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Cervera-Juanes R, Zimmerman KD, Wilhelm L, Zhu D, Bodie J, Kohama SG, Urbanski HF. Modulation of neural gene networks by estradiol in old rhesus macaque females. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.18.572105. [PMID: 38187564 PMCID: PMC10769303 DOI: 10.1101/2023.12.18.572105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
The postmenopausal decrease in circulating estradiol (E2) levels has been shown to contribute to several adverse physiological and psychiatric effects. To elucidate the molecular effects of E2 on the brain, we examined differential gene expression and DNA methylation (DNAm) patterns in the nonhuman primate brain following ovariectomy (Ov) and subsequent E2 treatment. We identified several dysregulated molecular networks, including MAPK signaling and dopaminergic synapse response, that are associated with ovariectomy and shared across two different brain areas, the occipital cortex (OC) and prefrontal cortex (PFC). The finding that hypomethylation (p=1.6×10-51) and upregulation (p=3.8×10-3) of UBE2M across both brain regions, provide strong evidence for molecular differences in the brain induced by E2 depletion. Additionally, differential expression (p=1.9×10-4; interaction p=3.5×10-2) of LTBR in the PFC, provides further support for the role E2 plays in the brain, by demonstrating that the regulation of some genes that are altered by ovariectomy may also be modulated by Ov followed by hormone replacement therapy (HRT). These results present real opportunities to understand the specific biological mechanisms that are altered with depleted E2. Given E2's potential role in cognitive decline and neuroinflammation, our findings could lead to the discovery of novel therapeutics to slow cognitive decline. Together, this work represents a major step towards understanding molecular changes in the brain that are caused by ovariectomy and how E2 treatment may revert or protect against the negative neuro-related consequences caused by a depletion in estrogen as women approach menopause.
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Affiliation(s)
- Rita Cervera-Juanes
- Department of Translational Neuroscience, Atrium Health Wake Forest Baptist, Winston-Salem, NC 27157
- Center for Precision Medicine, Atrium Health Wake Forest Baptist, Winston-Salem, NC 27157
| | - Kip D. Zimmerman
- Center for Precision Medicine, Atrium Health Wake Forest Baptist, Winston-Salem, NC 27157
- Department of Internal Medicine, Atrium Health Wake Forest Baptist, Winston-Salem, NC 27157
| | - Larry Wilhelm
- Department of Translational Neuroscience, Atrium Health Wake Forest Baptist, Winston-Salem, NC 27157
| | - Dongqin Zhu
- Department of Translational Neuroscience, Atrium Health Wake Forest Baptist, Winston-Salem, NC 27157
| | - Jessica Bodie
- Department of Translational Neuroscience, Atrium Health Wake Forest Baptist, Winston-Salem, NC 27157
| | - Steven G. Kohama
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, Oregon, USA
| | - Henryk F. Urbanski
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, Oregon, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Beaverton, Oregon, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, Oregon, USA
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PI3K/Akt pathway mediates the positive inotropic effects of insulin in Langendorff-perfused rat hearts. Sci Rep 2022; 12:9793. [PMID: 35697740 PMCID: PMC9192604 DOI: 10.1038/s41598-022-14092-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 06/01/2022] [Indexed: 11/08/2022] Open
Abstract
Insulin exerts positive inotropic effects on cardiac muscle; however, the relationship between cardiac contractility and phosphoinositol-3-kinase/Akt (PI3K/Akt) activation remains unclear. We hypothesized that the positive inotropic effects of insulin are dose-dependent and mediated via the PI3K/Akt pathway in isolated normal rat hearts. The Institutional Animal Investigation Committee approved the use of hearts excised from rats under pentobarbital anesthesia. The hearts were perfused at a constant pressure using the Langendorff technique. After stabilization (baseline), the hearts were randomly divided into the following four insulin (Ins) groups: 1) Ins0 (0 IU/L), 2) Ins0.5 (0.5 IU/L), 3) Ins5 (5 IU/L), and 4) Ins50 (50 IU/L) (n = 8 in each group). To clarify the role of the PI3K/Akt pathway in insulin-dependent inotropic effects, we also treated the insulin groups with the PI3K inhibitor wortmannin (InsW): 5) InsW0 (0 IU/L), 6) InsW0.5 (0.5 IU/L), 7) InsW5 (5 IU/L), and 8) InsW50 (50 IU/L). Hearts were perfused with Krebs–Henseleit buffer solution with or without wortmannin for 10 min, followed by 20 min perfusion with the solution containing each concentration of insulin. The data were recorded as the maximum left ventricular derivative of pressure development (LV dP/dt max). Myocardial p-Akt levels were measured at 3 min, 5 min, and at the end of the perfusion. In the Ins groups, LV dP/dt max in Ins5 and Ins50 increased by 14% and 48%, respectively, 3 min after insulin perfusion compared with the baseline. Tachyphylaxis was observed after 10 min in the Ins5 and Ins50 treatment groups. Wortmannin partially inhibited the positive inotropic effect of insulin; although insulin enhanced p-Akt levels at all time points compared with the control group, this increase was suppressed in the presence of wortmannin. The positive inotropic effect of insulin is dose-dependent and consistent with Akt activation. This effect mediated by high doses of insulin on cardiac tissue was temporary and caused tachyphylaxis, potentially triggered by Akt overactivation, which leads beta 1 deactivation.
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3
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RGS5-TGFβ-Smad2/3 axis switches pro- to anti-apoptotic signaling in tumor-residing pericytes, assisting tumor growth. Cell Death Differ 2021; 28:3052-3076. [PMID: 34012071 PMCID: PMC8564526 DOI: 10.1038/s41418-021-00801-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 04/29/2021] [Accepted: 05/03/2021] [Indexed: 02/04/2023] Open
Abstract
Regulator-of-G-protein-signaling-5 (RGS5), a pro-apoptotic/anti-proliferative protein, is a signature molecule of tumor-associated pericytes, highly expressed in several cancers, and is associated with tumor growth and poor prognosis. Surprisingly, despite the negative influence of intrinsic RGS5 expression on pericyte survival, RGS5highpericytes accumulate in progressively growing tumors. However, responsible factor(s) and altered-pathway(s) are yet to report. RGS5 binds with Gαi/q and promotes pericyte apoptosis in vitro, subsequently blocking GPCR-downstream PI3K-AKT signaling leading to Bcl2 downregulation and promotion of PUMA-p53-Bax-mediated mitochondrial damage. However, within tumor microenvironment (TME), TGFβ appeared to limit the cytocidal action of RGS5 in tumor-residing RGS5highpericytes. We observed that in the presence of high RGS5 concentrations, TGFβ-TGFβR interactions in the tumor-associated pericytes lead to the promotion of pSmad2-RGS5 binding and nuclear trafficking of RGS5, which coordinately suppressed RGS5-Gαi/q and pSmad2/3-Smad4 pairing. The RGS5-TGFβ-pSmad2 axis thus mitigates both RGS5- and TGFβ-dependent cellular apoptosis, resulting in sustained pericyte survival/expansion within the TME by rescuing PI3K-AKT signaling and preventing mitochondrial damage and caspase activation. This study reports a novel mechanism by which TGFβ fortifies and promotes survival of tumor pericytes by switching pro- to anti-apoptotic RGS5 signaling in TME. Understanding this altered RGS5 signaling might prove beneficial in designing future cancer therapy.
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ERK1/2: An Integrator of Signals That Alters Cardiac Homeostasis and Growth. BIOLOGY 2021; 10:biology10040346. [PMID: 33923899 PMCID: PMC8072600 DOI: 10.3390/biology10040346] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 12/24/2022]
Abstract
Integration of cellular responses to extracellular cues is essential for cell survival and adaptation to stress. Extracellular signal-regulated kinase (ERK) 1 and 2 serve an evolutionarily conserved role for intracellular signal transduction that proved critical for cardiomyocyte homeostasis and cardiac stress responses. Considering the importance of ERK1/2 in the heart, understanding how these kinases operate in both normal and disease states is critical. Here, we review the complexity of upstream and downstream signals that govern ERK1/2-dependent regulation of cardiac structure and function. Particular emphasis is given to cardiomyocyte hypertrophy as an outcome of ERK1/2 activation regulation in the heart.
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The GNAQ T96S Mutation Affects Cell Signaling and Enhances the Oncogenic Properties of Hepatocellular Carcinoma. Int J Mol Sci 2021; 22:ijms22063284. [PMID: 33807071 PMCID: PMC8004934 DOI: 10.3390/ijms22063284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/19/2021] [Accepted: 03/20/2021] [Indexed: 02/06/2023] Open
Abstract
Hepatocellular carcinoma (HCC), the most common malignant tumor in the liver, grows and metastasizes rapidly. Despite advances in treatment modalities, the five-year survival rate of HCC remains less than 30%. We sought genetic mutations that may affect the oncogenic properties of HCC, using The Cancer Genome Atlas (TCGA) data analysis. We found that the GNAQ T96S mutation (threonine 96 to serine alteration of the Gαq protein) was present in 12 out of 373 HCC patients (3.2%). To examine the effect of the GNAQ T96S mutation on HCC, we transfected the SK-Hep-1 cell line with the wild-type or the mutant GNAQ T96S expression vector. Transfection with the wild-type GNAQ expression vector enhanced anchorage-independent growth, migration, and the MAPK pathways in the SK-Hep-1 cells compared to control vector transfection. Moreover, cell proliferation, anchorage-independent growth, migration, and the MAPK pathways were further enhanced in the SK-Hep-1 cells transfected with the GNAQ T96S expression vector compared to the wild-type GNAQ-transfected cells. In silico structural analysis shows that the substitution of the GNAQ amino acid threonine 96 with a serine may destabilize the interaction between the regulator of G protein signaling (RGS) protein and GNAQ. This may reduce the inhibitory effect of RGS on GNAQ signaling, enhancing the GNAQ signaling pathway. Single nucleotide polymorphism (SNP) genotyping analysis for Korean HCC patients shows that the GNAQ T96S mutation was found in only one of the 456 patients (0.22%). Our data suggest that the GNAQ T96S hotspot mutation may play an oncogenic role in HCC by potentiating the GNAQ signal transduction pathway.
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Hernandez KR, Karim ZA, Qasim H, Druey KM, Alshbool FZ, Khasawneh FT. Regulator of G-Protein Signaling 16 Is a Negative Modulator of Platelet Function and Thrombosis. J Am Heart Assoc 2020; 8:e011273. [PMID: 30791801 PMCID: PMC6474914 DOI: 10.1161/jaha.118.011273] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Background Members of the regulator of G‐protein signaling (RGS) family inhibit G‐protein coupled receptor signaling by modulating G‐protein activity. In platelets, there are 3 different RGS isoforms that are expressed at the protein level, including RGS16. Recently, we have shown that CXCL12 regulates platelet function via RGS16. However, the role of RGS16 in platelet function and thrombus formation is poorly defined. Methods and Results We used a genetic knockout mouse model approach to examine the role(s) of RGS16 in platelet activation by using a host of in vitro and in vivo assays. We observed that agonist‐induced platelet aggregation, secretion, and integrin activation were much more pronounced in platelets from the RGS16 knockout (Rgs16−/−) mice relative to their wild type (Rgs16+/+) littermates. Furthermore, the Rgs16−/− mice had a markedly shortened bleeding time and were more susceptible to vascular injury–associated thrombus formation than the controls. Conclusions These findings support a critical role for RGS16 in regulating hemostatic and thrombotic functions of platelets in mice. Hence, RGS16 represents a potential therapeutic target for modulating platelet function.
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Affiliation(s)
- Keziah R Hernandez
- 1 Pharmaceutical Sciences, School of Pharmacy The University of Texas at El Paso TX
| | - Zubair A Karim
- 1 Pharmaceutical Sciences, School of Pharmacy The University of Texas at El Paso TX
| | - Hanan Qasim
- 1 Pharmaceutical Sciences, School of Pharmacy The University of Texas at El Paso TX
| | - Kirk M Druey
- 2 Molecular Signal Transduction Section Laboratory of Allergic Diseases NIAID/NIH Bethesda MD
| | - Fatima Z Alshbool
- 1 Pharmaceutical Sciences, School of Pharmacy The University of Texas at El Paso TX
| | - Fadi T Khasawneh
- 1 Pharmaceutical Sciences, School of Pharmacy The University of Texas at El Paso TX
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PPARγ Agonist PGZ Attenuates OVA-Induced Airway Inflammation and Airway Remodeling via RGS4 Signaling in Mouse Model. Inflammation 2019; 41:2079-2089. [PMID: 30022363 DOI: 10.1007/s10753-018-0851-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Peroxisome proliferator-activated receptor-γ (PPARγ) agonist pioglitazone (PGZ) exhibits potential protective effects in asthma. Recently, regulator of G protein 4 (RGS4) has been reported to be associated with immunological and inflammatory responses. However, no evidence has shown the influence of PPARγ on RGS4 expression in airway disorders. In this study, BALB/c mice received ovalbumin (OVA) sensitization followed by OVA intranasal challenge for 90 days to establish a chronic asthma mouse model. Accompanied with OVA challenge, the mice received administration of PPARγ agonist PGZ (10 mg/kg) intragastrically or RGS4 inhibitor CCG 63802 (0.5 mg/kg) intratracheally. Invasive pulmonary function tests were performed 24 h after last challenge. Serum, bronchoalveolar lavage fluid (BALF), and lung tissues were collected for further analyses after the mice were sacrificed. We found that PPARγ agonist PGZ administration significantly attenuated the pathophysiological features of OVA-induced asthma and increased the expression of RGS4. In addition, the attenuating effect of PGZ on airway inflammation, hyperresponsiveness (AHR), and remodeling was partially abrogated by administration of RGS4 inhibitor CCG 63802. We also found that the downregulation of RGS4 by CCG 63802 also significantly increased inflammatory cell accumulation and AHR, and increased levels of IL-4, IL-13, eotaxin, IFN-γ, and IL-17A in BALF, and total and OV-specific IgE in serum. Furthermore, the inhibitory effects of PGZ on the activations of ERK and Akt/mTOR signaling, and MMPs were apparently reversed by CCG 63802 administration. In conclusion, the protective effect of PGZ on OVA-induced airway inflammation and remodeling might be partly regulated by RGS4 expression through ERK and Akt/mTOR signaling.
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8
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Bilodeau J, Schwendt M. Post-cocaine changes in regulator of G-protein signaling (RGS) proteins in the dorsal striatum: Relevance for cocaine-seeking and protein kinase C-mediated phosphorylation. Synapse 2016; 70:432-40. [PMID: 27261631 DOI: 10.1002/syn.21917] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 05/19/2016] [Accepted: 06/01/2016] [Indexed: 12/27/2022]
Abstract
Persistent cocaine-induced neuroadaptations within the cortico-striatal circuitry might be related to elevated risk of relapse observed in human addicts even after months or years of drug-free abstinence. Identification of these neuroadaptations may lead development of novel, neurobiologically-based treatments of relapse. In the current study, 12 adult male Sprague-Dawley rats self-administered cocaine (or received yoked-saline) for two weeks followed by three weeks of home-cage abstinence. At this point, we analyzed expression of proteins involved in regulation of Gαi- and Gαq-protein signaling in the dorsal striatum (dSTR). Animals abstinent from chronic cocaine showed decreased expression of regulator of G-protein signaling 2 (RGS2) and RGS4, as well as upregulation of RGS9. These data, together with the increased ratio of Gαq-to-Gαi proteins indicated, "sensitized" Gαq signaling in the dSTR of abstinent cocaine animals. To evaluate activation of Gαq signaling during relapse, another group of abstinent cocaine animals (and yoked saline controls, 22 rats together) was reintroduced to the cocaine context and PKC-mediated phosphorylation in the dSTR was analyzed. Re-exposure to the cocaine context triggered cocaine seeking and increase in phosphorylation of cellular PKC substrates, including phospho-ERK and phospho-CREB. In conclusion, this study demonstrates persistent dysregulation of RGS proteins in the dSTR of abstinent cocaine animals that may produce an imbalance in local Gαq-to-Gαi signaling. This imbalance might be related to augmented PKC-mediated phosphorylation during relapse to cocaine-seeking. Future studies will address whether selective targeting of RGS proteins in the dSTR can be utilized to suppress PKC-mediated phosphorylation and relapse to cocaine-seeking.
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Affiliation(s)
- Jenna Bilodeau
- Psychology Department, University of Florida, Gainesville, Florida 32611-2250
| | - Marek Schwendt
- Psychology Department, University of Florida, Gainesville, Florida 32611-2250
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9
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EphrinB2/EphB4 pathway in postnatal angiogenesis: a potential therapeutic target for ischemic cardiovascular disease. Angiogenesis 2016; 19:297-309. [PMID: 27216867 DOI: 10.1007/s10456-016-9514-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 05/13/2016] [Indexed: 01/12/2023]
Abstract
Ischemic cardiovascular disease remains one of the leading causes of morbidity and mortality in the world. Proangiogenic therapy appears to be a promising and feasible strategy for the patients with ischemic cardiovascular disease, but the results of preclinical and clinical trials are limited due to the complicated mechanisms of angiogenesis. Facilitating the formation of functional vessels is important in rescuing the ischemic cardiomyocytes. EphrinB2/EphB4, a novel pathway in angiogenesis, plays a critical role in both microvascular growth and neovascular maturation. Hence, investigating the mechanisms of EphrinB2/EphB4 pathway in angiogenesis may contribute to the development of novel therapeutics for ischemic cardiovascular disease. Previous reviews mainly focused on the role of EphrinB2/EphB4 pathway in embryo vascular development, but their role in postnatal angiogenesis in ischemic heart disease has not been fully illustrated. Here, we summarized the current knowledge of EphrinB2/EphB4 in angiogenesis and their interaction with other angiogenic pathways in ischemic cardiovascular disease.
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Regulation of Gβγi-dependent PLC-β3 activity in smooth muscle: inhibitory phosphorylation of PLC-β3 by PKA and PKG and stimulatory phosphorylation of Gαi-GTPase-activating protein RGS2 by PKG. Cell Biochem Biophys 2015; 70:867-80. [PMID: 24777815 DOI: 10.1007/s12013-014-9992-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In gastrointestinal smooth muscle, agonists that bind to Gi-coupled receptors activate preferentially PLC-β3 via Gβγ to stimulate phosphoinositide (PI) hydrolysis and generate inositol 1,4,5-trisphosphate (IP3) leading to IP3-dependent Ca(2+) release and muscle contraction. In the present study, we identified the mechanism of inhibition of PLC-β3-dependent PI hydrolysis by cAMP-dependent protein kinase (PKA) and cGMP-dependent protein kinase (PKG). Cyclopentyl adenosine (CPA), an adenosine A1 receptor agonist, caused an increase in PI hydrolysis in a concentration-dependent fashion; stimulation was blocked by expression of the carboxyl-terminal sequence of GRK2(495-689), a Gβγ-scavenging peptide, or Gαi minigene but not Gαq minigene. Isoproterenol and S-nitrosoglutathione (GSNO) induced phosphorylation of PLC-β3 and inhibited CPA-induced PI hydrolysis, Ca(2+) release, and muscle contraction. The effect of isoproterenol on all three responses was inhibited by PKA inhibitor, myristoylated PKI, or AKAP inhibitor, Ht-31, whereas the effect of GSNO was selectively inhibited by PKG inhibitor, Rp-cGMPS. GSNO, but not isoproterenol, also phosphorylated Gαi-GTPase-activating protein, RGS2, and enhanced association of Gαi3-GTP and RGS2. The effect of GSNO on PI hydrolysis was partly reversed in cells (i) expressing constitutively active GTPase-resistant Gαi mutant (Q204L), (ii) phosphorylation-site-deficient RGS2 mutant (S46A/S64A), or (iii) siRNA for RGS2. We conclude that PKA and PKG inhibit Gβγi-dependent PLC-β3 activity by direct phosphorylation of PLC-β3. PKG, but not PKA, also inhibits PI hydrolysis indirectly by a mechanism involving phosphorylation of RGS2 and its association with Gαi-GTP. This allows RGS2 to accelerate Gαi-GTPase activity, enhance Gαβγi trimer formation, and inhibit Gβγi-dependent PLC-β3 activity.
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Doupnik CA. RGS Redundancy and Implications in GPCR-GIRK Signaling. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2015; 123:87-116. [PMID: 26422983 DOI: 10.1016/bs.irn.2015.05.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Regulators of G protein signaling (RGS proteins) are key components of GPCR complexes, interacting directly with G protein α-subunits to enhance their intrinsic GTPase activity. The functional consequence is an accelerated termination of G protein effectors including certain ion channels. RGS proteins have a profound impact on the membrane-delimited gating behavior of G-protein-activated inwardly rectifying K(+) (GIRK) channels as demonstrated in reconstitution assays and recent RGS knockout mice studies. Akin to GPCRs and G protein αβγ subunits, multiple RGS isoforms are expressed within single GIRK-expressing neurons, suggesting functional redundancy and/or specificity in GPCR-GIRK channel signaling. The extent and impact of RGS redundancy in neuronal GPCR-GIRK channel signaling is currently not fully appreciated; however, recent studies from RGS knockout mice are providing important new clues on the impact of individual endogenous RGS proteins and the extent of RGS functional redundancy. Incorporating "tools" such as engineered RGS-resistant Gαi/o subunits provide an important assessment method for determining the impact of all endogenous RGS proteins on a given GPCR response and an accounting benchmark to assess the impact of individual RGS knockouts on overall RGS redundancy within a given neuron. Elucidating the degree of regulation attributable to specific RGS proteins in GIRK channel function will aid in the assessment of individual RGS proteins as viable therapeutic targets in epilepsy, ataxia's, memory disorders, and a growing list of neurological disorders.
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Affiliation(s)
- Craig A Doupnik
- Department of Molecular Pharmacology & Physiology, University of South Florida College of Medicine, Tampa, Florida, USA.
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12
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Choi CY, Rho SB, Kim HS, Han J, Bae J, Lee SJ, Jung WW, Chun T. The ORF3 protein of porcine circovirus type 2 promotes secretion of IL-6 and IL-8 in porcine epithelial cells by facilitating proteasomal degradation of regulator of G protein signalling 16 through physical interaction. J Gen Virol 2015; 96:1098-1108. [DOI: 10.1099/vir.0.000046] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 01/06/2015] [Indexed: 12/27/2022] Open
Affiliation(s)
- Chang-Yong Choi
- Division of Biotechnology, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea
| | - Seung Bae Rho
- Research Institute, National Cancer Center, Goyang-si 410-769, Republic of Korea
| | - Hyun-Sook Kim
- Department of Integrated Biomedical and Life Science, College of Health Science, Korea University, Seoul 136-703, Republic of Korea
| | - Jihye Han
- Division of Biotechnology, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea
| | - Joonbeom Bae
- Division of Biotechnology, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea
| | - Suk Jun Lee
- Department of Biomedical Laboratory Science, College of Health Science, Cheongju University, Cheongju-si 360-764, Republic of Korea
| | - Woon-Won Jung
- Department of Biomedical Laboratory Science, College of Health Science, Cheongju University, Cheongju-si 360-764, Republic of Korea
| | - Taehoon Chun
- Division of Biotechnology, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea
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13
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Wu J, Pipathsouk A, Keizer-Gunnink A, Fusetti F, Alkema W, Liu S, Altschuler S, Wu L, Kortholt A, Weiner OD. Homer3 regulates the establishment of neutrophil polarity. Mol Biol Cell 2015; 26:1629-39. [PMID: 25739453 PMCID: PMC4436775 DOI: 10.1091/mbc.e14-07-1197] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 02/23/2015] [Accepted: 02/24/2015] [Indexed: 01/10/2023] Open
Abstract
Most chemoattractants rely on activation of the heterotrimeric G-protein Gαi to regulate directional cell migration, but few links from Gαi to chemotactic effectors are known. Through affinity chromatography using primary neutrophil lysate, we identify Homer3 as a novel Gαi2-binding protein. RNA interference-mediated knockdown of Homer3 in neutrophil-like HL-60 cells impairs chemotaxis and the establishment of polarity of phosphatidylinositol 3,4,5-triphosphate (PIP3) and the actin cytoskeleton, as well as the persistence of the WAVE2 complex. Most previously characterized proteins that are required for cell polarity are needed for actin assembly or activation of core chemotactic effectors such as the Rac GTPase. In contrast, Homer3-knockdown cells show normal magnitude and kinetics of chemoattractant-induced activation of phosphoinositide 3-kinase and Rac effectors. Chemoattractant-stimulated Homer3-knockdown cells also exhibit a normal initial magnitude of actin polymerization but fail to polarize actin assembly and intracellular PIP3 and are defective in the initiation of cell polarity and motility. Our data suggest that Homer3 acts as a scaffold that spatially organizes actin assembly to support neutrophil polarity and motility downstream of GPCR activation.
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Affiliation(s)
- Julie Wu
- Cardiovascular Research Institute and Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158
| | - Anne Pipathsouk
- Cardiovascular Research Institute and Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158
| | - A Keizer-Gunnink
- Department of Cell Biochemistry, Groningen Biological Sciences and Biotechnology Institute, University of Groningen, 9700 AB Groningen, Netherlands
| | - F Fusetti
- Department of Biochemistry and Netherlands Proteomics Centre, Groningen Biological Sciences and Biotechnology Institute, University of Groningen, 9700 AB Groningen, Netherlands
| | - W Alkema
- NIZO Food Research, 6718 ZB Ede, Netherlands Centre for Molecular and Biomolecular Informatics, Radboud University Medical Center, Nijmegen, 6525 GA Nijmegen, Netherlands
| | - Shanshan Liu
- Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Steven Altschuler
- Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Lani Wu
- Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Arjan Kortholt
- Department of Cell Biochemistry, Groningen Biological Sciences and Biotechnology Institute, University of Groningen, 9700 AB Groningen, Netherlands
| | - Orion D Weiner
- Cardiovascular Research Institute and Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158
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Pak HK, Gil M, Lee Y, Lee H, Lee AN, Roh J, Park CS. Regulator of G protein signaling 1 suppresses CXCL12-mediated migration and AKT activation in RPMI 8226 human plasmacytoma cells and plasmablasts. PLoS One 2015; 10:e0124793. [PMID: 25897806 PMCID: PMC4405207 DOI: 10.1371/journal.pone.0124793] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 03/09/2015] [Indexed: 12/14/2022] Open
Abstract
Migration of plasma cells to the bone marrow is critical factor to humoral immunity and controlled by chemokines. Regulator of G protein signaling 1 (RGS1) is a GTPase-activating protein that controls various crucial functions such as migration. Here, we show that RGS1 controls the chemotactic migration of RPMI 8226 human plasmacytoma cells and human plasmablasts. LPS strongly increased RGS1 expression and retarded the migration of RPMI 8226 cells by suppressing CXCL12-mediated AKT activation. RGS1 knockdown by siRNA abolished the retardation of migration and AKT suppression by LPS. RGS1-dependent regulation of migration via AKT is also observed in cultured plasmablasts. We propose novel functions of RGS1 that suppress AKT activation and the migration of RPMI 8226 cells and plasmablasts in CXCL12-mediated chemotaxis.
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Affiliation(s)
- Hyo-Kyung Pak
- Cell Dysfunction Research Center, University of Ulsan College of Medicine, Seoul, Korea
- Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Minchan Gil
- Cell Dysfunction Research Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Yoonkyung Lee
- Cell Dysfunction Research Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Hyunji Lee
- Cell Dysfunction Research Center, University of Ulsan College of Medicine, Seoul, Korea
| | - A-Neum Lee
- Cell Dysfunction Research Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Jin Roh
- Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Chan-Sik Park
- Cell Dysfunction Research Center, University of Ulsan College of Medicine, Seoul, Korea
- Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
- Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
- * E-mail:
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15
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Dunn HA, Ferguson SSG. PDZ Protein Regulation of G Protein–Coupled Receptor Trafficking and Signaling Pathways. Mol Pharmacol 2015; 88:624-39. [DOI: 10.1124/mol.115.098509] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 03/25/2015] [Indexed: 01/03/2023] Open
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Vakalopoulos C. The effect of deficient muscarinic signaling on commonly reported biochemical effects in schizophrenia and convergence with genetic susceptibility loci in explaining symptom dimensions of psychosis. Front Pharmacol 2014; 5:277. [PMID: 25566074 PMCID: PMC4266038 DOI: 10.3389/fphar.2014.00277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 11/27/2014] [Indexed: 11/13/2022] Open
Abstract
With the advent of DSM 5 criticism has generally centered on a lack of biological validity of the diagnostic criteria. Part of the problem in describing a nosology of psychosis is the tacit assumption of multiple genetic causes each with an incremental loading on the clinical picture that fails to differentiate a clear underlying pathophysiology of high impact. The aim of this paper is to consolidate a primary theory of deficient muscarinic signaling underlying key clinical features of schizophrenia and its regulation by several important genetic associations including neuregulin, DISC and dysbindin. Secondary reductions in markers for GABAergic function and changes in the levels of interneuron calcium binding proteins parvalbumin and calbindin can be attributed to dysfunctional muscarinic transduction. A parallel association exists for cytokine production. The convergent pathway hypothesis is likewise used to model dopaminergic and glutamatergic theories of schizophrenia. The negative symptom dimension is correlated with dysfunction of Akt and ERK transduction, a major point of convergence. The present paradigm predicts the importance of a recent finding of a deletion in a copy number variant of PLCB1 and its potential use if replicated, as one of the first testable biological markers differentiating schizophrenia from bipolar disorder and further subtyping of schizophrenia into deficit and non-deficit. Potential limitations of PLCB1 as a prospective marker are also discussed.
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Regulator of G-protein signaling-5 is a marker of hepatic stellate cells and expression mediates response to liver injury. PLoS One 2014; 9:e108505. [PMID: 25290689 PMCID: PMC4188519 DOI: 10.1371/journal.pone.0108505] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 08/22/2014] [Indexed: 12/11/2022] Open
Abstract
Liver fibrosis is mediated by hepatic stellate cells (HSCs), which respond to a variety of cytokine and growth factors to moderate the response to injury and create extracellular matrix at the site of injury. G-protein coupled receptor (GPCR)-mediated signaling, via endothelin-1 (ET-1) and angiotensin II (AngII), increases HSC contraction, migration and fibrogenesis. Regulator of G-protein signaling-5 (RGS5), an inhibitor of vasoactive GPCR agonists, functions to control GPCR-mediated contraction and hypertrophy in pericytes and smooth muscle cells (SMCs). Therefore we hypothesized that RGS5 controls GPCR signaling in activated HSCs in the context of liver injury. In this study, we localize RGS5 to the HSCs and demonstrate that Rgs5 expression is regulated during carbon tetrachloride (CCl4)-induced acute and chronic liver injury in Rgs5LacZ/LacZ reporter mice. Furthermore, CCl4 treated RGS5-null mice develop increased hepatocyte damage and fibrosis in response to CCl4 and have increased expression of markers of HSC activation. Knockdown of Rgs5 enhances ET-1-mediated signaling in HSCs in vitro. Taken together, we demonstrate that RGS5 is a critical regulator of GPCR signaling in HSCs and regulates HSC activation and fibrogenesis in liver injury.
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Papakonstantinou MP, Karoussiotis C, Georgoussi Z. RGS2 and RGS4 proteins: New modulators of the κ-opioid receptor signaling. Cell Signal 2014; 27:104-14. [PMID: 25289860 DOI: 10.1016/j.cellsig.2014.09.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 09/10/2014] [Accepted: 09/23/2014] [Indexed: 01/22/2023]
Abstract
Previous studies have shown that RGS4 associates with the C-termini of μ- and δ-opioid receptors in living cells and plays a key role in Gi/Go protein coupling selectivity and signalling of these receptors [12,20]. To deduce whether similar effects also occur for the κ-opioid receptor (κ-ΟR) and define the ability of members of the Regulators of G protein Signaling (RGS) of the B/R4 subfamily to interact with κ-ΟR subdomains we generated glutathione S-transferase fusion peptides encompassing the carboxyl-termini of κ-OR (κ-CT). Results from pull down experiments indicated that RGS2 and RGS4 directly interact within different domains of the κ-CT. Co-precipitation studies in living cells indicated that RGS2 and RGS4 associate with κ-ΟR constitutively and upon receptor activation and confer selectivity for coupling with a specific subset of G proteins. Expression of both members, RGS2 and/or RGS4, in 293F cells attenuated κ-agonist mediated-adenylyl cyclase inhibition and extracellular signal regulated kinase (ERK1,2) phosphorylation with a different amplitude in their modulatory effect in κ-ΟR signaling. Our findings demonstrate that RGS2 and RGS4 are new interacting partners that play key roles in G protein coupling to negatively regulate κ-ΟR signaling.
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Affiliation(s)
- Maria-Pagona Papakonstantinou
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Christos Karoussiotis
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Zafiroula Georgoussi
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece.
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Francelle L, Galvan L, Brouillet E. Possible involvement of self-defense mechanisms in the preferential vulnerability of the striatum in Huntington's disease. Front Cell Neurosci 2014; 8:295. [PMID: 25309327 PMCID: PMC4176035 DOI: 10.3389/fncel.2014.00295] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 09/03/2014] [Indexed: 01/01/2023] Open
Abstract
HD is caused by a mutation in the huntingtin gene that consists in a CAG repeat expansion translated into an abnormal poly-glutamine (polyQ) tract in the huntingtin (Htt) protein. The most striking neuropathological finding in HD is the atrophy of the striatum. The regional expression of mutant Htt (mHtt) is ubiquitous in the brain and cannot explain by itself the preferential vulnerability of the striatum in HD. mHtt has been shown to produce an early defect in transcription, through direct alteration of the function of key regulators of transcription and in addition, more indirectly, as a result of compensatory responses to cellular stress. In this review, we focus on gene products that are preferentially expressed in the striatum and have down- or up-regulated expression in HD and, as such, may play a crucial role in the susceptibility of the striatum to mHtt. Many of these striatal gene products are for a vast majority down-regulated and more rarely increased in HD. Recent research shows that some of these striatal markers have a pro-survival/neuroprotective role in neurons (e.g., MSK1, A2A, and CB1 receptors) whereas others enhance the susceptibility of striatal neurons to mHtt (e.g., Rhes, RGS2, D2 receptors). The down-regulation of these latter proteins may be considered as a potential self-defense mechanism to slow degeneration. For a majority of the striatal gene products that have been identified so far, their function in the striatum is unknown and their modifying effects on mHtt toxicity remain to be experimentally addressed. Focusing on these striatal markers may contribute to a better understanding of HD pathogenesis, and possibly the identification of novel therapeutic targets.
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Affiliation(s)
- Laetitia Francelle
- Neurodegenerative Disease Laboratory, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Direction des Sciences du Vivant, Institut d'Imagerie BioMédicale, Molecular Imaging Research Center Fontenay-aux-Roses, France ; Centre National de la Recherche Scientifique - Commissariat à l'Énergie Atomique et aux Énergies Alternatives Unité de Recherche Associée 2210 Fontenay-aux-Roses, France
| | - Laurie Galvan
- Neurodegenerative Disease Laboratory, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Direction des Sciences du Vivant, Institut d'Imagerie BioMédicale, Molecular Imaging Research Center Fontenay-aux-Roses, France ; Centre National de la Recherche Scientifique - Commissariat à l'Énergie Atomique et aux Énergies Alternatives Unité de Recherche Associée 2210 Fontenay-aux-Roses, France ; Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, Brain Research Institute, David Geffen School of Medicine, University of California Los Angeles Los Angeles, CA, USA
| | - Emmanuel Brouillet
- Neurodegenerative Disease Laboratory, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Direction des Sciences du Vivant, Institut d'Imagerie BioMédicale, Molecular Imaging Research Center Fontenay-aux-Roses, France ; Centre National de la Recherche Scientifique - Commissariat à l'Énergie Atomique et aux Énergies Alternatives Unité de Recherche Associée 2210 Fontenay-aux-Roses, France
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20
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Jang HS, Kim JI, Noh M, Rhee MH, Park KM. Regulator of G protein signaling 2 (RGS2) deficiency accelerates the progression of kidney fibrosis. Biochim Biophys Acta Mol Basis Dis 2014; 1842:1733-41. [PMID: 24973550 DOI: 10.1016/j.bbadis.2014.06.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/02/2014] [Accepted: 06/18/2014] [Indexed: 01/07/2023]
Abstract
The regulator of G protein signaling 2 (RGS2) is a potent negative regulator of Gq protein signals including the angiotensin II (AngII)/AngII receptor signal, which plays a critical role in the progression of fibrosis. However, the role of RGS2 on the progression of kidney fibrosis has not been assessed. Here, we investigated the role of RGS2 in kidney fibrosis induced by unilateral ureteral obstruction (UUO) in mice. UUO resulted in increased expression of RGS2 mRNA and protein in the kidney along with increases of AngII and its type 1 receptor (AT1R) signaling and fibrosis. Furthermore, UUO increased the levels of F4/80, Ly6G, myeloperoxidase, and CXCR4 in the kidneys. RGS2 deficiency significantly enhanced these changes in the kidney. RGS2 deletion in the bone marrow-derived cells by transplanting the bone marrow of RGS2 knock-out mice into wild type mice enhanced UUO-induced kidney fibrosis. Overexpression of RGS2 in HEK293 cells, a human embryonic kidney cell line, and RAW264.7 cells, a monocyte/macrophage line, inhibited the AngII-induced activation of ERK and increase of CXCR4 expression. These findings provide the first evidence that RGS2 negatively regulates the progression of kidney fibrosis following UUO, likely by suppressing fibrogenic and inflammatory responses through the inhibition of AngII/AT1R signaling.
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Affiliation(s)
- Hee-Seong Jang
- Department of Anatomy, Cardiovascular Research Institute, BK21 Plus Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea
| | - Jee In Kim
- Department of Molecular Medicine and Obesity-Mediated Disease Research Center, College of Medicine, Keimyung University, Daegu, 704-701, Republic of Korea
| | - Mira Noh
- Department of Anatomy, Cardiovascular Research Institute, BK21 Plus Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea
| | - Man Hee Rhee
- Laboratory of Physiology and Signaling, College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Kwon Moo Park
- Department of Anatomy, Cardiovascular Research Institute, BK21 Plus Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea.
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Keinan D, Yang S, Cohen RE, Yuan X, Liu T, Li YP. Role of regulator of G protein signaling proteins in bone. Front Biosci (Landmark Ed) 2014; 19:634-48. [PMID: 24389209 DOI: 10.2741/4232] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Regulators of G protein signaling (RGS) proteins are a family with more than 30 proteins that all contain an RGS domain. In the past decade, increasing evidence has indicated that RGS proteins play crucial roles in the regulation of G protein coupling receptors (GPCR), G proteins, and calcium signaling during cell proliferation, migration, and differentiation in a variety of tissues. In bone, those proteins modulate bone development and remodeling by influencing various signaling pathways such as GPCR-G protein signaling, Wnt, calcium oscillations and PTH. This review summarizes the recent advances in the understanding of the regulation of RGS gene expression, as well as the functions and mechanisms of RGS proteins, especially in regulating GPCR-G protein signaling, Wnt signaling, calcium oscillations signaling and PTH signaling during bone development and remodeling. This review also highlights the regulation of different RGS proteins in osteoblasts, chondrocytes and osteoclasts. The knowledge from the recent advances of RGS study summarized in the review would provide the insights into new therapies for bone diseases.
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Affiliation(s)
- David Keinan
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, The State University of New York, 3435 Main Street, Buffalo, NY 14214
| | - Shuying Yang
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, The State University of New York, 3435 Main Street, Buffalo, NY 14214
| | - Robert E Cohen
- Department of Periodontics and Endodontics, School of Dental Medicine, University at Buffalo, The State University of New York, 3435 Main Street, Buffalo, NY, 14214, USA
| | - Xue Yuan
- Department of Oral Biology School of Dental Medicine, University at Buffalo, The State University of New York, B36 Foster Hall, Buffalo, NY 14214
| | - Tongjun Liu
- Department of Oral Biology School of Dental Medicine, University at Buffalo, The State University of New York, B36 Foster Hall, Buffalo, NY 14214
| | - Yi-Ping Li
- Department of Pathology, University of Alabama at Birmingham (UAB), 1825 University Blvd, Birmingham AL 35294, USA
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Ziyatdinova NI, Sergeeva AM, Dementieva RE, Zefirov TL. Peculiar Effects of Muscarinic M1, M2, and M3 Receptor Blockers on Cardiac Chronotropic Function in Neonatal Rats. Bull Exp Biol Med 2012; 154:1-2. [DOI: 10.1007/s10517-012-1859-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Yang Z, Balenga N, Cooper PR, Damera G, Edwards R, Brightling CE, Panettieri RA, Druey KM. Regulator of G-protein signaling-5 inhibits bronchial smooth muscle contraction in severe asthma. Am J Respir Cell Mol Biol 2012; 46:823-32. [PMID: 22281988 DOI: 10.1165/rcmb.2011-0110oc] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Severe asthma is associated with fixed airway obstruction attributable to inflammation, copious luminal mucus, and increased airway smooth muscle (ASM) mass. Paradoxically, studies demonstrated that the hypertrophic and hyperplastic ASM characteristic of severe asthma has reduced contractile capacity. We compared the G-protein-coupled receptor (GPCR)-induced Ca(2+) mobilization and expression of GPCRs and signaling proteins related to procontractile signaling in ASM derived postmortem from subjects who died of nonrespiratory causes, with cells from subjects who died of asthma. Despite the increased or comparable expression of contraction-promoting GPCRs (bradykinin B2 or histamine H1 and protease-activated receptor 1, respectively) in asthmatic ASM cells relative to cells from healthy donors, asthmatic ASM cells exhibited reduced histamine-induced Ca(2+) mobilization and comparable responses to bradykinin and thrombin, suggesting a postreceptor signaling defect. Accordingly, the expression of regulator of G-protein signaling-5 (RGS5), an inhibitor of ASM contraction, was increased in cultured, asthmatic ASM cells and in bronchial smooth muscle bundles of both human subjects with asthma and allergen-challenged mice, relative to those of healthy human subjects or naive mice. The overexpression of RGS5 impaired the release of Ca(2+) to thrombin, histamine, and carbachol, and reduced the contraction of precision-cut lung slices to carbachol. These results suggest that increased RGS5 expression contributes to decreased myocyte shortening in severe and fatal asthma.
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Affiliation(s)
- Zhao Yang
- Molecular Signal Transduction Section, Laboratory of Allergic Diseases, National Insitute of Allergy and Infectious Diseases/NIH, 10 Center Drive, Bethesda, MD 20982, USA.
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Seredenina T, Gokce O, Luthi-Carter R. Decreased striatal RGS2 expression is neuroprotective in Huntington's disease (HD) and exemplifies a compensatory aspect of HD-induced gene regulation. PLoS One 2011; 6:e22231. [PMID: 21779398 PMCID: PMC3136499 DOI: 10.1371/journal.pone.0022231] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 06/17/2011] [Indexed: 02/04/2023] Open
Abstract
Background The molecular phenotype of Huntington's disease (HD) is known to comprise highly reproducible changes in gene expression involving striatal signaling genes. Here we test whether individual changes in striatal gene expression are capable of mitigating HD-related neurotoxicity. Methodology/Principal Findings We used protein-encoding and shRNA-expressing lentiviral vectors to evaluate the effects of RGS2, RASD2, STEP and NNAT downregulation in HD. Of these four genes, only RGS2 and RASD2 modified mutant htt fragment toxicity in cultured rat primary striatal neurons. In both cases, disease modulation was in the opposite of the predicted direction: whereas decreased expression of RGS2 and RASD2 was associated with the HD condition, restoring expression enhanced degeneration of striatal cells. Conversely, silencing of RGS2 or RASD2 enhanced disease-related changes in gene expression and resulted in significant neuroprotection. These results indicate that RGS2 and RASD2 downregulation comprises a compensatory response that allows neurons to better tolerate huntingtin toxicity. Assessment of the possible mechanism of RGS2-mediated neuroprotection showed that RGS2 downregulation enhanced ERK activation. These results establish a novel link between the inhibition of RGS2 and neuroprotective modulation of ERK activity. Conclusions Our findings both identify RGS2 downregulation as a novel compensatory response in HD neurons and suggest that RGS2 inhibition might be considered as an innovative target for neuroprotective drug development.
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Affiliation(s)
- Tamara Seredenina
- Laboratory of Functional Neurogenomics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Ozgun Gokce
- Laboratory of Functional Neurogenomics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Ruth Luthi-Carter
- Laboratory of Functional Neurogenomics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- * E-mail:
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Dokas LA, Malone AM, Williams FE, Nauli SM, Messer WS. Multiple protein kinases determine the phosphorylated state of the small heat shock protein, HSP27, in SH-SY5Y neuroblastoma cells. Neuropharmacology 2011; 61:12-24. [PMID: 21338617 PMCID: PMC3105189 DOI: 10.1016/j.neuropharm.2011.02.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 01/25/2011] [Accepted: 02/11/2011] [Indexed: 01/21/2023]
Abstract
In SH-SY5Y human neuroblastoma cells, the cholinergic agonist, carbachol, stimulates phosphorylation of the small heat shock protein 27 (HSP27). Carbachol increases phosphorylation of both Ser-82 and Ser-78 while the phorbol ester, phorbol-12, 13-dibutyrate (PDB) affects only Ser-82. Muscarinic receptor activation by carbachol was confirmed by sensitivity of Ser-82 phosphorylation to hyoscyamine with no effect of nicotine or bradykinin. This response to carbachol is partially reduced by inhibition of protein kinase C (PKC) with GF 109203X and p38 mitogen-activated protein kinase (MAPK) with SB 203580. In contrast, phosphorylation produced by PDB is completely reversed by GF 109203X or CID 755673, an inhibitor of PKD. Inhibition of phosphatidylinositol 3-kinase or Akt with LY 294002 or Akti-1/2 stimulates HSP27 phosphorylation while rapamycin, which inhibits mTORC1, does not. The stimulatory effect of Akti-1/2 is reversed by SB 203580 and correlates with increased p38 MAPK phosphorylation. SH-SY5Y cells differentiated with a low concentration of PDB and basic fibroblast growth factor to a more neuronal phenotype retain carbachol-, PDB- and Akti-1/2-responsive HSP27 phosphorylation. Immunofluorescence microscopy confirms increased HSP27 phosphorylation in response to carbachol or PDB. At cell margins, PDB causes f-actin to reorganize forming lamellipodial structures from which phospho-HSP27 is segregated. The resultant phenotypic change in cell morphology is dependent upon PKC, but not PKD, activity. The major conclusion from this study is that the phosphorylated state of HSP27 in SH-SY5Y cells results from integrated signaling involving PKC, p38 MAPK and Akt.
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Affiliation(s)
- Linda A. Dokas
- Department of Pharmacology, College of Pharmacy, 3000 Arlington Avenue, The University of Toledo, Toledo OH 43614 USA
| | - Amy M. Malone
- Department of Pharmacology, College of Pharmacy, 3000 Arlington Avenue, The University of Toledo, Toledo OH 43614 USA
| | - Frederick E. Williams
- Department of Pharmacology, College of Pharmacy, 3000 Arlington Avenue, The University of Toledo, Toledo OH 43614 USA
| | - Surya M. Nauli
- Department of Pharmacology, College of Pharmacy, 3000 Arlington Avenue, The University of Toledo, Toledo OH 43614 USA
- Department of Medicinal & Biological Chemistry, College of Pharmacy, 3000 Arlington Avenue, The University of Toledo, Toledo OH 43614 USA
| | - William S. Messer
- Department of Pharmacology, College of Pharmacy, 3000 Arlington Avenue, The University of Toledo, Toledo OH 43614 USA
- Department of Medicinal & Biological Chemistry, College of Pharmacy, 3000 Arlington Avenue, The University of Toledo, Toledo OH 43614 USA
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Sjögren B. Regulator of G protein signaling proteins as drug targets: current state and future possibilities. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2011; 62:315-47. [PMID: 21907914 DOI: 10.1016/b978-0-12-385952-5.00002-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Regulators of G protein signaling (RGS) proteins have emerged in the past two decades as novel drug targets in many areas of research. Their importance in regulating signaling via G protein-coupled receptors has become evident as numerous studies have been published on the structure and function of RGS proteins. A number of genetic models have also been developed, demonstrating the potential clinical importance of RGS proteins in various disease states, including central nervous system disorders, cardiovascular disease, diabetes, and several types of cancer. Apart from their classical mechanism of action as GTPase-activating proteins (GAPs), RGS proteins can also serve other noncanonical functions. This opens up a new approach to targeting RGS proteins in drug discovery as the view on the function of these proteins is constantly evolving. This chapter summarizes the latest development in RGS protein drug discovery with special emphasis on noncanonical functions and regulatory mechanisms of RGS protein expression. As more reports are being published on this group of proteins, it is becoming clear that modulation of GAP activity might not be the only way to therapeutically target RGS proteins.
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Affiliation(s)
- Benita Sjögren
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, USA
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Regulators of G Protein Signaling Proteins as Targets for Drug Discovery. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2010; 91:81-119. [DOI: 10.1016/s1877-1173(10)91004-1] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Pro- and anti-apoptotic dual functions of the C5a receptor: involvement of regulator of G protein signaling 3 and extracellular signal-regulated kinase. J Transl Med 2009; 89:676-94. [PMID: 19333232 PMCID: PMC7503222 DOI: 10.1038/labinvest.2009.27] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
When apoptosis is initiated by manganese (II) loading, hyperthermia or thapsigargin treatment, human HL-60 and AsPC-1 cells initiate de novo synthesis of the C5a receptor (C5aR) and generation of its ligand, the ribosomal protein S19 (RP S19) homodimer. The ligand-receptor interaction, in an autocrine/paracrine fashion, promotes apoptosis, which can be bypassed by exogenous administration of C5a, another ligand. The proapoptotic function of the RP S19 dimer is reproduced by a C5a/RPS19 chimera that contains the body of C5a and the C-terminal region (Ile134-His145) of RP S19. The RP S19 dimer or C5a/RPS19 and C5a inversely regulate the expression of Regulator of G protein Signaling 3 (RGS3) gene in the apoptosis-initiated cells. Namely, the RP S19-type proteins upregulate RGS3 expression, whereas the C5a reduce it. Transformation of HL-60 cells to overexpress RGS3 promotes apoptosis in association with the downregulation of the Extracellular signal-Regulated Kinase (ERK) signal, and vice versa in the RGS3 knocked-down cells. Consistent with this result, an inhibitor of ERK phosphorylation effectively enhances the apoptotic rate in wild-type HL-60 cells. Moreover, a dominant negative effect on the RP S19 dimer production encourages apoptosis-initiated HL-60 cells with a longer lifespan in mouse than the natural effect. Our data indicate that, in apoptosis-initiated cells, the ligand-dependent C5aR-mediated dual signal affects the fate of cells, either apoptosis execution or survival, through regulation of RGS3 gene expression and subsequent modulation of ERK signal.
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Novel signaling pathways promote a paracrine wave of prostacyclin-induced vascular smooth muscle differentiation. J Mol Cell Cardiol 2009; 46:682-94. [PMID: 19302827 DOI: 10.1016/j.yjmcc.2009.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2008] [Revised: 12/23/2008] [Accepted: 01/16/2009] [Indexed: 11/22/2022]
Abstract
The important athero-protective role of prostacyclin is becoming increasingly evident as recent studies have revealed adverse cardiovascular effects in mice lacking the prostacyclin receptor, in patients taking selective COX-2 inhibitors, and in patients in the presence of a dysfunctional prostacyclin receptor genetic variant. We have recently reported that this protective mechanism includes the promotion of a quiescent differentiated phenotype in human vascular smooth muscle cells (VSMC). Herein, we address the intriguing question of how localized endothelial release of the very unstable eicosanoid, prostacyclin, exerts a profound effect on the vascular media, often 30 cell layers thick. We report a novel PKA-, Akt-1- and ERK1/2-dependent prostacyclin-induced prostacyclin release that appears to play an important role in propagation of the quiescent, differentiated phenotype through adjacent arterial smooth muscle cells in the vascular media. Treating VSMC with the prostacyclin analog iloprost induced differentiation (contractile protein expression and contractile morphology), and also up-regulated COX-2 expression, leading to prostacyclin release by VSMC. This paracrine prostacyclin release, in turn, promoted differentiation and COX-2 induction in neighboring VSMC that were not exposed to iloprost. Using siRNA and pharmacologic inhibitors, we report that this positive feedback mechanism, prostacyclin-induced prostacyclin release, is mediated by cAMP/PKA signaling, ERK1/2 activation, and a novel prostacyclin receptor signaling pathway, inhibition of Akt-1. Furthermore, these pathways appear to be regulated by the prostacyclin receptor independently of one another. We conclude that prevention of de-differentiation and proliferation through a paracrine positive feedback mechanism is a major cardioprotective function of prostacyclin.
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Takimoto E, Koitabashi N, Hsu S, Ketner EA, Zhang M, Nagayama T, Bedja D, Gabrielson KL, Blanton R, Siderovski DP, Mendelsohn ME, Kass DA. Regulator of G protein signaling 2 mediates cardiac compensation to pressure overload and antihypertrophic effects of PDE5 inhibition in mice. J Clin Invest 2009; 119:408-20. [PMID: 19127022 DOI: 10.1172/jci35620] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Accepted: 11/12/2008] [Indexed: 01/19/2023] Open
Abstract
The heart initially compensates for hypertension-mediated pressure overload by enhancing its contractile force and developing hypertrophy without dilation. Gq protein-coupled receptor pathways become activated and can depress function, leading to cardiac failure. Initial adaptation mechanisms to reduce cardiac damage during such stimulation remain largely unknown. Here we have shown that this initial adaptation requires regulator of G protein signaling 2 (RGS2). Mice lacking RGS2 had a normal basal cardiac phenotype, yet responded rapidly to pressure overload, with increased myocardial Gq signaling, marked cardiac hypertrophy and failure, and early mortality. Swimming exercise, which is not accompanied by Gq activation, induced a normal cardiac response, while Rgs2 deletion in Galphaq-overexpressing hearts exacerbated hypertrophy and dilation. In vascular smooth muscle, RGS2 is activated by cGMP-dependent protein kinase (PKG), suppressing Gq-stimulated vascular contraction. In normal mice, but not Rgs2-/- mice, PKG activation by the chronic inhibition of cGMP-selective phosphodiesterase 5 (PDE5) suppressed maladaptive cardiac hypertrophy, inhibiting Gq-coupled stimuli. Importantly, PKG was similarly activated by PDE5 inhibition in myocardium from both genotypes, but PKG plasma membrane translocation was more transient in Rgs2-/- myocytes than in controls and was unaffected by PDE5 inhibition. Thus, RGS2 is required for early myocardial compensation to pressure overload and mediates the initial antihypertrophic and cardioprotective effects of PDE5 inhibitors.
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Affiliation(s)
- Eiki Takimoto
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
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Anger T, Grebe N, Osinski D, Stelzer N, Carson W, Daniel WG, Hoeher M, Garlichs CD. Role of endogenous RGS proteins on endothelial ERK 1/2 activation. Exp Mol Pathol 2008; 85:165-73. [PMID: 18977218 DOI: 10.1016/j.yexmp.2008.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2008] [Accepted: 09/23/2008] [Indexed: 11/27/2022]
Abstract
Endothelial cells are maintaining atherosclerotic signaling mediated by Extracellular Regulated Kinases 1 and 2 (ERK). Signaling gets activated upon stimulation of G protein-coupled receptors mediated by G(q) and G(i/o) proteins subjected to regulation by RGS proteins. The goal of the study was to delineate the specificity of RGS proteins modulating induced ERK phosphorylation. We used stimulated HUVEC, silenced specifically RGS proteins and compared assessed ERK 1/2 activation with immunohistochemical stainings on atherosclerotic plaques. Increased ERK phosphorylation was detected upon stimulation with Phenylephrine (2.6+/-0.1 times over basal), Endothelin-1 (1.8+/-0.2), Dopamine (5.1+/-0.2), TNF (9.8+/-0.7) or IL-4 (3.1+/-0.3). RGS silencing increased activation of ERK 1/2: Phen (RGS3, 5), ET-1 (RGS3, 4), Dopa (RGS3), TNF (RGS2, 3, 4) or IL-4 (RGS2, 3, 4). Immunohistochemically, increased ERK activation was detected on atherosclerotic plaques. This data supports the role of RGS proteins on ERK activation in human atherosclerosis which identifies RGS proteins as new therapeutical targets.
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Affiliation(s)
- Thomas Anger
- Department for Cardiology, Friedrich-Alexander University of Erlangen, Germany.
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Statins stimulate RGS-regulated ERK 1/2 activation in human calcified and stenotic aortic valves. Exp Mol Pathol 2008; 85:101-11. [DOI: 10.1016/j.yexmp.2008.06.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Accepted: 06/27/2008] [Indexed: 12/30/2022]
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Hendriks-Balk MC, Peters SLM, Michel MC, Alewijnse AE. Regulation of G protein-coupled receptor signalling: focus on the cardiovascular system and regulator of G protein signalling proteins. Eur J Pharmacol 2008; 585:278-91. [PMID: 18410914 DOI: 10.1016/j.ejphar.2008.02.088] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Revised: 01/18/2008] [Accepted: 02/06/2008] [Indexed: 11/17/2022]
Abstract
G protein-coupled receptors (GPCRs) are involved in many biological processes. Therefore, GPCR function is tightly controlled both at receptor level and at the level of signalling components. Well-known mechanisms by which GPCR function can be regulated comprise desensitization/resensitization processes and GPCR up- and downregulation. GPCR function can also be regulated by several proteins that directly interact with the receptor and thereby modulate receptor activity. An additional mechanism by which receptor signalling is regulated involves an emerging class of proteins, the so-called regulators of G protein signalling (RGS). In this review we will describe some of these control mechanisms in more detail with some specific examples in the cardiovascular system. In addition, we will provide an overview on RGS proteins and the involvement of RGS proteins in cardiovascular function.
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Affiliation(s)
- Mariëlle C Hendriks-Balk
- Department Pharmacology and Pharmacotherapy, Academic Medical Center, Amsterdam, The Netherlands
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