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Nürnberg B, Beer-Hammer S, Reisinger E, Leiss V. Non-canonical G protein signaling. Pharmacol Ther 2024; 255:108589. [PMID: 38295906 DOI: 10.1016/j.pharmthera.2024.108589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 12/18/2023] [Accepted: 01/08/2024] [Indexed: 02/17/2024]
Abstract
The original paradigm of classical - also referred to as canonical - cellular signal transduction of heterotrimeric G proteins (G protein) is defined by a hierarchical, orthograde interaction of three players: the agonist-activated G protein-coupled receptor (GPCR), which activates the transducing G protein, that in turn regulates its intracellular effectors. This receptor-transducer-effector concept was extended by the identification of regulators and adapters such as the regulators of G protein signaling (RGS), receptor kinases like βARK, or GPCR-interacting arrestin adapters that are integrated into this canonical signaling process at different levels to enable fine-tuning. Finally, the identification of atypical signaling mechanisms of classical regulators, together with the discovery of novel modulators, added a new and fascinating dimension to the cellular G protein signal transduction. This heterogeneous group of accessory G protein modulators was coined "activators of G protein signaling" (AGS) proteins and plays distinct roles in canonical and non-canonical G protein signaling pathways. AGS proteins contribute to the control of essential cellular functions such as cell development and division, intracellular transport processes, secretion, autophagy or cell movements. As such, they are involved in numerous biological processes that are crucial for diseases, like diabetes mellitus, cancer, and stroke, which represent major health burdens. Although the identification of a large number of non-canonical G protein signaling pathways has broadened the spectrum of this cellular communication system, their underlying mechanisms, functions, and biological effects are poorly understood. In this review, we highlight and discuss atypical G protein-dependent signaling mechanisms with a focus on inhibitory G proteins (Gi) involved in canonical and non-canonical signal transduction, review recent developments and open questions, address the potential of new approaches for targeted pharmacological interventions.
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Affiliation(s)
- Bernd Nürnberg
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, and ICePhA Mouse Clinic, University of Tübingen, Wilhelmstraße 56, D-72074 Tübingen, Germany.
| | - Sandra Beer-Hammer
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, and ICePhA Mouse Clinic, University of Tübingen, Wilhelmstraße 56, D-72074 Tübingen, Germany
| | - Ellen Reisinger
- Gene Therapy for Hearing Impairment Group, Department of Otolaryngology - Head & Neck Surgery, University of Tübingen Medical Center, Elfriede-Aulhorn-Straße 5, D-72076 Tübingen, Germany
| | - Veronika Leiss
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, and ICePhA Mouse Clinic, University of Tübingen, Wilhelmstraße 56, D-72074 Tübingen, Germany
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Beckers P, Doyen PJ, Hermans E. Modulation of Type 5 Metabotropic Glutamate Receptor-Mediated Intracellular Calcium Mobilization by Regulator of G Protein Signaling 4 (RGS4) in Cultured Astrocytes. Cells 2024; 13:291. [PMID: 38391904 PMCID: PMC10886878 DOI: 10.3390/cells13040291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 02/24/2024] Open
Abstract
Acting as GTPase activating proteins promoting the silencing of activated G-proteins, regulators of G protein signaling (RGSs) are generally considered negative modulators of cell signaling. In the CNS, the expression of RGS4 is altered in diverse pathologies and its upregulation was reported in astrocytes exposed to an inflammatory environment. In a model of cultured cortical astrocytes, we herein investigate the influence of RGS4 on intracellular calcium signaling mediated by type 5 metabotropic glutamate receptor (mGluR5), which is known to support the bidirectional communication between neurons and glial cells. RGS4 activity was manipulated by exposure to the inhibitor CCG 63802 or by infecting the cells with lentiviruses designed to achieve the silencing or overexpression of RGS4. The pharmacological inhibition or silencing of RGS4 resulted in a decrease in the percentage of cells responding to the mGluR5 agonist DHPG and in the proportion of cells showing typical calcium oscillations. Conversely, RGS4-lentivirus infection increased the percentage of cells showing calcium oscillations. While the physiological implication of cytosolic calcium oscillations in astrocytes is still under investigation, the fine-tuning of calcium signaling likely determines the coding of diverse biological events. Indirect signaling modulators such as RGS4 inhibitors, used in combination with receptor ligands, could pave the way for new therapeutic approaches for diverse neurological disorders with improved efficacy and selectivity.
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Affiliation(s)
| | | | - Emmanuel Hermans
- Institute of Neuroscience, Université Catholique de Louvain, 1200 Brussels, Belgium; (P.B.); (P.J.D.)
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3
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Schalamun M, Molin EM, Schmoll M. RGS4 impacts carbohydrate and siderophore metabolism in Trichoderma reesei. BMC Genomics 2023; 24:372. [PMID: 37400774 PMCID: PMC10316542 DOI: 10.1186/s12864-023-09467-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 06/20/2023] [Indexed: 07/05/2023] Open
Abstract
BACKGROUND Adaptation to complex, rapidly changing environments is crucial for evolutionary success of fungi. The heterotrimeric G-protein pathway belongs to the most important signaling cascades applied for this task. In Trichoderma reesei, enzyme production, growth and secondary metabolism are among the physiological traits influenced by the G-protein pathway in a light dependent manner. RESULTS Here, we investigated the function of the SNX/H-type regulator of G-protein signaling (RGS) protein RGS4 of T. reesei. We show that RGS4 is involved in regulation of cellulase production, growth, asexual development and oxidative stress response in darkness as well as in osmotic stress response in the presence of sodium chloride, particularly in light. Transcriptome analysis revealed regulation of several ribosomal genes, six genes mutated in RutC30 as well as several genes encoding transcription factors and transporters. Importantly, RGS4 positively regulates the siderophore cluster responsible for fusarinine C biosynthesis in light. The respective deletion mutant shows altered growth on nutrient sources related to siderophore production such as ornithine or proline in a BIOLOG phenotype microarray assay. Additionally, growth on storage carbohydrates as well as several intermediates of the D-galactose and D-arabinose catabolic pathway is decreased, predominantly in light. CONCLUSIONS We conclude that RGS4 mainly operates in light and targets plant cell wall degradation, siderophore production and storage compound metabolism in T. reesei.
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Affiliation(s)
- Miriam Schalamun
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Center for Health & Bioresources, Konrad Lorenz Strasse 24, Tulln, 3430 Austria
| | - Eva Maria Molin
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Center for Health & Bioresources, Konrad Lorenz Strasse 24, Tulln, 3430 Austria
| | - Monika Schmoll
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Center for Health & Bioresources, Konrad Lorenz Strasse 24, Tulln, 3430 Austria
- Division of Terrestrial Ecosystem Research, Centre of Microbiology and Ecosystem Science, University of Vienna, Djerassiplatz 1, Vienna, 1030 Austria
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Zhang Y, Chen R, Dong Y, Zhu J, Su K, Liu J, Xu J. Structural Studies Reveal Unique Non-canonical Regulators of G Protein Signaling Homology (RH) Domains in Sorting Nexins. J Mol Biol 2022; 434:167823. [PMID: 36103920 DOI: 10.1016/j.jmb.2022.167823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/30/2022] [Accepted: 09/06/2022] [Indexed: 11/24/2022]
Abstract
As a subgroup of sorting nexins (SNXs) that contain regulator of G protein signaling homology (RH) domain, SNX-RH proteins, including SNX13, SNX14 and SNX25, were proposed to play bifunctional roles in protein sorting and GPCR signaling regulation. However, mechanistic details of SNX-RH proteins functioning via RH domain remain to be illustrated. Here, we delineate crystal structures of the RH domains of SNX13 and SNX25, revealing a homodimer of SNX13 RH domain mediated by unique extended α4 and α5 helices, and a thiol modulated homodimer of SNX25-RH triggered by a unique cysteine on α6 helix. Further studies showed that RH domains of SNX-RH do not possess binding capacity toward Gα subunits, owing to the lack of critical residues for interaction. Thus, this study identifies a group of novel non-canonical RH domains that can act as a dimerization module in sorting nexins, which provides structural basis for mechanism studies on SNX-RH protein functions.
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Affiliation(s)
- Yulong Zhang
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rui Chen
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Yan Dong
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Jiabin Zhu
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Kai Su
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Jinsong Liu
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.
| | - Jinxin Xu
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.
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Zhao A, Jin H, Fan G, Li Y, Li C, Li Q, Ma X, Zhao T, Sun S, Liu S, Gao Y, Qi S. Inhibition of the expression of rgs-3 alleviates propofol-induced decline in learning and memory in Caenorhabditis elegans. CNS Neurosci Ther 2022; 29:306-316. [PMID: 36284438 PMCID: PMC9804065 DOI: 10.1111/cns.14004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 09/28/2022] [Accepted: 09/30/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Exposure to anesthesia leads to extensive neurodegeneration and long-term cognitive deficits in the developing brain. Caenorhabditis elegans also shows persistent behavioral changes during development after exposure to anesthetics. Clinical and rodent studies have confirmed that altered expression of the regulators of G protein signaling (RGS) in the nervous system is a factor contributing to neurodegenerative and psychological diseases. Evidence from preclinical studies has suggested that RGS controls drug-induced plasticity, including morphine tolerance and addiction. This study aimed to observe the effect of propofol exposure in the neurodevelopmental stage on learning and memory in the L4 stage and to study whether this effect is related to changes in rgs-3 expression. METHODS Caenorhabditis elegans were exposed to propofol at the L1 stage, and learning and memory abilities were observed at the L4 stage. The expression of rgs-3 and the nuclear distribution of EGL-4 were determined to study the relevant mechanisms. Finally, RNA interference was performed on rgs-3-expressing cells after propofol exposure. Then, we observed their learning and memory abilities. RESULTS Propofol time- and dose-dependently impaired the learning capacity. Propofol induced a decline in non-associative and associative long-term memory, rgs-3 upregulation, and a failure of nuclear accumulation of EGL-4/PKG in AWC neurons. Inhibition of rgs-3 could alleviate the propofol-induced changes. CONCLUSION Inhibition of the expression of rgs-3 alleviated propofol-induced learning and memory deficits in Caenorhabditis elegans.
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Affiliation(s)
- Ayang Zhao
- Department of AnesthesiologyThe Fourth Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Hongjiang Jin
- Department of AnesthesiologyThe Fourth Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Guibo Fan
- Department of AnesthesiologyThe Fourth Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Yan Li
- Department of AnesthesiologyThe Fourth Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Chenglong Li
- Department of AnesthesiologyThe Fourth Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Qi Li
- Department of AnesthesiologyThe Fourth Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Xiaofei Ma
- Department of ICUThe Fourth Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Tianyang Zhao
- Department of AnesthesiologyThe Fourth Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Siqi Sun
- Department of AnesthesiologyThe Fourth Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Shuai Liu
- Department of AnesthesiologyThe Fourth Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Yueyue Gao
- Department of AnesthesiologyThe Fourth Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Sihua Qi
- Department of AnesthesiologyThe Fourth Affiliated Hospital of Harbin Medical UniversityHarbinChina
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Akturk A, Day M, Tarchini B. RGS12 polarizes the GPSM2-GNAI complex to organize and elongate stereocilia in sensory hair cells. SCIENCE ADVANCES 2022; 8:eabq2826. [PMID: 36260679 PMCID: PMC9581478 DOI: 10.1126/sciadv.abq2826] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 08/31/2022] [Indexed: 06/10/2023]
Abstract
Inhibitory G proteins (GNAI/Gαi) bind to the scaffold G protein signaling modulator 2 (GPSM2) to form a conserved polarity complex that regulates cytoskeleton organization. GPSM2 keeps GNAI in a guanosine diphosphate (GDP)-bound state, but how GPSM2-GNAI is generated or relates to heterotrimeric G protein signaling remains unclear. We find that RGS12, a GTPase-activating protein (GAP), is required to polarize GPSM2-GNAI at the hair cell apical membrane and to organize mechanosensory stereocilia in rows of graded heights. Accordingly, RGS12 and the guanine nucleotide exchange factor (GEF) DAPLE are asymmetrically co-enriched at the hair cell apical junction, and Rgs12 mouse mutants are deaf. GPSM2 and RGS12 share GoLoco motifs that stabilize GNAI(GDP), and GPSM2 outcompetes RGS12 to bind GNAI. Our results suggest that polarized GEF/GAP junctional activity might dissociate heterotrimeric G proteins, generating free GNAI(GDP) for GPSM2 at the adjacent apical membrane. GPSM2-GNAI(GDP), in turn, imparts asymmetry to the forming stereocilia to enable sensory function in hair cells.
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Affiliation(s)
- Anil Akturk
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Matthew Day
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Basile Tarchini
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
- School of Medicine, Tufts University, Boston, MA 02111, USA
- Graduate School of Biomedical Science and Engineering (GSBSE), University of Maine, Orono, ME 04469, USA
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Chan KYY, Chung PY, Zhang C, Poon ENY, Leung AWK, Leung KT. R4 RGS proteins as fine tuners of immature and mature hematopoietic cell trafficking. J Leukoc Biol 2022; 112:785-797. [PMID: 35694792 DOI: 10.1002/jlb.1mr0422-475r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 04/28/2022] [Indexed: 11/08/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) are the largest and most diverse group of membrane receptors. They are involved in almost every physiologic process and consequently have a pivotal role in an extensive number of pathologies, including genetic, neurologic, and immune system disorders. Indeed, the vast array of GPCRs mechanisms have led to the development of a tremendous number of drug therapies and already account for about a third of marketed drugs. These receptors mediate their downstream signals primarily via G proteins. The regulators of G-protein signaling (RGS) proteins are now in the spotlight as the critical modulatory factors of active GTP-bound Gα subunits of heterotrimeric G proteins to fine-tune the biologic responses driven by the GPCRs. Also, they possess noncanonical functions by multiple mechanisms, such as protein-protein interactions. Essential roles and impacts of these RGS proteins have been revealed in physiology, including hematopoiesis and immunity, and pathologies, including asthma, cancers, and neurologic disorders. This review focuses on the largest subfamily of R4 RGS proteins and provides a brief overview of their structures and G-proteins selectivity. With particular interest, we explore and highlight, their expression in the hematopoietic system and the regulation in the engraftment of hematopoietic stem/progenitor cells (HSPCs). Distinct expression patterns of R4 RGS proteins in the hematopoietic system and their pivotal roles in stem cell trafficking pave the way for realizing new strategies for enhancing the clinical performance of hematopoietic stem cell transplantation. Finally, we discuss the exciting future trends in drug development by targeting RGS activity and expression with small molecules inhibitors and miRNA approaches.
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Affiliation(s)
- Kathy Yuen Yee Chan
- Department of Paediatrics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Po Yee Chung
- Department of Paediatrics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Chi Zhang
- Department of Paediatrics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Ellen Ngar Yun Poon
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Alex Wing Kwan Leung
- Department of Paediatrics, The Chinese University of Hong Kong, Shatin, Hong Kong, China.,Department of Paediatrics & Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong SAR, China
| | - Kam Tong Leung
- Department of Paediatrics, The Chinese University of Hong Kong, Shatin, Hong Kong, China.,Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Shatin, Hong Kong, China
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Yuan G, Yang S. Effect of Regulator of G Protein Signaling Proteins on Bone. Front Endocrinol (Lausanne) 2022; 13:842421. [PMID: 35573989 PMCID: PMC9098968 DOI: 10.3389/fendo.2022.842421] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 04/01/2022] [Indexed: 01/08/2023] Open
Abstract
Regulator of G protein signaling (RGS) proteins are critical negative molecules of G protein-coupled receptor (GPCR) signaling, which mediates a variety of biological processes in bone homeostasis and diseases. The RGS proteins are divided into nine subfamilies with a conserved RGS domain which plays an important role in regulating the GTPase activity. Mutations of some RGS proteins change bone development and/or metabolism, causing osteopathy. In this review, we summarize the recent findings of RGS proteins in regulating osteoblasts, chondrocytes, and osteoclasts. We also highlight the impacts of RGS on bone development, bone remodeling, and bone-related diseases. Those studies demonstrate that RGS proteins might be potential drug targets for bone diseases.
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Affiliation(s)
- Gongsheng Yuan
- Department of Basic and Translational Sciences, Penn Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Shuying Yang
- Department of Basic and Translational Sciences, Penn Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
- The Penn Center for Musculoskeletal Disorders, Penn Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Center for Innovation and Precision Dentistry, Penn Dental Medicine, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, United States
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Ren J, Wei W, Tan L, Yang Q, Lu Q, Ding H, Yue Y, Tian Y, Hao L, Wang M, Li J. Inhibition of regulator of G protein signaling 10, aggravates rheumatoid arthritis progression by promoting NF-κB signaling pathway. Mol Immunol 2021; 134:236-246. [PMID: 33836352 DOI: 10.1016/j.molimm.2021.03.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 02/10/2021] [Accepted: 03/18/2021] [Indexed: 02/05/2023]
Abstract
Rheumatoid arthritis (RA) is the most common inflammatory arthropathy, with evidence pointing to an immune-mediated etiology that propagates chronic inflammation. Although targeted immune therapeutics and aggressive treatment strategies have substantially improved, a complete understanding of the associated pathological mechanisms of the disease remains elusive. This study aimed at investigating whether regulator of G protein signaling 10 (RGS10) could affect rheumatoid arthritis (RA) pathology by regulating the immune response. A DBA/J1 mouse model of RA was established and evaluated for disease severity. RGS10 expression was inhibited by adeno-associated virus in vivo. Moreover, small interfering RNA was used to downregulate RGS10 expression in raw 264.7 cells in vitro. Results showed that RGS10 inhibition augmented RA severity, and attenuated the increase in expression of inflammatory factors. Furthermore, activated NF-κB signaling pathways were detected following RGS10 inhibition. These results revealed that RGS10 inhibition directly aggravated the RA pathological process by activating the NF-κB signaling pathway. Therefore, RGS10 is a promising novel therapeutic target for RA treatment with a potential clinical impact.
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Affiliation(s)
- Jie Ren
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Sichuan, People's Republic of China
| | - Wei Wei
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Sichuan, People's Republic of China
| | - Liangyu Tan
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Sichuan, People's Republic of China
| | - Qin Yang
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Sichuan, People's Republic of China
| | - Qiuyu Lu
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Sichuan, People's Republic of China
| | - Handong Ding
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Sichuan, People's Republic of China
| | - Yuan Yue
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Sichuan, People's Republic of China
| | - Ye Tian
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Sichuan, People's Republic of China
| | - Liang Hao
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Sichuan, People's Republic of China
| | - Min Wang
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Sichuan, People's Republic of China.
| | - Jinle Li
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Sichuan, People's Republic of China.
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10
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Squires KE, Gerber KJ, Tillman MC, Lustberg DJ, Montañez-Miranda C, Zhao M, Ramineni S, Scharer CD, Saha RN, Shu FJ, Schroeder JP, Ortlund EA, Weinshenker D, Dudek SM, Hepler JR. Human genetic variants disrupt RGS14 nuclear shuttling and regulation of LTP in hippocampal neurons. J Biol Chem 2021; 296:100024. [PMID: 33410399 PMCID: PMC7949046 DOI: 10.1074/jbc.ra120.016009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/26/2020] [Accepted: 11/04/2020] [Indexed: 12/13/2022] Open
Abstract
The human genome contains vast genetic diversity as naturally occurring coding variants, yet the impact of these variants on protein function and physiology is poorly understood. RGS14 is a multifunctional signaling protein that suppresses synaptic plasticity in dendritic spines of hippocampal neurons. RGS14 also is a nucleocytoplasmic shuttling protein, suggesting that balanced nuclear import/export and dendritic spine localization are essential for RGS14 functions. We identified genetic variants L505R (LR) and R507Q (RQ) located within the nuclear export sequence (NES) of human RGS14. Here we report that RGS14 encoding LR or RQ profoundly impacts protein functions in hippocampal neurons. RGS14 membrane localization is regulated by binding Gαi-GDP, whereas RGS14 nuclear export is regulated by Exportin 1 (XPO1). Remarkably, LR and RQ variants disrupt RGS14 binding to Gαi1-GDP and XPO1, nucleocytoplasmic equilibrium, and capacity to inhibit long-term potentiation (LTP). Variant LR accumulates irreversibly in the nucleus, preventing RGS14 binding to Gαi1, localization to dendritic spines, and inhibitory actions on LTP induction, while variant RQ exhibits a mixed phenotype. When introduced into mice by CRISPR/Cas9, RGS14-LR protein expression was detected predominantly in the nuclei of neurons within hippocampus, central amygdala, piriform cortex, and striatum, brain regions associated with learning and synaptic plasticity. Whereas mice completely lacking RGS14 exhibit enhanced spatial learning, mice carrying variant LR exhibit normal spatial learning, suggesting that RGS14 may have distinct functions in the nucleus independent from those in dendrites and spines. These findings show that naturally occurring genetic variants can profoundly alter normal protein function, impacting physiology in unexpected ways.
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Affiliation(s)
- Katherine E Squires
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta Georgia, USA
| | - Kyle J Gerber
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta Georgia, USA
| | | | - Daniel J Lustberg
- Department of Human Genetics, Emory University, Atlanta Georgia, USA
| | | | - Meilan Zhao
- National Institute of Environmental Health Sciences, Research Triangle Park, Raleigh North Carolina, USA
| | - Suneela Ramineni
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta Georgia, USA
| | | | - Ramendra N Saha
- Department of Molecular & Cell Biology, University of California-Merced, Merced California, USA
| | - Feng-Jue Shu
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta Georgia, USA
| | - Jason P Schroeder
- Department of Human Genetics, Emory University, Atlanta Georgia, USA
| | - Eric A Ortlund
- Department of Biochemistry, Emory University, Atlanta Georgia, USA
| | - David Weinshenker
- Department of Human Genetics, Emory University, Atlanta Georgia, USA
| | - Serena M Dudek
- National Institute of Environmental Health Sciences, Research Triangle Park, Raleigh North Carolina, USA
| | - John R Hepler
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta Georgia, USA.
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11
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Almutairi F, Lee JK, Rada B. Regulator of G protein signaling 10: Structure, expression and functions in cellular physiology and diseases. Cell Signal 2020; 75:109765. [PMID: 32882407 PMCID: PMC7579743 DOI: 10.1016/j.cellsig.2020.109765] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 01/22/2023]
Abstract
Regulator of G protein signaling 10 (RGS10) belongs to the superfamily of RGS proteins, defined by the presence of a conserved RGS domain that canonically binds and deactivates heterotrimeric G-proteins. RGS proteins act as GTPase activating proteins (GAPs), which accelerate GTP hydrolysis on the G-protein α subunits and result in termination of signaling pathways downstream of G protein-coupled receptors. RGS10 is the smallest protein of the D/R12 subfamily and selectively interacts with Gαi proteins. It is widely expressed in many cells and tissues, with the highest expression found in the brain and immune cells. RGS10 expression is transcriptionally regulated via epigenetic mechanisms. Although RGS10 lacks multiple of the defined regulatory domains found in other RGS proteins, RGS10 contains post-translational modification sites regulating its expression, localization, and function. Additionally, RGS10 is a critical protein in the regulation of physiological processes in multiple cells, where dysregulation of its expression has been implicated in various diseases including Parkinson's disease, multiple sclerosis, osteopetrosis, chemoresistant ovarian cancer and cardiac hypertrophy. This review summarizes RGS10 features and its regulatory mechanisms, and discusses the known functions of RGS10 in cellular physiology and pathogenesis of several diseases.
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Affiliation(s)
- Faris Almutairi
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA, USA; Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Jae-Kyung Lee
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Balázs Rada
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
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12
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Regulators of G protein signalling as pharmacological targets for the treatment of neuropathic pain. Pharmacol Res 2020; 160:105148. [PMID: 32858121 DOI: 10.1016/j.phrs.2020.105148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 07/24/2020] [Accepted: 08/10/2020] [Indexed: 12/30/2022]
Abstract
Neuropathic pain, a specific type of chronic pain resulting from persistent nervous tissue lesions, is a debilitating condition that affects about 7% of the population. This condition remains particularly difficult to treat because of the poor understanding of its underlying mechanisms. Drugs currently used to alleviate this chronic pain syndrome are of limited benefit due to their lack of efficacy and the elevated risk of side effects, especially after a prolonged period of treatment. Although drugs targeting G protein-coupled receptors (GPCR) also have several limitations, such as progressive loss of efficacy due to receptor desensitization or unavoidable side effects due to wide receptor distribution, the identification of several molecular partners that contribute to the fine-tuning of receptor activity has raised new opportunities for the development of alternative therapeutic approaches. Regulators of G protein signalling (RGS) act intracellularly by influencing the coupling process and activity of G proteins, and are amongst the best-characterized physiological modulators of GPCR. Changes in RGS expression have been documented in a range of models of neuropathic pain, or after prolonged treatment with diverse analgesics, and could participate in altered pain processing as well as impaired physiological or pharmacological control of nociceptive signals. The present review summarizes the experimental data that implicates RGS in the development of pain with focus on the pathological mechanisms of neuropathic pain, including the impact of neuropathic lesions on RGS expression and, reciprocally, the influence of modifying RGS on GPCRs involved in the modulation of nociception as well as on the outcome of pain. In this context, we address the question of the relevance of RGS as promising targets in the treatment of neuropathic pain.
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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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Abstract
Glucose-induced (physiological) insulin secretion from the islet β-cell involves interplay between cationic (i.e., changes in intracellular calcium) and metabolic (i.e., generation of hydrophobic and hydrophilic second messengers) events. A large body of evidence affirms support for novel regulation, by G proteins, of specific intracellular signaling events, including actin cytoskeletal remodeling, transport of insulin-containing granules to the plasma membrane for fusion, and secretion of insulin into the circulation. This article highlights the following aspects of GPCR-G protein biology of the islet. First, it overviews our current understanding of the identity of a wide variety of G protein regulators and their modulatory roles in GPCR-G protein-effector coupling, which is requisite for optimal β-cell function under physiological conditions. Second, it describes evidence in support of novel, noncanonical, GPCR-independent mechanisms of activation of G proteins in the islet. Third, it highlights the evidence indicating that abnormalities in G protein function lead to islet β-cell dysregulation and demise under the duress of metabolic stress and diabetes. Fourth, it summarizes observations of potential beneficial effects of GPCR agonists in preventing/halting metabolic defects in the islet β-cell under various pathological conditions (e.g., metabolic stress and inflammation). Lastly, it identifies knowledge gaps and potential avenues for future research in this evolving field of translational islet biology. Published 2020. Compr Physiol 10:453-490, 2020.
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Affiliation(s)
- Anjaneyulu Kowluru
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Center for Translational Research in Diabetes, Biomedical Research Service, John D. Dingell VA Medical Center, Wayne State University, Detroit, Michigan, USA
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15
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Functional screenings reveal different requirements for host microRNAs in Salmonella and Shigella infection. Nat Microbiol 2019; 5:192-205. [DOI: 10.1038/s41564-019-0614-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 10/18/2019] [Indexed: 12/15/2022]
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Karoussiotis C, Marti-Solano M, Stepniewski TM, Symeonof A, Selent J, Georgoussi Z. A highly conserved δ-opioid receptor region determines RGS4 interaction. FEBS J 2019; 287:736-748. [PMID: 31386272 DOI: 10.1111/febs.15033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 05/21/2019] [Accepted: 08/02/2019] [Indexed: 12/28/2022]
Abstract
The δ-opioid receptor (δ-OR) couples to Gi/Go proteins to modulate a variety of responses in the nervous system. Τhe regulator of G protein signalling 4 (RGS4) was previously shown to directly interact within the C-terminal region of δ-OR using its N-terminal domain to negatively modulate opioid receptor signalling. Herein, using molecular dynamics simulations and in vitro pull-down experiments we delimit this interaction to 12 helix 8 residues of δ-ΟR and to the first 17 N-terminal residues (NT) of RGS4. Monitoring the complex arrangement and stabilization between RGS4 and δ-OR by molecular dynamics simulations combined with mutagenesis studies, we defined that two critical interactions are formed: one between Phe329 of helix8 of δ-ΟR and Pro9 of the NT of RGS4 and the other a salt bridge between Glu323 of δ-ΟR and Lys17 of RGS4. Our observations allow drafting for the first time a structural model of a ternary complex including the δ-opioid receptor, a G protein and a RGS protein. Furthermore, the high degree of conservation among opioid receptors of the RGS4-binding region, points to a conserved interaction mode between opioid receptors and this important regulatory protein.
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Affiliation(s)
- Christos Karoussiotis
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Maria Marti-Solano
- Research Programme on Biomedical Informatics (GRIB) - Department of Experimental and Health Sciences, Hospital del Mar Medical Research Institute, Pompeu Fabra University, Barcelona, Spain
| | - Tomasz Maciej Stepniewski
- Research Programme on Biomedical Informatics (GRIB) - Department of Experimental and Health Sciences, Hospital del Mar Medical Research Institute, Pompeu Fabra University, Barcelona, Spain.,Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Poland
| | - Alexandra Symeonof
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Jana Selent
- Research Programme on Biomedical Informatics (GRIB) - Department of Experimental and Health Sciences, Hospital del Mar Medical Research Institute, Pompeu Fabra University, Barcelona, Spain
| | - 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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Schroer AB, Mohamed JS, Willard MD, Setola V, Oestreich E, Siderovski DP. A role for Regulator of G protein Signaling-12 (RGS12) in the balance between myoblast proliferation and differentiation. PLoS One 2019; 14:e0216167. [PMID: 31408461 PMCID: PMC6691989 DOI: 10.1371/journal.pone.0216167] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 04/15/2019] [Indexed: 12/28/2022] Open
Abstract
Regulators of G Protein Signaling (RGS proteins) inhibit G protein-coupled receptor (GPCR) signaling by accelerating the GTP hydrolysis rate of activated Gα subunits. Some RGS proteins exert additional signal modulatory functions, and RGS12 is one such protein, with five additional, functional domains: a PDZ domain, a phosphotyrosine-binding domain, two Ras-binding domains, and a Gα·GDP-binding GoLoco motif. RGS12 expression is temporospatially regulated in developing mouse embryos, with notable expression in somites and developing skeletal muscle. We therefore examined whether RGS12 is involved in the skeletal muscle myogenic program. In the adult mouse, RGS12 is expressed in the tibialis anterior (TA) muscle, and its expression is increased early after cardiotoxin-induced injury, suggesting a role in muscle regeneration. Consistent with a potential role in coordinating myogenic signals, RGS12 is also expressed in primary myoblasts; as these cells undergo differentiation and fusion into myotubes, RGS12 protein abundance is reduced. Myoblasts isolated from mice lacking Rgs12 expression have an impaired ability to differentiate into myotubes ex vivo, suggesting that RGS12 may play a role as a modulator/switch for differentiation. We also assessed the muscle regenerative capacity of mice conditionally deficient in skeletal muscle Rgs12 expression (via Pax7-driven Cre recombinase expression), following cardiotoxin-induced damage to the TA muscle. Eight days post-damage, mice lacking RGS12 in skeletal muscle had attenuated repair of muscle fibers. However, when mice lacking skeletal muscle expression of Rgs12 were cross-bred with mdx mice (a model of human Duchenne muscular dystrophy), no increase in muscle degeneration was observed over time. These data support the hypothesis that RGS12 plays a role in coordinating signals during the myogenic program in select circumstances, but loss of the protein may be compensated for within model syndromes of prolonged bouts of muscle damage and repair.
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Affiliation(s)
- Adam B. Schroer
- Department of Physiology & Pharmacology, WVU School of Medicine, West Virginia University, Morgantown, WV, United States of America
| | - Junaith S. Mohamed
- Division of Exercise Physiology, West Virginia University, Morgantown, WV, United States of America
| | - Melinda D. Willard
- Department of Pharmacology, The University of North Carolina, Chapel Hill, NC, United States of America
| | - Vincent Setola
- Department of Neuroscience, West Virginia University, Morgantown, WV, United States of America
| | - Emily Oestreich
- Department of Pharmacology, The University of North Carolina, Chapel Hill, NC, United States of America
- * E-mail: (EO); (DPS)
| | - David P. Siderovski
- Department of Physiology & Pharmacology, WVU School of Medicine, West Virginia University, Morgantown, WV, United States of America
- * E-mail: (EO); (DPS)
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18
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Alqinyah M, Almutairi F, Wendimu MY, Hooks SB. RGS10 Regulates the Expression of Cyclooxygenase-2 and Tumor Necrosis Factor Alpha through a G Protein-Independent Mechanism. Mol Pharmacol 2018; 94:1103-1113. [PMID: 30049816 DOI: 10.1124/mol.118.111674] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 07/11/2018] [Indexed: 01/18/2023] Open
Abstract
The small regulator of G protein signaling protein RGS10 is a key regulator of neuroinflammation and ovarian cancer cell survival; however, the mechanism for RGS10 function in these cells is unknown and has not been linked to specific G protein pathways. RGS10 is highly enriched in microglia, and loss of RGS10 expression in microglia amplifies production of the inflammatory cytokine tumor necrosis factor α (TNFα) and enhances microglia-induced neurotoxicity. RGS10 also regulates cell survival and chemoresistance of ovarian cancer cells. Cyclooxygenase-2 (COX-2)-mediated production of prostaglandins such as prostaglandin E2 (PGE2) is a key factor in both neuroinflammation and cancer chemoresistance, suggesting it may be involved in RGS10 function in both cell types, but a connection between RGS10 and COX-2 has not been reported. To address these questions, we completed a mechanistic study to characterize RGS10 regulation of TNFα and COX-2 and to determine if these effects are mediated through a G protein-dependent mechanism. Our data show for the first time that loss of RGS10 expression significantly elevates stimulated COX-2 expression and PGE2 production in microglia. Furthermore, the elevated inflammatory signaling resulting from RGS10 loss was not affected by Gαi inhibition, and a RGS10 mutant that is unable to bind activated G proteins was as effective as wild type in inhibiting TNFα expression. Similarly, suppression of RGS10 in ovarian cancer cells enhanced TNFα and COX-2 expression, and this effect did not require Gi activity. Together, our data strongly indicate that RGS10 inhibits COX-2 expression by a G protein-independent mechanism to regulate inflammatory signaling in microglia and ovarian cancer cells.
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Affiliation(s)
- Mohammed Alqinyah
- Hooks Laboratory, Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia
| | - Faris Almutairi
- Hooks Laboratory, Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia
| | - Menbere Y Wendimu
- Hooks Laboratory, Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia
| | - Shelley B Hooks
- Hooks Laboratory, Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia
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19
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Rot A, Massberg S, Khandoga AG, von Andrian UH. Chemokines and Hematopoietic Cell Trafficking. Hematology 2018. [DOI: 10.1016/b978-0-323-35762-3.00013-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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20
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Alqinyah M, Hooks SB. Regulating the regulators: Epigenetic, transcriptional, and post-translational regulation of RGS proteins. Cell Signal 2017; 42:77-87. [PMID: 29042285 DOI: 10.1016/j.cellsig.2017.10.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/06/2017] [Accepted: 10/13/2017] [Indexed: 12/11/2022]
Abstract
Regulators of G protein signaling (RGS) are a family of proteins classically known to accelerate the intrinsic GTPase activity of G proteins, which results in accelerated inactivation of heterotrimeric G proteins and inhibition of G protein coupled receptor signaling. RGS proteins play major roles in essential cellular processes, and dysregulation of RGS protein expression is implicated in multiple diseases, including cancer, cardiovascular and neurodegenerative diseases. The expression of RGS proteins is highly dynamic and is regulated by epigenetic, transcriptional and post-translational mechanisms. This review summarizes studies that report dysregulation of RGS protein expression in disease states, and presents examples of drugs that regulate RGS protein expression. Additionally, this review discusses, in detail, the transcriptional and post-transcriptional mechanisms regulating RGS protein expression, and further assesses the therapeutic potential of targeting these mechanisms. Understanding the molecular mechanisms controlling the expression of RGS proteins is essential for the development of therapeutics that indirectly modulate G protein signaling by regulating expression of RGS proteins.
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Affiliation(s)
- Mohammed Alqinyah
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA, USA
| | - Shelley B Hooks
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA, USA.
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21
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Kanai SM, Edwards AJ, Rurik JG, Osei-Owusu P, Blumer KJ. Proteolytic degradation of regulator of G protein signaling 2 facilitates temporal regulation of G q/11 signaling and vascular contraction. J Biol Chem 2017; 292:19266-19278. [PMID: 28974581 DOI: 10.1074/jbc.m117.797134] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/18/2017] [Indexed: 12/18/2022] Open
Abstract
Regulator of G protein signaling 2 (RGS2) controls signaling by receptors coupled to the Gq/11 class heterotrimeric G proteins. RGS2 deficiency causes several phenotypes in mice and occurs in several diseases, including hypertension in which a proteolytically unstable RGS2 mutant has been reported. However, the mechanisms and functions of RGS2 proteolysis remain poorly understood. Here we addressed these questions by identifying degradation signals in RGS2, and studying dynamic regulation of Gq/11-evoked Ca2+ signaling and vascular contraction. We identified a novel bipartite degradation signal in the N-terminal domain of RGS2. Mutations disrupting this signal blunted proteolytic degradation downstream of E3 ubiquitin ligase binding to RGS2. Analysis of RGS2 mutants proteolyzed at various rates and the effects of proteasome inhibition indicated that proteolytic degradation controls agonist efficacy by setting RGS2 protein expression levels, and affecting the rate at which cells regain agonist responsiveness as synthesis of RGS2 stops. Analyzing contraction of mesenteric resistance arteries supported the biological relevance of this mechanism. Because RGS2 mRNA expression often is strikingly and transiently up-regulated and then down-regulated upon cell stimulation, our findings indicate that proteolytic degradation tightly couples RGS2 transcription, protein levels, and function. Together these mechanisms provide tight temporal control of Gq/11-coupled receptor signaling in the cardiovascular, immune, and nervous systems.
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Affiliation(s)
- Stanley M Kanai
- From the Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110 and
| | - Alethia J Edwards
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Joel G Rurik
- From the Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110 and
| | - Patrick Osei-Owusu
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Kendall J Blumer
- From the Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110 and
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22
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Moretti M, Wang L, Grognet P, Lanver D, Link H, Kahmann R. Three regulators of G protein signaling differentially affect mating, morphology and virulence in the smut fungusUstilago maydis. Mol Microbiol 2017; 105:901-921. [DOI: 10.1111/mmi.13745] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2017] [Indexed: 12/30/2022]
Affiliation(s)
- Marino Moretti
- Department of Organismic Interactions; Max Planck Institute for Terrestrial Microbiology; Karl-von-Frisch-Strasse 10, Marburg D-35043 Germany
| | - Lei Wang
- Department of Organismic Interactions; Max Planck Institute for Terrestrial Microbiology; Karl-von-Frisch-Strasse 10, Marburg D-35043 Germany
| | - Pierre Grognet
- Department of Organismic Interactions; Max Planck Institute for Terrestrial Microbiology; Karl-von-Frisch-Strasse 10, Marburg D-35043 Germany
| | - Daniel Lanver
- Department of Organismic Interactions; Max Planck Institute for Terrestrial Microbiology; Karl-von-Frisch-Strasse 10, Marburg D-35043 Germany
| | - Hannes Link
- Dynamic Control of Metabolic Networks; Max Planck Institute for Terrestrial Microbiology; Karl-von-Frisch-Strasse 16, Marburg D-35043 Germany
| | - Regine Kahmann
- Department of Organismic Interactions; Max Planck Institute for Terrestrial Microbiology; Karl-von-Frisch-Strasse 10, Marburg D-35043 Germany
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Wu M, Kang X, Wang Q, Zhou C, Mohan C, Peng A. Regulator of G protein signaling-1 modulates paraquat-induced oxidative stress and longevity via the insulin like signaling pathway in Caenorhabditis elegans. Toxicol Lett 2017; 273:97-105. [PMID: 28366735 DOI: 10.1016/j.toxlet.2017.03.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 03/25/2017] [Accepted: 03/29/2017] [Indexed: 12/23/2022]
Abstract
Insulin or insulin like signaling (IIS) pathway is a crucial pathway in Caenorhabditis elegans associated with mediating longevity, and stress resistance. Regulators of G protein signaling (RGS) also modulate stress resistance and longevity in multiple in vitro and in vivo models. However, the mechanism underlying RGS mediating stress resistance and longevity remains largely unclear. Here we report that rgs-1, an important member of rgs family, is a novel modulator of IIS pathway in C. elegans. We found that the loss of rgs-1 dramatically promoted paraquat resistance in C. elegans. Further genetic analyses demonstrated that rgs-1 acted downstream of daf-2 and upstream of age-1, pdk-1, daf-16. Instead of affecting those IIS-associated genes in transcriptional process, loss of rgs-1 promoted DAF-16's nucleus translocation and subset genes' expression in paraquat-induced oxidative status. By this way, rgs-1 mutant worms exhibited lower ROS damage and longer survival time than wild type worms when both exposed to paraquat. Other than paraquat exposure, rgs-1 mutant also promoted lifespan and cadmium resistance relying on daf-16. As rgs is evolutionarily conserved, our findings open a new insight into rgs family and its role in paraquat-induced oxidative stress and longevity in C. elegans or even mammals.
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Affiliation(s)
- Mingyu Wu
- Center for Nephrology and Metabolomics, Division of Nephrology and Rheumatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Xin Kang
- Center for Nephrology and Metabolomics, Division of Nephrology and Rheumatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Qiang Wang
- Center for Nephrology and Metabolomics, Division of Nephrology and Rheumatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Chunyu Zhou
- Center for Nephrology and Metabolomics, Division of Nephrology and Rheumatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Chandra Mohan
- Center for Nephrology and Metabolomics, Division of Nephrology and Rheumatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China; Department of Biomedical Engineering, University of Houston, Houston, TX 77204, USA.
| | - Ai Peng
- Center for Nephrology and Metabolomics, Division of Nephrology and Rheumatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China.
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Pallaki P, Georganta EM, Serafimidis I, Papakonstantinou MP, Papanikolaou V, Koutloglou S, Papadimitriou E, Agalou A, Tserga A, Simeonof A, Thomaidou D, Gaitanou M, Georgoussi Z. A novel regulatory role of RGS4 in STAT5B activation, neurite outgrowth and neuronal differentiation. Neuropharmacology 2017; 117:408-421. [PMID: 28219718 DOI: 10.1016/j.neuropharm.2017.02.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 02/01/2017] [Accepted: 02/14/2017] [Indexed: 12/26/2022]
Abstract
The Regulator of G protein Signalling 4 (RGS4) is a multitask protein that interacts with and negatively modulates opioid receptor signalling. Previously, we showed that the δ-opioid receptor (δ-OR) forms a multiprotein signalling complex consisting of Gi/Go proteins and the Signal Transducer and Activator of Transcription 5B (STAT5B) that leads to neuronal differentiation and neurite outgrowth upon δ-ΟR activation. Here, we investigated whether RGS4 could participate in signalling pathways to regulate neurotropic events. We demonstrate that RGS4 interacts directly with STAT5B independently of δ-ΟR presence both in vitro and in living cells. This interaction involves the N-terminal portion of RGS4 and the DNA-binding SH3 domain of STAT5B. Expression of RGS4 in HEK293 cells expressing δ-OR and/or erythropoietin receptor results in inhibition of [D-Ser2, Leu5, Thr6]-enkephalin (DSLET)-and erythropoietin-dependent STAT5B phosphorylation and subsequent transcriptional activation. DSLET-dependent neurite outgrowth of neuroblastoma cells is also blocked by RGS4 expression, whereas primary cortical cultures of RGS4 knockout mice (RGS4-/-) exhibit enhanced neuronal sprouting after δ-OR activation. Additional studies in adult brain extracts from RGS4-/- mice revealed increased levels of p-STAT5B. Finally, neuronal progenitor cultures from RGS4-/- mice exhibit enhanced proliferation with concomitant increases in the mRNA levels of the anti-apoptotic STAT5B target genes bcl2 and bcl-xl. These observations suggest that RGS4 is implicated in opioid dependent neuronal differentiation and neurite outgrowth via a "non-canonical" signaling pathway regulating STAT5B-directed responses.
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Affiliation(s)
- Paschalina Pallaki
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research «Demokritos», 15310 Athens, Greece
| | - Eirini-Maria Georganta
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research «Demokritos», 15310 Athens, Greece
| | - Ioannis Serafimidis
- Laboratory of Developmental Biology, Biomedical Research Foundation of the Academy of Athens, 11527 Athens, Greece
| | - Maria-Pagona Papakonstantinou
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research «Demokritos», 15310 Athens, Greece
| | - Vassilis Papanikolaou
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research «Demokritos», 15310 Athens, Greece
| | - Sofia Koutloglou
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research «Demokritos», 15310 Athens, Greece
| | - Elsa Papadimitriou
- Laboratory of Cellular and Molecular Neurobiology, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Adamantia Agalou
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research «Demokritos», 15310 Athens, Greece
| | - Aggeliki Tserga
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research «Demokritos», 15310 Athens, Greece
| | - Alexandra Simeonof
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research «Demokritos», 15310 Athens, Greece
| | - Dimitra Thomaidou
- Laboratory of Cellular and Molecular Neurobiology, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Maria Gaitanou
- Laboratory of Cellular and Molecular Neurobiology, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Zafiroula Georgoussi
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research «Demokritos», 15310 Athens, Greece.
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Sjögren B. The evolution of regulators of G protein signalling proteins as drug targets - 20 years in the making: IUPHAR Review 21. Br J Pharmacol 2017; 174:427-437. [PMID: 28098342 DOI: 10.1111/bph.13716] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 12/11/2016] [Accepted: 01/08/2017] [Indexed: 12/11/2022] Open
Abstract
Regulators of G protein signalling (RGS) proteins are celebrating the 20th anniversary of their discovery. The unveiling of this new family of negative regulators of G protein signalling in the mid-1990s solved a persistent conundrum in the G protein signalling field, in which the rate of deactivation of signalling cascades in vivo could not be replicated in exogenous systems. Since then, there has been tremendous advancement in the knowledge of RGS protein structure, function, regulation and their role as novel drug targets. RGS proteins play an important modulatory role through their GTPase-activating protein (GAP) activity at active, GTP-bound Gα subunits of heterotrimeric G proteins. They also possess many non-canonical functions not related to G protein signalling. Here, an update on the status of RGS proteins as drug targets is provided, highlighting advances that have led to the inclusion of RGS proteins in the IUPHAR/BPS Guide to PHARMACOLOGY database of drug targets.
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Affiliation(s)
- B Sjögren
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
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Druey KM. Emerging Roles of Regulators of G Protein Signaling (RGS) Proteins in the Immune System. Adv Immunol 2017; 136:315-351. [PMID: 28950950 DOI: 10.1016/bs.ai.2017.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Kirk M Druey
- Molecular Signal Transduction Section, Laboratory of Allergic Diseases, NIAID/NIH, Bethesda, MD, United States.
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Jie L, Owens EA, Plante LA, Fang Z, Rensing DT, Moeller KD, Osei-Owusu P. RGS2 squelches vascular Gi/o and Gq signaling to modulate myogenic tone and promote uterine blood flow. Physiol Rep 2016; 4:4/2/e12692. [PMID: 26811058 PMCID: PMC4760385 DOI: 10.14814/phy2.12692] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Uterine artery blood flow (UABF) is critical to maintaining uterine perfusion in nonpregnant states and for uteroplacental delivery of nutrients and oxygen to the fetus during pregnancy. Impaired UABF is implicated in infertility and several pregnancy complications including fetal growth restriction, small for gestational age, and preeclampsia. The etiology of abnormal UABF is not known. Here, we determined whether deficiency or loss of RGS2, a GTPase-activating protein for Gq/11 and Gi/o class G proteins, affects UABF in nonpregnant mice. We used Doppler ultrasonography to assess UABF in wild type (WT), Rgs2 heterozygous (Rgs2+/-), and homozygous knockout (Rgs2-/-) mice. Video microscopy was used for ex vivo examination of uterine artery myogenic tone and fura-2 imaging for in vitro assessment of internal stores Ca(2+) release. We found that baseline UABF velocity was markedly decreased while impedance measured as resistive index (WT = 0.58 ± 0.04 vs. Rgs2-/- = 0.71 ± 0.03, P < 0.01) and pulsatile index (WT = 0.90 ± 0.06 vs. Rgs2-/- = 1.25 ± 0.11, P < 0.01) was increased in Rgs2-/- mice. Uterine artery tone was augmented in Rgs2+/- and Rgs2-/- mice, which was normalized to WT levels following Gi/o and Gq inactivation. Conversely, blockade of ryanodine receptors increased WT myogenic tone to RGS2 mutant levels. The data together indicate that RGS2 deficiency decreases UABF by increasing myogenic tone at least partly through prolonged G protein activation. Mutations that decrease vascular RGS2 expression may be a predisposition to decreased uterine blood flow. Targeting G protein signaling therefore might improve uterine and uteroplacental underperfusion disorders.
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Affiliation(s)
- Li Jie
- Department of Pharmacology & Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania Nanjing University of Traditional Chinese Medicine, Nanjing, Jiangsu, China
| | - Elizabeth A Owens
- Department of Pharmacology & Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Lauren A Plante
- Department of Obstetrics & Gynecology, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Zhuyuan Fang
- Jiangsu Hospital of Traditional Chinese Medicine, Nanjing, Jiangsu, China
| | - Derek T Rensing
- Department of Chemistry, Washington University, St. Louis, Missouri
| | - Kevin D Moeller
- Department of Chemistry, Washington University, St. Louis, Missouri
| | - Patrick Osei-Owusu
- Department of Pharmacology & Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania
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Vivot K, Moullé VS, Zarrouki B, Tremblay C, Mancini AD, Maachi H, Ghislain J, Poitout V. The regulator of G-protein signaling RGS16 promotes insulin secretion and β-cell proliferation in rodent and human islets. Mol Metab 2016; 5:988-996. [PMID: 27689011 PMCID: PMC5034687 DOI: 10.1016/j.molmet.2016.08.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 08/12/2016] [Accepted: 08/16/2016] [Indexed: 01/04/2023] Open
Abstract
Objective G protein-coupled receptor (GPCR) signaling regulates insulin secretion and pancreatic β cell-proliferation. While much knowledge has been gained regarding how GPCRs are activated in β cells, less is known about the mechanisms controlling their deactivation. In many cell types, termination of GPCR signaling is controlled by the family of Regulators of G-protein Signaling (RGS). RGS proteins are expressed in most eukaryotic cells and ensure a timely return to the GPCR inactive state upon removal of the stimulus. The aims of this study were i) to determine if RGS16, the most highly enriched RGS protein in β cells, regulates insulin secretion and β-cell proliferation and, if so, ii) to elucidate the mechanisms underlying such effects. Methods Mouse and human islets were infected with recombinant adenoviruses expressing shRNA or cDNA sequences to knock-down or overexpress RGS16, respectively. 60 h post-infection, insulin secretion and cAMP levels were measured in static incubations in the presence of glucose and various secretagogues. β-cell proliferation was measured in infected islets after 72 h in the presence of 16.7 mM glucose ± somatostatin and various inhibitors. Results RGS16 mRNA levels are strongly up-regulated in islets of Langerhans under hyperglycemic conditions in vivo and ex vivo. RGS16 overexpression stimulated glucose-induced insulin secretion in isolated mouse and human islets while, conversely, insulin secretion was impaired following RGS16 knock-down. Insulin secretion was no longer affected by RGS16 knock-down when islets were pre-treated with pertussis toxin to inactivate Gαi/o proteins, or in the presence of a somatostatin receptor antagonist. RGS16 overexpression increased intracellular cAMP levels, and its effects were blocked by an adenylyl cyclase inhibitor. Finally, RGS16 overexpression prevented the inhibitory effect of somatostatin on insulin secretion and β-cell proliferation. Conclusions Our results identify RGS16 as a novel regulator of β-cell function that coordinately controls insulin secretion and proliferation by limiting the tonic inhibitory signal exerted by δ-cell-derived somatostatin in islets. RGS16 is up-regulated under hyperglycemic conditions in islets. RGS16 is a key regulator of insulin secretion and β-cell proliferation. RGS16 attenuates Gαi/o protein activity downstream of δ-cell derived SST.
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Affiliation(s)
- Kevin Vivot
- Montreal Diabetes Research Center, CRCHUM, Montréal, QC, H2X 0A9, Canada
| | - Valentine S Moullé
- Montreal Diabetes Research Center, CRCHUM, Montréal, QC, H2X 0A9, Canada
| | - Bader Zarrouki
- Montreal Diabetes Research Center, CRCHUM, Montréal, QC, H2X 0A9, Canada
| | - Caroline Tremblay
- Montreal Diabetes Research Center, CRCHUM, Montréal, QC, H2X 0A9, Canada
| | - Arturo D Mancini
- Montreal Diabetes Research Center, CRCHUM, Montréal, QC, H2X 0A9, Canada
| | - Hasna Maachi
- Montreal Diabetes Research Center, CRCHUM, Montréal, QC, H2X 0A9, Canada; Department of Pharmacology, Université de Montréal, Montréal, QC, H3T 1J4, Canada
| | - Julien Ghislain
- Montreal Diabetes Research Center, CRCHUM, Montréal, QC, H2X 0A9, Canada
| | - Vincent Poitout
- Montreal Diabetes Research Center, CRCHUM, Montréal, QC, H2X 0A9, Canada; Department of Pharmacology, Université de Montréal, Montréal, QC, H3T 1J4, Canada; Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC, H3T 1J4, Canada; Department of Medicine, Université de Montréal, Montréal, QC, H3T 1J4, Canada.
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Salaga M, Storr M, Martemyanov KA, Fichna J. RGS proteins as targets in the treatment of intestinal inflammation and visceral pain: New insights and future perspectives. Bioessays 2016; 38:344-54. [PMID: 26817719 PMCID: PMC4916644 DOI: 10.1002/bies.201500118] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Regulators of G protein signaling (RGS) proteins provide timely termination of G protein-coupled receptor (GPCR) responses. Serving as a central control point in GPCR signaling cascades, RGS proteins are promising targets for drug development. In this review, we discuss the involvement of RGS proteins in the pathophysiology of the gastrointestinal inflammation and their potential to become a target for anti-inflammatory drugs. Specifically, we evaluate the emerging evidence for modulation of selected receptor families: opioid, cannabinoid and serotonin by RGS proteins. We discuss how the regulation of RGS protein level and activity may modulate immunological pathways involved in the development of intestinal inflammation. Finally, we propose that RGS proteins may serve as a prognostic factor for survival rate in colorectal cancer. The ideas introduced in this review set a novel conceptual framework for the utilization of RGS proteins in the treatment of gastrointestinal inflammation, a growing major concern worldwide.
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Affiliation(s)
- Maciej Salaga
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Poland
| | - Martin Storr
- Walter Brendel Center of Experimental Medicine, University of Munich, Germany
| | - Kirill A. Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL, USA
- Corresponding authors: J.F. Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland, Phone: ++48 42 272 57 07, Fax: ++48 42 272 56 94, . K.A.M., Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way C347, Jupiter, FL 33458, USA, Phone: ++1 561 228 2770,
| | - Jakub Fichna
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Poland
- Corresponding authors: J.F. Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland, Phone: ++48 42 272 57 07, Fax: ++48 42 272 56 94, . K.A.M., Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way C347, Jupiter, FL 33458, USA, Phone: ++1 561 228 2770,
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Lee JK, Bou Dagher J. Regulator of G-protein Signaling (RGS)1 and RGS10 Proteins as Potential Drug Targets for Neuroinflammatory and Neurodegenerative Diseases. AAPS JOURNAL 2016; 18:545-9. [PMID: 26902301 DOI: 10.1208/s12248-016-9883-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 02/02/2016] [Indexed: 01/25/2023]
Abstract
Regulator of G-protein signaling (RGS) proteins were originally identified as negative regulators of G-protein-coupled receptor (GPCR) signaling via their GTPase-accelerating protein (GAP) activity. All RGS proteins contain evolutionarily conserved RGS domain; however, they differ in their size and regulatory domains. RGS1 and RGS10 are smaller than other RGS proteins, and their functions involve various inflammatory responses including autoimmune responses in both the periphery and the central nervous system (CNS). Neuroinflammation is the chronic inflammatory response in the CNS. Acute inflammatory response in the CNS is believed to be beneficial by involving the neuroprotective actions of immune cells in the brain, particularly microglia, to limit tissue damage and to aid in neuronal repair. However, chronically elevated levels of cytokines serve to maintain activation of abundant numbers of immune cells potentiating prolonged inflammatory responses and creating an environment of oxidative stress, which further hastens oxidative damage of neurons. In this review, we describe the implications and features of RGS proteins (specifically RGS1 and RGS10) in neuroinflammation and neurodegenerative diseases. We will discuss the experimental and epidemiological evidence on the benefits of anti-inflammatory interventions by targeting RGS1 and/or RGS10 protein function or expression in order to delay or attenuate the progression of neurodegeneration, particularly in multiple sclerosis (MS) and Parkinson's disease (PD).
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Affiliation(s)
- Jae-Kyung Lee
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, 501 D. W. Brooks Dr., Athens, Georgia, 30602, USA.
| | - Josephine Bou Dagher
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, 501 D. W. Brooks Dr., Athens, Georgia, 30602, USA
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Karim ZA, Alshbool FZ, Vemana HP, Conlon C, Druey KM, Khasawneh FT. CXCL12 regulates platelet activation via the regulator of G-protein signaling 16. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1863:314-21. [PMID: 26628381 PMCID: PMC10983798 DOI: 10.1016/j.bbamcr.2015.11.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 10/27/2015] [Accepted: 11/24/2015] [Indexed: 01/17/2023]
Abstract
The regulators of G protein signaling (RGS) protein superfamily negatively controls G protein-coupled receptor signal transduction pathways. One of the members of this family, RGS16, is highly expressed in megakaryocytes and platelets. Studies of its function in platelet and megakaryocyte biology have been limited, in part, due to lack of pharmacological inhibitors. For example, RGS16 overexpression inhibited CXC chemokine receptor 4 (CXCR4)-mediated megakaryocyte migration. More recent studies showed that the chemokine stromal cell-derived factor (SDF1α or CXCL12) regulates platelet function via CXCR4. Based on these considerations, the present study investigated the capacity of RGS16 to regulate CXCL12-dependent platelet function, using the RGS16 knockout mouse model (Rgs16(-/-)). RGS16-deficient platelets had increased protease activated receptor 4 and collagen-induced aggregation, as well as increased CXCL12-dependent agonist-induced aggregation, dense and alpha granule secretion, integrin αIIbβ3 activation and phosphatidylserine exposure compared to those from WT littermates. CXCL12 alone did not stimulate aggregation or secretion in either RGS16-deficient or WT platelets. Furthermore, platelets from Rgs16(-/-) mice displayed enhanced phosphorylation of ERK and Akt following CXCL12 stimulation relative to controls. Finally, we also found that PKCδ is involved in regulating CXCL12-dependent activation of ERK and Akt, in the Rgs16-deficient platelets. Collectively, our findings provide the first evidence that RGS16 plays an important role in platelet function by modulating CXCL12-dependent platelet activation.
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Affiliation(s)
- Zubair A Karim
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Fatima Z Alshbool
- Department of Pharmacology, Loma Linda University, Loma Linda, CA 92354, USA
| | - Hari Priya Vemana
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Christine Conlon
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Kirk M Druey
- Molecular Signal Transduction Section, Laboratory of Allergic Diseases, NIAID/NIH, 50 South Drive Room 4154, Bethesda, MD 20892, USA
| | - Fadi T Khasawneh
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA.
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32
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Lee JK, Kannarkat GT, Chung J, Joon Lee H, Graham KL, Tansey MG. RGS10 deficiency ameliorates the severity of disease in experimental autoimmune encephalomyelitis. J Neuroinflammation 2016; 13:24. [PMID: 26831924 PMCID: PMC4736282 DOI: 10.1186/s12974-016-0491-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 01/23/2016] [Indexed: 11/16/2022] Open
Abstract
Background Regulator of G-protein signaling (RGS) family proteins, which are GTPase accelerating proteins (GAPs) that negatively regulate G-protein-coupled receptors (GPCRs), are known to be important modulators of immune cell activation and function. Various single-nucleotide polymorphisms in RGS proteins highly correlate with increased risk for multiple sclerosis (MS), an autoimmune, neurodegenerative disorder. An in-depth search of the gene expression omnibus profile database revealed higher levels of RGS10 and RGS1 transcripts in peripheral blood mononuclear cells (PBMCs) in MS patients, suggesting potential functional roles for RGS proteins in MS etiology and/or progression. Methods To define potential roles for RGS10 in regulating autoimmune responses, we evaluated RGS10-null and wild-type (WT) mice for susceptibility to experimental autoimmune encephalomyelitis (EAE), a widely studied model of MS. Leukocyte distribution and functional responses were assessed using biochemical, immunohistological, and flow cytometry approaches. Results RGS10-null mice displayed significantly milder clinical symptoms of EAE with reduced disease incidence and severity, as well as delayed onset. We observed fewer CD3+ T lymphocytes and CD11b+ myeloid cells in the central nervous system (CNS) tissues of RGS10-null mice with myelin oligodendrocyte protein (MOG)35–55-induced EAE. Lymph node cells and splenocytes of immunized RGS10-null mice demonstrated decreased proliferative and cytokine responses in response to in vitro MOG memory recall challenge. In adoptive recipients, transferred myelin-reactive RGS10-null Th1 cells (but not Th17 cells) induced EAE that was less severe than their WT counterparts. Conclusions These data demonstrate a critical role for RGS10 in mediating autoimmune disease through regulation of T lymphocyte function. This is the first study ever conducted to elucidate the function of RGS10 in effector lymphocytes in the context of EAE. The identification of RGS10 as an important regulator of inflammation might open possibilities for the development of more specific therapies for MS.
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Affiliation(s)
- Jae-Kyung Lee
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Dr, Athens, GA, 30602, USA.
| | - George T Kannarkat
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Jaegwon Chung
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Dr, Athens, GA, 30602, USA
| | - Hyun Joon Lee
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Kareem L Graham
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Malú G Tansey
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, USA
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Gerber KJ, Squires KE, Hepler JR. Roles for Regulator of G Protein Signaling Proteins in Synaptic Signaling and Plasticity. Mol Pharmacol 2015; 89:273-86. [PMID: 26655302 DOI: 10.1124/mol.115.102210] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 12/10/2015] [Indexed: 11/22/2022] Open
Abstract
The regulator of G protein signaling (RGS) family of proteins serves critical roles in G protein-coupled receptor (GPCR) and heterotrimeric G protein signal transduction. RGS proteins are best understood as negative regulators of GPCR/G protein signaling. They achieve this by acting as GTPase activating proteins (GAPs) for Gα subunits and accelerating the turnoff of G protein signaling. Many RGS proteins also bind additional signaling partners that either regulate their functions or enable them to regulate other important signaling events. At neuronal synapses, GPCRs, G proteins, and RGS proteins work in coordination to regulate key aspects of neurotransmitter release, synaptic transmission, and synaptic plasticity, which are necessary for central nervous system physiology and behavior. Accumulating evidence has revealed key roles for specific RGS proteins in multiple signaling pathways at neuronal synapses, regulating both pre- and postsynaptic signaling events and synaptic plasticity. Here, we review and highlight the current knowledge of specific RGS proteins (RGS2, RGS4, RGS7, RGS9-2, and RGS14) that have been clearly demonstrated to serve critical roles in modulating synaptic signaling and plasticity throughout the brain, and we consider their potential as future therapeutic targets.
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Affiliation(s)
- Kyle J Gerber
- Programs in Molecular and Systems Pharmacology (K.J.G., K.E.S., J.R.H.) and Neuroscience (J.R.H.), Department of Pharmacology (K.J.G., K.E.S., J.R.H.), Emory University School of Medicine, Atlanta, Georgia
| | - Katherine E Squires
- Programs in Molecular and Systems Pharmacology (K.J.G., K.E.S., J.R.H.) and Neuroscience (J.R.H.), Department of Pharmacology (K.J.G., K.E.S., J.R.H.), Emory University School of Medicine, Atlanta, Georgia
| | - John R Hepler
- Programs in Molecular and Systems Pharmacology (K.J.G., K.E.S., J.R.H.) and Neuroscience (J.R.H.), Department of Pharmacology (K.J.G., K.E.S., J.R.H.), Emory University School of Medicine, Atlanta, Georgia
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Altman MK, Alshamrani AA, Jia W, Nguyen HT, Fambrough JM, Tran SK, Patel MB, Hoseinzadeh P, Beedle AM, Murph MM. Suppression of the GTPase-activating protein RGS10 increases Rheb-GTP and mTOR signaling in ovarian cancer cells. Cancer Lett 2015; 369:175-83. [PMID: 26319900 DOI: 10.1016/j.canlet.2015.08.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 08/14/2015] [Accepted: 08/17/2015] [Indexed: 12/15/2022]
Abstract
The regulator of G protein signaling 10 (RGS10) protein is a GTPase activating protein that accelerates the hydrolysis of GTP and therefore canonically inactivates G proteins, ultimately terminating signaling. Rheb is a small GTPase protein that shuttles between its GDP- and GTP-bound forms to activate mTOR. Since RGS10 suppression augments ovarian cancer cell viability, we sought to elucidate the molecular mechanism. Following RGS10 suppression in serum-free conditions, phosphorylation of mTOR, the eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1), p70S6K and S6 Ribosomal Protein appear. Furthermore, suppressing RGS10 increases activated Rheb, suggesting RGS10 antagonizes mTOR signaling via the small G-protein. The effects of RGS10 suppression are enhanced after stimulating cells with the growth factor, lysophosphatidic acid, and reduced with mTOR inhibitors, temsirolimus and INK-128. Suppression of RGS10 leads to an increase in cell proliferation, even in the presence of etoposide. In summary, the RGS10 suppression increases Rheb-GTP and mTOR signaling in ovarian cancer cells. Our results suggest that RGS10 could serve in a novel, and previously unknown, role by accelerating the hydrolysis of GTP from Rheb in ovarian cancer cells.
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Affiliation(s)
- Molly K Altman
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, 240 W. Green Street, Athens, GA 30602, USA
| | - Ali A Alshamrani
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, 240 W. Green Street, Athens, GA 30602, USA
| | - Wei Jia
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, 240 W. Green Street, Athens, GA 30602, USA
| | - Ha T Nguyen
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, 240 W. Green Street, Athens, GA 30602, USA
| | - Jada M Fambrough
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, 240 W. Green Street, Athens, GA 30602, USA
| | - Sterling K Tran
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, 240 W. Green Street, Athens, GA 30602, USA
| | - Mihir B Patel
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, 240 W. Green Street, Athens, GA 30602, USA
| | - Pooya Hoseinzadeh
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, 240 W. Green Street, Athens, GA 30602, USA
| | - Aaron M Beedle
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, 240 W. Green Street, Athens, GA 30602, USA
| | - Mandi M Murph
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, 240 W. Green Street, Athens, GA 30602, USA.
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Abstract
The G12 family of heterotrimeric G proteins is defined by their α-subunits,
Gα12 and Gα13. These α-subunits
regulate cellular homeostasis, cell migration, and oncogenesis in a
context-specific manner primarily through their interactions with distinct
proteins partners that include diverse effector molecules and scaffold proteins.
With a focus on identifying any other novel regulatory protein(s) that can
directly interact with Gα13, we subjected Gα13
to tandem affinity purification-coupled mass spectrometric analysis. Our results
from such analysis indicate that Gα13 potently interacts with
mammalian Ric-8A. Our mass spectrometric analysis data also indicates that
Ric-8A, which was tandem affinity purified along with Gα13, is
phosphorylated at Ser-436, Thr-441, Thr-443 and Tyr-435. Using a serial deletion
approach, we have defined that the C-terminus of Gα13 containing
the guanine-ring interaction site is essential and sufficient for its
interaction with Ric-8A. Evaluation of Gα13-specific signaling
pathways in SKOV3 or HeyA8 ovarian cancer cell lines indicate that Ric-8A
potentiates Gα13-mediated activation of RhoA, Cdc42, and the
downstream p38MAPK. We also establish that the tyrosine phosphorylation of
Ric-8A, thus far unidentified, is potently stimulated by Gα13.
Our results also indicate that the stimulation of tyrosine-phosphorylation of
Ric-8A by Gα13 is partially sensitive to inhibitors of
Src-family of kinases, namely PP2 and SI. Furthermore, we demonstrate that
Gα13 promotes the translocation of Ric-8A to plasma membrane
and this translocation is attenuated by the Src-inhibitors, SI1 and PP2. Thus,
our results demonstrate for the first time that Gα13 stimulates
the tyrosine phosphorylation of Ric-8A and Gα13-mediated
tyrosine-phosphorylation plays a critical role in the translocation of Ric-8A to
plasma membrane.
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Osei-Owusu P, Blumer KJ. Regulator of G Protein Signaling 2: A Versatile Regulator of Vascular Function. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 133:77-92. [PMID: 26123303 DOI: 10.1016/bs.pmbts.2015.02.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Regulators of G protein signaling (RGS) proteins of the B/R4 family are widely expressed in the cardiovascular system where their role in fine-tuning G protein signaling is critical to maintaining homeostasis. Among members of this family, RGS2 and RGS5 have been shown to play key roles in cardiac and smooth muscle function by tightly regulating signaling pathways that are activated through Gq/11 and Gi/o classes of heterotrimeric G proteins. This chapter reviews accumulating evidence supporting a key role for RGS2 in vascular function and the implication of changes in RGS2 function and/or expression in the pathogenesis of blood pressure disorders, particularly hypertension. With such understanding, RGS2 and the signaling pathways it controls may emerge as novel targets for developing next-generation antihypertensive drugs/agents.
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Affiliation(s)
- Patrick Osei-Owusu
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.
| | - Kendall J Blumer
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, USA
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Carper MB, Denvir J, Boskovic G, Primerano DA, Claudio PP. RGS16, a novel p53 and pRb cross-talk candidate inhibits migration and invasion of pancreatic cancer cells. Genes Cancer 2015; 5:420-35. [PMID: 25568667 PMCID: PMC4279439 DOI: 10.18632/genesandcancer.43] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 11/26/2014] [Indexed: 12/11/2022] Open
Abstract
Data collected since the discovery of p53 and pRb/RB1 suggests these tumor suppressors cooperate to inhibit tumor progression. Patients who have mutations in both p53 and RB1 genes have increased tumor reoccurrence and decreased survival compared to patients with only one tumor suppressor gene inactivated. It remains unclear how p53 and pRb cooperate toward inhibiting tumorigenesis. Using RNA expression profiling we identified 179 p53 and pRb cross-talk candidates in normal lung fibroblasts (WI38) cells exogenously coexpressing p53 and pRb. Regulator of G protein signaling 16 (RGS16) was among the p53 and pRb cross-talk candidates and has been implicated in inhibiting activation of several oncogenic pathways associated with proliferation, migration, and invasion of cancer cells. RGS16 has been found to be downregulated in pancreatic cancer patients with metastases compared to patients without metastasis. Expression of RGS16 mRNA was decreased in the pancreatic cancer cell lines tested compared to control. Expression of RGS16 inhibited migration of the BxPC-3 and AsPC-1 but not PANC-1 cells and inhibited invasion of BxPC-3 and AsPC-1 cells with no impact on cell viability. We have identified for the first time p53 and pRb cross-talk candidates and a role for RGS16 to inhibit pancreatic cancer migration and invasion.
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Affiliation(s)
- Miranda B Carper
- McKown Translational Genomic Research Institute, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA ; Department of Biochemistry and Microbiology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
| | - James Denvir
- Department of Biochemistry and Microbiology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
| | - Goran Boskovic
- Department of Biochemistry and Microbiology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
| | - Donald A Primerano
- Department of Biochemistry and Microbiology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
| | - Pier Paolo Claudio
- McKown Translational Genomic Research Institute, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA ; Department of Biochemistry and Microbiology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA ; Department of Surgery, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
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Ji YR, Kim HJ, Park SJ, Bae KB, Park SJ, Jang WY, Kang MC, Jeong J, Sung YH, Choi M, Lee W, Lee DG, Park SJ, Lee S, Kim MO, Ryoo ZY. Critical role of Rgs19 in mouse embryonic stem cell proliferation and differentiation. Differentiation 2015; 89:42-50. [DOI: 10.1016/j.diff.2015.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 01/20/2015] [Accepted: 01/23/2015] [Indexed: 10/23/2022]
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de Velasco EMF, McCall N, Wickman K. GIRK Channel Plasticity and Implications for Drug Addiction. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2015; 123:201-38. [DOI: 10.1016/bs.irn.2015.05.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Physiology of RGS10 in Neurons and Immune Cells. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 133:153-67. [DOI: 10.1016/bs.pmbts.2015.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Ganss R. Keeping the Balance Right. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 133:93-121. [DOI: 10.1016/bs.pmbts.2015.02.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Genome-wide association study on susceptibility genes associated with yang-deficiency constitution: A small sample case-control study. Chin J Integr Med 2014; 21:601-9. [DOI: 10.1007/s11655-014-1957-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Indexed: 10/24/2022]
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Sayasith K, Sirois J, Lussier JG. Expression and regulation of regulator of G-protein signaling protein-2 (RGS2) in equine and bovine follicles prior to ovulation: molecular characterization of RGS2 transactivation in bovine granulosa cells. Biol Reprod 2014; 91:139. [PMID: 25339105 DOI: 10.1095/biolreprod.114.121186] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The luteinizing hormone preovulatory surge stimulates several signal pathways essential for ovulation, and the regulator of G-protein signaling protein-2 (RGS2) is thought to be involved in this process. The objectives of this study were to characterize the regulation of RGS2 transcripts in equine and bovine follicles prior to ovulation and to determine its transcriptional control in bovine granulosa cells. To assess the regulation of equine RGS2 prior to ovulation, RT-PCR was performed using total RNA extracted from equine follicles collected at various times after human chorionic gonadotropin (hCG) injection. Results showed that RGS2 mRNA levels were very low at 0 h but markedly increased 12-39 h post-hCG (P < 0.05). In the bovine species, results revealed that RGS2 mRNA levels were low in small and dominant follicles and in ovulatory follicles obtained at 0 h, but markedly increased in ovulatory follicles 6-24 h post-hCG (P < 0.05). To study the molecular control of RGS2 expression, primary cultures of bovine granulosa cells were used. Stimulation with forskolin induced an up-regulation of RGS2 mRNA in vitro. Studies using 5'-deletion mutants identified a minimal region containing full-length basal and forskolin-inducible RGS2 promoter activities. Site-directed mutagenesis indicated that these activities were dependent on CRE and ETS1 cis-elements. Electrophoretic mobility shift assays confirmed the involvement of these elements and revealed their interactions with CREB1 and ETS1 proteins. Chromatin immunoprecipitation assays confirmed endogenous interactions of these proteins with the RGS2 promoter in granulosa cells. Forskolin-inducible RGS2 promoter activity and mRNA expression were markedly decreased by PKA and ERK1/2 inhibitors, and treatment with an antagonist of PGR (RU486) and inhibitors of PTGS2 (NS398) and EGFR (PD153035) blocked the forskolin-dependent RGS2 transcript expression, suggesting the importance of RGS2 in ovulation. Collectively, this study reports for the first time the gonadotropin-dependent up-regulation of RGS2 in equine and bovine preovulatory follicles and presents some of the regulatory controls involved in RGS2 gene expression in granulosa cells.
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Affiliation(s)
- Khampoun Sayasith
- Centre de recherche en reproduction animale and the Département de biomédecine vétérinaire, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Jean Sirois
- Centre de recherche en reproduction animale and the Département de biomédecine vétérinaire, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Jacques G Lussier
- Centre de recherche en reproduction animale and the Département de biomédecine vétérinaire, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
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Obsilova V, Kopecka M, Kosek D, Kacirova M, Kylarova S, Rezabkova L, Obsil T. Mechanisms of the 14-3-3 protein function: regulation of protein function through conformational modulation. Physiol Res 2014; 63:S155-64. [PMID: 24564655 DOI: 10.33549/physiolres.932659] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Many aspects of protein function regulation require specific protein-protein interactions to carry out the exact biochemical and cellular functions. The highly conserved members of the 14-3-3 protein family mediate such interactions and through binding to hundreds of other proteins provide multitude of regulatory functions, thus playing key roles in many cellular processes. The 14-3-3 protein binding can affect the function of the target protein in many ways including the modulation of its enzyme activity, its subcellular localization, its structure and stability, or its molecular interactions. In this minireview, we focus on mechanisms of the 14-3-3 protein-dependent regulation of three important 14-3-3 binding partners: yeast neutral trehalase Nth1, regulator of G-protein signaling 3 (RGS3), and phosducin.
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Affiliation(s)
- V Obsilova
- Department of Protein Structure, Institute of Physiology Academy of Sciences of the Czech Republic, Prague, Czech Republic. and
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Lamberts JT, Traynor JR. Opioid receptor interacting proteins and the control of opioid signaling. Curr Pharm Des 2014; 19:7333-47. [PMID: 23448476 DOI: 10.2174/138161281942140105160625] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 02/18/2013] [Indexed: 12/31/2022]
Abstract
Opioid receptors are seven-transmembrane domain receptors that couple to intracellular signaling molecules by activating heterotrimeric G proteins. However, the receptor and G protein do not function in isolation but their activities are modulated by several accessory and scaffolding proteins. Examples include arrestins, kinases, and regulators of G protein signaling proteins. Accessory proteins contribute to the observed potency and efficacy of agonists, but also to the direction of signaling and the phenomenon of biased agonism. This review will present current knowledge of such proteins and how they may provide targets for future drug design.
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Affiliation(s)
| | - John R Traynor
- Department of Pharmacology, University of Michigan Medical School, 1301 MSRB III, 1150 West Medical Center Drive, Ann Arbor, MI 48109-5632, USA.
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Octeau JC, Schrader JM, Masuho I, Sharma M, Aiudi C, Chen CK, Kovoor A, Celver J. G protein beta 5 is targeted to D2-dopamine receptor-containing biochemical compartments and blocks dopamine-dependent receptor internalization. PLoS One 2014; 9:e105791. [PMID: 25162404 PMCID: PMC4146516 DOI: 10.1371/journal.pone.0105791] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 07/23/2014] [Indexed: 11/18/2022] Open
Abstract
G beta 5 (Gbeta5, Gβ5) is a unique G protein β subunit that is thought to be expressed as an obligate heterodimer with R7 regulator of G protein signaling (RGS) proteins instead of with G gamma (Gγ) subunits. We found that D2-dopamine receptor (D2R) coexpression enhances the expression of Gβ5, but not that of the G beta 1 (Gβ1) subunit, in HEK293 cells, and that the enhancement of expression occurs through a stabilization of Gβ5 protein. We had previously demonstrated that the vast majority of D2R either expressed endogenously in the brain or exogenously in cell lines segregates into detergent-resistant biochemical fractions. We report that when expressed alone in HEK293 cells, Gβ5 is highly soluble, but is retargeted to the detergent-resistant fraction after D2R coexpression. Furthermore, an in-cell biotin transfer proximity assay indicated that D2R and Gβ5 segregating into the detergent-resistant fraction specifically interacted in intact living cell membranes. Dopamine-induced D2R internalization was blocked by coexpression of Gβ5, but not Gβ1. However, the same Gβ5 coexpression levels had no effect on agonist-induced internalization of the mu opioid receptor (MOR), cell surface D2R levels, dopamine-mediated recruitment of β-arrestin to D2R, the amplitude of D2R-G protein coupling, or the deactivation kinetics of D2R-activated G protein signals. The latter data suggest that the interactions between D2R and Gβ5 are not mediated by endogenously expressed R7 RGS proteins.
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Affiliation(s)
- J. Christopher Octeau
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, United States of America
| | - Joseph M. Schrader
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, United States of America
| | - Ikuo Masuho
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Meenakshi Sharma
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, United States of America
| | - Christopher Aiudi
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, United States of America
| | - Ching-Kang Chen
- Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, United States of America
| | - Abraham Kovoor
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, United States of America
- * E-mail: (AK); (JC)
| | - Jeremy Celver
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, United States of America
- * E-mail: (AK); (JC)
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Chidiac P, Sobiesiak AJ, Lee KN, Gros R, Nguyen CH. The eIF2B-interacting domain of RGS2 protects against GPCR agonist-induced hypertrophy in neonatal rat cardiomyocytes. Cell Signal 2014; 26:1226-34. [PMID: 24576550 DOI: 10.1016/j.cellsig.2014.02.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 02/05/2014] [Accepted: 02/11/2014] [Indexed: 11/29/2022]
Abstract
The protective effect of Regulator of G protein Signaling 2 (RGS2) in cardiac hypertrophy is thought to occur through its ability to inhibit the chronic GPCR signaling that promotes pathogenic growth both in vivo and in cultured cardiomyocytes. However, RGS2 is known to have additional functions beyond its activity as a GTPase accelerating protein, such as the ability to bind to eukaryotic initiation factor, eIF2B, and inhibit protein synthesis. The RGS2 eIF2B-interacting domain (RGS2(eb)) was examined for its ability to regulate hypertrophy in neonatal ventricular myocytes. Both full-length RGS2 and RGS2(eb) were able to inhibit agonist-induced cardiomyocyte hypertrophy, but RGS2(eb) had no effect on receptor-mediated inositol phosphate production, cAMP production, or ERK 1/2 activation. These results suggest that the protective effects of RGS2 in cardiac hypertrophy may derive at least in part from its ability to govern protein synthesis.
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Affiliation(s)
- Peter Chidiac
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Alina J Sobiesiak
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Katherine N Lee
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Robert Gros
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Chau H Nguyen
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada; School of Pharmacy, D'Youville College, Buffalo, NY 14201, USA.
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Williams JW, Yau D, Sethakorn N, Kach J, Reed EB, Moore TV, Cannon J, Jin X, Xing H, Muslin AJ, Sperling AI, Dulin NO. RGS3 controls T lymphocyte migration in a model of Th2-mediated airway inflammation. Am J Physiol Lung Cell Mol Physiol 2013; 305:L693-701. [PMID: 24077945 DOI: 10.1152/ajplung.00214.2013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
T cell migration toward sites of antigen exposure is mediated by G protein signaling and is a key function in the development of immune responses. Regulators of G protein signaling (RGS) proteins modulate G protein signaling; however, their role in the regulation of adaptive immune responses has not been thoroughly explored. Herein we demonstrated abundant expression of the Gi/Gq-specific RGS3 in activated T cells, and that diminished RGS3 expression in a T cell thymoma increased cytokine-induced migration. To examine the role of endogenous RGS3 in vivo, mice deficient in the RGS domain (RGS3(ΔRGS)) were generated and tested in an experimental model of asthma. Compared with littermate controls, the inflammation in the RGS3(ΔRGS) mice was characterized by increased T cell numbers and the striking development of perivascular lymphoid structures. Surprisingly, while innate inflammatory cells were also increased in the lungs of RGS3(ΔRGS) mice, eosinophil numbers and Th2 cytokine production were equivalent to control mice. In contrast, T cell numbers in the draining lymph nodes (dLN) were reduced in the RGS3(ΔRGS), demonstrating a redistribution of T cells from the dLN to the lungs via increased RGS3(ΔRGS) T cell migration. Together these novel findings show a nonredundant role for endogenous RGS3 in controlling T cell migration in vitro and in an in vivo model of inflammation.
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Affiliation(s)
- Jesse W Williams
- Section of Pulmonary and Critical Care, Dept. of Medicine, The Univ. of Chicago, 5841 S. Maryland Ave., MC6076, Rm. M-648, Chicago, IL 60637.
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Zhang P, Mende U. Functional role, mechanisms of regulation, and therapeutic potential of regulator of G protein signaling 2 in the heart. Trends Cardiovasc Med 2013; 24:85-93. [PMID: 23962825 DOI: 10.1016/j.tcm.2013.07.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 07/08/2013] [Accepted: 07/10/2013] [Indexed: 12/22/2022]
Abstract
G protein-mediated signal transduction is essential for the regulation of cardiovascular function, including heart rate, growth, contraction, and vascular tone. Regulators of G protein Signaling (RGS proteins) fine-tune G protein-coupled receptor-induced signaling by regulating its magnitude and duration through direct interaction with the α subunits of heterotrimeric G proteins. Changes in the RGS protein expression and/or function in the heart often lead to pathophysiological changes and are associated with cardiac disease in animals and humans, including hypertrophy, fibrosis development, heart failure, and arrhythmias. This article focuses on Regulator of G protein Signaling 2 (RGS2), which is widely expressed in many tissues and is highly regulated in its expression and function. Most information to date has been obtained in biochemical, cellular, and animal studies, but data from humans is emerging. We review recent advances on the functional role of cardiovascular RGS2 and the mechanisms that determine its signaling selectivity, expression, and functionality. We highlight key unanswered questions and discuss the potential of RGS2 as a therapeutic target.
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Affiliation(s)
- Peng Zhang
- Cardiovascular Research Center, Cardiology Division, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, RI, USA
| | - Ulrike Mende
- Cardiovascular Research Center, Cardiology Division, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, RI, USA.
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Regulator of G protein signaling 19 suppresses Ras-induced neoplastic transformation and tumorigenesis. Cancer Lett 2013; 339:33-41. [PMID: 23911936 DOI: 10.1016/j.canlet.2013.07.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 07/12/2013] [Accepted: 07/24/2013] [Indexed: 11/20/2022]
Abstract
Regulator of G protein signaling 19 (RGS19) has recently been shown to inhibit Ras activation by upregulating the tumor metastasis suppressor Nm23. Here, we have examined the effect of RGS19 on Ras-induced oncogenesis. Coexpression of RGS19, but not RGS20, in NIH3T3 cells effectively suppressed neoplastic transformation and tumorigenesis induced by the oncogenic Ras(GV) mutant. In non-small cell lung carcinoma H1299 cells that harbor Ras mutations, shRNA-mediated knockdown of RGS19 facilitated tumorigenesis with the early appearance of large tumors in nude mice assays. Collectively, these results suggest that expression of RGS19 can suppress the oncogenic actions of Ras.
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