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Woo JR, Bae SH, Wales TE, Engen JR, Lee J, Jang H, Park S. The serine phosphorylations in the IRS-1 PIR domain abrogate IRS-1 and IR interaction. Proc Natl Acad Sci U S A 2024; 121:e2401716121. [PMID: 38625937 DOI: 10.1073/pnas.2401716121] [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: 02/02/2024] [Accepted: 03/16/2024] [Indexed: 04/18/2024] Open
Abstract
Serine phosphorylations on insulin receptor substrate 1 (IRS-1) by diverse kinases aoccur widely during obesity-, stress-, and inflammation-induced conditions in models of insulin resistance and type 2 diabetes. In this study, we define a region within the human IRS-1, which is directly C-terminal to the PTB domain encompassing numerous serine phosphorylation sites including Ser307 (mouse Ser302) and Ser312 (mouse 307) creating a phosphorylation insulin resistance (PIR) domain. We demonstrate that the IRS-1 PTB-PIR with its unphosphorylated serine residues interacts with the insulin receptor (IR) but loses the IR-binding when they are phosphorylated. Surface plasmon resonance studies further confirm that the PTB-PIR binds stronger to IR than just the PTB domain, and that phosphorylations at Ser307, Ser312, Ser315, and Ser323 within the PIR domain result in abrogating the binding. Insulin-responsive cells containing the mutant IRS-1 with all these four serines changed into glutamates to mimic phosphorylations show decreased levels of phosphorylations in IR, IRS-1, and AKT compared to the wild-type IRS-1. Hydrogen-deuterium exchange mass spectrometry experiments indicating the PIR domain interacting with the N-terminal lobe and the hinge regions of the IR kinase domain further suggest the possibility that the IRS-1 PIR domain protects the IR from the PTP1B-mediated dephosphorylation.
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Affiliation(s)
- Ju Rang Woo
- Division of Convergence Technology, New Drug Development Center, KBIOHealth, Cheongju 28160, Republic of Korea
| | - Seung-Hyun Bae
- Division of Rare and Refractory Cancer, Research Institute, National Cancer Center, Goyang 10408, Republic of Korea
- Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang 10408, Republic of Korea
| | - Thomas E Wales
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
| | - John R Engen
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
| | - Jongsoon Lee
- Soonchunhyang Institute of Medi-Bio Science, Soonchunhyang University, Cheonan 31151, Republic of Korea
| | - Hyonchol Jang
- Division of Rare and Refractory Cancer, Research Institute, National Cancer Center, Goyang 10408, Republic of Korea
- Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang 10408, Republic of Korea
| | - SangYoun Park
- School of Systems Biomedical Science, Soongsil University, Seoul 06978, Republic of Korea
- Integrative Institute of Basic Sciences, Soongsil University, Seoul 06978, Republic of Korea
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Mihiret YE, Schaaf G, Kamleitner M. Protein pyrophosphorylation by inositol phosphates: a novel post-translational modification in plants? Front Plant Sci 2024; 15:1347922. [PMID: 38455731 PMCID: PMC10917965 DOI: 10.3389/fpls.2024.1347922] [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] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 02/01/2024] [Indexed: 03/09/2024]
Abstract
Inositol pyrophosphates (PP-InsPs) are energy-rich molecules harboring one or more diphosphate moieties. PP-InsPs are found in all eukaryotes evaluated and their functional versatility is reflected in the various cellular events in which they take part. These include, among others, insulin signaling and intracellular trafficking in mammals, as well as innate immunity and hormone and phosphate signaling in plants. The molecular mechanisms by which PP-InsPs exert such functions are proposed to rely on the allosteric regulation via direct binding to proteins, by competing with other ligands, or by protein pyrophosphorylation. The latter is the focus of this review, where we outline a historical perspective surrounding the first findings, almost 20 years ago, that certain proteins can be phosphorylated by PP-InsPs in vitro. Strikingly, in vitro phosphorylation occurs by an apparent enzyme-independent but Mg2+-dependent transfer of the β-phosphoryl group of an inositol pyrophosphate to an already phosphorylated serine residue at Glu/Asp-rich protein regions. Ribosome biogenesis, vesicle trafficking and transcription are among the cellular events suggested to be modulated by protein pyrophosphorylation in yeast and mammals. Here we discuss the latest efforts in identifying targets of protein pyrophosphorylation, pointing out the methodological challenges that have hindered the full understanding of this unique post-translational modification, and focusing on the latest advances in mass spectrometry that finally provided convincing evidence that PP-InsP-mediated pyrophosphorylation also occurs in vivo. We also speculate about the relevance of this post-translational modification in plants in a discussion centered around the protein kinase CK2, whose activity is critical for pyrophosphorylation of animal and yeast proteins. This enzyme is widely present in plant species and several of its functions overlap with those of PP-InsPs. Until now, there is virtually no data on pyrophosphorylation of plant proteins, which is an exciting field that remains to be explored.
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Affiliation(s)
| | | | - Marília Kamleitner
- Department of Plant Nutrition, Institute of Crop Science and Resource Conservation, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
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Parra-Rivas LA, Madhivanan K, Aulston BD, Wang L, Prakashchand DD, Boyer NP, Saia-Cereda VM, Branes-Guerrero K, Pizzo DP, Bagchi P, Sundar VS, Tang Y, Das U, Scott DA, Rangamani P, Ogawa Y, Subhojit Roy. Serine-129 phosphorylation of α-synuclein is an activity-dependent trigger for physiologic protein-protein interactions and synaptic function. Neuron 2023; 111:4006-4023.e10. [PMID: 38128479 PMCID: PMC10766085 DOI: 10.1016/j.neuron.2023.11.020] [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: 02/28/2023] [Revised: 10/08/2023] [Accepted: 11/19/2023] [Indexed: 12/23/2023]
Abstract
Phosphorylation of α-synuclein at the serine-129 site (α-syn Ser129P) is an established pathologic hallmark of synucleinopathies and a therapeutic target. In physiologic states, only a fraction of α-syn is phosphorylated at this site, and most studies have focused on the pathologic roles of this post-translational modification. We found that unlike wild-type (WT) α-syn, which is widely expressed throughout the brain, the overall pattern of α-syn Ser129P is restricted, suggesting intrinsic regulation. Surprisingly, preventing Ser129P blocked activity-dependent synaptic attenuation by α-syn-thought to reflect its normal function. Exploring mechanisms, we found that neuronal activity augments Ser129P, which is a trigger for protein-protein interactions that are necessary for mediating α-syn function at the synapse. AlphaFold2-driven modeling and membrane-binding simulations suggest a scenario where Ser129P induces conformational changes that facilitate interactions with binding partners. Our experiments offer a new conceptual platform for investigating the role of Ser129 in synucleinopathies, with implications for drug development.
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Affiliation(s)
- Leonardo A Parra-Rivas
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Kayalvizhi Madhivanan
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Brent D Aulston
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Lina Wang
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Dube Dheeraj Prakashchand
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA, USA
| | - Nicholas P Boyer
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Veronica M Saia-Cereda
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Kristen Branes-Guerrero
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Donald P Pizzo
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Pritha Bagchi
- Emory Integrated Proteomics Core, Emory University, Atlanta, GA, USA
| | - V S Sundar
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Yong Tang
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Utpal Das
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA; Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - David A Scott
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA, USA
| | - Yuki Ogawa
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Subhojit Roy
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA; Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA.
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4
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Tiwari M, Lovelace AH. Playing with FIRE: How an RXLR Oomycete Effector Fuels Disease by Hijacking 14-3-3 Proteins. Mol Plant Microbe Interact 2023; 36:313-314. [PMID: 37516252 DOI: 10.1094/mpmi-05-23-0062-cm] [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] [Indexed: 07/31/2023]
Abstract
The plant pathogen Phytophthora palmivora causes rot disease in several monocots and dicots. The plant 14-3-3 proteins are targets of different types of effector molecules secreted by the pathogens. An RXLR-type effector FIRE (14-3-3 interacting RXLR effector) and its target 14-3-3 proteins that localize to haustoria have been identified, pointing to a potential site of interaction. The pathogen hijacks the host 14-3-3 proteins through FIRE-mediated interaction and lowers the immunity for disease progression. The effector FIRE and 14-3-3 interaction deciphered in this study could pave the way for genetic modification of plants with altered 14-3-3 protein for broad host resistance. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Manish Tiwari
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, U.S.A
| | - Amelia H Lovelace
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, U.K
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5
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Garcia-Garcia T, Douché T, Giai Gianetto Q, Poncet S, El Omrani N, Smits WK, Cuenot E, Matondo M, Martin-Verstraete I. In-Depth Characterization of the Clostridioides difficile Phosphoproteome to Identify Ser/Thr Kinase Substrates. Mol Cell Proteomics 2022; 21:100428. [PMID: 36252736 PMCID: PMC9674922 DOI: 10.1016/j.mcpro.2022.100428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 03/29/2022] [Revised: 09/13/2022] [Accepted: 10/13/2022] [Indexed: 11/17/2022] Open
Abstract
Clostridioides difficile is the leading cause of postantibiotic diarrhea in adults. During infection, the bacterium must rapidly adapt to the host environment by using survival strategies. Protein phosphorylation is a reversible post-translational modification employed ubiquitously for signal transduction and cellular regulation. Hanks-type serine/threonine kinases (STKs) and serine/threonine phosphatases have emerged as important players in bacterial cell signaling and pathogenicity. C. difficile encodes two STKs (PrkC and CD2148) and one phosphatase. We optimized a titanium dioxide phosphopeptide enrichment approach to determine the phosphoproteome of C. difficile. We identified and quantified 2500 proteins representing 63% of the theoretical proteome. To identify STK and serine/threonine phosphatase targets, we then performed comparative large-scale phosphoproteomics of the WT strain and isogenic ΔprkC, CD2148, Δstp, and prkC CD2148 mutants. We detected 635 proteins containing phosphorylated peptides. We showed that PrkC is phosphorylated on multiple sites in vivo and autophosphorylates in vitro. We were unable to detect a phosphorylation for CD2148 in vivo, whereas this kinase was phosphorylated in vitro only in the presence of PrkC. Forty-one phosphoproteins were identified as phosphorylated under the control of CD2148, whereas 114 proteins were phosphorylated under the control of PrkC including 27 phosphoproteins more phosphorylated in the ∆stp mutant. We also observed enrichment for phosphothreonine among the phosphopeptides more phosphorylated in the Δstp mutant. Both kinases targeted pathways required for metabolism, translation, and stress response, whereas cell division and peptidoglycan metabolism were more specifically controlled by PrkC-dependent phosphorylation in agreement with the phenotypes of the ΔprkC mutant. Using a combination of approaches, we confirmed that FtsK was phosphorylated in vivo under the control of PrkC and that Spo0A was a substrate of PrkC in vitro. This study provides a detailed mapping of kinase-substrate relationships in C. difficile, paving the way for the identification of new biomarkers and therapeutic targets.
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Affiliation(s)
- Transito Garcia-Garcia
- Laboratoire Pathogénese des Bactéries Anaérobies, UMR CNRS 6047, Institut Pasteur, Université Paris Cité, Paris, France
| | - Thibaut Douché
- Plateforme Protéomique, Unité de Technologie et Service Spectrométrie de Masse pour la biologie, CNRS USR 2000, Institut Pasteur, Université Paris Cité, Paris, France
| | - Quentin Giai Gianetto
- Plateforme Protéomique, Unité de Technologie et Service Spectrométrie de Masse pour la biologie, CNRS USR 2000, Institut Pasteur, Université Paris Cité, Paris, France,Hub de bioinformatique et biostatistiques, Departement de Biologie computationelle, Institut Pasteur, Université Paris Cité, Paris, France
| | - Sandrine Poncet
- INRAE, AgroParisTech, Micalis Institute, Université Paris-Saclay, Jouy-en-Josas, France
| | - Nesrine El Omrani
- Plateforme Protéomique, Unité de Technologie et Service Spectrométrie de Masse pour la biologie, CNRS USR 2000, Institut Pasteur, Université Paris Cité, Paris, France
| | - Wiep Klaas Smits
- Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Elodie Cuenot
- Laboratoire Pathogénese des Bactéries Anaérobies, UMR CNRS 6047, Institut Pasteur, Université Paris Cité, Paris, France
| | - Mariette Matondo
- Plateforme Protéomique, Unité de Technologie et Service Spectrométrie de Masse pour la biologie, CNRS USR 2000, Institut Pasteur, Université Paris Cité, Paris, France,For correspondence: Isabelle Martin-Verstraete; Mariette Matondo
| | - Isabelle Martin-Verstraete
- Laboratoire Pathogénese des Bactéries Anaérobies, UMR CNRS 6047, Institut Pasteur, Université Paris Cité, Paris, France,Institut Universitaire de France, Paris, France,For correspondence: Isabelle Martin-Verstraete; Mariette Matondo
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6
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Fu ZP, Wu LL, Xue JY, Zhang LE, Li C, You HJ, Luo DL. Connexin 43 hyper-phosphorylation at serine 282 triggers apoptosis in rat cardiomyocytes via activation of mitochondrial apoptotic pathway. Acta Pharmacol Sin 2022; 43:1970-1978. [PMID: 34931018 PMCID: PMC9343349 DOI: 10.1038/s41401-021-00824-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [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: 09/22/2021] [Accepted: 11/16/2021] [Indexed: 12/12/2022] Open
Abstract
Cx43 is the major connexin in ventricular gap junctions, and plays a pivotal role in control of electrical and metabolic communication among adjacent cardiomyocytes. We previously found that Cx43 dephosphorylation at serine 282 (pS282) caused cardiomyocyte apoptosis, which is involved in cardiac ischemia/reperfusion injury. In this study we investigated whether Cx43-S282 hyper-phosphorylation could protect cardiomyocytes against apoptosis. Adenovirus carrying rat full length Cx43 gene (Cx43-wt) or a mutant gene at S282 substituted with aspartic acid (S282D) were transfected into neonatal rat ventricular myocytes (NRVMs) or injected into rat ventricular wall. Rat abdominal aorta constriction model (AAC) was used to assess Cx43-S282 phosphorylation status. We showed that Cx43 phosphorylation at S282 was increased over 2-times compared to Cx43-wt cells at 24 h after transfection, while pS262 and pS368 were unaltered. S282D-transfected cells displayed enhanced gap junctional communication, and increased basal intracellular Ca2+ concentration and spontaneous Ca2+ transients compared to Cx43-wt cells. However, spontaneous apoptosis appeared in NRVMs transfected with S282D for 34 h. Rat ventricular myocardium transfected with S282D in vivo also exhibited apoptotic responses, including increased Bax/Bcl-xL ratio, cytochrome c release as well as caspase-3 and caspase-9 activities, while factor-associated suicide (Fas)/Fas-associated death domain expression and caspase-8 activity remained unaltered. In addition, AAC-induced hypertrophic ventricles had apoptotic injury with Cx43-S282 hyper-phosphorylation compared with Sham ventricles. In conclusion, Cx43 hyper-phosphorylation at S282, as dephosphorylation, also triggers cardiomyocyte apoptosis, but through activation of mitochondrial apoptosis pathway, providing a fine-tuned Cx43-S282 phosphorylation range required for the maintenance of cardiomyocyte function and survival.
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Affiliation(s)
- Zhi-ping Fu
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
| | - Lu-lin Wu
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
| | - Jing-yi Xue
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
| | - Lan-e Zhang
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
| | - Chen Li
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
| | - Hong-jie You
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
| | - Da-li Luo
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
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7
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Ren L, Shen D, Liu C, Ding Y. Protein Tyrosine and Serine/Threonine Phosphorylation in Oral Bacterial Dysbiosis and Bacteria-Host Interaction. Front Cell Infect Microbiol 2022; 11:814659. [PMID: 35087767 PMCID: PMC8787120 DOI: 10.3389/fcimb.2021.814659] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [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: 11/14/2021] [Accepted: 12/13/2021] [Indexed: 02/05/2023] Open
Abstract
The human oral cavity harbors approximately 1,000 microbial species, and dysbiosis of the microflora and imbalanced microbiota-host interactions drive many oral diseases, such as dental caries and periodontal disease. Oral microbiota homeostasis is critical for systemic health. Over the last two decades, bacterial protein phosphorylation systems have been extensively studied, providing mounting evidence of the pivotal role of tyrosine and serine/threonine phosphorylation in oral bacterial dysbiosis and bacteria-host interactions. Ongoing investigations aim to discover novel kinases and phosphatases and to understand the mechanism by which these phosphorylation events regulate the pathogenicity of oral bacteria. Here, we summarize the structures of bacterial tyrosine and serine/threonine kinases and phosphatases and discuss the roles of tyrosine and serine/threonine phosphorylation systems in Porphyromonas gingivalis and Streptococcus mutans, emphasizing their involvement in bacterial metabolism and virulence, community development, and bacteria-host interactions.
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Affiliation(s)
- Liang Ren
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Daonan Shen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Chengcheng Liu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yi Ding
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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Lubyova B, Tikalova E, Krulova K, Hodek J, Zabransky A, Hirsch I, Weber J. ATM-Dependent Phosphorylation of Hepatitis B Core Protein in Response to Genotoxic Stress. Viruses 2021; 13:v13122438. [PMID: 34960710 PMCID: PMC8705010 DOI: 10.3390/v13122438] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/29/2021] [Accepted: 12/02/2021] [Indexed: 12/31/2022] Open
Abstract
Chronic hepatitis caused by infection with the Hepatitis B virus is a life-threatening condition. In fact, 1 million people die annually due to liver cirrhosis or hepatocellular carcinoma. Recently, several studies demonstrated a molecular connection between the host DNA damage response (DDR) pathway and HBV replication and reactivation. Here, we investigated the role of Ataxia-telangiectasia-mutated (ATM) and Ataxia telangiectasia and Rad3-related (ATR) PI3-kinases in phosphorylation of the HBV core protein (HBc). We determined that treatment of HBc-expressing hepatocytes with genotoxic agents, e.g., etoposide or hydrogen peroxide, activated the host ATM-Chk2 pathway, as determined by increased phosphorylation of ATM at Ser1981 and Chk2 at Thr68. The activation of ATM led, in turn, to increased phosphorylation of cytoplasmic HBc at serine-glutamine (SQ) motifs located in its C-terminal domain. Conversely, down-regulation of ATM using ATM-specific siRNAs or inhibitor effectively reduced etoposide-induced HBc phosphorylation. Detailed mutation analysis of S-to-A HBc mutants revealed that S170 (S168 in a 183-aa HBc variant) is the primary site targeted by ATM-regulated phosphorylation. Interestingly, mutation of two major phosphorylation sites involving serines at positions 157 and 164 (S155 and S162 in a 183-aa HBc variant) resulted in decreased etoposide-induced phosphorylation, suggesting that the priming phosphorylation at these serine-proline (SP) sites is vital for efficient phosphorylation of SQ motifs. Notably, the mutation of S172 (S170 in a 183-aa HBc variant) had the opposite effect and resulted in massively up-regulated phosphorylation of HBc, particularly at S170. Etoposide treatment of HBV infected HepG2-NTCP cells led to increased levels of secreted HBe antigen and intracellular HBc protein. Together, our studies identified HBc as a substrate for ATM-mediated phosphorylation and mapped the phosphorylation sites. The increased expression of HBc and HBe antigens in response to genotoxic stress supports the idea that the ATM pathway may provide growth advantage to the replicating virus.
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Affiliation(s)
- Barbora Lubyova
- IOCB Gilead Research Center, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 160 00 Prague, Czech Republic; (E.T.); (K.K.); (J.H.); (A.Z.); (I.H.)
- Correspondence: (B.L.); (J.W.)
| | - Eva Tikalova
- IOCB Gilead Research Center, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 160 00 Prague, Czech Republic; (E.T.); (K.K.); (J.H.); (A.Z.); (I.H.)
| | - Kristyna Krulova
- IOCB Gilead Research Center, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 160 00 Prague, Czech Republic; (E.T.); (K.K.); (J.H.); (A.Z.); (I.H.)
| | - Jan Hodek
- IOCB Gilead Research Center, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 160 00 Prague, Czech Republic; (E.T.); (K.K.); (J.H.); (A.Z.); (I.H.)
| | - Ales Zabransky
- IOCB Gilead Research Center, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 160 00 Prague, Czech Republic; (E.T.); (K.K.); (J.H.); (A.Z.); (I.H.)
| | - Ivan Hirsch
- IOCB Gilead Research Center, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 160 00 Prague, Czech Republic; (E.T.); (K.K.); (J.H.); (A.Z.); (I.H.)
- Department of Genetics and Microbiology, Faculty of Science, Charles University, BIOCEV, 252 50 Vestec, Czech Republic
| | - Jan Weber
- IOCB Gilead Research Center, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 160 00 Prague, Czech Republic; (E.T.); (K.K.); (J.H.); (A.Z.); (I.H.)
- Correspondence: (B.L.); (J.W.)
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9
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Chai Q, Li S, Collins MK, Li R, Ahmad I, Johnson SF, Frabutt DA, Yang Z, Shen X, Sun L, Hu J, Hultquist JF, Peterlin BM, Zheng YH. HIV-1 Nef interacts with the cyclin K/CDK13 complex to antagonize SERINC5 for optimal viral infectivity. Cell Rep 2021; 36:109514. [PMID: 34380030 PMCID: PMC8385645 DOI: 10.1016/j.celrep.2021.109514] [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: 10/30/2020] [Revised: 06/17/2021] [Accepted: 07/20/2021] [Indexed: 11/03/2022] Open
Abstract
HIV-1-negative factor (Nef) protein antagonizes serine incorporator 5 (SERINC5) by redirecting this potent restriction factor to the endosomes and lysosomes for degradation. However, the precise mechanism remains unclear. Using affinity purification/mass spectrometry, we identify cyclin K (CycK) and cyclin-dependent kinase 13 (CDK13) as a Nef-associated kinase complex. CycK/CDK13 phosphorylates the serine at position 360 (S360) in SERINC5, which is required for Nef downregulation of SERINC5 from the cell surface and its counteractivity of the SERINC5 antiviral activity. To understand the role of S360 phosphorylation, we generate chimeric proteins between CD8 and SERINC5 to study their response to Nef. Nef not only downregulates but, importantly, also binds to this chimera in an S360-dependent manner. Thus, S360 phosphorylation increases interactions between Nef and SERINC5 and initiates the destruction of SERINC5 by the endocytic machinery.
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Affiliation(s)
- Qingqing Chai
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Sunan Li
- Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Morgan K Collins
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Rongrong Li
- Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Iqbal Ahmad
- Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Silas F Johnson
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA; Department of Biology, Hillsdale College, Hillsdale, MI, USA
| | - Dylan A Frabutt
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Zhichang Yang
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - Xiaojing Shen
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - Liangliang Sun
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - Jian Hu
- Department of Chemistry, Michigan State University, East Lansing, MI, USA; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Judd F Hultquist
- Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - B Matija Peterlin
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
| | - Yong-Hui Zheng
- Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin, China; Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA.
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10
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Sweet ME, Zhang X, Erdjument-Bromage H, Dubey V, Khandelia H, Neubert TA, Pedersen BP, Stokes DL. Serine phosphorylation regulates the P-type potassium pump KdpFABC. eLife 2020; 9:55480. [PMID: 32955430 PMCID: PMC7535926 DOI: 10.7554/elife.55480] [Citation(s) in RCA: 12] [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: 01/25/2020] [Accepted: 09/19/2020] [Indexed: 12/22/2022] Open
Abstract
KdpFABC is an ATP-dependent K+ pump that ensures bacterial survival in K+-deficient environments. Whereas transcriptional activation of kdpFABC expression is well studied, a mechanism for down-regulation when K+ levels are restored has not been described. Here, we show that KdpFABC is inhibited when cells return to a K+-rich environment. The mechanism of inhibition involves phosphorylation of Ser162 on KdpB, which can be reversed in vitro by treatment with serine phosphatase. Mutating Ser162 to Alanine produces constitutive activity, whereas the phosphomimetic Ser162Asp mutation inactivates the pump. Analyses of the transport cycle show that serine phosphorylation abolishes the K+-dependence of ATP hydrolysis and blocks the catalytic cycle after formation of the aspartyl phosphate intermediate (E1~P). This regulatory mechanism is unique amongst P-type pumps and this study furthers our understanding of how bacteria control potassium homeostasis to maintain cell volume and osmotic potential.
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Affiliation(s)
- Marie E Sweet
- Skirball Institute, Dept. of Cell Biology, New York University School of Medicine, New York, United States
| | - Xihui Zhang
- Skirball Institute, Dept. of Cell Biology, New York University School of Medicine, New York, United States
| | - Hediye Erdjument-Bromage
- Skirball Institute, Dept. of Cell Biology, New York University School of Medicine, New York, United States
| | - Vikas Dubey
- PHYLIFE, Physical Life Science, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark
| | - Himanshu Khandelia
- PHYLIFE, Physical Life Science, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark
| | - Thomas A Neubert
- Skirball Institute, Dept. of Cell Biology, New York University School of Medicine, New York, United States
| | - Bjørn P Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - David L Stokes
- Skirball Institute, Dept. of Cell Biology, New York University School of Medicine, New York, United States
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11
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Gratz R, Brumbarova T, Ivanov R, Trofimov K, Tünnermann L, Ochoa-Fernandez R, Blomeier T, Meiser J, Weidtkamp-Peters S, Zurbriggen MD, Bauer P. Phospho-mutant activity assays provide evidence for alternative phospho-regulation pathways of the transcription factor FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR. New Phytol 2020; 225:250-267. [PMID: 31487399 PMCID: PMC6916400 DOI: 10.1111/nph.16168] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 08/16/2019] [Indexed: 05/03/2023]
Abstract
The key basic helix-loop-helix (bHLH) transcription factor in iron (Fe) uptake, FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (FIT), is controlled by multiple signaling pathways, important to adjust Fe acquisition to growth and environmental constraints. FIT protein exists in active and inactive protein pools, and phosphorylation of serine Ser272 in the C-terminus, a regulatory domain of FIT, provides a trigger for FIT activation. Here, we use phospho-mutant activity assays and study phospho-mimicking and phospho-dead mutations of three additional predicted phosphorylation sites, namely at Ser221 and at tyrosines Tyr238 and Tyr278, besides Ser 272. Phospho-mutations at these sites affect FIT activities in yeast, plant, and mammalian cells. The diverse array of cellular phenotypes is seen at the level of cellular localization, nuclear mobility, homodimerization, and dimerization with the FIT-activating partner bHLH039, promoter transactivation, and protein stability. Phospho-mimicking Tyr mutations of FIT disturb fit mutant plant complementation. Taken together, we provide evidence that FIT is activated through Ser and deactivated through Tyr site phosphorylation. We therefore propose that FIT activity is regulated by alternative phosphorylation pathways.
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Affiliation(s)
- Regina Gratz
- Institute of Botany, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Tzvetina Brumbarova
- Institute of Botany, Heinrich-Heine University, 40225, Düsseldorf, Germany
- Department of Biosciences-Plant Biology, Saarland University, 66123, Saarbruecken, Germany
| | - Rumen Ivanov
- Institute of Botany, Heinrich-Heine University, 40225, Düsseldorf, Germany
- Department of Biosciences-Plant Biology, Saarland University, 66123, Saarbruecken, Germany
| | - Ksenia Trofimov
- Institute of Botany, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Laura Tünnermann
- Institute of Botany, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Rocio Ochoa-Fernandez
- Institute of Synthetic Biology, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Tim Blomeier
- Institute of Synthetic Biology, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Johannes Meiser
- Department of Biosciences-Plant Biology, Saarland University, 66123, Saarbruecken, Germany
- Department of Oncology, Luxembourg Institute of Health, 1445, Strassen, Luxembourg
| | | | - Matias D Zurbriggen
- Institute of Synthetic Biology, Heinrich-Heine University, 40225, Düsseldorf, Germany
- Cluster of Excellence on Plant Sciences, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Petra Bauer
- Institute of Botany, Heinrich-Heine University, 40225, Düsseldorf, Germany
- Department of Biosciences-Plant Biology, Saarland University, 66123, Saarbruecken, Germany
- Cluster of Excellence on Plant Sciences, Heinrich-Heine University, 40225, Düsseldorf, Germany
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12
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Xu J, Wu W, Tang Y, Lin Y, Xue Y, Hu J, Lin D. PRL-3 exerts oncogenic functions in myeloid leukemia cells via aberrant dephosphorylation of stathmin and activation of STAT3 signaling. Aging (Albany NY) 2019; 11:7817-7829. [PMID: 31546234 PMCID: PMC6781976 DOI: 10.18632/aging.102290] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 05/25/2019] [Accepted: 09/14/2019] [Indexed: 04/28/2023]
Abstract
PRL-3, an oncogenic dual-specificity phosphatase, is overexpressed in 50% of acute myeloid leukemia patients. Stathmin has been identified as a downstream target of PRL-3 in colorectal cancer. However, the correlation between PRL-3 and stathmin in myeloid leukemia is unclear. In this study, we revealed the positive correlation between PRL-3 and stathmin in myeloid leukemia. Knockdown of the PRL-3 gene by shRNA reduced the expression of downstream stathmin, suppressed cell proliferation, induced G2/M arrest and cell apoptosis, and inhibited migration and invasion in myeloid leukemia cells. Moreover, our study was the first to provide evidence that silencing PRL-3 increased the phosphorylation level in Ser16, Ser25, Ser38, and Ser63 of stathmin, and in turn inhibited the STAT3 and STAT5 signaling in myeloid leukemia cells. This evidence points to a promoted role for PRL-3 in the progression of myeloid leukemia, and PRL-3 could be a possible new treatment target.
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Affiliation(s)
- Jianping Xu
- Department of Laboratory Medicine, School of Medical Technology and Engineering, Fujian Medical University, Fuzhou 350004, Fujian, China
| | - Wei Wu
- Department of Laboratory Medicine, Quanzhou Medical College, Quanzhou 362011, Fujian, China
| | - Yao Tang
- Department of Laboratory Medicine, School of Medical Technology and Engineering, Fujian Medical University, Fuzhou 350004, Fujian, China
| | - Yanfeng Lin
- Department of Laboratory Medicine, School of Medical Technology and Engineering, Fujian Medical University, Fuzhou 350004, Fujian, China
| | - Yan Xue
- Department of Laboratory Medicine, School of Medical Technology and Engineering, Fujian Medical University, Fuzhou 350004, Fujian, China
| | - Jianda Hu
- Fujian Institute of Hematology, Fujian Medical University Union Hospital, Fuzhou 350001, Fujian, China
| | - Donghong Lin
- Department of Laboratory Medicine, School of Medical Technology and Engineering, Fujian Medical University, Fuzhou 350004, Fujian, China
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13
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Wang W, Tanokashira D, Fukui Y, Maruyama M, Kuroiwa C, Saito T, Saido TC, Taguchi A. Serine Phosphorylation of IRS1 Correlates with Aβ-Unrelated Memory Deficits and Elevation in Aβ Level Prior to the Onset of Memory Decline in AD. Nutrients 2019; 11:E1942. [PMID: 31426549 DOI: 10.3390/nu11081942] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [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: 07/23/2019] [Revised: 08/03/2019] [Accepted: 08/14/2019] [Indexed: 12/16/2022] Open
Abstract
The biological effects of insulin signaling are regulated by the phosphorylation of insulin receptor substrate 1 (IRS1) at serine (Ser) residues. In the brain, phosphorylation of IRS1 at specific Ser sites increases in patients with Alzheimer’s disease (AD) and its animal models. However, whether the activation of Ser sites on neural IRS1 is related to any type of memory decline remains unclear. Here, we show the modifications of IRS1 through its phosphorylation at etiology-specific Ser sites in various animal models of memory decline, such as diabetic, aged, and amyloid precursor protein (APP) knock-in NL-G-F (APPKINL-G-F) mice. Substantial phosphorylation of IRS1 at specific Ser sites occurs in type 2 diabetes- or age-related memory deficits independently of amyloid-β (Aβ). Furthermore, we present the first evidence that, in APPKINL-G-F mice showing Aβ42 elevation, the increased phosphorylation of IRS1 at multiple Ser sites occurs without memory impairment. Our findings suggest that the phosphorylation of IRS1 at specific Ser sites is a potential marker of Aβ-unrelated memory deficits caused by type 2 diabetes and aging; however, in Aβ-related memory decline, the modifications of IRS1 may be a marker of early detection of Aβ42 elevation prior to the onset of memory decline in AD.
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14
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Abstract
Type 2 diabetes—associated with impaired insulin/insulin-like growth factor-1 (IGF1) signaling (IIS)—is a risk factor for cognitive impairment and dementia including Alzheimer’s disease (AD). The insulin receptor substrate (IRS) proteins are major components of IIS, which transmit upstream signals via the insulin receptor and/or IGF1 receptor to multiple intracellular signaling pathways, including AKT/protein kinase B and extracellular-signal-regulated kinase cascades. Of the four IRS proteins in mammals, IRS1 and IRS2 play key roles in regulating growth and survival, metabolism, and aging. Meanwhile, the roles of IRS1 and IRS2 in the central nervous system with respect to cognitive abilities remain to be clarified. In contrast to IRS2 in peripheral tissues, inactivation of neural IRS2 exerts beneficial effects, resulting in the reduction of amyloid β accumulation and premature mortality in AD mouse models. On the other hand, the increased phosphorylation of IRS1 at several serine sites is observed in the brains from patients with AD and animal models of AD or cognitive impairment induced by type 2 diabetes. However, these serine sites are also activated in a mouse model of type 2 diabetes, in which the diabetes drug metformin improves memory impairment. Because IRS1 and IRS2 signaling pathways are regulated through complex mechanisms including positive and negative feedback loops, whether the elevated phosphorylation of IRS1 at specific serine sites found in AD brains is a primary response to cognitive dysfunction remains unknown. Here, we examine the associations between IRS1/IRS2-mediated signaling in the central nervous system and cognitive decline.
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Affiliation(s)
- Daisuke Tanokashira
- Department of Integrative Aging Neuroscience, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
| | - Wataru Fukuokaya
- Division of Neurology, Endocrinology, and Metabolism, Faculty of Medicine University of Miyazaki, Miyazaki, Japan
| | - Akiko Taguchi
- Department of Integrative Aging Neuroscience, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
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15
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Ruberto AA, Logan SM, Storey KB. Temperature and serine phosphorylation regulate glycerol-3-phosphate dehydrogenase in skeletal muscle of hibernating Richardson's ground squirrels. Biochem Cell Biol 2018; 97:148-157. [PMID: 30253108 DOI: 10.1139/bcb-2018-0198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glycerol-3-phosphate dehydrogenase (G3PDH) bridges carbohydrate and lipid metabolism by interconverting glycerol-3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP). This reversible reaction converts G3P derived from triglyceride hydrolysis to DHAP that can then enter glycolysis or gluconeogenesis and, in the reverse reaction, makes G3P for use in triglyceride biosynthesis. Small hibernating mammals rely almost exclusively on triglyceride reserves as their fuel for energy production during torpor and the recovery of glycerol after lipolysis is an important source of carbohydrate over the nonfeeding winter months. G3PDH (∼37 kDa) was purified from skeletal muscle of euthermic and hibernating Richardson's ground squirrels (Urocitellus richardsonii) using three column chromatography steps. Analysis of enzyme kinetic properties revealed that G3PDH from hibernator muscle had higher affinities for G3P and NAD at low (5 °C) assay temperature compared with high (21 or 37 °C) and a greater stability in the presence of denaturing agents (urea, guanidine hydrochloride) or high temperature (50 °C). Immunoblotting showed that hibernator muscle G3PDH had a higher phosphoserine content than the enzyme from euthermic controls and incubation studies showed that enzyme affinity for G3P changed significantly by stimulating endogenous protein kinases or phosphatases. Overall, this study suggests that the properties of ground squirrel muscle G3PDH are modulated by temperature and post-translational phosphorylation to alter enzyme function under euthermic versus hibernating states.
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Affiliation(s)
- Anthony A Ruberto
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.,Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
| | - Samantha M Logan
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.,Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
| | - Kenneth B Storey
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.,Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
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16
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Kozin SA, Barykin EP, Telegin GB, Chernov AS, Adzhubei AA, Radko SP, Mitkevich VA, Makarov AA. Intravenously Injected Amyloid-β Peptide With Isomerized Asp7 and Phosphorylated Ser8 Residues Inhibits Cerebral β-Amyloidosis in AβPP/PS1 Transgenic Mice Model of Alzheimer's Disease. Front Neurosci 2018; 12:518. [PMID: 30210271 PMCID: PMC6119768 DOI: 10.3389/fnins.2018.00518] [Citation(s) in RCA: 12] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 07/11/2018] [Indexed: 11/13/2022] Open
Abstract
Cerebral β-amyloidosis, an accumulation in the patient's brain of aggregated amyloid-β (Aβ) peptides abnormally saturated by divalent biometal ions, is one of the hallmarks of Alzheimer's disease (AD). Earlier, we found that exogenously administrated synthetic Aβ with isomerized Asp7 (isoD7-Aβ) induces Aβ fibrillar aggregation in the transgenic mice model of AD. IsoD7-Aβ molecules have been implied to act as seeds enforcing endogenous Aβ to undergo pathological aggregation through zinc-mediated interactions. On the basis of our findings on zinc-induced oligomerization of the metal-binding domain of various Aβ species, we hypothesize that upon phosphorylation of Ser8, isoD7-Aβ loses its ability to form zinc-bound oligomeric seeds. In this work, we found that (i) in vitro isoD7-Aβ with phosphorylated Ser8 (isoD7-pS8-Aβ) is less prone to spontaneous and zinc-induced aggregation in comparison with isoD7-Aβ and intact Aβ as shown by thioflavin T fluorimetry and dynamic light scattering data, and (ii) intravenous injections of isoD7-pS8-Aβ significantly slow down the progression of institutional β-amyloidosis in AβPP/PS1 transgenic mice as shown by the reduction of the congophilic amyloid plaques' number in the hippocampus. The results support the role of the zinc-mediated oligomerization of Aβ species in the modulation of cerebral β-amyloidosis and demonstrate that isoD7-pS8-Aβ can serve as a potential molecular tool to block the aggregation of endogenous Aβ in AD.
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Affiliation(s)
- Sergey A Kozin
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Evgeny P Barykin
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Georgy B Telegin
- Pushchino Branch of Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alexander S Chernov
- Pushchino Branch of Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alexei A Adzhubei
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Sergey P Radko
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.,Institute of Biomedical Chemistry, Moscow, Russia
| | - Vladimir A Mitkevich
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Alexander A Makarov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
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17
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Si M, Goodluck H, Zeng C, Pan S, Todd EM, Morley SC, Qin X, Mohan S, Xing W. LRRK1 regulation of actin assembly in osteoclasts involves serine 5 phosphorylation of L-plastin. J Cell Biochem 2018; 119:10351-10357. [PMID: 30136304 PMCID: PMC6218268 DOI: 10.1002/jcb.27377] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [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: 03/28/2018] [Accepted: 07/02/2018] [Indexed: 12/11/2022]
Abstract
Mice with disruption of Lrrk1 and patients with nonfunctional mutant Lrrk1 exhibit severe osteopetrosis phenotypes because of osteoclast cytoskeletal dysfunction. To understand how Lrrk1 regulates osteoclast function by modulating cytoskeleton rearrangement, we examined the proteins that are differentially phosphorylated in wild‐type mice and Lrrk1‐deficient osteoclasts by metal affinity purification coupled liquid chromatography/mass spectrometry (LC/MS) analyses. One of the candidates that we identified by LC/MS is L‐plastin, an actin bundling protein. We found that phosphorylation of L‐plastin at serine (Ser) residues 5 was present in wild‐type osteoclasts but not in Lrrk1‐deficient cells. Western blot analyses with antibodies specific for Ser5 phosphorylated L‐plastin confirmed the reduced L‐plastin Ser5 phosphorylation in Lrrk1 knockout (KO) osteoclasts. micro computed tomography (Micro‐CT) analyses revealed that the trabecular bone volume of the distal femur was increased by 27% in the 16 to 21‐week‐old L‐plastin KO females as compared with the wild‐type control mice. The ratio of bone volume to tissue volume and connectivity density were increased by 44% and 47% (both P < 0.05), respectively, in L‐plastin KO mice. Our data suggest that targeted disruption of L‐plastin increases trabecular bone volume, and phosphorylation of Ser5 in L‐plastin in the Lrrk1 signaling pathway may in part contribute to actin assembly in mature osteoclasts.
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Affiliation(s)
- Mingjue Si
- Department of Radiology, Shanghai Ninth People's Hospital, Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.,Department of Medicine, Loma Linda University, Loma Linda, California
| | - Helen Goodluck
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center, Loma Linda, California
| | - Canjun Zeng
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center, Loma Linda, California.,Department of Orthopedics, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China
| | - Songqin Pan
- Proteomics Core Facility, University of California, Riverside, California
| | - Elizabeth M Todd
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - Sharon Celeste Morley
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri.,Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri
| | - Xuezhong Qin
- Department of Medicine, Loma Linda University, Loma Linda, California.,Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center, Loma Linda, California
| | - Subburaman Mohan
- Department of Medicine, Loma Linda University, Loma Linda, California.,Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center, Loma Linda, California
| | - Weirong Xing
- Department of Medicine, Loma Linda University, Loma Linda, California.,Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center, Loma Linda, California.,Department of Orthopedics, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China
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18
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Banday AA. Chronic insulin treatment phosphorylates the renal Na-K-ATPase α1-subunit at serine 16/23 and reduces its activity involving PI3-kinase-dependent PKC activation. Am J Physiol Renal Physiol 2016; 311:F958-F966. [PMID: 27605582 DOI: 10.1152/ajprenal.00355.2016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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: 06/14/2016] [Accepted: 08/31/2016] [Indexed: 11/22/2022] Open
Abstract
The regulation of Na-K-ATPase in various tissues is under the control of a number of hormones and peptides that exert both short- and long-term control over its activity. The present study was performed to investigate the effect of chronic insulin treatment on Na-K-ATPase in renal proximal tubular cells. Incubation of opossum kidney (OK) cells, transfected with the rat Na-K-ATPase α1-subunit, with 1 nmol/l insulin for 48 h decreased Na-K-ATPase activity. Insulin decreased α1-protein content and increased α1-serine phosphorylation and α1-adaptor protein 2 (AP2) interaction. Removal of the 26 NH2-terminal (-NT) amino acid from the α1-subunit containing serine/threonine sites abolished the insulin-mediated serine phosphorylation and inhibition of Na-K-ATPase. Substitution of serine 16 and 23 with alanine showed a comparable effect on -NT. Insulin increased the activity of protein kinase C (PKC), which was blocked by the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin. Both PI3K and PKC inhibitors abolished the insulin-mediated inhibition of Na-K-ATPase. Insulin increased the expression of PKC-β1, -δ, -ξ, and-λ; however, only PKC-ξ/λ-specific inhibitors blocked insulin-induced phosphorylation and inhibition of Na-K-ATPase. Our data demonstrate that insulin activates the atypical PKC isoforms-ξ/λ via the PI3K pathway. PKC-ξ/λ-induced phosphorylation of the α1-subunit at serine 16 and 23 leads to AP2 recruitment, degradation, and a decrease in Na-K-ATPase activity.
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19
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Li Y, Xie N, Gleave ME, Rennie PS, Dong X. AR-v7 protein expression is regulated by protein kinase and phosphatase. Oncotarget 2016; 6:33743-54. [PMID: 26378044 PMCID: PMC4741799 DOI: 10.18632/oncotarget.5608] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [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: 08/04/2015] [Accepted: 08/27/2015] [Indexed: 01/13/2023] Open
Abstract
Failure of androgen-targeted therapy and progression of castration-resistant prostate cancer (CRPC) are often attributed to sustained expression of the androgen receptor (AR) and its major splice variant, AR-v7. Although the new generation of anti-androgens such as enzalutamide effectively inhibits AR activity, accumulating pre-clinical and clinical evidence indicates that AR-v7 remains constitutively active in driving CRPC progression. However, molecular mechanisms which control AR-v7 protein expression remain unclear. We apply multiple prostate cancer cell models to demonstrate that enzalutamide induces differential activation of protein phosphatase-1 (PP-1) and Akt kinase depending on the gene context of cancer cells. The balance between PP-1 and Akt activation governs AR phosphorylation status and activation of the Mdm2 ubiquitin ligase. Mdm2 recognizes phosphorylated serine 213 of AR-v7, and induces AR-v7 ubiquitination and protein degradation. These findings highlight the decisive roles of PP-1 and Akt for AR-v7 protein expression and activities when AR is functionally blocked.
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Affiliation(s)
- Yinan Li
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, Vancouver, Canada
| | - Ning Xie
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, Vancouver, Canada
| | - Martin E Gleave
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, Vancouver, Canada
| | - Paul S Rennie
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, Vancouver, Canada
| | - Xuesen Dong
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, Vancouver, Canada
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20
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Fortuin S, Tomazella GG, Nagaraj N, Sampson SL, Gey van Pittius NC, Soares NC, Wiker HG, de Souza GA, Warren RM. Phosphoproteomics analysis of a clinical Mycobacterium tuberculosis Beijing isolate: expanding the mycobacterial phosphoproteome catalog. Front Microbiol 2015; 6:6. [PMID: 25713560 PMCID: PMC4322841 DOI: 10.3389/fmicb.2015.00006] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [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: 10/31/2014] [Accepted: 01/04/2015] [Indexed: 11/29/2022] Open
Abstract
Reversible protein phosphorylation, regulated by protein kinases and phosphatases, mediates a switch between protein activity and cellular pathways that contribute to a large number of cellular processes. The Mycobacterium tuberculosis genome encodes 11 Serine/Threonine kinases (STPKs) which show close homology to eukaryotic kinases. This study aimed to elucidate the phosphoproteomic landscape of a clinical isolate of M. tuberculosis. We performed a high throughput mass spectrometric analysis of proteins extracted from an early-logarithmic phase culture. Whole cell lysate proteins were processed using the filter-aided sample preparation method, followed by phosphopeptide enrichment of tryptic peptides by strong cation exchange (SCX) and Titanium dioxide (TiO2) chromatography. The MaxQuant quantitative proteomics software package was used for protein identification. Our analysis identified 414 serine/threonine/tyrosine phosphorylated sites, with a distribution of S/T/Y sites; 38% on serine, 59% on threonine and 3% on tyrosine; present on 303 unique peptides mapping to 214 M. tuberculosis proteins. Only 45 of the S/T/Y phosphorylated proteins identified in our study had been previously described in the laboratory strain H37Rv, confirming previous reports. The remaining 169 phosphorylated proteins were newly identified in this clinical M. tuberculosis Beijing strain. We identified 5 novel tyrosine phosphorylated proteins. These findings not only expand upon our current understanding of the protein phosphorylation network in clinical M. tuberculosis but the data set also further extends and complements previous knowledge regarding phosphorylated peptides and phosphorylation sites in M. tuberculosis.
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Affiliation(s)
- Suereta Fortuin
- Division of Molecular Biology and Human Genetics, Faculty Medicine and Health Sciences, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, SAMRC Centre for Tuberculosis Research, Stellenbosch University Cape Town, South Africa
| | - Gisele G Tomazella
- The Gade Research Group for Infection and Immunity, Department of Clinical Science, University of Bergen Bergen, Norway
| | | | - Samantha L Sampson
- Division of Molecular Biology and Human Genetics, Faculty Medicine and Health Sciences, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, SAMRC Centre for Tuberculosis Research, Stellenbosch University Cape Town, South Africa
| | - Nicolaas C Gey van Pittius
- Division of Molecular Biology and Human Genetics, Faculty Medicine and Health Sciences, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, SAMRC Centre for Tuberculosis Research, Stellenbosch University Cape Town, South Africa
| | - Nelson C Soares
- Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town Cape Town, South Africa
| | - Harald G Wiker
- The Gade Research Group for Infection and Immunity, Department of Clinical Science, University of Bergen Bergen, Norway
| | - Gustavo A de Souza
- Norway Proteomics Core Facility, Department of Immunology, Oslo University Oslo, Norway
| | - Robin M Warren
- Division of Molecular Biology and Human Genetics, Faculty Medicine and Health Sciences, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, SAMRC Centre for Tuberculosis Research, Stellenbosch University Cape Town, South Africa
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21
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Stahl P, Schwarz RT, Debierre-Grockiego F, Meyer T. Trypanosoma cruzi parasites fight for control of the JAK-STAT pathway by disarming their host. JAKSTAT 2015; 3:e1012964. [PMID: 26413423 DOI: 10.1080/21623996.2015.1012964] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [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: 01/03/2015] [Revised: 01/23/2015] [Accepted: 01/26/2015] [Indexed: 12/13/2022] Open
Abstract
The zoonotic Chagas' disease is caused by infections with the hemoflagellate Trypanosoma cruzi (T. cruzi) which is endemic in Latin America. Despite recent advances in our understanding of the pathogenesis of the disease, the underlying molecular processes involved in host-parasite interactions are only poorly understood. In particular, the mechanisms for parasite persistence in host cells remain largely unknown. Cytokine-driven transcription factors from the family of STAT (signal transducer and activator of transcription) proteins appear to play a central role in the fight against T. cruzi infection. However, amastigotes proliferating in the cytoplasm of infected host cells develop effective strategies to circumvent the attack executed by STAT proteins. This review highlights the interactions between T. cruzi parasites and human host cells in terms of cytokine signaling and, in particular, discusses the impact of STATs on the balance between parasite invasion and clearance.
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Affiliation(s)
- Philipp Stahl
- Institute of Virology; Parasitology Unit; University of Marburg ; Marburg, Germany
| | - Ralph T Schwarz
- Institute of Virology; Parasitology Unit; University of Marburg ; Marburg, Germany ; Laboratory for Structural and Functional Glycobiology; University of Lille 1 for Sciences and Technologies ; Lille, France
| | - Françoise Debierre-Grockiego
- Mixed Research Unit 1282; François Rabelais University of Tours-INRA; Infectious Diseases and Public Health ; Tours, France
| | - Thomas Meyer
- Department of Psychosomatic Medicine and Psychotherapy; University of Göttingen ; Göttingen, Germany ; German Center for Cardiovascular Research ; Göttingen, Germany
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Abstract
Whereas cytokine-induced tyrosine phosphorylation of STAT (signal transducer and activator of transcription) proteins by JAK kinases has been well studied, much less is known about STAT-specific serine kinases and their signal-dependent regulation. The paper by Joanna Bancerek and colleagues published recently in Immunity reports that upon interferon-γ (IFNγ) stimulation of cells the chromatin-associated cyclin-dependent kinase 8 (CDK8) phosphorylates the regulatory serine residue 727 in the transactivation domain of STAT1. The authors state that the CDK8 module of the Mediator complex is a key component in the STAT1 signal pathway, linking serine phosphorylation to gene-specific transcriptional events.
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Affiliation(s)
- Julia Staab
- Department of Psychosomatic Medicine and Psychotherapy; University of Göttingen; Göttingen, Germany
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Abstract
The CAS (CRK-associated substrate) family of adaptor proteins comprises 4 members, which share a conserved modular domain structure that enables multiple protein-protein interactions, leading to the assembly of intracellular signaling platforms. Besides their physiological role in signal transduction downstream of a variety of cell surface receptors, CAS proteins are also critical for oncogenic transformation and cancer cell malignancy through associations with a variety of regulatory proteins and downstream effectors. Among the regulatory partners, the 3 recently identified adaptor proteins constituting the NSP (novel SH2-containing protein) family avidly bind to the conserved carboxy-terminal focal adhesion-targeting (FAT) domain of CAS proteins. NSP proteins use an anomalous nucleotide exchange factor domain that lacks catalytic activity to form NSP-CAS signaling modules. Additionally, the NSP SH2 domain can link NSP-CAS signaling assemblies to tyrosine-phosphorylated cell surface receptors. NSP proteins can potentiate CAS function by affecting key CAS attributes such as expression levels, phosphorylation state, and subcellular localization, leading to effects on cell adhesion, migration, and invasion as well as cell growth. The consequences of these activities are well exemplified by the role that members of both families play in promoting breast cancer cell invasiveness and resistance to antiestrogens. In this review, we discuss the intriguing interplay between the NSP and CAS families, with a particular focus on cancer signaling networks.
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Affiliation(s)
- Yann Wallez
- Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
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Li Y, Deng C, Hu X, Patel B, Fu X, Qiu Y, Brand M, Zhao K, Huang S. Dynamic interaction between TAL1 oncoprotein and LSD1 regulates TAL1 function in hematopoiesis and leukemogenesis. Oncogene 2012; 31:5007-18. [PMID: 22310283 PMCID: PMC3510314 DOI: 10.1038/onc.2012.8] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [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: 10/22/2011] [Revised: 12/15/2011] [Accepted: 12/30/2011] [Indexed: 12/29/2022]
Abstract
TAL1/SCL is a hematopoietic-specific oncogene and its activity is regulated by associated transcriptional co-activators and corepressors. Dysregulation of TAL1 activity has been associated with T-cell leukemogenesis. However, it remains unclear how the interactions between TAL1 and corepressors versus co-activators are properly regulated. Here, we reported that protein kinase A (PKA)-mediated phosphorylation regulates TAL1 interaction with the lysine-specific demethylase (LSD1) that removes methyl group from methylated Lys 4 on histone H3 tails. Phosphorylation of serine 172 in TAL1 specifically destabilizes the TAL1-LSD1 interaction leading to promoter H3K4 hypermethylation and activation of target genes that have been suppressed in normal and malignant hematopoiesis. Knockdown of TAL1 or LSD1 led to a derepression of the TAL1 target genes in T-cell acute lymphoblast leukemia (T-ALL) Jurkat cells, which is accompanied by elevating promoter H3K4 methylation. Similarly, treatment of PKA activator forskolin resulted in derepression of target genes by reducing its interaction with LSD1 while PKA inhibitor H89 represses them by suppressing H3K4 methylation levels. Consistent with the dual roles of TAL1 in transcription, TAL1-associated LSD1 is decreased while recruitment of hSET1 is increased at the TAL1 targets during erythroid differentiation. This process is accompanied by a dramatic increase in H3K4 methylation. Thus, our data revealed a novel interplay between PKA phosphorylation and TAL1-mediated epigenetic regulation that regulates hematopoietic transcription and differentiation programs during hematopoiesis and leukemogenesis.
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Affiliation(s)
- Ying Li
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, FL 32610
- College of Life Science, Jilin University, Changchun 130023, China
| | - Changwang Deng
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, FL 32610
| | - Xin Hu
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, FL 32610
- College of Life Science, Jilin University, Changchun 130023, China
| | - Bhavita Patel
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, FL 32610
| | - Xueqi Fu
- College of Life Science, Jilin University, Changchun 130023, China
| | - Yi Qiu
- Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, FL 32610
- Shands Cancer Center, University of Florida College of Medicine, Gainesville, FL 32610
| | - Marjorie Brand
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Canada
| | - Keji Zhao
- Laboratory of Molecular Immunology, NHLBI, NIH, Bethesda, MD
| | - Suming Huang
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, FL 32610
- Shands Cancer Center, University of Florida College of Medicine, Gainesville, FL 32610
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25
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Copps KD, White MF. Regulation of insulin sensitivity by serine/threonine phosphorylation of insulin receptor substrate proteins IRS1 and IRS2. Diabetologia 2012; 55:2565-2582. [PMID: 22869320 PMCID: PMC4011499 DOI: 10.1007/s00125-012-2644-8] [Citation(s) in RCA: 668] [Impact Index Per Article: 55.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 04/23/2012] [Indexed: 12/11/2022]
Abstract
The insulin receptor substrate proteins IRS1 and IRS2 are key targets of the insulin receptor tyrosine kinase and are required for hormonal control of metabolism. Tissues from insulin-resistant and diabetic humans exhibit defects in IRS-dependent signalling, implicating their dysregulation in the initiation and progression of metabolic disease. However, IRS1 and IRS2 are regulated through a complex mechanism involving phosphorylation of >50 serine/threonine residues (S/T) within their long, unstructured tail regions. In cultured cells, insulin-stimulated kinases (including atypical PKC, AKT, SIK2, mTOR, S6K1, ERK1/2 and ROCK1) mediate feedback (autologous) S/T phosphorylation of IRS, with both positive and negative effects on insulin sensitivity. Additionally, insulin-independent (heterologous) kinases can phosphorylate IRS1/2 under basal conditions (AMPK, GSK3) or in response to sympathetic activation and lipid/inflammatory mediators, which are present at elevated levels in metabolic disease (GRK2, novel and conventional PKCs, JNK, IKKβ, mPLK). An emerging view is that the positive/negative regulation of IRS by autologous pathways is subverted/co-opted in disease by increased basal and other temporally inappropriate S/T phosphorylation. Compensatory hyperinsulinaemia may contribute strongly to this dysregulation. Here, we examine the links between altered patterns of IRS S/T phosphorylation and the emergence of insulin resistance and diabetes.
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Affiliation(s)
- K D Copps
- Howard Hughes Medical Institute, Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, CLS 16020, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - M F White
- Howard Hughes Medical Institute, Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, CLS 16020, 300 Longwood Avenue, Boston, MA, 02115, USA.
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Jarmuła A, Fraczyk T, Cieplak P, Rode W. Mechanism of influence of phosphorylation on serine 124 on a decrease of catalytic activity of human thymidylate synthase. Bioorg Med Chem 2010; 18:3361-70. [PMID: 20430630 PMCID: PMC4127429 DOI: 10.1016/j.bmc.2010.04.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [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: 01/05/2010] [Revised: 04/01/2010] [Accepted: 04/06/2010] [Indexed: 10/19/2022]
Abstract
Regulation by phosphorylation is a well-established mechanism for controlling biological activity of proteins. Recently, phosphorylation of serine 124 in human thymidylate synthase (hTS) has been shown to lower the catalytic activity of the enzyme. To clarify a possible mechanism of the observed influence, molecular dynamics (MD), essential dynamics (ED) and MM-GBSA studies were undertaken. Structures derived from the MD trajectories reveal incorrect binding alignment between the pyrimidine ring of the substrate, dUMP, and the pterine ring of the cofactor analogue, THF, in the active site of the phosphorylated enzyme. The ED analysis indicates changes in the behavior of collective motions in the phosphorylated enzyme, suggesting that the formation of the closed ternary complex is hindered. Computed free energies, in agreement with structural analysis, predict that the binding of dUMP and THF to hTS is favored in the native compared to phosphorylated state of the enzyme. The paper describes at the structural level how phosphorylation at the distant site influences the ligand binding. We propose that the 'phosphorylation effect' is transmitted from the outside loop of Ser 124 into the active site via a subtle mechanism initiated by the long-range electrostatic repulsion between the phosphate groups of dUMP and Ser124. The mechanism can be described in terms of the interplay between the two groups of amino acids: the link (residues 125-134) and the patch (residues 189-192), resulting in the change of orientation of the pyrimidine ring of dUMP, which, in turn, prevents the correct alignment between the latter ring and the pterin ring of THF.
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Affiliation(s)
- Adam Jarmuła
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warszawa, Poland.
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27
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Niture SK, Jain AK, Jaiswal AK. Antioxidant-induced modification of INrf2 cysteine 151 and PKC-delta-mediated phosphorylation of Nrf2 serine 40 are both required for stabilization and nuclear translocation of Nrf2 and increased drug resistance. J Cell Sci 2009; 122:4452-64. [PMID: 19920073 PMCID: PMC2787459 DOI: 10.1242/jcs.058537] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.9] [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] [Accepted: 09/17/2009] [Indexed: 11/20/2022] Open
Abstract
Antioxidants cause dissociation of nuclear factor erythroid 2-related factor 2 (Nrf2) from inhibitor of Nrf2 (INrf2) and so Nrf2:INrf2 can serve as a sensor of oxidative stress. Nrf2 translocates to the nucleus, binds to antioxidant response element (ARE) and activates defensive gene expression, which protects cells. Controversies exist regarding the role of antioxidant-induced modification of INrf2 cysteine 151 or protein kinase C (PKC)-mediated phosphorylation of Nrf2 serine 40 in the release of Nrf2 from INrf2. In addition, the PKC isoform that phosphorylates Nrf2S40 remains unknown. Here, we demonstrate that antioxidant-induced PKC-delta-mediated phosphorylation of Nrf2S40 leads to release of Nrf2 from INrf2. This was evident from specific chemical inhibitors of PKC isoenzymes in reporter assays, in vitro kinase assays with purified Nrf2 and PKC isoenzymes, in vivo analysis with dominant-negative mutants and siRNA against PKC isoforms, use of PKC-delta(+/+) and PKC-delta(-/-) cells, and use of Nrf2S40 phospho-specific antibody. The studies also showed that antioxidant-induced INrf2C151 modification was insufficient for the dissociation of Nrf2 from INrf2. PKC-delta-mediated Nrf2S40 phosphorylation was also required. Nrf2 and mutant Nrf2S40A both bind to INrf2. However, antioxidant treatment led to release of Nrf2 but not Nrf2S40A from INrf2. In addition, Nrf2 and mutant Nrf2S40A both failed to dissociate from mutant INrf2C151A. Furthermore, antioxidant-induced ubiquitylation of INrf2 in PKC-delta(+/+) and PKC-delta(-/-) cells occurred, but Nrf2 failed to be released in PKC-delta(-/-) cells. The antioxidant activation of Nrf2 reduced etoposide-mediated DNA fragmentation and promoted cell survival in PKC-delta(+/+) but not in PKC-delta(-/-) cells. These data together demonstrate that both modification of INrf2C151 and PKC-delta-mediated phosphorylation of Nrf2S40 play crucial roles in Nrf2 release from INrf2, antioxidant induction of defensive gene expression, promoting cell survival, and increasing drug resistance.
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Affiliation(s)
| | | | - Anil K. Jaiswal
- Department of Pharmacology and Experimental Therapeutics, University of
Maryland School of Medicine, Baltimore, MD 21201, USA
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Krungkasem C, Ueda K, Tachibana H, Shirahata S. Further investigation of the light chain shifting phenomenon: light chain replacement through secondary rearrangement induced by lectin stimulation in the hybridoma cell line HB4C5. Cytotechnology 1997; 25:145-54. [PMID: 9474807 PMCID: PMC3466735 DOI: 10.1023/a:1007943228587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [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] [Indexed: 02/06/2023] Open
Abstract
We found that when the hybridoma cell line HB4C5 was stimulated with wheat germ agglutinin (WGA), loss of production of the original lambda light chain occurred, followed by production of new light chain, which mirrored the reaction when stimulated with concanavalin A (ConA). We previously reported that the RAG genes are expressed not only in HB4C5 and its ConA-treated variant subclones, but also in the in the parental Namalwa cells, which are known to be in the plasma state. However, the new lambda light chains were expressed only in the HB4C5 cells and not in the parental Namalwa cells. Here we found that the RAG genes are expressed in HB4C5 cells after continuous stimulation with WGA. To further investigate the mechanism of this loss of original lambda light chain production by stimulation with lectins in HB4C5 cells, which leads to a sIg-negative subpopulation, we analyzed the differences between HB4C5 and Namalwa cells. In this present study, we found that a 70 kDa phosphorylated protein in HB4C5 cells became undetectable after stimulation with lectins (WGA and ConA), and was not detected in Namalwa cells before or after lectin stimulation. It has been believed that the RAG genes and loss of original lambda light chain production are required to induce expression of a new lambda light chain in the HB4C5 cells. We suggested that the phosphorylated 70 kDa protein in HB4C5 cells play important roles in regulating the production of new lambda light chains which is induced by lectins.
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Affiliation(s)
- C Krungkasem
- Graduate School of Genetic Resources Technology, Kyushu University, Fukuoka, Japan
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