Selective inhibition of G protein-mediated pathways using RGS domains.

Regulators of G protein signaling (RGS) proteins are recently identified regulators of G protein-mediated pathways. These proteins recognize specific members of G protein alpha subunits and, in most cases, act as GTPase activating proteins (GAPs). RGS proteins interact with activated forms of G alpha subunits through RGS domain of about 120 amino acids. Thus, the overexpression of the RGS domain in cells can specifically block the signalling pathways that are mediated by the interacting G proteins. The method is particularly useful to differentiate between Gq-mediated and G12/13-mediated pathways.