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

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 Interactions of GIPC with Dopamine D2, D3 but not D4 Receptors Define a Novel Mode of Regulation of G Protein-coupled Receptors

2004 ◽  
Vol 15 (2) ◽  
pp. 696-705 ◽  
Author(s):  
Freddy Jeanneteau ◽  
Jorge Diaz ◽  
Pierre Sokoloff ◽  
Nathalie Griffon
Keyword(s):  
Rat Brain ◽  
G Protein ◽  
Plasma Membranes ◽  
Pdz Domain ◽  
G Protein Coupled Receptors ◽  
Interacting Protein ◽  
R And D ◽  
C Terminus ◽  
Endogenous Proteins ◽  
G Protein Coupled

The C-terminus domain of G protein-coupled receptors confers a functional cytoplasmic interface involved in protein association. By screening a rat brain cDNA library using the yeast two-hybrid system with the C-terminus domain of the dopamine D3 receptor (D3R) as bait, we characterized a new interaction with the PDZ domain-containing protein, GIPC (GAIP interacting protein, C terminus). This interaction was specific for the dopamine D2 receptor (D2R) and D3R, but not for the dopamine D4 receptor (D4R) subtype. Pull-down and affinity chromatography assays confirmed this interaction with recombinant and endogenous proteins. Both GIPC mRNA and protein are widely expressed in rat brain and together with the D3R in neurons of the islands of Calleja at plasma membranes and in vesicles. GIPC reduced D3R signaling, cointernalized with D2R and D3R, and sequestered receptors in sorting vesicles to prevent their lysosomal degradation. Through its dimerization, GIPC acts as a selective scaffold protein to assist receptor functions. Our results suggest a novel function for GIPC in the maintenance, trafficking, and signaling of GPCRs.

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