Compartmentation of G-protein-coupled receptors and their signalling components in lipid rafts and caveolae

2005 ◽  
Vol 33 (5) ◽  
pp. 1131-1134 ◽  
Author(s):  
P.A. Insel ◽  
B.P. Head ◽  
H.H. Patel ◽  
D.M. Roth ◽  
R.A. Bundey ◽  
...  
Keyword(s):  
G Protein ◽  
Lipid Rafts ◽  
Plasma Membranes ◽  
Subcellular Fractionation ◽  
G Protein Coupled Receptors ◽  
Membrane Microdomains ◽  
Adult Cardiac Myocytes ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
G Protein Coupled

G-protein-coupled receptors (GPCRs) and post-GPCR signalling components are expressed at low overall abundance in plasma membranes, yet they evoke rapid, high-fidelity responses. Considerable evidence suggests that GPCR signalling components are organized together in membrane microdomains, in particular lipid rafts, enriched in cholesterol and sphingolipids, and caveolae, a subset of lipid rafts that also possess the protein caveolin, whose scaffolding domain may serve as an anchor for signalling components. Caveolae were originally identified based on their morphological appearance but their role in compartmentation of GPCR signalling has been primarily studied by biochemical techniques, such as subcellular fractionation and immunoprecipitation. Our recent studies obtained using both microscopic and biochemical methods with adult cardiac myocytes show expression of caveolin not only in surface sarcolemmal domains but also at, or close to, internal regions located at transverse tubules/sarcoplasmic reticulum. Other results show co-localization in lipid rafts/caveolae of AC (adenylyl cyclase), in particular AC6, certain GPCRs, G-proteins and eNOS (endothelial nitric oxide synthase; NOS3), which generates NO, a modulator of AC6. Existence of multiple caveolin-rich microdomains and their expression of multiple modulators of signalling strengthen the evidence that caveolins and lipid rafts/caveolae organize and regulate GPCR signal transduction in eukaryotic cells.

scholarly journals G-protein coupled receptors in lipid rafts and caveolae: how, when and why do they go there?

2004 ◽  
Vol 32 (2) ◽  
pp. 325-338 ◽  
Author(s):  
B Chini ◽  
M Parenti
Keyword(s):  
G Protein ◽  
Lipid Rafts ◽  
G Protein Coupled Receptors ◽  
Fine Tuning ◽  
Membrane Microdomains ◽  
Signalling Molecules ◽  
Cell Functions ◽  
Experimental Approaches ◽  
G Protein Coupled

This review describes the advances in our understanding of the role of G-protein coupled receptor (GPCR) localisation in membrane microdomains known as lipid rafts and caveolae. The growing interest in these specialised regions is due to the recognition that they are involved in the regulation of a number of cell functions, including the fine-tuning of various signalling molecules. As a number of GPCRs have been found to be enriched in lipid rafts and/or caveolae by means of different experimental approaches, we first discuss the pitfalls and uncertainties related to the use of these different procedures. We then analyse the addressing signals that drive and/or stabilise GPCRs in lipid rafts and caveolae, and explore the role of rafts/caveolae in regulating GPCR trafficking, particularly in receptor exo- and endocytosis. Finally, we review the growing evidence that lipid rafts and caveolae participate in the regulation of GPCR signalling by affecting both signalling selectivity and coupling efficacy.

Consequences of lipid raft association on G-protein-coupled receptor function.

2005 ◽  
Vol 72 ◽  
pp. 151-164 ◽  
Author(s):  
Anja Becher ◽  
R. A. Jeffrey McIlhinney
Keyword(s):  
G Protein ◽  
Lipid Rafts ◽  
Lipid Raft ◽  
Neurological Disorders ◽  
G Protein Coupled Receptors ◽  
Membrane Microdomains ◽  
Pharmaceutical Drug ◽  
Cellular Processes ◽  
G Protein Coupled ◽  
Specific Membrane

GPCRs (G-protein-coupled receptors) play key roles in many cellular processes, and malfunction may lead to a range of pathologies, including psychiatric and neurological disorders. It is therefore not surprising that this group of receptors supplies a majority of the targets for pharmaceutical drug development. Despite their importance, the mechanisms that regulate their function and signalling still remain only partially understood. Recently, it has become evident that a subset of GPCRs is not homogeneously distributed in the plasma membrane, but localizes instead to specific membrane microdomains known as lipid rafts. Lipid rafts are characterized by their enrichment in cholesterol and sphingolipids, and have been suggested to serve as platforms for a range of cellular signalling complexes. In the present review, we will be discussing the effects of the lipid raft environment on trafficking, signalling and internalization of raft-associated GPCRs.

scholarly journals Endothelial nitric oxide synthase interactions with G-protein-coupled receptors

1999 ◽  
Vol 343 (2) ◽  
pp. 335 ◽  
Author(s):  
Mario B. MARRERO ◽  
Virginia J. VENEMA ◽  
Hong JU ◽  
Han HE ◽  
Haiying LIANG ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
G Protein ◽  
Endothelial Nitric Oxide Synthase ◽  
G Protein Coupled Receptors ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
G Protein Coupled

scholarly journals Pseudotypes of Vesicular Stomatitis Virus with CD4 Formed by Clustering of Membrane Microdomains during Budding

2005 ◽  
Vol 79 (11) ◽  
pp. 7077-7086 ◽  
Author(s):  
Erica L. Brown ◽  
Douglas S. Lyles
Keyword(s):  
Plasma Membrane ◽  
G Protein ◽  
Lipid Rafts ◽  
Immunoelectron Microscopy ◽  
Vesicular Stomatitis Virus ◽  
Plasma Membranes ◽  
Membrane Microdomains ◽  
Virus Budding ◽  
Vesicular Stomatitis ◽  
Membrane Components

ABSTRACT Many plasma membrane components are organized into detergent-resistant membrane microdomains referred to as lipid rafts. However, there is much less information about the organization of membrane components into microdomains outside of lipid rafts. Furthermore, there are few approaches to determine whether different membrane components are colocalized in microdomains as small as lipid rafts. We have previously described a new method of determining the extent of organization of proteins into membrane microdomains by analyzing the distribution of pairwise distances between immunogold particles in immunoelectron micrographs. We used this method to analyze the microdomains involved in the incorporation of the T-cell antigen CD4 into the envelope of vesicular stomatitis virus (VSV). In cells infected with a recombinant virus that expresses CD4 from the viral genome, both CD4 and the VSV envelope glycoprotein (G protein) were found in detergent-soluble (nonraft) membrane fractions. However, analysis of the distribution of CD4 and G protein in plasma membranes by immunoelectron microscopy showed that both were organized into membrane microdomains of similar sizes, approximately 100 to 150 nm. In regions of plasma membrane outside of virus budding sites, CD4 and G protein were present in separate membrane microdomains, as shown by double-label immunoelectron microscopy data. However, virus budding occurred from membrane microdomains that contained both G protein and CD4, and extended to approximately 300 nm, indicating that VSV pseudotype formation with CD4 occurs by clustering of G protein- and CD4-containing microdomains.

Compartmentation of G-protein-coupled receptors and their signalling components in lipid rafts and caveolae

2005 ◽  
Vol 33 (5) ◽  
pp. 1131 ◽  
Author(s):  
B.P. Head ◽  
P.A. Insel ◽  
H.H. Patel ◽  
D.M. Roth ◽  
R.A. Bundey ◽  
...  
Keyword(s):  
G Protein ◽  
Lipid Rafts ◽  
G Protein Coupled Receptors ◽  
G Protein Coupled

Activation of G-Protein-Coupled Receptors in Cell-Derived Plasma Membranes Supported on Porous Beads

2011 ◽  
Vol 133 (42) ◽  
pp. 16868-16874 ◽  
Author(s):  
Sophie Roizard ◽  
Christophe Danelon ◽  
Ghérici Hassaïne ◽  
Joachim Piguet ◽  
Katrin Schulze ◽  
...  
Keyword(s):  
G Protein ◽  
Plasma Membranes ◽  
G Protein Coupled Receptors ◽  
Porous Beads ◽  
G Protein Coupled

scholarly journals G-protein-coupled Receptor Kinase Interactor-1 (GIT1) Is a New Endothelial Nitric-oxide Synthase (eNOS) Interactor with Functional Effects on Vascular Homeostasis

2012 ◽  
Vol 287 (15) ◽  
pp. 12309-12320 ◽  
Author(s):  
Songling Liu ◽  
Richard T. Premont ◽  
Don C. Rockey
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cell ◽  
Liver Injury ◽  
G Protein ◽  
Enzyme Activation ◽  
G Protein Coupled Receptor ◽  
Post Translational Modifications ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
G Protein Coupled

Endothelial cell nitric-oxide (NO) synthase (eNOS), the enzyme responsible for synthesis of NO in the vasculature, undergoes extensive post-translational modifications that modulate its activity. Here we have identified a novel eNOS interactor, G-protein-coupled receptor (GPCR) kinase interactor-1 (GIT1), which plays an unexpected role in GPCR stimulated NO signaling. GIT1 interacted with eNOS in the endothelial cell cytoplasm, and this robust association was associated with stimulatory eNOS phosphorylation (Ser1177), enzyme activation, and NO synthesis. GIT1 knockdown had the opposite effect. Additionally, GIT1 expression was reduced in sinusoidal endothelial cells after liver injury, consistent with previously described endothelial dysfunction in this disease. Re-expression of GIT1 after liver injury rescued the endothelial phenotype. These data emphasize the role of GPCR signaling partners in eNOS function and have fundamental implications for vascular disorders involving dysregulated eNOS.

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