Molecular architecture of Galphao and the structural basis for RGS16-mediated deactivation.

ABSTRACT: Heterotrimeric G proteins relay extracellular cues from heptahelical transmembrane receptors to downstream effector molecules. Composed of an alpha subunit with intrinsic GTPase activity and a betagamma heterodimer, the trimeric complex dissociates upon receptor-mediated nucleotide exchange on the alpha subunit, enabling each component to engage downstream effector targets for either activation or inhibition as dictated in a particular pathway. To mitigate excessive effector engagement and concomitant signal transmission, the Galpha subunit's intrinsic activation timer (the rate of GTP hydrolysis) is regulated spatially and temporally by a class of GTPase accelerating proteins (GAPs) known as the regulator of G protein signaling (RGS) family. The array of G protein-coupled receptors, Galph

SUBMITTER: Slep KC 

PROVIDER: S-EPMC2359805 | biostudies-literature | 2008 Apr

REPOSITORIES: biostudies-literature