scholarly journals G-Protein–Coupled Receptors in Heart Disease

2018 ◽  
Vol 123 (6) ◽  
pp. 716-735 ◽  
Author(s):  
Jialu Wang ◽  
Clarice Gareri ◽  
Howard A. Rockman
Keyword(s):  
G Protein ◽  
Physiological Role ◽  
Guanine Nucleotide Binding Protein ◽  
Surface Receptors ◽  
Downstream Signaling ◽  
Gpcr Activation ◽  
Wide Range ◽  
Health And Disease ◽  
Artery Disease ◽  
Guanine Nucleotide Binding

GPCRs (G-protein [guanine nucleotide-binding protein]–coupled receptors) play a central physiological role in the regulation of cardiac function in both health and disease and thus represent one of the largest class of surface receptors targeted by drugs. Several antagonists of GPCRs, such as βARs (β-adrenergic receptors) and Ang II (angiotensin II) receptors, are now considered standard of therapy for a wide range of cardiovascular disease, such as hypertension, coronary artery disease, and heart failure. Although the mechanism of action for GPCRs was thought to be largely worked out in the 80s and 90s, recent discoveries have brought to the fore new and previously unappreciated mechanisms for GPCR activation and subsequent downstream signaling. In this review, we focus on GPCRs most relevant to the cardiovascular system and discuss traditional components of GPCR signaling and highlight evolving concepts in the field, such as ligand bias, β-arrestin–mediated signaling, and conformational heterogeneity.

scholarly journals Applications of molecular replacement to G protein-coupled receptors

2013 ◽  
Vol 69 (11) ◽  
pp. 2287-2292 ◽  
Author(s):  
Andrew C. Kruse ◽  
Aashish Manglik ◽  
Brian K. Kobilka ◽  
William I. Weis
Keyword(s):  
G Protein ◽  
Structural Biology ◽  
Structural Information ◽  
G Protein Coupled Receptors ◽  
Integral Membrane Proteins ◽  
Molecular Replacement ◽  
Gpcr Activation ◽  
Health And Disease ◽  
Almost All ◽  
G Protein Coupled

G protein-coupled receptors (GPCRs) are a large class of integral membrane proteins involved in regulating virtually every aspect of human physiology. Despite their profound importance in human health and disease, structural information regarding GPCRs has been extremely limited until recently. With the advent of a variety of new biochemical and crystallographic techniques, the structural biology of GPCRs has advanced rapidly, offering key molecular insights into GPCR activation and signal transduction. To date, almost all GPCR structures have been solved using molecular-replacement techniques. Here, the unique aspects of molecular replacement as applied to individual GPCRs and to signaling complexes of these important proteins are discussed.

scholarly journals Heterotrimeric Gα12/13 proteins in kidney injury and disease

2020 ◽  
Vol 318 (3) ◽  
pp. F660-F672
Author(s):  
Elena Tutunea-Fatan ◽  
Jasper C. Lee ◽  
Bradley M. Denker ◽  
Lakshman Gunaratnam
Keyword(s):  
Kidney Injury ◽  
Cell Types ◽  
Therapeutic Strategies ◽  
Interaction Networks ◽  
Renal Diseases ◽  
Accessory Proteins ◽  
Guanine Nucleotide ◽  
Guanine Nucleotide Binding Protein ◽  
Surface Receptors ◽  
Guanine Nucleotide Binding

Gα12 and Gα13 are ubiquitous members of the heterotrimeric guanine nucleotide-binding protein (G protein) family that play central and integrative roles in the regulation of signal transduction cascades within various cell types in the kidney. Gα12/Gα13 proteins enable the kidney to adapt to an ever-changing environment by transducing stimuli from cell surface receptors and accessory proteins to effector systems. Therefore, perturbations in Gα12/Gα13 levels or their activity can contribute to the pathogenesis of various renal diseases, including renal cancer. This review will highlight and discuss the complex and expanding roles of Gα12/Gα13 proteins on distinct renal pathologies, with emphasis on more recently reported findings. Deciphering how the different Gα12/Gα13 interaction networks participate in the onset and development of renal diseases may lead to the discovery of new therapeutic strategies.

Role of G proteins and KCa channels in the muscarinic and beta-adrenergic regulation of airway smooth muscle

1995 ◽  
Vol 268 (2) ◽  
pp. L221-L229 ◽  
Author(s):  
H. Kume ◽  
K. Mikawa ◽  
K. Takagi ◽  
M. I. Kotlikoff
Keyword(s):  
Smooth Muscle ◽  
Adenylyl Cyclase ◽  
G Protein ◽  
Muscarinic Receptor ◽  
G Proteins ◽  
Isometric Tension ◽  
Guanine Nucleotide Binding Protein ◽  
Kca Channels ◽  
Stimulatory G Protein ◽  
Guanine Nucleotide Binding

We have examined the functional consequences of G protein coupling to calcium-activated potassium (KCa) channels using isometric tension records from guinea pig tracheal smooth muscle. After incubation with 1 microgram/ml pertussis toxin (PTX) for 6 h, the contraction response to 1 microM methacholine (MCh) was suppressed by 31.7 +/- 5.0% (n = 10). Similarly, the contraction was inhibited by 29.1 +/- 5.0% (n = 6) after application of 0.1 microM AF-DX 116, an M2-selective muscarinic receptor antagonist. Cholera toxin (CTX, 2.0 micrograms/ml for 6 h), which activates the stimulatory G protein of adenylyl cyclase (Gs), also suppressed contraction by 43.9 +/- 3.3% (n = 11). The inhibitory effects of PTX, AF-DX 116, or CTX were reversed in the presence of 100 nM charybdotoxin (ChTX), a selective KCa channel inhibitor. These findings suggest that disruption of inhibitory coupling between muscarinic receptor and KCa channels mediated by PTX-sensitive G proteins, or KCa channel activation induced by Gs/adenylyl cyclase-linked processes, antagonizes muscarinic contraction. The isoproterenol concentration-inhibition curves for precontracted trachea (1 microM MCh) were shifted to the left after perfusion with PTX or AF-DX 116, and the leftward shift of the curve was blocked by ChTX. Thus direct or indirect regulation of KCa channels mediated by the inhibitory guanine nucleotide binding protein (Gi) and Gs may play a functionally important role in the mechanical antagonism by the two receptor agonists.

scholarly journals Regulation of bombesin-stimulated inositol 1,4,5-trisphosphate generation in Swiss 3T3 fibroblasts by a guanine-nucleotide-binding protein

1990 ◽  
Vol 268 (3) ◽  
pp. 605-610 ◽  
Author(s):  
R Plevin ◽  
S Palmer ◽  
S D Gardner ◽  
M J O Wakelam
Keyword(s):  
G Protein ◽  
Protein Interactions ◽  
Inositol Phosphate ◽  
Early Time ◽  
Lag Time ◽  
Maximal Response ◽  
Guanine Nucleotide Binding Protein ◽  
3T3 Fibroblasts ◽  
Swiss 3T3 ◽  
Guanine Nucleotide Binding

The stimulation of inositol phosphate generation by bombesin and GTP analogues was studied in Swiss 3T3 cells permeabilized by electroporation. Bombesin-stimulated inositol phosphate generation is potentiated by guanosine 5′-[gamma-thio]triphosphate (GTP[S]) and inhibited by guanosine 5′-[beta-thio]diphosphate at all peptide concentrations tested, with no change in the EC50 value (concn. giving half-maximal response) for the agonist. Kinetic analysis showed that, although bombesin-stimulated [3H]InsP3 generation in [3H]inositol-labelled cells was rapid (maximal by 5-10 s), the response to GTP[S] alone displayed a distinct lag time of 20-30 s. This lag time was significantly decreased by the addition of bombesin, suggesting that in this system agonist-stimulated GTP/GDP exchange occurs. In addition, bombesin-stimulated generation of Ins(1,4,5)P3 mass at 10 s was enhanced by GTP[S] in the absence of a nucleotide response alone, a result consistent with this proposal. Pretreatment of the cells with phorbol 12-myristate 13-acetate (PMA) resulted in a dose-dependent inhibition of bombesin-, but not GTP[S]-, stimulated inositol phosphate generation. Furthermore, although PMA pretreatment did not affect the lag time for InsP3 formation in response to GTP[S] alone, the degree of synergy between bombesin and the nucleotide was severely decreased at early time points. The results therefore demonstrate that the high-affinity bombesin receptor is coupled via a G-protein to phospholipase C in a manner consistent with a general model for receptor-G-protein interactions and that this coupling is sensitive to phosphorylation by protein kinase C.

scholarly journals The mutational landscape of human olfactory G protein-coupled receptors

2020 ◽  
Author(s):  
Ramón Cierco Jimenez ◽  
Nil Casajuana-Martin ◽  
Adrián García-Recio ◽  
Lidia Alcántara ◽  
Leonardo Pardo ◽  
...  
Keyword(s):  
G Protein ◽  
Web Application ◽  
Large Family ◽  
Activation Mechanism ◽  
Human Populations ◽  
Gene Repertoire ◽  
Functional Interpretation ◽  
Gpcr Activation ◽  
Wide Range ◽  
G Protein Coupled

ABSTRACTOlfactory receptors (ORs) constitute a large family of sensory proteins that enable us to recognize a wide range of chemical volatiles in the environment. By contrast to the extensive information about human olfactory thresholds for thousands of odorants, studies of the genetic influence on olfaction are limited to a few examples. Here, we analyzed a compendium of 118,057 natural variants in human ORs collected from the public domain. OR mutations were categorized depending on their genomic and protein contexts, as well as their frequency of occurrence in several human populations. Functional interpretation of the natural changes was estimated from the increasing knowledge of the structure and function of the G protein-coupled receptor (GPCR) family, to which ORs belong. Our analysis reveals an extraordinary diversity of natural variations in the olfactory gene repertoire between individuals and populations, with a significant number of changes occurring at structural conserved regions. A particular attention is paid to mutations in positions linked to the conserved GPCR activation mechanism that could imply phenotypic variation in the olfactory perception. An interactive web application (available at http://lmc.uab.cat/hORMdb) was developed for the management and visualization of this mutational dataset.

Guanine Nucleotide Binding Protein (G Protein), Gamma

2012 ◽  
pp. 831-831
Author(s):  
Thomas E. Meigs ◽  
Alex Lyakhovich ◽  
Hoon Shim ◽  
Ching-Kang Chen ◽  
Denis J. Dupré ◽  
...  
Keyword(s):  
G Protein ◽  
Binding Protein ◽  
Nucleotide Binding ◽  
Protein G ◽  
Guanine Nucleotide ◽  
Guanine Nucleotide Binding Protein ◽  
Guanine Nucleotide Binding ◽  
Nucleotide Binding Protein

The G protein alpha o subunit alters morphology, growth kinetics, and phospholipid metabolism of somatic cells

1989 ◽  
Vol 9 (12) ◽  
pp. 5434-5439
Author(s):  
D B Bloch ◽  
J V Bonventre ◽  
E J Neer ◽  
J G Seidman
Keyword(s):  
Cell Line ◽  
G Protein ◽  
Cellular Proliferation ◽  
Physiological Role ◽  
Immunoblot Analysis ◽  
Parental Cell ◽  
Phospholipid Metabolism ◽  
Parental Cell Line ◽  
Subunit Expression ◽  
Guanine Nucleotide Binding

The physiological role of the alpha o subunit of guanine nucleotide-binding (G) protein was investigated with a murine adrenal cell line (Y1) transfected with a rat alpha o cDNA cloned in a retroviral expression vector. The parental cell line lacked detectable alpha o subunit. Expression of the alpha o cDNA in transfected cell lines was confirmed by Western blot (immunoblot) analysis. The rat alpha o subunit interacted with murine beta and gamma subunits and associated with cell membranes. Y1 cells containing large amounts of alpha o subunit had altered cellular morphology and reduced rate of cell division. In addition, GTP-gamma S-stimulated release of arachidonic acid from these cells was significantly increased compared with that in control cells. The alpha o subunit appears directly or indirectly to regulate cellular proliferation, morphology, and phospholipid metabolism.

scholarly journals Inhibition by pertussis toxin of the activation of Na+-dependent uridine transport in dimethyl-sulphoxide-induced HL-60 leukaemia cells

1991 ◽  
Vol 280 (2) ◽  
pp. 515-519 ◽  
Author(s):  
J A Sokoloski ◽  
A C Sartorelli ◽  
R E Handschumacher ◽  
C W Lee
Keyword(s):  
Cholera Toxin ◽  
G Protein ◽  
Pertussis Toxin ◽  
Nucleotide Binding ◽  
Dimethyl Sulphoxide ◽  
Protein G ◽  
Guanine Nucleotide ◽  
Guanine Nucleotide Binding Protein ◽  
Guanine Nucleotide Binding ◽  
Dependent Transport

The effects of pertussis toxin on the Na(+)-dependent transport of uridine were studied in HL-60 leukaemia cells induced to differentiate along the granulocytic or monocytic pathways by dimethyl sulphoxide (DMSO) or phorbol 12-myristate 13-acetate (PMA) respectively. Pertussis toxin at 50 ng/ml completely inhibited the activation of Na(+)-dependent uridine transport and consequently prevented the formation of intracellular pools of free uridine which occurs in HL-60 cells induced to differentiate by DMSO. The inhibition of Na(+)-dependent uridine transport by pertussis toxin in cells exposed to DMSO was associated with a 14-fold decrease in affinity, with no change in Vmax. Pertussis toxin, however, had no effect on Na(+)-dependent uridine transport in PMA-induced HL-60 cells. Furthermore, 500 ng of cholera toxin/ml had no effect on the Na(+)-dependent uptake of uridine in DMSO-treated HL-60 cells. These results suggest that the activation of the Na(+)-dependent transport of uridine in HL-60 cells induced to differentiate along the granulocytic pathway by DMSO is coupled to a pertussis-toxin-sensitive guanine-nucleotide binding protein (G-protein).

scholarly journals Crystal structure of rhodopsin in complex with a mini-Gosheds light on the principles of G protein selectivity

2018 ◽  
Vol 4 (9) ◽  
pp. eaat7052 ◽  
Author(s):  
Ching-Ju Tsai ◽  
Filip Pamula ◽  
Rony Nehmé ◽  
Jonas Mühle ◽  
Tobias Weinert ◽  
...  
Keyword(s):  
Crystal Structure ◽  
G Protein ◽  
Maximum Efficiency ◽  
Guanine Nucleotide Binding Protein ◽  
Precise Position ◽  
Protein Activation ◽  
Signaling Complex ◽  
G Protein Activation ◽  
Clinical Drugs ◽  
Guanine Nucleotide Binding

Selective coupling of G protein (heterotrimeric guanine nucleotide–binding protein)–coupled receptors (GPCRs) to specific Gα-protein subtypes is critical to transform extracellular signals, carried by natural ligands and clinical drugs, into cellular responses. At the center of this transduction event lies the formation of a signaling complex between the receptor and G protein. We report the crystal structure of light-sensitive GPCR rhodopsin bound to an engineered mini-Goprotein. The conformation of the receptor is identical to all previous structures of active rhodopsin, including the complex with arrestin. Thus, rhodopsin seems to adopt predominantly one thermodynamically stable active conformation, effectively acting like a “structural switch,” allowing for maximum efficiency in the visual system. Furthermore, our analysis of the well-defined GPCR–G protein interface suggests that the precise position of the carboxyl-terminal “hook-like” element of the G protein (its four last residues) relative to the TM7/helix 8 (H8) joint of the receptor is a significant determinant in selective G protein activation.

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