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Cai Z, Yu C, Li S, Wang C, Fan Y, Ji Q, Chen F, Li W. A Novel Classification of Glioma Subgroup, Which Is Highly Correlated With the Clinical Characteristics and Tumor Tissue Characteristics, Based on the Expression Levels of Gβ and Gγ Genes. Front Oncol 2021; 11:685823. [PMID: 34222011 PMCID: PMC8250418 DOI: 10.3389/fonc.2021.685823] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/26/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose Glioma is a classical type of primary brain tumors that is most common seen in adults, and its high heterogeneity used to be a reference standard for subgroup classification. Glioma has been diagnosed based on histopathology, grade, and molecular markers including IDH mutation, chromosome 1p/19q loss, and H3K27M mutation. This subgroup classification cannot fully meet the current needs of clinicians and researchers. We, therefore, present a new subgroup classification for glioma based on the expression levels of Gβ and Gγ genes to complement studies on glioma and Gβγ subunits, and to support clinicians to assess a patient’s tumor status. Methods Glioma samples retrieved from the CGGA database and the TCGA database. We clustered the gliomas into different groups by using expression values of Gβ and Gγ genes extracted from RNA sequencing data. The Kaplan–Meier method with a two-sided log-rank test was adopted to compare the OS of the patients between GNB2 group and non-GNB2 group. Univariate Cox regression analysis was referred to in order to investigate the prognostic role of each Gβ and Gγ genes. KEGG and ssGSEA analysis were applied to identify highly activated pathways. The “estimate” package, “GSVA” package, and the online analytical tools CIBERSORTx were employed to evaluate immune cell infiltration in glioma samples. Results Three subgroups were identified. Each subgroup had its own specific pathway activation pattern and other biological characteristics. High M2 cell infiltration was observed in the GNB2 subgroup. Different subgroups displayed different sensitivities to chemotherapeutics. GNB2 subgroup predicted poor survival in patients with gliomas, especially in patients with LGG with mutation IDH and non-codeleted 1p19q. Conclusion The subgroup classification we proposed has great application value. It can be used to select chemotherapeutic drugs and the prognosis of patients with target gliomas. The unique relationships between subgroups and tumor-related pathways are worthy of further investigation to identify therapeutic Gβγ heterodimer targets.
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Affiliation(s)
- Zehao Cai
- Department of Neuro-oncology, Cancer Center, Beijing Tiantan Hospital, Capital Medical Unversity, Beijing, China
| | - Chunna Yu
- Department of Neuro-oncology, Cancer Center, Beijing Tiantan Hospital, Capital Medical Unversity, Beijing, China
| | - Shenglan Li
- Department of Neuro-oncology, Cancer Center, Beijing Tiantan Hospital, Capital Medical Unversity, Beijing, China
| | - Can Wang
- Department of Neuro-oncology, Cancer Center, Beijing Tiantan Hospital, Capital Medical Unversity, Beijing, China
| | - Yaqiong Fan
- Department of Neuro-oncology, Cancer Center, Beijing Tiantan Hospital, Capital Medical Unversity, Beijing, China
| | - Qiang Ji
- Department of Neuro-oncology, Cancer Center, Beijing Tiantan Hospital, Capital Medical Unversity, Beijing, China
| | - Feng Chen
- Department of Neuro-oncology, Cancer Center, Beijing Tiantan Hospital, Capital Medical Unversity, Beijing, China
| | - Wenbin Li
- Department of Neuro-oncology, Cancer Center, Beijing Tiantan Hospital, Capital Medical Unversity, Beijing, China
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Chung YK, Wong YH. Re‐examining the ‘Dissociation Model’ of G protein activation from the perspective of Gβγ signaling. FEBS J 2020; 288:2490-2501. [DOI: 10.1111/febs.15605] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 10/14/2020] [Accepted: 10/19/2020] [Indexed: 12/27/2022]
Affiliation(s)
- Yin Kwan Chung
- Division of Life Science and Biotechnology Research Institute Hong Kong University of Science and Technology Hong Kong China
| | - Yung Hou Wong
- Division of Life Science and Biotechnology Research Institute Hong Kong University of Science and Technology Hong Kong China
- State Key Laboratory of Molecular Neuroscience the Molecular Neuroscience Center Hong Kong University of Science and Technology Kowloon China
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Greenwood IA, Stott JB. The Gβ1 and Gβ3 Subunits Differentially Regulate Rat Vascular Kv7 Channels. Front Physiol 2020; 10:1573. [PMID: 31992990 PMCID: PMC6971187 DOI: 10.3389/fphys.2019.01573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 12/16/2019] [Indexed: 11/17/2022] Open
Abstract
Within the vasculature Kv7 channels are key regulators of basal tone and contribute to a variety of receptor mediated vasorelaxants. The Kv7.4 isoform, abundant within the vasculature, is key to these processes and was recently shown to have an obligatory requirement of G-protein βγ subunits for its voltage dependent activity. There is an increasing appreciation that with 5 Gβ subunits and 12 Gγ subunits described in mammalian cells that different Gβxγx combinations can confer selectivity in Gβγ effector stimulation. Therefore, we aimed to characterize the Gβ subunit(s) which basally regulate Kv7.4 channels and native vascular Kv7 channels. In Chinese Hamster Ovary cells overexpressing Kv7.4 and different Gβx subunits only Gβ1, Gβ3, and Gβ5 enhanced Kv7.4 currents, increasing the activation kinetics and negatively shifting the voltage dependence of activation. In isolated rat renal artery myocytes, proximity ligation assay detected an interaction of Kv7.4 with Gβ1 and Gβ3 subunits, but not other isoforms. Morpholino directed knockdown of Gβ1 in rat renal arteries did not alter Kv7 dependent currents but reduced Kv7.4 protein expression. Knockdown of Gβ3 in rat renal arteries resulted in decreased basal K+ currents which were not sensitive to pharmacological inhibition of Kv7 channels. These studies implicate the Gβ1 subunit in the synthesis or stability of Kv7.4 proteins, whilst revealing that the Gβ3 isoform is responsible for the basal activity of Kv7 channels in native rat renal myocytes. These findings demonstrate that different Gβ subunits have important individual roles in ion channel regulation.
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Affiliation(s)
- Iain A Greenwood
- Vascular Biology Research Centre, Institute of Molecular and Clinical Sciences, St George's University of London, London, United Kingdom
| | - Jennifer B Stott
- Vascular Biology Research Centre, Institute of Molecular and Clinical Sciences, St George's University of London, London, United Kingdom
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Transducin β-Subunit Can Interact with Multiple G-Protein γ-Subunits to Enable Light Detection by Rod Photoreceptors. eNeuro 2018; 5:eN-NWR-0144-18. [PMID: 29911170 PMCID: PMC6001135 DOI: 10.1523/eneuro.0144-18.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/07/2018] [Accepted: 05/10/2018] [Indexed: 11/21/2022] Open
Abstract
The heterotrimeric G-protein transducin mediates visual signaling in vertebrate photoreceptor cells. Many aspects of the function of transducin were learned from knock-out mice lacking its individual subunits. Of particular interest is the knockout of its rod-specific γ-subunit (Gγ1). Two studies using independently generated mice documented that this knockout results in a considerable >60-fold reduction in the light sensitivity of affected rods, but provided different interpretations of how the remaining α-subunit (Gαt) mediates phototransduction without its cognate Gβ1γ1-subunit partner. One study found that the light sensitivity reduction matched a corresponding reduction in Gαt content in the light-sensing rod outer segments and proposed that Gαt activation is supported by remaining Gβ1 associating with other Gγ subunits naturally expressed in photoreceptors. In contrast, the second study reported the same light sensitivity loss but a much lower, only approximately sixfold, reduction of Gαt and proposed that the light responses of these rods do not require Gβγ at all. To resolve this controversy and elucidate the mechanism driving visual signaling in Gγ1 knock-out rods, we analyzed both mouse lines side by side. We first determined that the outer segments of both mice have identical Gαt content, which is reduced ∼65-fold from the wild-type (WT) level. We further demonstrated that the remaining Gβ1 is present in a complex with endogenous Gγ2 and Gγ3 subunits and that these complexes exist in wild-type rods as well. Together, these results argue against the idea that Gαt alone supports light responses of Gγ1 knock-out rods and suggest that Gβ1γ1 is not unique in its ability to mediate vertebrate phototransduction.
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Ozdemir AC, Wynn GM, Vester A, Weitzmann MN, Neigh GN, Srinivasan S, Rudd MK. GNB3 overexpression causes obesity and metabolic syndrome. PLoS One 2017; 12:e0188763. [PMID: 29206867 PMCID: PMC5716578 DOI: 10.1371/journal.pone.0188763] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Accepted: 11/13/2017] [Indexed: 11/19/2022] Open
Abstract
The G-protein beta subunit 3 (GNB3) gene has been implicated in obesity risk; however, the molecular mechanism of GNB3-related disease is unknown. GNB3 duplication is responsible for a syndromic form of childhood obesity, and an activating DNA sequence variant (C825T) in GNB3 is also associated with obesity. To test the hypothesis that GNB3 overexpression causes obesity, we created bacterial artificial chromosome (BAC) transgenic mice that carry an extra copy of the human GNB3 risk allele. Here we show that GNB3-T/+ mice have increased adiposity, but not greater food intake or a defect in satiety. GNB3-T/+ mice have elevated fasting plasma glucose, insulin, and C-peptide, as well as glucose intolerance, indicating type 2 diabetes. Fasting plasma leptin, triglycerides, cholesterol and phospholipids are elevated, suggesting metabolic syndrome. Based on a battery of behavioral tests, GNB3-T/+ mice did not exhibit anxiety- or depressive-like phenotypes. GNB3-T/+ and wild-type animals have similar activity levels and heat production; however, GNB3-T/+ mice exhibit dysregulation of acute thermogenesis. Finally, Ucp1 expression is significantly lower in white adipose tissue (WAT) in GNB3-T/+ mice, suggestive of WAT remodeling that could lead to impaired cellular thermogenesis. Taken together, our study provides the first functional link between GNB3 and obesity, and presents insight into novel pathways that could be applied to combat obesity and type 2 diabetes.
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Affiliation(s)
- Alev Cagla Ozdemir
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Grace M. Wynn
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Aimee Vester
- Department of Environmental Health Sciences, Rollins School of Public Health, Emory University, Atlanta, GA, United States of America
| | - M. Neale Weitzmann
- Division of Endocrinology, Metabolism, and Lipids, Emory University School of Medicine, Atlanta, GA, United States of America
- Atlanta VA Medical Center, Decatur, GA, United States of America
| | - Gretchen N. Neigh
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States of America
- Department of Anatomy & Neurobiology, Virginia Commonwealth University, Richmond, VA, United States of America
| | - Shanthi Srinivasan
- Atlanta VA Medical Center, Decatur, GA, United States of America
- Division of Digestive Diseases, Emory University School of Medicine, Atlanta, GA, United States of America
| | - M. Katharine Rudd
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, United States of America
- * E-mail:
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Shi Y, Lai X, Ye L, Chen K, Cao Z, Gong W, Jin L, Wang C, Liu M, Liao Y, Wang JM, Zhou N. Activated niacin receptor HCA2 inhibits chemoattractant-mediated macrophage migration via Gβγ/PKC/ERK1/2 pathway and heterologous receptor desensitization. Sci Rep 2017; 7:42279. [PMID: 28186140 PMCID: PMC5301212 DOI: 10.1038/srep42279] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 01/08/2017] [Indexed: 12/18/2022] Open
Abstract
The niacin receptor HCA2 is implicated in controlling inflammatory host responses with yet poorly understood mechanistic basis. We previously reported that HCA2 in A431 epithelial cells transduced Gβγ-protein kinase C- and Gβγ-metalloproteinase/EGFR-dependent MAPK/ERK signaling cascades. Here, we investigated the role of HCA2 in macrophage-mediated inflammation and the underlying mechanisms. We found that proinflammatory stimulants LPS, IL-6 and IL-1β up-regulated the expression of HCA2 on macrophages. Niacin significantly inhibited macrophage chemotaxis in response to chemoattractants fMLF and CCL2 by disrupting polarized distribution of F-actin and Gβ protein. Niacin showed a selected additive effect on chemoattractant-induced activation of ERK1/2, JNK and PI3K pathways, but only the MEK inhibitor UO126 reduced niacin-mediated inhibition of macrophage chemotaxis, while activation of ERK1/2 by EGF alone did not inhibit fMLF-mediated migration of HEK293T cells co-expressing HCA2 and fMLF receptor FPR1. In addition, niacin induced heterologous desensitization and internalization of FPR1. Furthermore, niacin rescued mice from septic shock by diminishing inflammatory symptoms and the effect was abrogated in HCA2-/- mice. These results suggest that Gβγ/PKC-dependent ERK1/2 activation and heterologous desensitization of chemoattractant receptors are involved in the inhibition of chemoattractant-induced migration of macrophages by niacin. Thus, HCA2 plays a critical role in host protection against pro-inflammatory insults.
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Affiliation(s)
- Ying Shi
- College of Life Sciences, Zhejiang University, Yu Hang Tang Load 388, Hangzhou, PR China
| | - Xiangru Lai
- College of Life Sciences, Zhejiang University, Yu Hang Tang Load 388, Hangzhou, PR China
| | - Lingyan Ye
- College of Life Sciences, Zhejiang University, Yu Hang Tang Load 388, Hangzhou, PR China
| | - Keqiang Chen
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute-Frederick, NIH, Frederick, MD 21702, USA
| | - Zheng Cao
- College of Life Sciences, Zhejiang University, Yu Hang Tang Load 388, Hangzhou, PR China
| | - Wanghua Gong
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute-Frederick, NIH, Frederick, MD 21702, USA
| | - Lili Jin
- College of Life Sciences, Zhejiang University, Yu Hang Tang Load 388, Hangzhou, PR China
| | - Chunyan Wang
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute-Frederick, NIH, Frederick, MD 21702, USA.,Xuzhou Yes Biotech Laboratories Ltd. Xuzhou, Jiangsu, PR China
| | - Mingyong Liu
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute-Frederick, NIH, Frederick, MD 21702, USA.,Department of Spine Surgery, Daping Hospital, Third Military Medical University, Chongqing, PR China
| | - Yuan Liao
- College of Life Sciences, Zhejiang University, Yu Hang Tang Load 388, Hangzhou, PR China
| | - Ji Ming Wang
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute-Frederick, NIH, Frederick, MD 21702, USA
| | - Naiming Zhou
- College of Life Sciences, Zhejiang University, Yu Hang Tang Load 388, Hangzhou, PR China
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Chan ASL, Lau WWI, Szeto ACH, Wang J, Wong YH. Differential Regulation of CXCL8 Production by Different G Protein Subunits with Synergistic Stimulation by Gi- and Gq-Regulated Pathways. J Mol Biol 2016; 428:3869-84. [PMID: 27040396 DOI: 10.1016/j.jmb.2016.03.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/22/2016] [Accepted: 03/24/2016] [Indexed: 01/14/2023]
Abstract
CXCL8 (also known as interleukin-8 or IL-8) is a proinflammatory chemokine that not only modulates the inflammatory and immune responses, but whose upregulation is often associated with diseases including various types of cancer. Although numerous ligands for G protein-coupled receptors (GPCRs) have been shown to stimulate the production of CXCL8, the specificity of the G protein signal remains undefined. By expressing the constitutively active Gα subunits in HEK293 cells, CXCL8 production was herein demonstrated to be most effectively stimulated by Gαq family members, while those of Gαs and Gα12 elicited much weaker activities, and Gαi being totally ineffective. However, in cell lines such as HepG2, HeLa, and MCF-7 that endogenously express Gβγ-responsive phospholipase Cβ isoforms (PLCβ2/3), activation of the Gi-coupled α2-adrenoceptor significantly stimulated CXCL8 production. This Gi-induced CXCL8 production was apparently mediated via specific Gβγ dimers and required the presence of PLCβ2/3. Co-activation of Gi-coupled α2-adrenoceptor and Gq-coupled bradykinin receptor resulted in a synergistic CXCL8 production, with Gβγ-responsive PLCβ2/3, Src, ERK, and STAT3 serving as critical signaling intermediates. The treatment of HepG2 and B-10 endothelial cells with bradykinin stimulated CXCL8 production and cell proliferation. Interestingly, the latter response was driven by CXCL8 autocrine signaling because it was abolished by SB225002, an antagonist that prevents CXCL8 from binding to CXCR2. Collectively, our results provide a mechanistic basis for various G protein subfamilies to regulate the production of CXCL8, which may then lead to paracrine and/or autocrine signaling with major implications in both normal physiology and pathophysiological conditions.
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Affiliation(s)
- Anthony S L Chan
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Winnie W I Lau
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Aydan C H Szeto
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Jiuling Wang
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Yung H Wong
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
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McGlinchey JCP, Tummala H, Lester DH. Correction of the Pathogenic Alternative Splicing, Caused by the Common GNB3 c.825C>T Allele, Using a Novel, Antisense Morpholino. Nucleic Acid Ther 2016; 26:257-65. [PMID: 27028457 DOI: 10.1089/nat.2015.0571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The very common GNB3 c.825C>T polymorphism (rs5443) is present in approximately half of all human chromosomes. Significantly, the presence of the GNB3 825T allele has been strongly associated with predisposition to essential hypertension. Paradoxically the presence of the GNB3 825T allele, in exon 10, introduces a pathogenic alternative RNA splice site into the middle of exon 9. To attempt to correct this pathogenic aberrant splicing, we, therefore, bioinformatically designed, using a Gene Tools(®) algorithm, a GNB3-specific, antisense morpholino. It was hoped that this morpholino would behave in vitro as either a potential splice blocker and/or exon skipper, to both bind and inhibit/reduce the aberrant splicing of the GNB3 825T allele. On transfecting a human lymphoblast cell line homozygous for the 825T allele, with this antisense morpholino, we encouragingly observed both a significant reduction (from ∼58% to ∼5%) in the production of the aberrant smaller GNB3 transcript, and a subsequent increase in the normal GNB3 transcript (from ∼42% to ∼95%). Our results demonstrate the potential use of a GNB3-specific antisense morpholino, as a pharmacogenetic therapy for essential hypertension.
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Affiliation(s)
- Jonathan C P McGlinchey
- 1 School of Science, Engineering & Technology, Abertay University , Dundee, United Kingdom .,2 Blood Sciences Laboratory, Department of Haematology, Ninewells Hospital , Dundee, United Kingdom
| | - Hemanth Tummala
- 3 Centre for Paediatrics, Barts and The London School of Medicine and Dentistry, Queen Mary University of London , Barts and The London Children's Hospital, London, United Kingdom
| | - Douglas H Lester
- 1 School of Science, Engineering & Technology, Abertay University , Dundee, United Kingdom
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Stewart A, Fisher RA. Introduction: G Protein-coupled Receptors and RGS Proteins. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 133:1-11. [PMID: 26123299 DOI: 10.1016/bs.pmbts.2015.03.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Here, we provide an overview of the role of regulator of G protein-signaling (RGS) proteins in signaling by G protein-coupled receptors (GPCRs), the latter of which represent the largest class of cell surface receptors in humans responsible for transducing diverse extracellular signals into the intracellular environment. Given that GPCRs regulate virtually every known physiological process, it is unsurprising that their dysregulation plays a causative role in many human diseases and they are targets of 40-50% of currently marketed pharmaceuticals. Activated GPCRs function as GTPase exchange factors for Gα subunits of heterotrimeric G proteins, promoting the formation of Gα-GTP and dissociated Gβγ subunits that regulate diverse effectors including enzymes, ion channels, and protein kinases. Termination of signaling is mediated by the intrinsic GTPase activity of Gα subunits leading to reformation of the inactive Gαβγ heterotrimer. RGS proteins determine the magnitude and duration of cellular responses initiated by many GPCRs by functioning as GTPase-accelerating proteins (GAPs) for specific Gα subunits. Twenty canonical mammalian RGS proteins, divided into four subfamilies, act as functional GAPs while almost 20 additional proteins contain nonfunctional RGS homology domains that often mediate interaction with GPCRs or Gα subunits. RGS protein biochemistry has been well elucidated in vitro, but the physiological functions of each RGS family member remain largely unexplored. This book summarizes recent advances employing modified model organisms that reveal RGS protein functions in vivo, providing evidence that RGS protein modulation of G protein signaling and GPCRs can be as important as initiation of signaling by GPCRs.
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Affiliation(s)
- Adele Stewart
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Rory A Fisher
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.
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Comprehensive analysis of heterotrimeric G-protein complex diversity and their interactions with GPCRs in solution. Proc Natl Acad Sci U S A 2015; 112:E1181-90. [PMID: 25733868 DOI: 10.1073/pnas.1417573112] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Agonist binding to G-protein-coupled receptors (GPCRs) triggers signal transduction cascades involving heterotrimeric G proteins as key players. A major obstacle for drug design is the limited knowledge of conformational changes upon agonist binding, the details of interaction with the different G proteins, and the transmission to movements within the G protein. Although a variety of different GPCR/G protein complex structures would be needed, the transient nature of this complex and the intrinsic instability against dissociation make this endeavor very challenging. We have previously evolved GPCR mutants that display higher stability and retain their interaction with G proteins. We aimed at finding all G-protein combinations that preferentially interact with neurotensin receptor 1 (NTR1) and our stabilized mutants. We first systematically analyzed by coimmunoprecipitation the capability of 120 different G-protein combinations consisting of αi1 or αsL and all possible βγ-dimers to form a heterotrimeric complex. This analysis revealed a surprisingly unrestricted ability of the G-protein subunits to form heterotrimeric complexes, including βγ-dimers previously thought to be nonexistent, except for combinations containing β5. A second screen on coupling preference of all G-protein heterotrimers to NTR1 wild type and a stabilized mutant indicated a preference for those Gαi1βγ combinations containing γ1 and γ11. Heterotrimeric G proteins, including combinations believed to be nonexistent, were purified, and complexes with the GPCR were prepared. Our results shed new light on the combinatorial diversity of G proteins and their coupling to GPCRs and open new approaches to improve the stability of GPCR/G-protein complexes.
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11
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Jin JM, Yang WX. Molecular regulation of hypothalamus-pituitary-gonads axis in males. Gene 2014; 551:15-25. [PMID: 25168889 DOI: 10.1016/j.gene.2014.08.048] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 07/24/2014] [Accepted: 08/24/2014] [Indexed: 10/24/2022]
Abstract
The hypothalamic-pituitary-gonadal axis (HPG) plays vital roles in reproduction and steroid hormone production in both sexes. The focus of this review is upon gene structures, receptor structures and the signaling pathways of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The hormones' functions in reproduction as well as consequences resulting from mutations are also summarized. Specific characteristics of hormones such as the pulsatile secretions of GnRH are also covered. The different regulators of the HPG axis are introduced including kisspeptin, activin, inhibin, follistatin, androgens and estrogen. This review includes not only their basic information, but also their unique function in the HPG axis. Here we view the HPG axis as a whole, so relations between ligands and receptors are well described crossing different levels of the HPG axis. Hormone interactions and transformations are also considered. The major information of this article is depicted in three figures summarizing the current discoveries on the HPG axis. This article systematically introduces the basic knowledge of the HPG axis and provides information of the current advances relating to reproductive hormones.
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Affiliation(s)
- Jia-Min Jin
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
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Huang J, Nalli AD, Mahavadi S, Kumar DP, Murthy KS. Inhibition of Gαi activity by Gβγ is mediated by PI 3-kinase-γ- and cSrc-dependent tyrosine phosphorylation of Gαi and recruitment of RGS12. Am J Physiol Gastrointest Liver Physiol 2014; 306:G802-10. [PMID: 24578342 PMCID: PMC4010651 DOI: 10.1152/ajpgi.00440.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Others and we have characterized several Gβγ-dependent effectors in smooth muscle, including G protein-coupled receptor kinase 2 (GRK2), PLCβ3, and phosphatidylinositol (PI) 3-kinase-γ, and have identified various signaling targets downstream of PI 3-kinase-γ, including cSrc, integrin-linked kinase, and Rac1-Cdc42/p21-activated kinase/p38 MAP kinase. This study identified a novel mechanism whereby Gβγ acting via PI 3-kinase-γ and cSrc exerts an inhibitory influence on Gαi activity. The Gi2-coupled δ-opioid receptor agonist d-penicillamine (2,5)-enkephalin (DPDPE) activated cSrc, stimulated tyrosine phosphorylation of Gαi2, and induced regulator of G protein signaling 12 (RGS12) association; all three events were blocked by PI 3-kinase (LY294002) and cSrc (PP2) inhibitors and by expression of the COOH-terminal sequence of GRK2-(495-689), a Gβγ-scavenging peptide. Inhibition of forskolin-stimulated cAMP and muscle relaxation by DPDPE was augmented by PP2, LY294002, and a selective PI 3-kinase-γ inhibitor, AS-605420. Expression of tyrosine-deficient (Y69F, Y231F, or Y321F) Gαi2 mutant or knockdown of RGS12 blocked Gαi2 phosphorylation and Gαi2-RGS12 association and caused greater inhibition of cAMP. Parallel studies using somatostatin, cyclopentyl adenosine, or ACh to activate, respectively, Gi1-coupled somatostatin (sstr3) receptors, and Gi3-coupled adenosine A1 or muscarinic m2 receptors elicited cSrc activation, Gαi1 or Gαi3 phosphorylation, Gαi1-RGS12 or Gαi3-RGS12 association, and inhibition of cAMP. Inhibition of cAMP and muscle relaxation was greatly increased by AS-605240 and PP2. The results demonstrate that Gβγ-dependent tyrosine phosphorylation of Gαi1/2/3 by cSrc facilitated recruitment of RGS12, a Gαi-specific RGS protein with a unique phosphotyrosine-binding domain, resulting in rapid deactivation of Gαi and facilitation of smooth muscle relaxation.
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Affiliation(s)
- Jiean Huang
- Department of Physiology and Biophysics, Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Ancy D. Nalli
- Department of Physiology and Biophysics, Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Sunila Mahavadi
- Department of Physiology and Biophysics, Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Divya P. Kumar
- Department of Physiology and Biophysics, Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Karnam S. Murthy
- Department of Physiology and Biophysics, Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
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13
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Lau WW, Chan AS, Poon LS, Zhu J, Wong YH. Gβγ-mediated activation of protein kinase D exhibits subunit specificity and requires Gβγ-responsive phospholipase Cβ isoforms. Cell Commun Signal 2013; 11:22. [PMID: 23561540 PMCID: PMC3637504 DOI: 10.1186/1478-811x-11-22] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 03/22/2013] [Indexed: 11/29/2022] Open
Abstract
Background Protein kinase D (PKD) constitutes a novel family of serine/threonine protein kinases implicated in fundamental biological activities including cell proliferation, survival, migration, and immune responses. Activation of PKD in these cellular activities has been linked to many extracellular signals acting through antigen receptor engagement, receptor tyrosine kinases, as well as G protein-coupled receptors. In the latter case, it is generally believed that the Gα subunits of the Gq family are highly effective in mediating PKD activation, whereas little is known with regard to the ability of Gβγ dimers and other Gα subunits to stimulate PKD. It has been suggested that the interaction between Gβγ and the PH domain of PKD, or the Gβγ-induced PLCβ/PKC activity is critical for the induction of PKD activation. However, the relative contribution of these two apparently independent events to Gβγ-mediated PKD activation has yet to be addressed. Results In this report, we demonstrate that among various members in the four G protein families, only the Gα subunits of the Gq family effectively activate all the three PKD isoforms (PKD1/2/3), while Gα subunits of other G protein families (Gs, Gi, and G12) are ineffective. Though the Gα subunits of Gi family are unable to stimulate PKD, receptors linked to Gi proteins are capable of triggering PKD activation in cell lines endogenously expressing (HeLa cells and Jurkat T-cells) or exogenously transfected with (HEK293 cells) Gβγ-sensitive PLCβ2/3 isoforms. This indicates that the Gi-mediated PKD activation is dependent on the released Gβγ dimers upon stimulation. Further investigation on individual Gβγ combinations (i.e. Gβ1 with Gγ1–13) revealed that, even if they can stimulate the PLCβ activity in a comparable manner, only those Gβ1γ dimers with γ2, γ3, γ4, γ5, γ7, and γ10 can serve as effective activators of PKD. We also demonstrated that Gi-mediated PKD activation is essential for the SDF-1α-induced chemotaxis on Jurkat T-cells. Conclusions Our current report illustrates that Gβγ dimers from the Gi proteins may activate PKD in a PLCβ2/3-dependent manner, and the specific identities of Gγ components within Gβγ dimers may determine this stimulatory action.
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Affiliation(s)
- Winnie Wi Lau
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
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14
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Abstract
G protein-coupled receptors (GPCRs) are the largest class of integral membrane protein receptors in the human genome. We examined here the reports whether the GnRH receptor (GnRHR) interacts with a single or multiple types of G proteins. It seems that the GnRHR, as other GPCRs, alternates between various conformations and is stabilized by its ligands, other modulators and intracellular partners in selective conformations culminating in coupling with a single type or multiple G proteins in a cell- and context-specific manner.
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Affiliation(s)
- Zvi Naor
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
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15
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Khan SM, Sleno R, Gora S, Zylbergold P, Laverdure JP, Labbé JC, Miller GJ, Hébert TE. The expanding roles of Gβγ subunits in G protein-coupled receptor signaling and drug action. Pharmacol Rev 2013; 65:545-77. [PMID: 23406670 DOI: 10.1124/pr.111.005603] [Citation(s) in RCA: 172] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Gβγ subunits from heterotrimeric G proteins perform a vast array of functions in cells with respect to signaling, often independently as well as in concert with Gα subunits. However, the eponymous term "Gβγ" does not do justice to the fact that 5 Gβ and 12 Gγ isoforms have evolved in mammals to serve much broader roles beyond their canonical roles in cellular signaling. We explore the phylogenetic diversity of Gβγ subunits with a view toward understanding these expanded roles in different cellular organelles. We suggest that the particular content of distinct Gβγ subunits regulates cellular activity, and that the granularity of individual Gβ and Gγ action is only beginning to be understood. Given the therapeutic potential of targeting Gβγ action, this larger view serves as a prelude to more specific development of drugs aimed at individual isoforms.
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Affiliation(s)
- Shahriar M Khan
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir-William-Osler, Room 1303, Montréal, Québec H3G 1Y6, Canada
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16
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Abstract
Heterotrimeric G-proteins, comprising Gα and Gβγ subunits, couple metabotropic receptors to various downstream effectors and contribute to assembling and trafficking receptor-based signaling complexes. A G-protein β subunit, Gβ(3), plays a critical role in several physiological processes, as a polymorphism in its gene is associated with a risk factor for several disorders. Retinal ON bipolar cells express Gβ(3), and they provide an excellent system to study its role. In the ON bipolar cells, mGluR6 inverts the photoreceptor's signal via a cascade in which glutamate released from photoreceptors closes the TRPM1 channel. This cascade is essential for vision since deficiencies in its proteins lead to complete congenital stationary night blindness. Here we report that Gβ(3) participates in the G-protein heterotrimer that couples mGluR6 to TRPM1. Gβ(3) deletion in mouse greatly reduces the light response under both scotopic and photopic conditions, but it does not eliminate it. In addition, Gβ(3) deletion causes mislocalization and downregulation of most cascade elements and modulators. Furthermore, Gβ(3) may play a role in synaptic maintenance since in its absence, the number of invaginating rod bipolar dendrites is greatly reduced, a deficit that was not observed at 3 weeks, the end of the developmental period.
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17
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Sun Z, Runne C, Tang X, Lin F, Chen S. The Gβ3 splice variant associated with the C825T gene polymorphism is an unstable and functionally inactive protein. Cell Signal 2012; 24:2349-59. [PMID: 22940628 DOI: 10.1016/j.cellsig.2012.08.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 08/27/2012] [Indexed: 12/13/2022]
Abstract
A splice variant of Gβ3, termed Gβ3s, has been associated with the C825T polymorphism in the Gβ3 gene and linked with many human disorders. However, the biochemical properties and functionality of Gβ3s remain controversial. Here, using multidisciplinary approaches including co-immunoprecipitation analysis and bioluminescence resonance energy transfer (BRET) measurements, we showed that unlike Gβ3, Gβ3s failed to form complexes with either Gγ or Gα subunits. Moreover, using a mutant Gγ2 deficient in lipid modification to purify Gβ3s from Sf9 cells without the use of detergents, we further showed that the failure of Gβ3s to form dimers with Gγ was not due to the instability of the dimers in detergents, but rather, reflected the intrinsic properties of Gβ3s. Additional studies indicated that Gβ3s is unstable, and unable to localize properly to the plasma membrane and to activate diverse Gβγ effectors including PLCβ2/3, PI3Kγ, ERKs and the Rho guanine exchange factor (RhoGEF) PLEKHG2. Thus, these data suggest that the pathological effects of Gβ3 C825T polymorphism may result from the downregulation of Gβ3 function. However, we found that the chemokine SDF1α transmits signals primarily through Gβ1 and Gβ2, but not Gβ3, to regulate chemotaxis of several human lymphocytic cell lines, indicating the effects of Gβ3 C825T polymorphism are likely to be tissue and/or stimuli specific and its association with various disorders in different tissues should be interpreted with great caution.
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Affiliation(s)
- Zhizeng Sun
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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18
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Liu Z, Fenech C, Cadiou H, Grall S, Tili E, Laugerette F, Wiencis A, Grosmaitre X, Montmayeur JP. Identification of new binding partners of the chemosensory signaling protein Gγ13 expressed in taste and olfactory sensory cells. Front Cell Neurosci 2012; 6:26. [PMID: 22737109 PMCID: PMC3380295 DOI: 10.3389/fncel.2012.00026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Accepted: 05/31/2012] [Indexed: 01/19/2023] Open
Abstract
Tastant detection in the oral cavity involves selective receptors localized at the apical extremity of a subset of specialized taste bud cells called taste receptor cells (TRCs). The identification of the genes coding for the taste receptors involved in this process have greatly improved our understanding of the molecular mechanisms underlying detection. However, how these receptors signal in TRCs, and whether the components of the signaling cascades interact with each other or are organized in complexes is mostly unexplored. Here we report on the identification of three new binding partners for the mouse G protein gamma 13 subunit (Gγ13), a component of the bitter taste receptors signaling cascade. For two of these Gγ13 associated proteins, namely GOPC and MPDZ, we describe the expression in taste bud cells for the first time. Furthermore, we demonstrate by means of a yeast two-hybrid interaction assay that the C terminal PDZ binding motif of Gγ13 interacts with selected PDZ domains in these proteins. In the case of the PDZ domain-containing protein zona occludens-1 (ZO-1), a major component of the tight junction defining the boundary between the apical and baso-lateral region of TRCs, we identified the first PDZ domain as the site of strong interaction with Gγ13. This association was further confirmed by co-immunoprecipitation experiments in HEK 293 cells. In addition, we present immunohistological data supporting partial co-localization of GOPC, MPDZ, or ZO-1, and Gγ13 in taste buds cells. Finally, we extend this observation to olfactory sensory neurons (OSNs), another type of chemosensory cells known to express both ZO-1 and Gγ13. Taken together our results implicate these new interaction partners in the sub-cellular distribution of Gγ13 in olfactory and gustatory primary sensory cells.
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Affiliation(s)
- Zhenhui Liu
- Chemosensory Perception, Centre des Sciences du Goût et de l'Alimentation, UMR-6265 CNRS, UMR-1324 INRA Dijon, France
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19
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Dingus J, Hildebrandt JD. Synthesis and assembly of G protein βγ dimers: comparison of in vitro and in vivo studies. Subcell Biochem 2012; 63:155-80. [PMID: 23161138 DOI: 10.1007/978-94-007-4765-4_9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The heterotrimeric GTP-binding proteins (G proteins) are the canonical cellular machinery used with the approximately 700 G protein-coupled receptors (GPCRs) in the human genome to transduce extracellular signals across the plasma membrane. The synthesis of the constituent G protein subunits, and their assembly into Gβγ dimers and G protein heterotrimers, determines the signaling repertoire for G-protein/GPCR signaling in cells. These synthesis/assembly -processes are intimately related to two other overlapping events in the intricate pathway leading to formation of G protein signaling complexes, posttranslational modification and intracellular trafficking of G proteins. The assembly of the Gβγ dimer is a complex process involving multiple accessory proteins and organelles. The mechanisms involved are becoming increasingly appreciated, but are still incompletely understood. In vitro and in vivo (cellular) studies provide different perspectives of these processes, and a comparison of them can provide insight into both our current level of understanding and directions to be taken in future investigations.
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Affiliation(s)
- Jane Dingus
- Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Charleston, SC, 29425, USA
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20
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Hatziapostolou M, Koukos G, Polytarchou C, Kottakis F, Serebrennikova O, Kuliopulos A, Tsichlis PN. Tumor progression locus 2 mediates signal-induced increases in cytoplasmic calcium and cell migration. Sci Signal 2011; 4:ra55. [PMID: 21868363 DOI: 10.1126/scisignal.2002006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The mitogen-activated protein kinase kinase kinase (MAPKKK or MAP3K) tumor progression locus 2 (Tpl2) is required for the transduction of signals initiated by the thrombin-activated G protein-coupled receptor (GPCR) protease-activated receptor-1 (PAR1), which promote reorganization of the actin cytoskeleton and cell migration. Here, we show that Tpl2 is activated through Gα(i2)-transduced GPCR signals. Activated Tpl2 promoted the phosphorylation and activation of phospholipase C-β3 (PLCβ(3)); consequently, Tpl2 was required for thrombin-dependent production of inositol 1,4,5-trisphosphate (IP(3)), IP(3)-mediated cytoplasmic calcium ion (Ca(2+)) signals, and the activation of classical and novel members of the protein kinase C (PKC) family. A PKC-mediated feedback loop facilitated extracellular signal-regulated kinase (ERK) activation in response to Tpl2 and contributed to the coordinate regulation of the ERK and Ca(2+) signaling pathways. Pharmacological and genetic studies revealed that stimulation of cell migration by Tpl2 depends on both of these pathways. Tpl2 also promoted Ca(2+) signals and cell migration from sphingosine 1-phosphate-responsive GPCRs, which also couple to Gα(i); from Wnt5a; and from the interleukin-1β (IL-1β) receptor, a member of the Toll-IL-1R (TIR) domain family. Our data provide new insights into the role of Tpl2 in GPCR-mediated Ca(2+) signaling and cell migration.
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Affiliation(s)
- Maria Hatziapostolou
- Molecular Oncology Research Institute, Tufts Medical Center, Boston, MA 02111, USA
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21
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Piotrowska U, Adler G, Kozicki I. Diverse β subunits of heterotrimeric G proteins are present in thyroid plasma membranes. Biochem Biophys Res Commun 2011; 414:350-4. [PMID: 21964289 DOI: 10.1016/j.bbrc.2011.09.075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 09/14/2011] [Indexed: 10/17/2022]
Abstract
The functioning of heterotrimeric G protein α subunits in the transduction of hormonal signals to appropriate intracellular responses is well recognized. Much less is known about the distribution of isoforms and functions of G protein β subunits. Here, using specific antibodies, we documented that in plasma membranes of the thyroid cell line Nthy-ori 3-1 all Gβ isoforms-Gβ(1), Gβ(2), Gβ(3), Gβ(4) and Gβ(5) are present, while the Gβ(3) occurs in minute amount. In plasma membrane fraction isolated from pooled postoperative thyroids of patients with nodular goiter and Graves' disease, the Gβ(1), Gβ(2), Gβ(4) and Gβ(5) subunits were found, whereas Gβ(3) could not be detected. Competition studies revealed that the Gβ(2) is the principal Gβ subunit in membranes from cultured thyroid cells, originated from normal thyroid, as well as in membranes from patients' thyroids. This suggests that Gβ(2) subunit cooperates with Gα(s) subunit, the most active of the Gα variants, during stimulation of adenylate cyclase which constitutes the main route of physiological thyroid stimulation.
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Affiliation(s)
- Urszula Piotrowska
- Medical Centre of Postgraduate Education, Department of Biochemistry, 01 813 Warsaw, Poland
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22
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Tummala H, Fleming S, Hocking PM, Wehner D, Naseem Z, Ali M, Inglehearn CF, Zhelev N, Lester DH. The D153del mutation in GNB3 gene causes tissue specific signalling patterns and an abnormal renal morphology in Rge chickens. PLoS One 2011; 6:e21156. [PMID: 21887213 PMCID: PMC3159573 DOI: 10.1371/journal.pone.0021156] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 05/21/2011] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The GNB3 gene is expressed in cone but not rod photoreceptors of vertebrates, where it acts as the β transducin subunit in the colour visual transduction process. A naturally occurring mutation 'D153del' in the GNB3 gene causes the recessively inherited blinding phenotype retinopathy globe enlarged (rge) disease in chickens. GNB3 is however also expressed in most other vertebrate tissues suggesting that the D153del mutation may exert pathological effects that outlie from eye. PRINCIPAL FINDINGS Recombinant studies in COS-7 cells that were transfected with normal and mutant recombinant GNB3 constructs and subjected to cycloheximide chase showed that the mutant GNB3d protein had a much shorter half life compared to normal GNB3. GNB3 codes for the Gβ3 protein subunit that, together with different Gγ and Gα subunits, activates and regulates phosphorylation cascades in different tissues. As expected, the relative levels of cGMP and cAMP secondary messengers and their activated kinases such as MAPK, AKT and GRK2 were also found to be altered significantly in a tissue specific manner in rge chickens. Histochemical analysis on kidney tissue sections, from rge homozygous affected chickens, showed the chickens had enlargement of the glomerular capsule, causing glomerulomegaly and tubulointerstitial inflammation whereas other tissues (brain, heart, liver, pancreas) were unaffected. SIGNIFICANCE These findings confirm that the D153del mutation in GNB3 gene targets GNB3 protein to early degradation. Lack of GNB3 signalling causes reduced phosphorylation activity of ERK2 and AKT leading to severe pathological phenotypes such as blindness and renal abnormalities in rge chickens.
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Affiliation(s)
- Hemanth Tummala
- School of Contemporary Sciences, University of Abertay Dundee, Dundee, Scotland, United Kingdom
| | - Stewart Fleming
- Division of Medical Sciences, Centre for Oncology and Molecular Medicine, College of Medicine Dentistry and Nursing, Ninewells Hospital and Medical School, Dundee, Scotland, United Kingdom
| | - Paul M. Hocking
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, Scotland, United Kingdom
| | - Daniel Wehner
- School of Contemporary Sciences, University of Abertay Dundee, Dundee, Scotland, United Kingdom
| | - Zahid Naseem
- School of Contemporary Sciences, University of Abertay Dundee, Dundee, Scotland, United Kingdom
| | - Manir Ali
- Section of Ophthalmology and Neuroscience, Leeds Institute of Molecular Medicine, St James's University Hospital, Leeds, United Kingdom
| | - Christopher F. Inglehearn
- Section of Ophthalmology and Neuroscience, Leeds Institute of Molecular Medicine, St James's University Hospital, Leeds, United Kingdom
| | - Nikolai Zhelev
- School of Contemporary Sciences, University of Abertay Dundee, Dundee, Scotland, United Kingdom
| | - Douglas H. Lester
- School of Contemporary Sciences, University of Abertay Dundee, Dundee, Scotland, United Kingdom
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Sun J, Liu X, Pan Y. The physical interaction between LdPLCs and Arabidopsis G beta in a yeast two-hybrid system. ACTA ACUST UNITED AC 2011. [DOI: 10.1007/s11703-011-1063-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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