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Yang W, Xia F, Mei F, Shi S, Robichaux WG, Lin W, Zhang W, Liu H, Cheng X. Upregulation of Epac1 Promotes Pericyte Loss by Inducing Mitochondrial Fission, Reactive Oxygen Species Production, and Apoptosis. Invest Ophthalmol Vis Sci 2023; 64:34. [PMID: 37651112 PMCID: PMC10476449 DOI: 10.1167/iovs.64.11.34] [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: 03/30/2023] [Accepted: 08/09/2023] [Indexed: 09/01/2023] Open
Abstract
Purpose The pathogenic mechanisms behind the development of ischemic retinopathy are complex and poorly understood. This study investigates the involvement of exchange protein directly activated by cAMP (Epac)1 signaling in pericyte injury during ischemic retinopathy, including diabetic retinopathy, a disease that threatens vision. Methods Mouse models of retinal ischemia-reperfusion injury and type 1 diabetes induced by streptozotocin were used to investigate the pathogenesis of these diseases. The roles of Epac1 signaling in the pathogenesis of ischemic retinopathy were determined by an Epac1 knockout mouse model. The cellular and molecular mechanisms of Epac1-mediated pericyte dysfunction in response to high glucose were investigated by specific modulation of Epac1 activity in primary human retinal pericytes using Epac1-specific RNA interference and a pharmacological inhibitor. Results Ischemic injury or diabetes-induced retinal capillary degeneration were associated with an increased expression of Epac1 in the mouse retinal vasculature, including both endothelial cells and pericytes. Genetic deletion of Epac1 protected ischemic injury-induced pericyte loss and capillary degeneration in the mouse retina. Furthermore, high glucose-induced Epac1 expression in retinal pericytes was accompanied by increased Drp1 phosphorylation, mitochondrial fission, reactive oxygen species production, and caspase 3 activation. Inhibition of Epac1 via RNA interference or pharmacological approaches blocked high glucose-mediated mitochondrial dysfunction and caspase 3 activation. Conclusions Our study reveals an important role of Epac1 signaling in mitochondrial dynamics, reactive oxygen species production, and apoptosis in retinal pericytes and identifies Epac1 as a therapeutic target for treating ischemic retinopathy.
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Affiliation(s)
- Wenli Yang
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, Texas, United States
- Texas Therapeutics Institute, University of Texas Health Science Center, Houston, Texas, United States
| | - Fan Xia
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Fang Mei
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, Texas, United States
- Texas Therapeutics Institute, University of Texas Health Science Center, Houston, Texas, United States
| | - Shuizhen Shi
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - William G. Robichaux
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, Texas, United States
- Texas Therapeutics Institute, University of Texas Health Science Center, Houston, Texas, United States
| | - Wei Lin
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, Texas, United States
- Texas Therapeutics Institute, University of Texas Health Science Center, Houston, Texas, United States
| | - Wenbo Zhang
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
- Department of Neurobiology, University of Texas Medical Branch, Galveston, Texas, United States
| | - Hua Liu
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, Texas, United States
- Texas Therapeutics Institute, University of Texas Health Science Center, Houston, Texas, United States
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Yang W, Robichaux WG, Mei F, Lin W. Epac1 Regulates Cellular SUMOylation by Promoting The Formation of SUMO‐activating Nuclear Condensates. FASEB J 2022. [DOI: 10.1096/fasebj.2022.36.s1.r4009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Fang Mei
- Dept of Intergative Bio and PharmUTHealthHoustonTX
| | - Wei Lin
- Dept of Intergative Bio and PharmUTHealthHoustonTX
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Yang W, Robichaux WG, Mei FC, Lin W, Li L, Pan S, White MA, Chen Y, Cheng X. Epac1 activation by cAMP regulates cellular SUMOylation and promotes the formation of biomolecular condensates. Sci Adv 2022; 8:eabm2960. [PMID: 35442725 PMCID: PMC9020664 DOI: 10.1126/sciadv.abm2960] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
Protein SUMOylation plays an essential role in maintaining cellular homeostasis when cells are under stress. However, precisely how SUMOylation is regulated, and a molecular mechanism linking cellular stress to SUMOylation, remains elusive. Here, we report that cAMP, a major stress-response second messenger, acts through Epac1 as a regulator of cellular SUMOylation. The Epac1-associated proteome is highly enriched with components of the SUMOylation pathway. Activation of Epac1 by intracellular cAMP triggers phase separation and the formation of nuclear condensates containing Epac1 and general components of the SUMOylation machinery to promote cellular SUMOylation. Furthermore, genetic knockout of Epac1 obliterates oxidized low-density lipoprotein-induced cellular SUMOylation in macrophages, leading to suppression of foam cell formation. These results provide a direct nexus connecting two major cellular stress responses to define a molecular mechanism in which cAMP regulates the dynamics of cellular condensates to modulate protein SUMOylation.
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Affiliation(s)
- Wenli Yang
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, TX, USA
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, USA
| | - William G. Robichaux
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, TX, USA
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, USA
| | - Fang C. Mei
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, TX, USA
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, USA
| | - Wei Lin
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, TX, USA
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, USA
| | - Li Li
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, USA
| | - Sheng Pan
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, USA
| | - Mark A. White
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX, USA
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Yuan Chen
- Department of Surgery and Moores Cancer Center, UC San Diego Health, La Jolla, CA, USA
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, TX, USA
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, USA
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Robichaux WG, Mei FC, Yang W, Wang H, Sun H, Zhou Z, Milewicz DM, Teng BB, Cheng X. Epac1 (Exchange Protein Directly Activated by cAMP 1) Upregulates LOX-1 (Oxidized Low-Density Lipoprotein Receptor 1) to Promote Foam Cell Formation and Atherosclerosis Development. Arterioscler Thromb Vasc Biol 2020; 40:e322-e335. [PMID: 33054390 DOI: 10.1161/atvbaha.119.314238] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVE The cAMP second messenger system, a major stress-response pathway, plays essential roles in normal cardiovascular functions and in pathogenesis of heart diseases. Here, we test the hypothesis that the Epac1 (exchange protein directly activated by cAMP 1) acts as a major downstream effector of cAMP signaling to promote atherogenesis and represents a novel therapeutic target. Approach and Results: To ascertain Epac1's function in atherosclerosis development, a triple knockout mouse model (LTe) was generated by crossing Epac1-/- mice with atherosclerosis-prone LDb mice lacking both Ldlr and Apobec1. Deletion of Epac1 led to a significant reduction of atherosclerotic lesion formation as measured by postmortem staining, accompanied by attenuated macrophage/foam cell infiltrations within atherosclerotic plaques as determined by immunofluorescence staining in LTe animals compared with LDb littermates. Primary bone marrow-derived macrophages were isolated from Epac1-null and wild-type mice to investigate the role of Epac1 in lipid uptake and foam cell formation. ox-LDLs (oxidized low-density lipoproteins) stimulation of bone marrow-derived macrophages led to elevated intracellular cAMP and Epac1 levels, whereas an Epac-specific agonist, increased lipid accumulation in wild-type, but not Epac1-null, bone marrow-derived macrophages. Mechanistically, Epac1 acts through PKC (protein kinase C) to upregulate LOX-1 (ox-LDL receptor 1), a major scavenger receptor for ox-LDL uptake, exerting a feedforward mechanism with ox-LDL to increase lipid uptake and propel foam cell formation and atherogenesis. CONCLUSIONS Our study demonstrates a fundamental role of cAMP/Epac1 signaling in vascular remodeling by promoting ox-LDL uptake and foam cell formation during atherosclerosis lesion development. Therefore, Epac1 represents a promising, unexplored therapeutic target for atherosclerosis.
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Affiliation(s)
- William G Robichaux
- Department of Integrative Biology and Pharmacology (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Texas Therapeutics Institute (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Brown Foundation Institute of Molecular Medicine (W.G.R., F.C.M., W.Y., H.W., H.S., B.-B.T.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Fang C Mei
- Department of Integrative Biology and Pharmacology (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Texas Therapeutics Institute (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Brown Foundation Institute of Molecular Medicine (W.G.R., F.C.M., W.Y., H.W., H.S., B.-B.T.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Wenli Yang
- Department of Integrative Biology and Pharmacology (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Texas Therapeutics Institute (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Brown Foundation Institute of Molecular Medicine (W.G.R., F.C.M., W.Y., H.W., H.S., B.-B.T.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Hui Wang
- Department of Integrative Biology and Pharmacology (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Texas Therapeutics Institute (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Brown Foundation Institute of Molecular Medicine (W.G.R., F.C.M., W.Y., H.W., H.S., B.-B.T.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Hua Sun
- Brown Foundation Institute of Molecular Medicine (W.G.R., F.C.M., W.Y., H.W., H.S., B.-B.T.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Zhen Zhou
- Division of Medical Genetics, Department of Internal Medicine (Z.Z., D.M.M.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Dianna M Milewicz
- Division of Medical Genetics, Department of Internal Medicine (Z.Z., D.M.M.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Ba-Bie Teng
- Brown Foundation Institute of Molecular Medicine (W.G.R., F.C.M., W.Y., H.W., H.S., B.-B.T.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Texas Therapeutics Institute (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston
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Robichaux WG, Cheng X. Intracellular cAMP Sensor EPAC: Physiology, Pathophysiology, and Therapeutics Development. Physiol Rev 2018; 98:919-1053. [PMID: 29537337 PMCID: PMC6050347 DOI: 10.1152/physrev.00025.2017] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 12/13/2022] Open
Abstract
This review focuses on one family of the known cAMP receptors, the exchange proteins directly activated by cAMP (EPACs), also known as the cAMP-regulated guanine nucleotide exchange factors (cAMP-GEFs). Although EPAC proteins are fairly new additions to the growing list of cAMP effectors, and relatively "young" in the cAMP discovery timeline, the significance of an EPAC presence in different cell systems is extraordinary. The study of EPACs has considerably expanded the diversity and adaptive nature of cAMP signaling associated with numerous physiological and pathophysiological responses. This review comprehensively covers EPAC protein functions at the molecular, cellular, physiological, and pathophysiological levels; and in turn, the applications of employing EPAC-based biosensors as detection tools for dissecting cAMP signaling and the implications for targeting EPAC proteins for therapeutic development are also discussed.
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Affiliation(s)
- William G Robichaux
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
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Robichaux WG, Branham-O'Connor M, Hwang IY, Vural A, Kehrl JH, Blumer JB. Regulation of Chemokine Signal Integration by Activator of G-Protein Signaling 4 (AGS4). J Pharmacol Exp Ther 2017; 360:424-433. [PMID: 28062526 DOI: 10.1124/jpet.116.238436] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 12/28/2016] [Indexed: 12/15/2022] Open
Abstract
Activator of G-protein signaling 4 (AGS4)/G-protein signaling modulator 3 (Gpsm3) contains three G-protein regulatory (GPR) motifs, each of which can bind Gαi-GDP free of Gβγ We previously demonstrated that the AGS4-Gαi interaction is regulated by seven transmembrane-spanning receptors (7-TMR), which may reflect direct coupling of the GPR-Gαi module to the receptor analogous to canonical Gαβγ heterotrimer. We have demonstrated that the AGS4-Gαi complex is regulated by chemokine receptors in an agonist-dependent manner that is receptor-proximal. As an initial approach to investigate the functional role(s) of this regulated interaction in vivo, we analyzed leukocytes, in which AGS4/Gpsm3 is predominantly expressed, from AGS4/Gpsm3-null mice. Loss of AGS4/Gpsm3 resulted in mild but significant neutropenia and leukocytosis. Dendritic cells, T lymphocytes, and neutrophils from AGS4/Gpsm3-null mice also exhibited significant defects in chemoattractant-directed chemotaxis and extracellular signal-regulated kinase activation. An in vivo peritonitis model revealed a dramatic reduction in the ability of AGS4/Gpsm3-null neutrophils to migrate to primary sites of inflammation. Taken together, these data suggest that AGS4/Gpsm3 is required for proper chemokine signal processing in leukocytes and provide further evidence for the importance of the GPR-Gαi module in the regulation of leukocyte function.
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Affiliation(s)
- William G Robichaux
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina (W.G.R., M.B.-O., J.B.B.); and B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (I.-Y.H., A.V., J.H.K.)
| | - Melissa Branham-O'Connor
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina (W.G.R., M.B.-O., J.B.B.); and B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (I.-Y.H., A.V., J.H.K.)
| | - Il-Young Hwang
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina (W.G.R., M.B.-O., J.B.B.); and B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (I.-Y.H., A.V., J.H.K.)
| | - Ali Vural
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina (W.G.R., M.B.-O., J.B.B.); and B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (I.-Y.H., A.V., J.H.K.)
| | - Johne H Kehrl
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina (W.G.R., M.B.-O., J.B.B.); and B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (I.-Y.H., A.V., J.H.K.)
| | - Joe B Blumer
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina (W.G.R., M.B.-O., J.B.B.); and B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (I.-Y.H., A.V., J.H.K.)
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Robichaux WG, Oner SS, Lanier SM, Blumer JB. Direct Coupling of a Seven-Transmembrane-Span Receptor to a Gαi G-Protein Regulatory Motif Complex. Mol Pharmacol 2015; 88:231-7. [PMID: 25972449 DOI: 10.1124/mol.115.097741] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 05/12/2015] [Indexed: 12/29/2022] Open
Abstract
Group II activator of G-protein signaling (AGS) proteins contain one or more G-protein regulatory motifs (GPR), which serve as docking sites for GαiGDP independent of Gβγ and stabilize the GDP-bound conformation of Gαi, acting as guanine nucleotide dissociation inhibitors. The GαGPR interaction is regulated by seven-transmembrane-spanning (7TM) receptors in the intact cell as determined by bioluminescence resonance energy transfer (BRET). It is hypothesized that a 7TM receptor directly couples to the GαGPR complex in a manner analogous to receptor coupling to the Gαβγ heterotrimer. As an initial approach to test this hypothesis, we used BRET to examine 7TM receptor-mediated regulation of GαGPR in the intact cell when Gαi2 yellow fluorescent protein (YFP) was tethered to the carboxyl terminus of the α2A adrenergic receptor (α2AAR-Gαi2YFP). AGS3- and AGS4-Renilla luciferase (Rluc) exhibited robust BRET with the tethered GαiYFP, and this interaction was regulated by receptor activation localizing the regulation to the receptor microenvironment. Agonist regulation of the receptor-Gαi-GPR complex was also confirmed by coimmunoprecipitation and cell fractionation. The tethered Gαi2 was rendered pertussis toxin-insensitive by a C352I mutation, and receptor coupling to endogenous Gαi/oβγ was subsequently eliminated by cell treatment with pertussis toxin (PT). Basal and agonist-induced regulation of α2AAR-Gαi2YFP(C352I):AGS3Rluc and α2AAR-Gαi2YFP(C352I):AGS4Rluc BRET was not altered by PT treatment or Gβγ antagonists. Thus, the localized regulation of GαGPR by receptor activation appears independent of endogenous Gαi/oβγ, suggesting that GαiAGS3 and GαiAGS4 directly sense agonist-induced conformational changes in the receptor, as is the case for 7TM receptor coupling to the Gαβγ heterotrimer. The direct coupling of a receptor to the GαiGPR complex provides an unexpected platform for signal propagation with broad implications.
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Affiliation(s)
- William G Robichaux
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (W.G.R., S.S.O., S.M.L., J.B.B.) and Department of Neurosciences (J.B.B.), Medical University of South Carolina, Charleston, South Carolina
| | - Sukru S Oner
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (W.G.R., S.S.O., S.M.L., J.B.B.) and Department of Neurosciences (J.B.B.), Medical University of South Carolina, Charleston, South Carolina
| | - Stephen M Lanier
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (W.G.R., S.S.O., S.M.L., J.B.B.) and Department of Neurosciences (J.B.B.), Medical University of South Carolina, Charleston, South Carolina
| | - Joe B Blumer
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (W.G.R., S.S.O., S.M.L., J.B.B.) and Department of Neurosciences (J.B.B.), Medical University of South Carolina, Charleston, South Carolina
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Branham-O'Connor M, Robichaux WG, Zhang XK, Cho H, Kehrl JH, Lanier SM, Blumer JB. Defective chemokine signal integration in leukocytes lacking activator of G protein signaling 3 (AGS3). J Biol Chem 2014; 289:10738-10747. [PMID: 24573680 DOI: 10.1074/jbc.m113.515031] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [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: 11/06/2022] Open
Abstract
Activator of G-protein signaling 3 (AGS3, gene name G-protein signaling modulator-1, Gpsm1), an accessory protein for G-protein signaling, has functional roles in the kidney and CNS. Here we show that AGS3 is expressed in spleen, thymus, and bone marrow-derived dendritic cells, and is up-regulated upon leukocyte activation. We explored the role of AGS3 in immune cell function by characterizing chemokine receptor signaling in leukocytes from mice lacking AGS3. No obvious differences in lymphocyte subsets were observed. Interestingly, however, AGS3-null B and T lymphocytes and bone marrow-derived dendritic cells exhibited significant chemotactic defects as well as reductions in chemokine-stimulated calcium mobilization and altered ERK and Akt activation. These studies indicate a role for AGS3 in the regulation of G-protein signaling in the immune system, providing unexpected venues for the potential development of therapeutic agents that modulate immune function by targeting these regulatory mechanisms.
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Affiliation(s)
- Melissa Branham-O'Connor
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina 29425
| | - William G Robichaux
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Xian-Kui Zhang
- Department of Medicine, Division of Rheumatology, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Hyeseon Cho
- B-cell Section, NIAID, National Institutes of Health, Bethesda, Maryland 20892
| | - John H Kehrl
- B-cell Section, NIAID, National Institutes of Health, Bethesda, Maryland 20892
| | - Stephen M Lanier
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Joe B Blumer
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina 29425.
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Branham‐O'Connor M, Robichaux WG, Maher EM, Zhang X, Blumer JB. Activator of G protein Signaling‐3 (AGS3) regulates CXCR4 and CCR7 signaling in murine lymphocytes and bone marrow‐derived dendritic cells. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1095.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Ellen M. Maher
- PharmacologyMedical University of South CarolinaCharlestonSC
| | - Xian Zhang
- MedicineMedical University of South CarolinaCharlestonSC
| | - Joe B. Blumer
- PharmacologyMedical University of South CarolinaCharlestonSC
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