Referenced in: none

Automatically associated channels: Kir3.1

Title: Heterotrimeric G proteins form stable complexes with adenylyl cyclase and Kir3.1 channels in living cells.

Authors: R Victor Rebois, Mélanie Robitaille, Céline Galés, Denis J Dupré, Alessandra Baragli, Phan Trieu, Nathalie Ethier, Michel Bouvier, Terence E Hebert

Journal, date & volume: J. Cell. Sci., 2006 Jul 1 , 119, 2807-18

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/16787947

Abstract
Bioluminescence resonance energy transfer (BRET) and co-immunoprecipitation experiments revealed that heterotrimeric G proteins and their effectors were found in stable complexes that persisted during signal transduction. Adenylyl cyclase, Kir3.1 channel subunits and several G-protein subunits (Galpha(s), Galpha(i), Gbeta(1) and Ggamma(2)) were tagged with luciferase (RLuc) or GFP, or the complementary fragments of YFP (specifically Gbeta(1)-YFP(1-158) and Ggamma(2)-YFP(159-238), which heterodimerize to produce fluorescent YFP-Gbeta(1)gamma(2)). BRET was observed between adenylyl-cyclase-RLuc or Kir3.1-RLuc and GFP-Ggamma(2), GFP-Gbeta(1) or YFP-Gbeta(1)gamma(2). Galpha subunits were also stably associated with both effectors regardless of whether or not signal transduction was initiated by a receptor agonist. Although BRET between effectors and Gbetagamma was increased by receptor stimulation, our data indicate that these changes are likely to be conformational in nature. Furthermore, receptor-sensitive G-protein-effector complexes could be detected before being transported to the plasma membrane, providing the first direct evidence for an intracellular site of assembly.