit of detection (LOD) was 0.4 μg/L and the linear range is 0.4 μg/L - 5 μg/L. Finally, we evaluated 65 environmental samples where MCs was measured by ELISA test containing from 0 μg/L to 625 μg/L. The PPIA showed excellent correlation (Pearson correlation coefficient = 0.967), no false negative and no false positives above the 1 μg/L WHO guideline (0.11 false positive rate). In conclusion, we optimized and validated a PPIA to be an effective and accessible alternative to available commercial tests.
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Affiliation(s)
- Ezequiel Jorge Alba Posse
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Instituto de Biociencias, Biotecnología y Biología Traslacional (iB3), Universidad de Buenos Aires, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Buenos Aires, Argentina
| | - Carolina González
- Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución, Instituto IEGEBA (CONICET-UBA), Universidad de Buenos Aires, Argentina; Centro de investigaciones, Agua y Saneamientos Argentinos, CABA, Argentina
| | - Pedro Carriquiriborde
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Buenos Aires, Argentina; Centro de Investigaciones Del Medio Ambiente (CIM),Universidad Nacional de la Plata-CONICET, La Plata, Argentina
| | - Alejandro Nadra
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Instituto de Biociencias, Biotecnología y Biología Traslacional (iB3), Universidad de Buenos Aires, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Buenos Aires, Argentina
| | - Javier Gasulla
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Instituto de Biociencias, Biotecnología y Biología Traslacional (iB3), Universidad de Buenos Aires, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Buenos Aires, Argentina; Centro de Investigaciones Del Medio Ambiente (CIM),Universidad Nacional de la Plata-CONICET, La Plata, Argentina.
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17
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Zhang J, Fang P, Ren J, Xia S, Zhang H, Zhu X, Ding T, Xiao S, Fang L. Porcine Epidemic Diarrhea Virus nsp7 Inhibits MDA5 Dephosphorylation to Antagonize Type I Interferon Production. Microbiol Spectr 2023:e0501722. [PMID: 36975829 PMCID: PMC10100820 DOI: 10.1128/spectrum.05017-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
Abstract
Porcine epidemic diarrhea virus (PEDV) is a reemerging enteropathogenic coronavirus that causes high mortality in piglets and has catastrophic effects on the global pig industry. PEDV-encoded nonstructural protein 7 (nsp7) is an important component of the viral replication and transcription complex, and a previous study reported that it inhibits poly(I:C)-induced type I interferon (IFN) production, but the mechanism by which this occurs remains unclear. Here, we demonstrated that ectopic expression of PEDV nsp7 antagonized Sendai virus (SeV)-induced interferon beta (IFN-β) production, as well as the activation of transcription factors interferon regulatory factor 3 (IRF3) and nuclear factor-kappa B (NF-κB) in both HEK-293T and LLC-PK1 cells. Mechanistically, PEDV nsp7 targets melanoma differentiation-associated gene 5 (MDA5) and interacts with its caspase activation and recruitment domains (CARDs), which sequester the interactions between MDA5 and the protein phosphatase 1 (PP1) catalytic subunits (PP1α and PP1γ), thereby suppressing MDA5 S828 dephosphorylation and keeping MDA5 inactive. Furthermore, PEDV infection attenuated MDA5 multimerization and MDA5-PP1α/-γ interactions. We also tested the nsp7 orthologs of five other mammalian coronaviruses and found that all of them except severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nsp7 inhibited MDA5 multimerization and SeV- or MDA5-induced IFN-β production. Collectively, these results suggest that the inhibition of MDA5 dephosphorylation and multimerization may be a common strategy employed by PEDV and some other coronaviruses to antagonize MDA5-mediated IFN production. IMPORTANCE Since late 2010, a reemerging porcine epidemic diarrhea virus variant with high pathogenesis has swept through most pig farms in many countries, resulting in significant economic losses. Coronavirus nonstructural protein 7 (nsp7), conserved within the family Coronaviridae, combines with nsp8 and nsp12 to form the viral replication and transcription complex that is indispensable for viral replication. However, the function of nsp7 in the infection and pathogenesis of coronaviruses remains largely unknown. Our present study demonstrates that PEDV nsp7 specifically competes with PP1 for binding MDA5 and impedes the PP1-mediated dephosphorylation of MDA5 at S828, thereby blocking MDA5-mediated IFN production, revealing the complex mechanism utilized by PEDV nsp7 to efficiently escape host innate immunity.
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Affiliation(s)
- Jiansong Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, the Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Puxian Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, the Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Jie Ren
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, the Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Sijin Xia
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, the Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Huichang Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, the Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Xuerui Zhu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, the Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Tong Ding
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, the Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Shaobo Xiao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, the Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Liurong Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, the Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Zhang K, Da Silva F, Seidl C, Wilsch-Bräuninger M, Herbst J, Huttner WB, Niehrs C. Primary cilia are WNT-transducing organelles whose biogenesis is controlled by a WNT- PP1 axis. Dev Cell 2023; 58:139-154.e8. [PMID: 36693320 DOI: 10.1016/j.devcel.2022.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 10/18/2022] [Accepted: 12/19/2022] [Indexed: 01/24/2023]
Abstract
WNT signaling is important in development, stem cell maintenance, and disease. WNT ligands typically signal via receptor activation across the plasma membrane to induce β-catenin-dependent gene activation. Here, we show that in mammalian primary cilia, WNT receptors relay a WNT/GSK3 signal that β-catenin-independently promotes ciliogenesis. Characterization of a LRP6 ciliary targeting sequence and monitoring of acute WNT co-receptor activation (phospho-LRP6) support this conclusion. Ciliary WNT signaling inhibits protein phosphatase 1 (PP1) activity, a negative regulator of ciliogenesis, by preventing GSK3-mediated phosphorylation of the PP1 regulatory inhibitor subunit PPP1R2. Concordantly, deficiency of WNT/GSK3 signaling by depletion of cyclin Y and cyclin-Y-like protein 1 induces primary cilia defects in mouse embryonic neuronal precursors, kidney proximal tubules, and adult mice preadipocytes.
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Affiliation(s)
- Kaiqing Zhang
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Fabio Da Silva
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Carina Seidl
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Michaela Wilsch-Bräuninger
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraβe 108, 01307 Dresden, Germany
| | - Jessica Herbst
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Wieland B Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraβe 108, 01307 Dresden, Germany
| | - Christof Niehrs
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany; Institute of Molecular Biology (IMB), 55128 Mainz, Germany.
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20
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Kuroiwa M, Shuto T, Nagai T, Amano M, Kaibuchi K, Nairn AC, Nishi A. DARPP-32/protein phosphatase 1 regulates Rasgrp2 as a novel component of dopamine D1 receptor signaling in striatum. Neurochem Int 2023; 162:105438. [PMID: 36351540 DOI: 10.1016/j.neuint.2022.105438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/14/2022] [Accepted: 11/01/2022] [Indexed: 11/09/2022]
Abstract
Dopamine regulates psychomotor function by D1 receptor/PKA-dependent phosphorylation of DARPP-32. DARPP-32, phosphorylated at Thr34 by PKA, inhibits protein phosphatase 1 (PP1), and amplifies the phosphorylation of other PKA/PP1 substrates following D1 receptor activation. In addition to the D1 receptor/PKA/DARPP-32 signaling pathway, D1 receptor stimulation is known to activate Rap1/ERK signaling. Rap1 activation is mediated through the phosphorylation of Rasgrp2 (guanine nucleotide exchange factor; activation) and Rap1gap (GTPase-activating protein; inhibition) by PKA. In this study, we investigated the role of PP1 inhibition by phospho-Thr34 DARPP-32 in the D1 receptor-induced phosphorylation of Rasgrp2 and Rap1gap at PKA sites. The analyses in striatal and NAc slices from wild-type and DARPP-32 knockout mice revealed that the phosphorylation of Rasgrp2 at Ser116/Ser117 and Ser586, but not of Rasgrp2 at Ser554 or Rap1gap at Ser441 or Ser499 induced by a D1 receptor agonist, is under the control of the DARPP-32/PP1. The results were supported by pharmacological analyses using a selective PP1 inhibitor, tautomycetin. In addition, analyses using a PP1 and PP2A inhibitor, okadaic acid, revealed that all sites of Rasgrp2 and Rap1gap were regulated by PP2A. Thus, the interactive machinery of DARPP-32/PP1 may contribute to efficient D1 receptor signaling via Rasgrp2/Rap1 in the striatum.
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Affiliation(s)
- Mahomi Kuroiwa
- Department of Pharmacology, Kurume University School of Medicine, Kurume, Fukuoka, 830-0011, Japan
| | - Takahide Shuto
- Department of Pharmacology, Kurume University School of Medicine, Kurume, Fukuoka, 830-0011, Japan
| | - Taku Nagai
- Division of Behavioral Neuropharmacology, International Center for Brain Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Mutsuki Amano
- Department of Cell Pharmacology, Graduate School of Medicine, Nagoya University, Nagoya, Aichi, 466-8550, Japan
| | - Kozo Kaibuchi
- Department of Cell Pharmacology, Graduate School of Medicine, Nagoya University, Nagoya, Aichi, 466-8550, Japan; Division of Cell Biology, International Center for Brain Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Angus C Nairn
- Department of Psychiatry, Yale School of Medicine, Connecticut Mental Health Center, New Haven, CT, 06519, United States
| | - Akinori Nishi
- Department of Pharmacology, Kurume University School of Medicine, Kurume, Fukuoka, 830-0011, Japan.
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21
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Acharya D, Reis R, Volcic M, Liu G, Wang MK, Chia BS, Nchioua R, Groß R, Münch J, Kirchhoff F, Sparrer KMJ, Gack MU. Actin cytoskeleton remodeling primes RIG-I-like receptor activation. Cell 2022; 185:3588-3602.e21. [PMID: 36113429 PMCID: PMC9680832 DOI: 10.1016/j.cell.2022.08.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 06/17/2022] [Accepted: 08/10/2022] [Indexed: 01/26/2023]
Abstract
The current dogma of RNA-mediated innate immunity is that sensing of immunostimulatory RNA ligands is sufficient for the activation of intracellular sensors and induction of interferon (IFN) responses. Here, we report that actin cytoskeleton disturbance primes RIG-I-like receptor (RLR) activation. Actin cytoskeleton rearrangement induced by virus infection or commonly used reagents to intracellularly deliver RNA triggers the relocalization of PPP1R12C, a regulatory subunit of the protein phosphatase-1 (PP1), from filamentous actin to cytoplasmic RLRs. This allows dephosphorylation-mediated RLR priming and, together with the RNA agonist, induces effective RLR downstream signaling. Genetic ablation of PPP1R12C impairs antiviral responses and enhances susceptibility to infection with several RNA viruses including SARS-CoV-2, influenza virus, picornavirus, and vesicular stomatitis virus. Our work identifies actin cytoskeleton disturbance as a priming signal for RLR-mediated innate immunity, which may open avenues for antiviral or adjuvant design.
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Affiliation(s)
- Dhiraj Acharya
- Florida Research and Innovation Center, Cleveland Clinic, Port Saint Lucie, FL 34987, USA; Department of Microbiology, The University of Chicago, Chicago, IL 60637, USA
| | - Rebecca Reis
- Department of Microbiology, The University of Chicago, Chicago, IL 60637, USA
| | - Meta Volcic
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - GuanQun Liu
- Florida Research and Innovation Center, Cleveland Clinic, Port Saint Lucie, FL 34987, USA; Department of Microbiology, The University of Chicago, Chicago, IL 60637, USA
| | - May K Wang
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Bing Shao Chia
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Rayhane Nchioua
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Rüdiger Groß
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Jan Münch
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | | | - Michaela U Gack
- Florida Research and Innovation Center, Cleveland Clinic, Port Saint Lucie, FL 34987, USA; Department of Microbiology, The University of Chicago, Chicago, IL 60637, USA.
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22
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Jadoon S, Qin Q, Shi W, Longfeng Y, Hou S. Rice protein phosphatase 1 regulatory subunits OsINH2 and OsINH3 participate actively in growth and adaptive responses under abscisic acid. Front Plant Sci 2022; 13:990575. [PMID: 36186070 PMCID: PMC9521630 DOI: 10.3389/fpls.2022.990575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 08/11/2022] [Indexed: 06/16/2023]
Abstract
Rice (Oryza sativa L.), a worldwide staple food crop, is affected by various environmental stressors that ultimately reduce yield. However, diversified physiological and molecular responses enable it to cope with adverse factors. It includes the integration of numerous signaling in which protein phosphatase 1 (PP1) plays a pivotal role. Research on PP1 has been mostly limited to the PP1 catalytic subunit in numerous cellular progressions. Therefore, we focused on the role of PP1 regulatory subunits (PP1r), OsINH2 and OsINH3, homologs of AtINH2 and AtINH3 in Arabidopsis, in rice growth and stress adaptations. Our observations revealed that these are ubiquitously expressed regulatory subunits that interacted and colocalized with their counter partners, type 1 protein phosphatase (OsTOPPs) but could not change their subcellular localization. The mutation in OsINH2 and OsINH3 reduced pollen viability, thereby affected rice fertility. They were involved in abscisic acid (ABA)-mediated inhibition of seed germination, perhaps by interacting with osmotic stress/ABA-activated protein kinases (OsSAPKs). Meanwhile, they positively participated in osmotic adjustment by proline biosynthesis, detoxifying reactive oxygen species (ROS) through peroxidases (POD), reducing malondialdehyde formation (MDA), and regulating stress-responsive genes. Moreover, their co-interaction proposed they might mediate cellular processes together or by co-regulation; however, the special behavior of two different PP1r is needed to explore. In a nutshell, this research enlightened the involvement of OsINH2 and OsINH3 in the reproductive growth of rice and adaptive strategies under stress. Hence, their genetic interaction with ABA components and deep mechanisms underlying osmotic regulation and ROS adjustment would explain their role in complex signaling. This research offers the basis for introducing stress-resistant crops.
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23
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Beacham GM, Wei DT, Beyrent E, Zhang Y, Zheng J, Camacho MMK, Florens L, Hollopeter G. The Caenorhabditis elegans ASPP homolog APE-1 is a junctional protein phosphatase 1 modulator. Genetics 2022; 222:iyac102. [PMID: 35792852 PMCID: PMC9434228 DOI: 10.1093/genetics/iyac102] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 06/28/2022] [Indexed: 08/19/2023] Open
Abstract
How serine/threonine phosphatases are spatially and temporally tuned by regulatory subunits is a fundamental question in cell biology. Ankyrin repeat, SH3 domain, proline-rich-region-containing proteins are protein phosphatase 1 catalytic subunit binding partners associated with cardiocutaneous diseases. Ankyrin repeat, SH3 domain, proline-rich-region-containing proteins localize protein phosphatase 1 catalytic subunit to cell-cell junctions, but how ankyrin repeat, SH3 domain, proline-rich-region-containing proteins localize and whether they regulate protein phosphatase 1 catalytic subunit activity in vivo is unclear. Through a Caenorhabditis elegans genetic screen, we find that loss of the ankyrin repeat, SH3 domain, proline-rich-region-containing protein homolog, APE-1, suppresses a pathology called "jowls," providing us with an in vivo assay for APE-1 activity. Using immunoprecipitations and mass spectrometry, we find that APE-1 binds the protein phosphatase 1 catalytic subunit called GSP-2. Through structure-function analysis, we discover that APE-1's N-terminal half directs the APE-1-GSP-2 complex to intercellular junctions. Additionally, we isolated mutations in highly conserved residues of APE-1's ankyrin repeats that suppress jowls yet do not preclude GSP-2 binding, implying APE-1 does more than simply localize GSP-2. Indeed, in vivo reconstitution of APE-1 suggests the ankyrin repeats modulate phosphatase output, a function we find to be conserved among vertebrate homologs.
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Affiliation(s)
| | - Derek T Wei
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Erika Beyrent
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Ying Zhang
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Jian Zheng
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Mari M K Camacho
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Laurence Florens
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Gunther Hollopeter
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
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24
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Fréville A, Gnangnon B, Tremp AZ, De Witte C, Cailliau K, Martoriati A, Aliouat EM, Fernandes P, Chhuon C, Silvie O, Marion S, Guerrera IC, Dessens JT, Pierrot C, Khalife J. Plasmodium berghei leucine-rich repeat protein 1 downregulates protein phosphatase 1 activity and is required for efficient oocyst development. Open Biol 2022; 12:220015. [PMID: 35920043 PMCID: PMC9346556 DOI: 10.1098/rsob.220015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 07/07/2022] [Indexed: 12/14/2022] Open
Abstract
Protein phosphatase 1 (PP1) is a key enzyme for Plasmodium development. However, the detailed mechanisms underlying its regulation remain to be deciphered. Here, we report the functional characterization of the Plasmodium berghei leucine-rich repeat protein 1 (PbLRR1), an orthologue of SDS22, one of the most ancient and conserved PP1 interactors. Our study shows that PbLRR1 is expressed during intra-erythrocytic development of the parasite, and up to the zygote stage in mosquitoes. PbLRR1 can be found in complex with PbPP1 in both asexual and sexual stages and inhibits its phosphatase activity. Genetic analysis demonstrates that PbLRR1 depletion adversely affects the development of oocysts. PbLRR1 interactome analysis associated with phospho-proteomics studies identifies several novel putative PbLRR1/PbPP1 partners. Some of these partners have previously been characterized as essential for the parasite sexual development. Interestingly, and for the first time, Inhibitor 3 (I3), a well-known and direct interactant of Plasmodium PP1, was found to be drastically hypophosphorylated in PbLRR1-depleted parasites. These data, along with the detection of I3 with PP1 in the LRR1 interactome, strongly suggest that the phosphorylation status of PbI3 is under the control of the PP1-LRR1 complex and could contribute (in)directly to oocyst development. This study provides new insights into previously unrecognized PbPP1 fine regulation of Plasmodium oocyst development through its interaction with PbLRR1.
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Affiliation(s)
- Aline Fréville
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Centre d'Infection et d'Immunité de Lille, 59000 Lille, France
| | - Bénédicte Gnangnon
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Centre d'Infection et d'Immunité de Lille, 59000 Lille, France
| | - Annie Z. Tremp
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Tropical Medicine and Hygiene, Keppel Street, WC1E 7HT London, UK
| | - Caroline De Witte
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Centre d'Infection et d'Immunité de Lille, 59000 Lille, France
| | - Katia Cailliau
- Univ. Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France
| | - Alain Martoriati
- Univ. Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France
| | - El Moukthar Aliouat
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Centre d'Infection et d'Immunité de Lille, 59000 Lille, France
| | - Priyanka Fernandes
- Sorbonne Université, INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses, F-75013 Paris, France
| | - Cerina Chhuon
- Proteomics platform 3P5-Necker, Université Paris Descartes - Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, Paris, France
| | - Olivier Silvie
- Sorbonne Université, INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses, F-75013 Paris, France
| | - Sabrina Marion
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Centre d'Infection et d'Immunité de Lille, 59000 Lille, France
| | - Ida Chiara Guerrera
- Proteomics platform 3P5-Necker, Université Paris Descartes - Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, Paris, France
| | - Johannes T. Dessens
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Tropical Medicine and Hygiene, Keppel Street, WC1E 7HT London, UK
| | - Christine Pierrot
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Centre d'Infection et d'Immunité de Lille, 59000 Lille, France
| | - Jamal Khalife
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Centre d'Infection et d'Immunité de Lille, 59000 Lille, France
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25
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Xu X, He X, Zhang Z, Chen Y, Li J, Ma S, Huang Q, Li M. CREB Inactivation by HDAC1/ PP1γ Contributes to Dopaminergic Neurodegeneration in Parkinson's Disease. J Neurosci 2022; 42:4594-4604. [PMID: 35501151 PMCID: PMC9172078 DOI: 10.1523/jneurosci.1419-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 04/19/2022] [Accepted: 04/21/2022] [Indexed: 11/21/2022] Open
Abstract
Understanding the pathogenesis of nigral dopaminergic neurodegeneration is critical for developing mechanism-based treatments for Parkinson's disease (PD). In the nigral dopaminergic neurons of postmortem human PD brains, we found that CREB, a well-recognized pro-survival transcription factor in neurons, was inactivated by dephosphorylation at Ser133. CREB dephosphorylation correlated with decreased expression of NURR1, one of its target genes crucial for dopaminergic neuron survival, confirming that CREB function was impaired in nigral dopaminergic neurons in PD. An MPTP mouse model was used to further elucidate the mechanism underlying CREB dephosphorylation. Protein phosphatase 1γ (PP1γ), which dephosphorylates CREB, was constitutively associated with histone deacetylase 1 (HDAC1). HDAC1 promotes CREB Ser133 dephosphorylation via a stable interaction with PP1γ. We found that CREB interacted with the HDAC1/PP1γ complex during dopaminergic neurodegeneration. Importantly, increased CREB/HDAC1 interaction occurred in the nigral dopaminergic neurons of PD patients as demonstrated using a proximity ligation assay. Disrupting CREB/HDAC1 interaction via either overexpression of GAL4 M1, a CREB mutant, or administration of trichostatin A, a pan-HDAC inhibitor, restored the expression levels of phospho-CREB (Ser133) and NURR1, and protected nigral dopaminergic neurons in the MPTP-treated mouse brain. Collectively, our results demonstrated that HDAC1/PP1γ-mediated CREB inactivation contributed to dopaminergic neuronal degeneration. Disruption of CREB/HDAC1 interaction has the potential to be a new approach for PD therapy.SIGNIFICANCE STATEMENT Parkinson's disease (PD) is the most common movement disorder attributed to the progressive loss of dopaminergic neurons in the substantia nigra. Understanding the pathogenesis of nigral dopaminergic neurodegeneration is critical for developing mechanism-based treatments for PD. We found in nigral dopaminergic neurons of postmortem human PD brains that CREB, a well-recognized pro-survival transcription factor in neurons, was inactivated by dephosphorylation at Ser133. HDAC1, constitutively associated with PP1γ, interacted with CREB to mediate its dephosphorylation during dopaminergic neurodegeneration. Disrupting CREB/HDAC1 interaction restored CREB activity and protected nigral dopaminergic neurons in the MPTP mouse brains. This work suggests that disruption of the CREB/HDAC1 interaction to restore CREB activity may be a potential therapeutic approach in PD.
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Affiliation(s)
- Xiaoyi Xu
- Guangdong Provincial Key Laboratory of Brain Function and Disease and Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Xin He
- Guangdong Provincial Key Laboratory of Brain Function and Disease and Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Zeyan Zhang
- Guangdong Provincial Key Laboratory of Brain Function and Disease and Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Yanyi Chen
- Guangdong Provincial Key Laboratory of Brain Function and Disease and Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Junyu Li
- Guangdong Provincial Key Laboratory of Brain Function and Disease and Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Shanshan Ma
- Guangdong Provincial Key Laboratory of Brain Function and Disease and Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Qiaoying Huang
- Guangdong Provincial Key Laboratory of Brain Function and Disease and Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Mingtao Li
- Guangdong Provincial Key Laboratory of Brain Function and Disease and Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
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26
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Keith RE, Ogoe RH, Dumas TC. Behind the scenes: Are latent memories supported by calcium independent plasticity? Hippocampus 2022; 32:73-88. [PMID: 33905147 PMCID: PMC8548406 DOI: 10.1002/hipo.23332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 04/08/2021] [Accepted: 04/11/2021] [Indexed: 02/03/2023]
Abstract
N-methyl-D-aspartate receptors (NMDARs) can be considered to be the de facto "plasticity" receptors in the brain due to their central role in the activity-dependent modification of neuronal morphology and synaptic transmission. Since the 1980s, research on NMDARs has focused on the second messenger properties of calcium and the downstream signaling pathways that mediate alterations in neural form and function. Recently, NMDARs were shown to drive activity-dependent synaptic plasticity without calcium influx. How this "nonionotropic" plasticity occurs in vitro is becoming clearer, but research on its involvement in behavior and cognition is in its infancy. There is a partial overlap in the downstream signaling molecules that are involved in ionotropic and nonionotropic NMDAR-dependent plasticity. Given this, and prior studies of the cognitive impacts of ionotropic NMDAR plasticity, a preliminary model explaining how NMDAR nonionotropic plasticity affects learning and memory can be established. We hypothesize that nonionotropic NMDAR plasticity takes part in latent memory encoding in immature rodents through nonassociative depression of synaptic efficacy, and possibly shrinking of dendritic spines. Further, the late postnatal alteration in NMDAR composition in the hippocampus appears to reduce nonionotropic signaling and remove a restriction on memory retrieval. This framework substantially alters the canonical model of NMDAR involvement in spatial cognition and hippocampal maturation and provides novel and exciting inroads for future studies.
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Affiliation(s)
- Rachel E. Keith
- Interdisciplinary Program in Neuroscience, College of Science, George Mason University, Fairfax, Virginia
| | - Richard H. Ogoe
- Department of Psychology, College of Humanities and Social Sciences, George Mason University, Fairfax, Virginia
| | - Theodore C. Dumas
- Interdisciplinary Program in Neuroscience, College of Science, George Mason University, Fairfax, Virginia,Department of Psychology, College of Humanities and Social Sciences, George Mason University, Fairfax, Virginia
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27
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Gu SH, Lin PL. Expressions of the Protein Phosphatases PP1 and PP4 during the Embryonic Diapause Process of the Silkworm Bombyx mori. Zool Stud 2022; 61:e61. [PMID: 37007811 PMCID: PMC10061206 DOI: 10.6620/zs.2022.61-61] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 08/11/2022] [Indexed: 04/04/2023]
Abstract
Reversible protein phosphorylation is accomplished by the opposing activities of kinases and phosphatases. We previously demonstrated the regulation of serine/threonine protein phosphatase (PP) type 2A (PP2A) and 2B (PP2B or calcineurin) during the embryonic diapause process of Bombyx mori. In the present study, we further examine the expressions of other PPs (PP1 and PP4) during embryonic stages. An immunoblot analysis showed that Bombyx eggs contained a 38-kDa PP1 catalytic subunit (PP1-C), a 38-kDa PP4 catalytic subunit (PP4-C), and a 120-kDa PP1 nuclear targeting subunit (PNUTS), each of which underwent differential changes between diapause and developing eggs during the embryonic process. In non-diapause eggs, eggs whose diapause initiation was prevented by HCl, and eggs in which diapause had been terminated by chilling diapausing eggs at 5°C for 70 days and then were transferred to 25°C, protein levels of PP1-C and PP4-C remained relatively high during the early embryonic stages and then decreased during middle (for PP1-C) or later (for PP4-C) embryonic stages. However, protein levels of PP1-C and PP4-C in diapause eggs remained at high levels during the first 8 days after oviposition. PNUTS protein levels showed inverse temporal changes, with increased levels being detected during the later embryonic stages of developing eggs. The direct determination of PP1 enzymatic activity showed higher activity in developing eggs than in diapause eggs. Examination of temporal changes in mRNA expression levels of PP1-C and PP4-C showed no difference between HCl-treated and diapause eggs. These results indicated that differential protein levels of PP1-C/PNUTS and PP4-C, and increased enzymatic activity of PP1 were likely related to the embryonic development of B. mori.
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Affiliation(s)
- Shi-Hong Gu
- Department of Biology, National Museum of Natural Science, 1 Kuan-Chien Road, Taichung 404, Taiwan. E-mail: (Gu); (Lin)
| | - Pei-Ling Lin
- Department of Biology, National Museum of Natural Science, 1 Kuan-Chien Road, Taichung 404, Taiwan. E-mail: (Gu); (Lin)
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28
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Abstract
Phosphorylation of the translation initiation factor eIF2α is a rapid and vital cellular defence against many forms of stress. In mammals, the levels of eIF2α phosphorylation are set through the antagonistic action of four protein kinases and two heterodimeric protein phosphatases. The phosphatases are composed of the catalytic subunit PP1 and one of two related non-catalytic subunits, PPP1R15A or PPP1R15B (R15A or R15B). Here, we generated a series of R15 truncation mutants and tested their properties in mammalian cells. We show that substrate recruitment is encoded by an evolutionary conserved region in R15s, R15A325-554 and R15B340-639. G-actin, which has been proposed to confer selectivity to R15 phosphatases, does not bind these regions, indicating that it is not required for substrate binding. Fragments containing the substrate-binding regions but lacking the PP1-binding motif trapped the phospho-substrate and caused accumulation of phosphorylated eIF2α in unstressed cells. Activity assays in cells showed that R15A325-674 and R15B340-713, encompassing the substrate-binding region and the PP1-binding region, exhibit wild-type activity. This work identifies the substrate-binding region in R15s, that functions as a phospho-substrate trapping mutant, thereby defining a key region of R15s for follow up studies.
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Affiliation(s)
- George Hodgson
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Antonina Andreeva
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Anne Bertolotti
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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29
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Klapproth E, Kämmerer S, El-Armouche A. Function and regulation of phosphatase 1 in healthy and diseased heart. Cell Signal 2022; 90:110203. [PMID: 34822978 DOI: 10.1016/j.cellsig.2021.110203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 11/12/2021] [Accepted: 11/18/2021] [Indexed: 12/12/2022]
Abstract
Reversible phosphorylation of ion channels and calcium-handling proteins provides precise post-translational regulation of cardiac excitation and contractility. Serine/threonine phosphatases govern dephosphorylation of the majority of cardiac proteins. Accordingly, dysfunction of this regulation contributes to the development and progression of heart failure and atrial fibrillation. On the molecular level, these changes include alterations in the expression level and phosphorylation status of Ca2+ handling and excitation-contraction coupling proteins provoked by dysregulation of phosphatases. The serine/threonine protein phosphatase PP1 is one a major player in the regulation of cardiac excitation-contraction coupling. PP1 essentially impacts on cardiac physiology and pathophysiology via interactions with the cardiac ion channels Cav1.2, NKA, NCX and KCNQ1, sarcoplasmic reticulum-bound Ca2+ handling proteins such as RyR2, SERCA and PLB as well as the contractile proteins MLC2, TnI and MyBP-C. PP1 itself but also PP1-regulatory proteins like inhibitor-1, inhibitor-2 and heat-shock protein 20 are dysregulated in cardiac disease. Therefore, they represent interesting targets to gain more insights in heart pathophysiology and to identify new treatment strategies for patients with heart failure or atrial fibrillation. We describe the genetic and holoenzymatic structure of PP1 and review its role in the heart and cardiac disease. Finally, we highlight the importance of the PP1 regulatory proteins for disease manifestation, provide an overview of genetic models to study the role of PP1 for the development of heart failure and atrial fibrillation and discuss possibilities of pharmacological interventions.
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Huang F, Nguyen TT, Echeverria I, Rakesh R, Cary DC, Paculova H, Sali A, Weiss A, Peterlin BM, Fujinaga K. Reversible phosphorylation of cyclin T1 promotes assembly and stability of P-TEFb. eLife 2021; 10:68473. [PMID: 34821217 PMCID: PMC8648303 DOI: 10.7554/elife.68473] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 11/19/2021] [Indexed: 01/06/2023] Open
Abstract
The positive transcription elongation factor b (P-TEFb) is a critical coactivator for transcription of most cellular and viral genes, including those of HIV. While P-TEFb is regulated by 7SK snRNA in proliferating cells, P-TEFb is absent due to diminished levels of CycT1 in quiescent and terminally differentiated cells, which has remained unexplored. In these cells, we found that CycT1 not bound to CDK9 is rapidly degraded. Moreover, productive CycT1:CDK9 interactions are increased by PKC-mediated phosphorylation of CycT1 in human cells. Conversely, dephosphorylation of CycT1 by PP1 reverses this process. Thus, PKC inhibitors or removal of PKC by chronic activation results in P-TEFb disassembly and CycT1 degradation. This finding not only recapitulates P-TEFb depletion in resting CD4+ T cells but also in anergic T cells. Importantly, our studies reveal mechanisms of P-TEFb inactivation underlying T cell quiescence, anergy, and exhaustion as well as proviral latency and terminally differentiated cells.
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Affiliation(s)
- Fang Huang
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States.,Department of Medicine, San Francisco, United States
| | - Trang Tt Nguyen
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States.,Department of Medicine, San Francisco, United States.,The Howard Hughes Medical Institute, San Francisco, United States
| | - Ignacia Echeverria
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States.,Departmentof Cellular Molecular Pharmacology, California Institute for Quantitative Biosciences (QBI), and Department of Bioengineering and Therapeutic Sciences, San Francisco, United States
| | - Ramachandran Rakesh
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States.,Departmentof Cellular Molecular Pharmacology, California Institute for Quantitative Biosciences (QBI), and Department of Bioengineering and Therapeutic Sciences, San Francisco, United States
| | - Daniele C Cary
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States.,Department of Medicine, San Francisco, United States
| | - Hana Paculova
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States
| | - Andrej Sali
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States.,Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, and California Institute for Quantitative Biosciences (QBI), San Francisco, United States
| | - Arthur Weiss
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States.,Department of Medicine, San Francisco, United States.,The Howard Hughes Medical Institute, San Francisco, United States
| | - Boris Matija Peterlin
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States.,Department of Medicine, San Francisco, United States
| | - Koh Fujinaga
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States.,Department of Medicine, San Francisco, United States
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Lagomarsino VN, Pearse RV, Liu L, Hsieh YC, Fernandez MA, Vinton EA, Paull D, Felsky D, Tasaki S, Gaiteri C, Vardarajan B, Lee H, Muratore CR, Benoit CR, Chou V, Fancher SB, He A, Merchant JP, Duong DM, Martinez H, Zhou M, Bah F, Vicent MA, Stricker JMS, Xu J, Dammer EB, Levey AI, Chibnik LB, Menon V, Seyfried NT, De Jager PL, Noggle S, Selkoe DJ, Bennett DA, Young-Pearse TL. Stem cell-derived neurons reflect features of protein networks, neuropathology, and cognitive outcome of their aged human donors. Neuron 2021; 109:3402-3420.e9. [PMID: 34473944 DOI: 10.1016/j.neuron.2021.08.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 06/30/2021] [Accepted: 08/05/2021] [Indexed: 11/26/2022]
Abstract
We have generated a controlled and manipulable resource that captures genetic risk for Alzheimer's disease: iPSC lines from 53 individuals coupled with RNA and proteomic profiling of both iPSC-derived neurons and brain tissue of the same individuals. Data collected for each person include genome sequencing, longitudinal cognitive scores, and quantitative neuropathology. The utility of this resource is exemplified here by analyses of neurons derived from these lines, revealing significant associations between specific Aβ and tau species and the levels of plaque and tangle deposition in the brain and, more importantly, with the trajectory of cognitive decline. Proteins and networks are identified that are associated with AD phenotypes in iPSC neurons, and relevant associations are validated in brain. The data presented establish this iPSC collection as a resource for investigating person-specific processes in the brain that can aid in identifying and validating molecular pathways underlying AD.
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Affiliation(s)
- Valentina N Lagomarsino
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Richard V Pearse
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Lei Liu
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Yi-Chen Hsieh
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Marty A Fernandez
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Elizabeth A Vinton
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Daniel Paull
- New York Stem Cell Foundation Research Institute, New York, NY, USA
| | - Daniel Felsky
- Krembil Centre for Neuroinformatics, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Psychiatry and Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Shinya Tasaki
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Chris Gaiteri
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Badri Vardarajan
- Center for Translational and Computational Neuroimmunology, Department of Neurology and the Taub Institute for the Study of Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY, USA
| | - Hyo Lee
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Christina R Muratore
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Courtney R Benoit
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Vicky Chou
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Seeley B Fancher
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Amy He
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Julie P Merchant
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Duc M Duong
- Department of Biochemistry, Emory School of Medicine, Atlanta, GA, USA
| | - Hector Martinez
- New York Stem Cell Foundation Research Institute, New York, NY, USA
| | - Monica Zhou
- New York Stem Cell Foundation Research Institute, New York, NY, USA
| | - Fatmata Bah
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Maria A Vicent
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Jonathan M S Stricker
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Jishu Xu
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Eric B Dammer
- Department of Biochemistry, Emory School of Medicine, Atlanta, GA, USA
| | - Allan I Levey
- Department of Neurology, Emory School of Medicine, Atlanta, GA, USA
| | - Lori B Chibnik
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Vilas Menon
- Center for Translational and Computational Neuroimmunology, Department of Neurology and the Taub Institute for the Study of Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY, USA
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory School of Medicine, Atlanta, GA, USA; Department of Neurology, Emory School of Medicine, Atlanta, GA, USA
| | - Philip L De Jager
- Center for Translational and Computational Neuroimmunology, Department of Neurology and the Taub Institute for the Study of Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY, USA
| | - Scott Noggle
- New York Stem Cell Foundation Research Institute, New York, NY, USA
| | - Dennis J Selkoe
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Tracy L Young-Pearse
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA; Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA.
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Kocakaplan D, Karabürk H, Dilege C, Kirdök I, Bektas SN, Caydasi AK. Protein phosphatase 1 in association with Bud14 inhibits mitotic exit in Saccharomyces cerevisiae. eLife 2021; 10:72833. [PMID: 34633288 PMCID: PMC8577847 DOI: 10.7554/elife.72833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/08/2021] [Indexed: 11/18/2022] Open
Abstract
Mitotic exit in budding yeast is dependent on correct orientation of the mitotic spindle along the cell polarity axis. When accurate positioning of the spindle fails, a surveillance mechanism named the spindle position checkpoint (SPOC) prevents cells from exiting mitosis. Mutants with a defective SPOC become multinucleated and lose their genomic integrity. Yet, a comprehensive understanding of the SPOC mechanism is missing. In this study, we identified the type 1 protein phosphatase, Glc7, in association with its regulatory protein Bud14 as a novel checkpoint component. We further showed that Glc7-Bud14 promotes dephosphorylation of the SPOC effector protein Bfa1. Our results suggest a model in which two mechanisms act in parallel for a robust checkpoint response: first, the SPOC kinase Kin4 isolates Bfa1 away from the inhibitory kinase Cdc5, and second, Glc7-Bud14 dephosphorylates Bfa1 to fully activate the checkpoint effector.
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Affiliation(s)
- Dilara Kocakaplan
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Hüseyin Karabürk
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Cansu Dilege
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Idil Kirdök
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Seyma Nur Bektas
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Ayse Koca Caydasi
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
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Ai X, Yan J, Pogwizd SM. Serine-threonine protein phosphatase regulation of Cx43 dephosphorylation in arrhythmogenic disorders. Cell Signal 2021; 86:110070. [PMID: 34217833 PMCID: PMC8963383 DOI: 10.1016/j.cellsig.2021.110070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 06/11/2021] [Accepted: 06/29/2021] [Indexed: 12/11/2022]
Abstract
Regulation of cell-to-cell communication in the heart by the gap junction protein Connexin43 (Cx43) involves modulation of Cx43 phosphorylation state by protein kinases, and dephosphorylation by protein phosphatases. Dephosphorylation of Cx43 has been associated with impaired intercellular coupling and enhanced arrhythmogenesis in various pathologic states. While there has been extensive study of the protein kinases acting on Cx43, there has been limited studies of the protein phosphatases that may underlie Cx43 dephosphorylation. The focus of this review is to introduce serine-threonine protein phosphatase regulation of Cx43 phosphorylation state and cell-to-cell communication, and its impact on arrhythmogenesis in the setting of chronic heart failure and myocardial ischemia, as well as on atrial fibrillation. We also discuss the therapeutic potential of modulating protein phosphatases to treat arrhythmias in these clinical settings.
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Affiliation(s)
- Xun Ai
- Department of Physiology & Biophysics, Rush University, Chicago, IL, United States of America
| | - Jiajie Yan
- Department of Physiology & Biophysics, Rush University, Chicago, IL, United States of America
| | - Steven M Pogwizd
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States of America.
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Volpi I, Gillespie PJ, Chadha GS, Blow JJ. The role of DDK and Treslin-MTBP in coordinating replication licensing and pre-initiation complex formation. Open Biol 2021; 11:210121. [PMID: 34699733 PMCID: PMC8548084 DOI: 10.1098/rsob.210121] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 09/21/2021] [Indexed: 01/04/2023] Open
Abstract
Treslin/Ticrr is required for the initiation of DNA replication and binds to MTBP (Mdm2 Binding Protein). Here, we show that in Xenopus egg extract, MTBP forms an elongated tetramer with Treslin containing two molecules of each protein. Immunodepletion and add-back experiments show that Treslin-MTBP is rate limiting for replication initiation. It is recruited onto chromatin before S phase starts and recruitment continues during S phase. We show that DDK activity both increases and strengthens the interaction of Treslin-MTBP with licensed chromatin. We also show that DDK activity cooperates with CDK activity to drive the interaction of Treslin-MTBP with TopBP1 which is a regulated crucial step in pre-initiation complex formation. These results suggest how DDK works together with CDKs to regulate Treslin-MTBP and plays a crucial in selecting which origins will undergo initiation.
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Affiliation(s)
- Ilaria Volpi
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Peter J. Gillespie
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Gaganmeet Singh Chadha
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - J. Julian Blow
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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Bradai M, Amorim-Silva V, Belgaroui N, Esteban del Valle A, Chabouté ME, Schmit AC, Lozano-Duran R, Botella MA, Hanin M, Ebel C. Wheat Type One Protein Phosphatase Participates in the Brassinosteroid Control of Root Growth via Activation of BES1. Int J Mol Sci 2021; 22:ijms221910424. [PMID: 34638765 PMCID: PMC8508605 DOI: 10.3390/ijms221910424] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/07/2021] [Accepted: 08/10/2021] [Indexed: 11/16/2022] Open
Abstract
Brassinosteroids (BRs) play key roles in diverse plant growth processes through a complex signaling pathway. Components orchestrating the BR signaling pathway include receptors such as kinases, transcription factors, protein kinases and phosphatases. The proper functioning of the receptor kinase BRI1 and the transcription factors BES1/BZR1 depends on their dephosphorylation by type 2A protein phosphatases (PP2A). In this work, we report that an additional phosphatase family, type one protein phosphatases (PP1), contributes to the regulation of the BR signaling pathway. Co-immunoprecipitation and BiFC experiments performed in Arabidopsis plants overexpressing durum wheat TdPP1 showed that TdPP1 interacts with dephosphorylated BES1, but not with the BRI1 receptor. Higher levels of dephosphorylated, active BES1 were observed in these transgenic lines upon BR treatment, indicating that TdPP1 modifies the BR signaling pathway by activating BES1. Moreover, ectopic expression of durum wheat TdPP1 lead to an enhanced growth of primary roots in comparison to wild-type plants in presence of BR. This phenotype corroborates with a down-regulation of the BR-regulated genes CPD and DWF4. These data suggest a role of PP1 in fine-tuning BR-driven responses, most likely via the control of the phosphorylation status of BES1.
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Affiliation(s)
- Mariem Bradai
- Laboratory of Biotechnology and Plant Improvement, Center of Biotechnology of Sfax, BP “1177”, University of Sfax, Sfax 3018, Tunisia;
- Plant Physiology and Functional Genomics Research Unit, Institute of Biotechnology of Sfax, BP “1175”, University of Sfax, Sfax 3038, Tunisia; (N.B.); (M.H.)
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, Shanghai 201602, China;
| | - Vitor Amorim-Silva
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterranea “La Mayora”, Universidad de Malaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain; (V.A.-S.); (A.E.d.V.); (M.A.B.)
| | - Nibras Belgaroui
- Plant Physiology and Functional Genomics Research Unit, Institute of Biotechnology of Sfax, BP “1175”, University of Sfax, Sfax 3038, Tunisia; (N.B.); (M.H.)
| | - Alicia Esteban del Valle
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterranea “La Mayora”, Universidad de Malaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain; (V.A.-S.); (A.E.d.V.); (M.A.B.)
| | - Marie-Edith Chabouté
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg 12, rue du Général Zimmer, 67084 Strasbourg, France; (M.-E.C.); (A.-C.S.)
| | - Anne-Catherine Schmit
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg 12, rue du Général Zimmer, 67084 Strasbourg, France; (M.-E.C.); (A.-C.S.)
| | - Rosa Lozano-Duran
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, Shanghai 201602, China;
| | - Miguel Angel Botella
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterranea “La Mayora”, Universidad de Malaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain; (V.A.-S.); (A.E.d.V.); (M.A.B.)
| | - Moez Hanin
- Plant Physiology and Functional Genomics Research Unit, Institute of Biotechnology of Sfax, BP “1175”, University of Sfax, Sfax 3038, Tunisia; (N.B.); (M.H.)
| | - Chantal Ebel
- Plant Physiology and Functional Genomics Research Unit, Institute of Biotechnology of Sfax, BP “1175”, University of Sfax, Sfax 3038, Tunisia; (N.B.); (M.H.)
- Correspondence: ; Tel.:+216-74-871-816
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Kim W, LeBlanc B, Matthews WL, Zhang ZY, Zhang Y. Advancements in chemical biology targeting the kinases and phosphatases of RNA polymerase II-mediated transcription. Curr Opin Chem Biol 2021; 63:68-77. [PMID: 33714893 PMCID: PMC8384638 DOI: 10.1016/j.cbpa.2021.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/21/2021] [Accepted: 02/01/2021] [Indexed: 11/30/2022]
Abstract
Phosphorylation of RNA polymerase II (RNAP II) coordinates the temporal progression of eukaryotic transcription. The development and application of chemical genetic methods have enhanced our ability to investigate the intricate and intertwined pathways regulated by the kinases and phosphatases targeting RNAP II to ensure transcription accuracy and efficiency. Although identifying small molecules that modulate these enzymes has been challenging due to their highly conserved structures, powerful new chemical biology strategies such as targeted covalent inhibitors and small molecule degraders have significantly improved chemical probe specificity. The recent success in discovering phosphatase holoenzyme activators and inhibitors, which demonstrates the feasibility of selective targeting of individual phosphatase complexes, opens up new avenues into the study of transcription. Herein, we summarize how chemical biology is used to delineate kinases' identities involved in RNAP II regulation and new concepts in inhibitor/activator design implemented for kinases/phosphatases involved in modulating RNAP II-mediated transcription.
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Affiliation(s)
- Wantae Kim
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, 78712, USA
| | - Blase LeBlanc
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Wendy L Matthews
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Zhong-Yin Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, Department of Chemistry, and Institute for Drug Discovery, Purdue University, West Lafayette, IN, 47907, USA
| | - Yan Zhang
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA; The Institute for Cellular and Molecular Biology. University of Texas at Austin, Austin, TX, 78712, USA.
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Feng J, Zhang X, Shan C, Xia J, Zhang Z, Shi H, Leng K, Wu Y, Ji C, Zhong T. Src family kinases involved in the differentiation of human preadipocytes. Mol Cell Endocrinol 2021; 533:111323. [PMID: 34000351 DOI: 10.1016/j.mce.2021.111323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 04/14/2021] [Accepted: 05/10/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Obesity is characterized by the excess accumulation of white adipose tissue (WAT). Src family kinases (SFKs) are non-receptor tyrosine kinases consisting of eight members (SRC, FYN, YES1, HCK, LCK, LYN, FGR and BLK) that have been studied extensively in mammalian cells. Although individual members in murine cells provide some clues that are associated with the regulation of adipogenesis, the specific role of this family in adipocyte differentiation has rarely been assessed, especially in human adipocytes. METHODS Herein, we first explored the expression profiles of SFKs during human preadipocyte differentiation. Then, we used the pyrazolo-pyrimidinyl-amine compound PP1, a potent SFK inhibitor, to evaluate the function of SFKs during adipocyte differentiation. Furthermore, we adopted a loss-of-function strategy with siRNAs to determine the role of FGR in adipocyte differentiation. RESULTS Here, we found that SRC, FYN, YES1, LYN and FGR were expressed in human preadipocytes and induced after the initiation of differentiation. Furthermore, the SFK inhibitor PP1 suppressed adipocyte differentiation. We also found that PP1 significantly suppressed the SFK activity in preadipocytes and decreased the expression of adipogenic genes in early and late differentiation. Given that FGR exhibited the most expression enhancement in mature adipocytes, we focused on FGR and found that its knockdown reduced lipid accumulation and adipogenic gene expression. CONCLUSIONS Collectively, these findings suggest that SFKs, especially FGR, are involved in the differentiation of human preadipocytes. Our results lay a foundation for further understanding the role of SFKs in adipocyte differentiation and provide new clues for anti-obesity therapies.
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Affiliation(s)
- Jie Feng
- Nanjing Maternal and Child Health Medical Institute, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu 210004, China; Jiangsu Health Development Research Center, Nanjing, Jiangsu 210036, China
| | - Xiaoxiao Zhang
- Nanjing Maternal and Child Health Medical Institute, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu 210004, China
| | - Chunjian Shan
- Nanjing Maternal and Child Health Medical Institute, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu 210004, China
| | - Jiaai Xia
- Nanjing Maternal and Child Health Medical Institute, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu 210004, China
| | - Zhenxing Zhang
- Department of Pediatrics, The First Affiliated Hospital, Nanjing Medical University, No. 300 Guang Zhou Road, Nanjing, Jiangsu 210029, China
| | - Hui Shi
- Jiangsu Health Development Research Center, Nanjing, Jiangsu 210036, China
| | - Kai Leng
- Department of Information, The First Affiliated Hospital, Nanjing Medical University, No. 300 Guang Zhou Road, Nanjing, Jiangsu 210029, China; Department of Medical Informatics, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Yangyang Wu
- Nanjing Maternal and Child Health Medical Institute, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu 210004, China
| | - Chenbo Ji
- Nanjing Maternal and Child Health Medical Institute, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu 210004, China.
| | - Tianying Zhong
- Nanjing Maternal and Child Health Medical Institute, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu 210004, China.
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38
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Stecher C, Marinkov S, Mayr-Harting L, Katic A, Kastner MT, Rieder-Rommer FJJ, Lin X, Nekhai S, Steininger C. Protein Phosphatase 1 Regulates Human Cytomegalovirus Protein Translation by Restraining AMPK Signaling. Front Microbiol 2021; 12:698603. [PMID: 34335531 PMCID: PMC8320725 DOI: 10.3389/fmicb.2021.698603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 05/31/2021] [Indexed: 11/22/2022] Open
Abstract
Human cytomegalovirus (HCMV) carries the human protein phosphatase 1 (PP1) and other human proteins important for protein translation in its tegument layer for a rapid supply upon infection. However, the biological relevance behind PP1 incorporation and its role during infection is unclear. Additionally, PP1 is a difficult molecular target due to its promiscuity and similarities between the catalytic domain of multiple phosphatases. In this study, we circumvented these shortcomings by using 1E7-03, a small molecule protein–protein interaction inhibitor, as a molecular tool of noncatalytic PP1 inhibition. 1E7-03 treatment of human fibroblasts severely impaired HCMV replication and viral protein translation. More specifically, PP1 inhibition led to the deregulation of metabolic signaling pathways starting at very early time points post-infection. This effect was at least partly mediated by the prevention of AMP-activated protein kinase dephosphorylation, leading to elongation factor 2 hyperphosphorylation and reduced translation rates. These findings reveal an important mechanism of PP1 for lytic HCMV infection.
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Affiliation(s)
- Carmen Stecher
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Sanja Marinkov
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Lucia Mayr-Harting
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Ana Katic
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Marie-Theres Kastner
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Franz J J Rieder-Rommer
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Xionghao Lin
- Center for Sickle Cell Disease, Howard University, Washington, DC, United States
| | - Sergei Nekhai
- Center for Sickle Cell Disease, Howard University, Washington, DC, United States
| | - Christoph Steininger
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria
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Isobe SY, Hiraga SI, Nagao K, Sasanuma H, Donaldson AD, Obuse C. Protein phosphatase 1 acts as a RIF1 effector to suppress DSB resection prior to Shieldin action. Cell Rep 2021; 36:109383. [PMID: 34260925 PMCID: PMC8293623 DOI: 10.1016/j.celrep.2021.109383] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 04/14/2021] [Accepted: 06/21/2021] [Indexed: 12/29/2022] Open
Abstract
DNA double-strand breaks (DSBs) are repaired mainly by non-homologous end joining (NHEJ) or homologous recombination (HR). RIF1 negatively regulates resection through the effector Shieldin, which associates with a short 3' single-stranded DNA (ssDNA) overhang by the MRN (MRE11-RAD50-NBS1) complex, to prevent further resection and HR repair. In this study, we show that RIF1, but not Shieldin, inhibits the accumulation of CtIP at DSB sites immediately after damage, suggesting that RIF1 has another effector besides Shieldin. We find that protein phosphatase 1 (PP1), a known RIF1 effector in replication, localizes at damage sites dependent on RIF1, where it suppresses downstream CtIP accumulation and limits the resection by the MRN complex. PP1 therefore acts as a RIF1 effector distinct from Shieldin. Furthermore, PP1 deficiency in the context of Shieldin depletion elevates HR immediately after irradiation. We conclude that PP1 inhibits resection before the action of Shieldin to prevent precocious HR in the early phase of the damage response.
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Affiliation(s)
- Shin-Ya Isobe
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-Cho, Toyonaka, Osaka 560-0043, Japan
| | - Shin-Ichiro Hiraga
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Koji Nagao
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-Cho, Toyonaka, Osaka 560-0043, Japan
| | - Hiroyuki Sasanuma
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Anne D Donaldson
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Chikashi Obuse
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-Cho, Toyonaka, Osaka 560-0043, Japan.
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40
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Forer A, Adil A, Berns MW. Blocking Protein Phosphatase 1 [ PP1] Prevents Loss of Tether Elasticity in Anaphase Crane-Fly Spermatocytes. Front Mol Biosci 2021; 8:636746. [PMID: 34169091 PMCID: PMC8218814 DOI: 10.3389/fmolb.2021.636746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/16/2021] [Indexed: 11/24/2022] Open
Abstract
In normal anaphase cells, telomeres of each separating chromosome pair are connected to each other by tethers. Tethers are elastic at the start of anaphase: arm fragments cut from anaphase chromosomes in early anaphase move across the equator to the oppositely-moving chromosome, telomere moving toward telomere. Tethers become inelastic later in anaphase as the tethers become longer: arm fragments no longer move to their partners. When early anaphase cells are treated with Calyculin A (CalA), an inhibitor of protein phosphatases 1 (PP1) and 2A (PP2A), at the end of anaphase chromosomes move backward from the poles, with telomeres moving toward partner telomeres. Experiments described herein show that in cells treated with CalA, backwards movements are stopped in a variety of ways, by cutting the tethers of backwards moving chromosomes, by severing arms of backwards moving chromosomes, by severing arms before the chromosomes reach the poles, and by cutting the telomere toward which a chromosome is moving backwards. Measurements of arm-fragment velocities show that CalA prevents tethers from becoming inelastic as they lengthen. Since treatment with CalA causes tethers to remain elastic throughout anaphase and since inhibitors of PP2A do not cause the backwards movements, PP1 activity during anaphase causes the tethers to become inelastic.
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Affiliation(s)
- Arthur Forer
- Biology Department, York University, Toronto, ON, Canada
| | - Aisha Adil
- Biology Department, York University, Toronto, ON, Canada
| | - Michael W Berns
- Beckman Laser Institute, University of California, Irvine, Irvine, CA, United States.,Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, United States.,Department of Surgery, University of California, Irvine, Irvine, CA, United States.,Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, United States.,Department of Bioengineering, University of California, San Diego, San Diego, CA, United States.,Institute of Engineering in Medicine, University of California, San Diego, San Diego, CA, United States
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41
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Klemm C, Thorpe PH, Ólafsson G. Cell-cycle phospho-regulation of the kinetochore. Curr Genet 2021; 67:177-93. [PMID: 33221975 DOI: 10.1007/s00294-020-01127-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/27/2020] [Accepted: 10/29/2020] [Indexed: 02/07/2023]
Abstract
The kinetochore is a mega-dalton protein assembly that forms within centromeric regions of chromosomes and directs their segregation during cell division. Here we review cell cycle-mediated phosphorylation events at the kinetochore, with a focus on the budding yeast Saccharomyces cerevisiae and the insight gained from forced associations of kinases and phosphatases. The point centromeres found in the budding yeast S. cerevisiae are one of the simplest such structures found in eukaryotes. The S. cerevisiae kinetochore comprises a single nucleosome, containing a centromere-specific H3 variant Cse4CENP-A, bound to a set of kinetochore proteins that connect to a single microtubule. Despite the simplicity of the budding yeast kinetochore, the proteins are mostly homologous with their mammalian counterparts. In some cases, human proteins can complement their yeast orthologs. Like its mammalian equivalent, the regulation of the budding yeast kinetochore is complex: integrating signals from the cell cycle, checkpoints, error correction, and stress pathways. The regulatory signals from these diverse pathways are integrated at the kinetochore by post-translational modifications, notably phosphorylation and dephosphorylation, to control chromosome segregation. Here we highlight the complex interplay between the activity of the different cell-cycle kinases and phosphatases at the kinetochore, emphasizing how much more we have to understand this essential structure.
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42
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Uchida KSK, Jo M, Nagasaka K, Takahashi M, Shindo N, Shibata K, Tanaka K, Masumoto H, Fukagawa T, Hirota T. Kinetochore stretching-mediated rapid silencing of the spindle-assembly checkpoint required for failsafe chromosome segregation. Curr Biol 2021; 31:1581-1591.e3. [PMID: 33651990 DOI: 10.1016/j.cub.2021.01.062] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/20/2020] [Accepted: 01/19/2021] [Indexed: 11/15/2022]
Abstract
The spindle-assembly checkpoint facilitates mitotic fidelity by delaying anaphase onset in response to microtubule vacancy at kinetochores. Following microtubule attachment, kinetochores receive microtubule-derived force, which causes kinetochores to undergo repetitive cycles of deformation; this phenomenon is referred to as kinetochore stretching. The nature of the forces and the relevance relating this deformation are not well understood. Here, we show that kinetochore stretching occurs within a framework of single end-on attached kinetochores, irrespective of microtubule poleward pulling force. An experimental method to conditionally interfere with the stretching allowed us to determine that kinetochore stretching comprises an essential process of checkpoint silencing by promoting PP1 phosphatase recruitment after the establishment of end-on attachments and removal of the majority of checkpoint-activating kinase Mps1 from kinetochores. Remarkably, we found that a lower frequency of kinetochore stretching largely correlates with a prolonged metaphase in cancer cell lines with chromosomal instability. Perturbation of kinetochore stretching and checkpoint silencing in chromosomally stable cells produced anaphase bridges, which can be alleviated by reducing chromosome-loaded cohesin. These observations indicate that kinetochore stretching-mediated checkpoint silencing provides an unanticipated etiology underlying chromosomal instability and underscores the importance of a rapid metaphase-to-anaphase transition in sustaining mitotic fidelity.
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Affiliation(s)
- Kazuhiko S K Uchida
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan; Division of Functional Genomics, Faculty of Pharmaceutical Sciences, Himeji Dokkyo University, Himeji, Japan
| | - Minji Jo
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Kota Nagasaka
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Motoko Takahashi
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Norihisa Shindo
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Katsushi Shibata
- Division of Functional Genomics, Faculty of Pharmaceutical Sciences, Himeji Dokkyo University, Himeji, Japan
| | - Kozo Tanaka
- Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Hiroshi Masumoto
- Laboratory of Chromosome Engineering, Kazusa DNA Research Institute, Kisarazu, Japan
| | - Tatsuo Fukagawa
- Laboratory of Chromosome Biology, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Toru Hirota
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan.
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43
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Garvanska DH, Nilsson J. Specificity determinants of phosphoprotein phosphatases controlling kinetochore functions. Essays Biochem 2020; 64:325-36. [PMID: 32501472 DOI: 10.1042/EBC20190065] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [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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Marakhonov AV, Přechová M, Konovalov FA, Filatova AY, Zamkova MA, Kanivets IV, Solonichenko VG, Semenova NA, Zinchenko RA, Treisman R, Skoblov MY. Mutation in PHACTR1 associated with multifocal epilepsy with infantile spasms and hypsarrhythmia. Clin Genet 2021; 99:673-683. [PMID: 33463715 PMCID: PMC8629116 DOI: 10.1111/cge.13926] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/07/2021] [Accepted: 01/13/2021] [Indexed: 11/28/2022]
Abstract
A young boy with multifocal epilepsy with infantile spasms and hypsarrhythmia with minimal organic lesions of brain structures underwent DNA diagnosis using whole‐exome sequencing. A heterozygous amino‐acid substitution p.L519R in a PHACTR1 gene was identified. PHACTR1 belongs to a protein family of G‐actin binding protein phosphatase 1 (PP1) cofactors and was not previously associated with a human disease. The missense single nucleotide variant in the proband was shown to occur de novo in the paternal allele. The mutation was shown in vitro to reduce the affinity of PHACTR1 for G‐actin, and to increase its propensity to form complexes with the catalytic subunit of PP1. These properties are associated with altered subcellular localization of PHACTR1 and increased ability to induce cytoskeletal rearrangements. Although the molecular role of the PHACTR1 in neuronal excitability and differentiation remains to be defined, PHACTR1 has been previously shown to be involved in Slack channelopathy pathogenesis, consistent with our findings. We conclude that this activating mutation in PHACTR1 causes a severe type of sporadic multifocal epilepsy in the patient.
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Affiliation(s)
- Andrey V Marakhonov
- Laboratory of Genetic Epidemiology, Laboratory of Functional Genomics, Department of Genetic Counseling, Research Centre for Medical Genetics, Moscow, Russia
| | - Magdalena Přechová
- Laboratory of Integrative Biology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic.,Signalling and Transcription Laboratory, Francis Crick Institute, London, UK
| | | | - Alexandra Yu Filatova
- Laboratory of Genetic Epidemiology, Laboratory of Functional Genomics, Department of Genetic Counseling, Research Centre for Medical Genetics, Moscow, Russia
| | - Maria A Zamkova
- Laboratory of Regulatory Mechanisms in Immunity, Institute of Carcinogenesis, N.N. Blokhin Russian Cancer Research Center, Moscow, Russia
| | - Ilya V Kanivets
- Laboratory of Molecular Pathology, Genomed Ltd., Moscow, Russia.,Medical Genetic Centre, Filatov Moscow Pediatric Clinical Hospital, Moscow, Russia
| | | | - Natalia A Semenova
- Laboratory of Genetic Epidemiology, Laboratory of Functional Genomics, Department of Genetic Counseling, Research Centre for Medical Genetics, Moscow, Russia
| | - Rena A Zinchenko
- Laboratory of Genetic Epidemiology, Laboratory of Functional Genomics, Department of Genetic Counseling, Research Centre for Medical Genetics, Moscow, Russia.,N.A. Semashko National Research Institute of Public Health, Moscow, Russia
| | - Richard Treisman
- Signalling and Transcription Laboratory, Francis Crick Institute, London, UK
| | - Mikhail Yu Skoblov
- Laboratory of Genetic Epidemiology, Laboratory of Functional Genomics, Department of Genetic Counseling, Research Centre for Medical Genetics, Moscow, Russia
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45
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Morris SL, Tsai MY, Aloe S, Bechberger K, König S, Morfini G, Brady ST. Defined Tau Phosphospecies Differentially Inhibit Fast Axonal Transport Through Activation of Two Independent Signaling Pathways. Front Mol Neurosci 2021; 13:610037. [PMID: 33568975 PMCID: PMC7868336 DOI: 10.3389/fnmol.2020.610037] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 12/28/2020] [Indexed: 12/30/2022] Open
Abstract
Tau protein is subject to phosphorylation by multiple kinases at more than 80 different sites. Some of these sites are associated with tau pathology and neurodegeneration, but other sites are modified in normal tau as well as in pathological tau. Although phosphorylation of tau at residues in the microtubule-binding repeats is thought to reduce tau association with microtubules, the functional consequences of other sites are poorly understood. The AT8 antibody recognizes a complex phosphoepitope site on tau that is detectable in a healthy brain but significantly increased in Alzheimer's disease (AD) and other tauopathies. Previous studies showed that phosphorylation of tau at the AT8 site leads to exposure of an N-terminal sequence that promotes activation of a protein phosphatase 1 (PP1)/glycogen synthase 3 (GSK3) signaling pathway, which inhibits kinesin-1-based anterograde fast axonal transport (FAT). This finding suggests that phosphorylation may control tau conformation and function. However, the AT8 includes three distinct phosphorylated amino acids that may be differentially phosphorylated in normal and disease conditions. To evaluate the effects of specific phosphorylation sites in the AT8 epitope, recombinant, pseudophosphorylated tau proteins were perfused into the isolated squid axoplasm preparation to determine their effects on axonal signaling pathways and FAT. Results from these studies suggest a mechanism where specific phosphorylation events differentially impact tau conformation, promoting activation of independent signaling pathways that differentially affect FAT. Implications of findings here to our understanding of tau function in health and disease conditions are discussed.
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Affiliation(s)
- Sarah L. Morris
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
- Marine Biological Laboratory, Woods Hole, MA, United States
| | - Ming-Ying Tsai
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
| | - Sarah Aloe
- Marine Biological Laboratory, Woods Hole, MA, United States
| | | | - Svenja König
- Marine Biological Laboratory, Woods Hole, MA, United States
| | - Gerardo Morfini
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
- Marine Biological Laboratory, Woods Hole, MA, United States
| | - Scott T. Brady
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
- Marine Biological Laboratory, Woods Hole, MA, United States
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Verdugo-Sivianes EM, Rojas AM, Muñoz-Galván S, Otero-Albiol D, Carnero A. Mutation of SPINOPHILIN (P PP1R9B) found in human tumors promotes the tumorigenic and stemness properties of cells. Am J Cancer Res 2021; 11:3452-3471. [PMID: 33537097 PMCID: PMC7847670 DOI: 10.7150/thno.53572] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 12/20/2020] [Indexed: 12/17/2022] Open
Abstract
Rationale: SPINOPHILIN (SPN, PPP1R9B) is an important tumor suppressor involved in the progression and malignancy of different tumors depending on its association with protein phosphatase 1 (PP1) and the ability of the PP1-SPN holoenzyme to dephosphorylate retinoblastoma (pRB). Methods: We performed a mutational analysis of SPN in human tumors, focusing on the region of interaction with PP1 and pRB. We explored the effect of the SPN-A566V mutation in an immortalized non-tumorigenic cell line of epithelial breast tissue, MCF10A, and in two different p53-mutated breast cancer cells lines, T47D and MDA-MB-468. Results: We characterized an oncogenic mutation of SPN found in human tumor samples, SPN-A566V, that affects both the SPN-PP1 interaction and its phosphatase activity. The SPN-A566V mutation does not affect the interaction of the PP1-SPN holoenzyme with pocket proteins pRB, p107 and p130, but it affects its ability to dephosphorylate them during G0/G1 and G1, indicating that the PP1-SPN holoenzyme regulates cell cycle progression. SPN-A566V also promoted stemness, establishing a connection between the cell cycle and stem cell biology via pocket proteins and PP1-SPN regulation. However, only cells with both SPN-A566V and mutant p53 have increased tumorigenic and stemness properties. Conclusions: SPN-A566V, or other equivalent mutations, could be late events that promote tumor progression by increasing the CSC pool and, eventually, the malignant behavior of the tumor.
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47
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Khaliq SA, Baek MO, Cho HJ, Chon SJ, Yoon MS. C-Peptide Inhibits Decidualization in Human Endometrial Stromal Cells via GSK3β- PP1. Front Cell Dev Biol 2020; 8:609551. [PMID: 33330513 PMCID: PMC7734312 DOI: 10.3389/fcell.2020.609551] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 11/12/2020] [Indexed: 12/17/2022] Open
Abstract
Decidualization refers to the functional differentiation of endometrial stromal cells and plays a significant role in embryo implantation and pregnancy. C-peptide is excreted in equimolar concentrations as that of insulin during the metabolism of proinsulin in pancreatic beta-cells. High levels of C-peptide are correlated with hyperinsulinemia and polycystic ovarian syndrome, which show a defect in decidualization. However, the role of C-peptide in decidualization has not yet been studied. Here, we identified C-peptide as an endogenous antideciduogenic factor. This inhibitory function was confirmed by the reduced expression of decidual markers, including prolactin, insulin-like growth factor-binding protein-1, and Forkhead box protein O1 as well as by the fibroblastic morphological change in the presence of C-peptide. C-peptide also enhanced cellular senescence and decreased the proportion of apoptotic cells during decidualization. In addition, C-peptide potentiated the inhibitory effects of both insulin and palmitic acid in an AKT- and autophagy-independent manner, respectively. Furthermore, C-peptide augmented protein phosphatase 1 (PP1) activity, leading to a reduction in the inhibitory phosphorylation of glycogen synthase kinase (GSK)3β, which resulted in enhanced cellular senescence and decreased apoptosis during decidualization. Taken together, our findings suggest that C-peptide is an antideciduogenic factor acting via the regulation between PP1 and GSK3β in patients with hyperinsulinemia.
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Affiliation(s)
- Sana Abdul Khaliq
- Department of Molecular Medicine, School of Medicine, Gachon University, Incheon, South Korea.,Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, South Korea.,Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon, South Korea
| | - Mi-Ock Baek
- Department of Molecular Medicine, School of Medicine, Gachon University, Incheon, South Korea.,Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, South Korea.,Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon, South Korea
| | - Hye-Jeong Cho
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, South Korea
| | - Seung Joo Chon
- Department of Obstetrics and Gynecology, Gachon University Gil Medical Center, College of Medicine, Gachon University, Incheon, South Korea
| | - Mee-Sup Yoon
- Department of Molecular Medicine, School of Medicine, Gachon University, Incheon, South Korea.,Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, South Korea.,Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon, South Korea
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48
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Abstract
How ER exit sites disassemble during mitosis is not well understood. Transport ANd Golgi Organization 1 (TANGO1, also known as MIA3), a cargo receptor originally identified for collagens, acts as a hub for ER exit site disassembly under the control of Casein Kinase 1 (CK1)-mediated phosphorylation and Protein Phosphatase 1 (PP1)-mediated dephosphorylation. Impaired dephosphorylation during mitosis induces ER exit site disassembly.
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Affiliation(s)
- Miharu Maeda
- Department of Biological Informatics and Experimental Therapeutics, Graduate School of Medicine, Akita University, Akita, Japan
| | - Yukie Komatsu
- Department of Biological Informatics and Experimental Therapeutics, Graduate School of Medicine, Akita University, Akita, Japan
| | - Kota Saito
- Department of Biological Informatics and Experimental Therapeutics, Graduate School of Medicine, Akita University, Akita, Japan
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49
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De Munter S, Van der Hoeven G, Bollen M. RepoMan stimulates the chromosome-dependent pathway of microtubule assembly. Cell Cycle 2020; 19:3029-3041. [PMID: 33054506 PMCID: PMC7747800 DOI: 10.1080/15384101.2020.1830607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 07/28/2020] [Accepted: 08/25/2020] [Indexed: 10/23/2022] Open
Abstract
RepoMan is a chromosome-associated scaffold protein that integrates signaling of multiple kinases and phosphatases to coordinate spindle-kinetochore interactions, chromosome (de)condensation and nuclear envelope (dis)assembly during mitosis. Another key mitotic event is the assembly of a microtubule-based spindle, which involves redundant pathways emanating from the centrosomes, microtubules and chromosomes. Here we describe a novel mitotic function of RepoMan in regulating chromosome-dependent microtubule assembly. At limiting concentrations of microtubule-destabilizing agents, RepoMan-depleted cells showed enhanced chromosome clustering. This clustering was completely dependent on the partial inhibition of microtubule growth originating from the chromosome-dependent pathway. We also demonstrated that RepoMan interacts with prime regulators of the chromosome-dependent spindle assembly such as NuSAP1, NuMA, and TPX2. In addition, RepoMan was required to enable or maintain phosphorylation of NuSAP1 at CDK sites, thereby enabling activation of NuSAP1 through dissociation of inhibitory importin β/7. Our data identify RepoMan as an enhancer of microtubule assembly at chromosomes.
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Affiliation(s)
- Sofie De Munter
- Department of Cellular and Molecular Medicine, Laboratory of Biosignaling & Therapeutics, KU Leuven, Leuven, Belgium
| | - Gerd Van der Hoeven
- Department of Cellular and Molecular Medicine, Laboratory of Biosignaling & Therapeutics, KU Leuven, Leuven, Belgium
| | - Mathieu Bollen
- Department of Cellular and Molecular Medicine, Laboratory of Biosignaling & Therapeutics, KU Leuven, Leuven, Belgium
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Gu X, Huang X, Li D, Bi N, Yu X, Wang HL. Nuclear accumulation of histone deacetylase 4 (HDAC4) by PP1-mediated dephosphorylation exerts neurotoxicity in Pb-exposed neural cells. Neurotoxicology 2020; 81:395-405. [PMID: 33080273 DOI: 10.1016/j.neuro.2020.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 10/13/2020] [Accepted: 10/13/2020] [Indexed: 10/23/2022]
Abstract
Lead (Pb) is an environmental contaminant that primarily affects the central nervous system, particularly the developing brain. Recently, increasing evidence indicates the important roles of histone deacetylases (HDACs) in Pb-induced neurotoxicity. However, the precise molecular mechanisms involving HDAC4 remains unknown. The purpose of this study was to investigate the role of HDAC4 in Pb-induced neurotoxicity both in vivo and in vitro. In vitro study, PC12 cells were exposed to Pb (10 μM) for 24 h, then the mRNA and protein levels of HDAC4 were analyzed. In vivo study, pregnant rats and their female offspring were treated with lead (50 ppm) until postnatal day 30. Then the pups were sacrificed and the mRNA and protein levels of HDAC4 in the hippocampus were analyzed. The results showed that HDAC4 was significantly increased in both PC12 cells and rat hippocampus upon Pb exposure. Blockade of HDAC4 with either LMK-235 (an inhibitor of HDAC4) or shHDAC4 (HDAC4-knocking down plasmid) ameliorated the Pb-induced neurite outgrowth deficits. Interestingly, HDAC4 was aberrantly accumulated in the nucleus upon Pb exposure. By contrast, blocking the HDAC4 shuffling from the cytosol to the nucleus with ΔNLS2-HDAC4 (the cytosol-localized HDAC4 mutant) was able to rescue the neuronal impairment. In addition, Pb increased PP1 (protein phosphatase 1) expression which in turn influenced the subcellular localization of HDAC4 by dephosphorylation of specific serine/threonine residues. What's more, blockade of PP1 with PP1-knocking down construct (shPP1) ameliorated Pb-induced neurite outgrowth deficits. Taken together, nuclear accumulation of HDAC4 by PP1-mediated dephosphorylation involved in Pb-induced neurotoxicity. This study might provide a promising molecular target for medical intervention with environmental cues.
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Affiliation(s)
- Xiaozhen Gu
- School of Food and Biological Engineering, Hefei University of Technology, No. 193 of Tunxi Road, Baohe District, 230009, Hefei, China
| | - Xiyao Huang
- School of Food and Biological Engineering, Hefei University of Technology, No. 193 of Tunxi Road, Baohe District, 230009, Hefei, China
| | - Danyang Li
- School of Food and Biological Engineering, Hefei University of Technology, No. 193 of Tunxi Road, Baohe District, 230009, Hefei, China
| | - Nanxi Bi
- School of Food and Biological Engineering, Hefei University of Technology, No. 193 of Tunxi Road, Baohe District, 230009, Hefei, China
| | - Xi Yu
- School of Food and Biological Engineering, Hefei University of Technology, No. 193 of Tunxi Road, Baohe District, 230009, Hefei, China
| | - Hui-Li Wang
- School of Food and Biological Engineering, Hefei University of Technology, No. 193 of Tunxi Road, Baohe District, 230009, Hefei, China.
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