scholarly journals Noncanonical scaffolding of Gαi and β-arrestin by G protein–coupled receptors

Science ◽  
2021 ◽  
pp. eaay1833
Author(s):  
Jeffrey S. Smith ◽  
Thomas F. Pack ◽  
Asuka Inoue ◽  
Claudia Lee ◽  
Kevin Zheng ◽  
...  
Keyword(s):  
G Protein ◽  
Drug Targets ◽  
Direct Interaction ◽  
Adaptor Proteins ◽  
G Protein Coupled Receptors ◽  
Guanine Nucleotide Binding Protein ◽  
Signaling Mechanism ◽  
Protein Activation ◽  
Guanine Nucleotide Binding ◽  
G Protein Coupled

Heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs) are common drug targets and canonically couple to specific Gα protein subtypes and β-arrestin adaptor proteins. G protein- and β-arrestin-mediated signaling have been considered separable. We show GPCRs promote a direct interaction between Gαi protein subtype family members and β-arrestins, regardless of their canonical Gαi protein subtype coupling. Gαi:β-arrestin complexes bound extracellular signal-regulated kinase (ERK) and their disruption impaired both ERK activation and cell migration, consistent with β-arrestins requiring a functional interaction with Gαi for certain signaling events. These results introduce a GPCR signaling mechanism distinct from canonical G protein activation in which GPCRs cause the formation of Gαi:β-arrestin signaling complexes.

Mapping the Heart

2010 ◽  
Vol 18 (4) ◽  
pp. 6-8
Author(s):  
Stephen W. Carmichael
Keyword(s):  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
G Protein Coupled Receptors ◽  
Receptor Subtypes ◽  
Cardiac Muscle Cells ◽  
Guanine Nucleotide Binding Protein ◽  
The Common ◽  
Guanine Nucleotide Binding ◽  
First Time ◽  
G Protein Coupled

Some of the receptors on the surface of cardiac muscle cells (cardiomyocytes) mediate the response of these cells to catecholamines by causing the production of the common second messenger cyclic adenosine monophosphate (cAMP). An example of such receptors are the β1- and β2-adrenergic receptors (βARs) that are heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors. Selective stimulation of these two receptor subtypes leads to distinct physiological and pathophysiological responses, but their precise location on the surface of cardiomyocytes has not been correlated with these responses. In an ingenious combination of techniques, Viacheslav Nikolaev, Alexey Moshkov, Alexander Lyon, Michele Miragoli, Pavel Novak, Helen Paur, Martin Lohse, Yuri Korchev, Sian Harding, and Julia Gorelik have mapped the function of these receptors for the first time.

scholarly journals The relevance of adhesion G protein-coupled receptors in metabolic functions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Isabell Kaczmarek ◽  
Tomáš Suchý ◽  
Simone Prömel ◽  
Torsten Schöneberg ◽  
Ines Liebscher ◽  
...  
Keyword(s):  
G Protein ◽  
Drug Targets ◽  
Metabolic Diseases ◽  
Current Knowledge ◽  
G Protein Coupled Receptors ◽  
Specific Expression ◽  
Physiological Functions ◽  
Metabolic Functions ◽  
Central Nervous Systems ◽  
G Protein Coupled

Abstract G protein-coupled receptors (GPCRs) modulate a variety of physiological functions and have been proven to be outstanding drug targets. However, approximately one-third of all non-olfactory GPCRs are still orphans in respect to their signal transduction and physiological functions. Receptors of the class of Adhesion GPCRs (aGPCRs) are among these orphan receptors. They are characterized by unique features in their structure and tissue-specific expression, which yields them interesting candidates for deorphanization and testing as potential therapeutic targets. Capable of G-protein coupling and non-G protein-mediated function, aGPCRs may extend our repertoire of influencing physiological function. Besides their described significance in the immune and central nervous systems, growing evidence indicates a high importance of these receptors in metabolic tissue. RNAseq analyses revealed high expression of several aGPCRs in pancreatic islets, adipose tissue, liver, and intestine but also in neurons governing food intake. In this review, we focus on aGPCRs and their function in regulating metabolic pathways. Based on current knowledge, this receptor class represents high potential for future pharmacological approaches addressing obesity and other metabolic diseases.

CCK receptor phosphorylation exposes regulatory domains affecting phosphorylation and receptor trafficking

2000 ◽  
Vol 279 (6) ◽  
pp. C1986-C1992 ◽  
Author(s):  
Rammohan V. Rao ◽  
Eileen L. Holicky ◽  
Susan M. Kuntz ◽  
Laurence J. Miller
Keyword(s):  
G Protein ◽  
Chinese Hamster ◽  
G Protein Coupled Receptors ◽  
Receptor Internalization ◽  
Ovary Cell ◽  
Guanine Nucleotide Binding Protein ◽  
Receptor Phosphorylation ◽  
Regulatory Domains ◽  
Ovary Cell Line ◽  
G Protein Coupled

Agonist-stimulated phosphorylation of guanine nucleotide-binding protein (G protein)-coupled receptors has been recognized as an important mechanism for desensitization by interfering with coupling of the activated receptor with its G protein. We recently described a mutant of the CCK receptor that modified two of five key sites of phosphorylation (S260,264A) and eliminated agonist-stimulated receptor phosphorylation, despite normal ligand binding and signaling (20). As expected, this nonphosphorylated mutant had impaired rapid desensitization but was ultimately able to be desensitized by normal receptor internalization. Here we demonstrate that this mutant receptor is also defective in resensitization, with abnormal recycling to the cell surface. To explore this, another receptor mutant was prepared, replacing the same serines with aspartates to mimic the charge of serine-phosphate (S260,264D). This mutant was expressed in a Chinese hamster ovary cell line and shown to bind CCK normally. It had accelerated kinetics of signaling and desensitization and was phosphorylated in response to agonist occupation, with all other normal sites of phosphorylation modified. It was internalized like wild-type receptors and was resensitized and trafficked normally. This provides evidence for an additional important function for phosphorylation of G protein-coupled receptors. Phosphorylation may induce a conformational change in the receptor to expose other potential sites of phosphorylation and to expose domains involved in the targeting and trafficking of endosomes. The hierarchical phosphorylation of these sites may play a key role in receptor regulation.

scholarly journals Beyond the Flavour: The Potential Druggability of Chemosensory G Protein-Coupled Receptors

2019 ◽  
Vol 20 (6) ◽  
pp. 1402 ◽  
Author(s):  
Antonella Di Pizio ◽  
Maik Behrens ◽  
Dietmar Krautwurst
Keyword(s):  
G Protein ◽  
Drug Targets ◽  
Current Knowledge ◽  
Chemical Space ◽  
G Protein Coupled Receptors ◽  
The Body ◽  
Odorant Receptors ◽  
Taste Receptors ◽  
Umami Taste ◽  
G Protein Coupled

G protein-coupled receptors (GPCRs) belong to the largest class of drug targets. Approximately half of the members of the human GPCR superfamily are chemosensory receptors, including odorant receptors (ORs), trace amine-associated receptors (TAARs), bitter taste receptors (TAS2Rs), sweet and umami taste receptors (TAS1Rs). Interestingly, these chemosensory GPCRs (csGPCRs) are expressed in several tissues of the body where they are supposed to play a role in biological functions other than chemosensation. Despite their abundance and physiological/pathological relevance, the druggability of csGPCRs has been suggested but not fully characterized. Here, we aim to explore the potential of targeting csGPCRs to treat diseases by reviewing the current knowledge of csGPCRs expressed throughout the body and by analysing the chemical space and the drug-likeness of flavour molecules.

G-Protein-Coupled Receptors in Drug Discovery: Nanosizing Using Cell-Free Technologies and Molecular Biology Approaches

2005 ◽  
Vol 10 (8) ◽  
pp. 765-779 ◽  
Author(s):  
Wayne R. Leifert ◽  
Amanda L. Aloia ◽  
Olgatina Bucco ◽  
Richard V. Glatz ◽  
Edward J. McMurchie
Keyword(s):  
Signal Transduction ◽  
G Protein ◽  
Drug Targets ◽  
G Protein Coupled Receptors ◽  
Orphan Receptors ◽  
Molecular Switching ◽  
Physiological Processes ◽  
Current Cell ◽  
G Protein Coupled ◽  
Signaling Components

Signal transduction by G-protein-coupled receptors (GPCRs) underpins a multitude of physiological processes. Ligand recognition by the receptor leads to activation of a genericmolecular switch involving heterotrimeric G-proteins and guanine nucleotides. Signal transduction has been studied extensively with both cell-based systems and assays comprising isolated signaling components. Interest and commercial investment in GPCRs in areas such as drug targets, orphan receptors, highthroughput screening, biosensors, and so on will focus greater attention on assay development to allow for miniaturization, ultra-high throughput and, eventually, microarray/biochip assay formats. Although cell-based assays are adequate for many GPCRs, it is likely that these formatswill limit the development of higher density GPCRassay platforms mandatory for other applications. Stable, robust, cell-free signaling assemblies comprising receptor and appropriate molecular switching components will form the basis of future GPCR assay platforms adaptable for such applications as microarrays. The authors review current cell-free GPCR assay technologies and molecular biological approaches for construction of novel, functional GPCR assays.

Heterodimers of G protein-coupled receptors as novel and distinct drug targets

2006 ◽  
Vol 3 (4) ◽  
pp. 437-443 ◽  
Author(s):  
Raphael Rozenfeld ◽  
Fabien M. Décaillot ◽  
Adriaan P. IJzerman ◽  
Lakshmi A. Devi
Keyword(s):  
G Protein ◽  
Drug Targets ◽  
G Protein Coupled Receptors ◽  
G Protein Coupled

scholarly journals Development of OPLS-AA/M Parameters for Simulations of G Protein-Coupled Receptors and Other Membrane Proteins

2022 ◽  
Author(s):  
Michael J. Robertson ◽  
Georgios Skiniotis
Keyword(s):  
Membrane Proteins ◽  
Force Field ◽  
G Protein ◽  
Drug Targets ◽  
G Protein Coupled Receptors ◽  
Dynamic Nature ◽  
Post Translational Modifications ◽  
Dynamics Simulations ◽  
High Level ◽  
G Protein Coupled

G protein-coupled receptors (GPCRs) and other membrane proteins are valuable drug targets, and their dynamic nature makes them attractive systems for study with molecular dynamics simulations and free energy approaches. Here, we report the development, implementation, and validation of OPLS-AA/M force field parameters to enable simulations of these systems. These efforts include the introduction of post-translational modifications including lipidations and phosphorylation. We also modify previously reported parameters for lipids to be more consistent with the OPLS-AA force field standard and extend their coverage. These new parameters are validated on a variety of test systems, with the results compared to high-level quantum mechanics calculations, experimental data, and simulations with CHARMM36m where relevant. The results demonstrate that the new parameters reliably reproduce the behavior of membrane protein systems.

scholarly journals Lipid nanoparticle technologies for the study of G protein-coupled receptors in lipid environments

2020 ◽  
Vol 12 (6) ◽  
pp. 1287-1302 ◽  
Author(s):  
Steven Lavington ◽  
Anthony Watts
Keyword(s):  
Membrane Proteins ◽  
G Protein ◽  
Drug Targets ◽  
Large Family ◽  
G Protein Coupled Receptors ◽  
Integral Membrane Proteins ◽  
Lipid Nanoparticle ◽  
Wide Range ◽  
Biophysical Studies ◽  
G Protein Coupled

AbstractG protein-coupled receptors (GPCRs) are a large family of integral membrane proteins which conduct a wide range of biological roles and represent significant drug targets. Most biophysical and structural studies of GPCRs have been conducted on detergent-solubilised receptors, and it is clear that detergents can have detrimental effects on GPCR function. Simultaneously, there is increasing appreciation of roles for specific lipids in modulation of GPCR function. Lipid nanoparticles such as nanodiscs and styrene maleic acid lipid particles (SMALPs) offer opportunities to study integral membrane proteins in lipid environments, in a form that is soluble and amenable to structural and biophysical experiments. Here, we review the application of lipid nanoparticle technologies to the study of GPCRs, assessing the relative merits and limitations of each system. We highlight how these technologies can provide superior platforms to detergents for structural and biophysical studies of GPCRs and inform on roles for protein-lipid interactions in GPCR function.

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