G-PROTEIN-MEDIATED REGULATION OF PHOSPHOLIPASE-C - INVOLVEMENT OF BETA-GAMMA-SUBUNITS

The protein components of the G-protein-linked cell surface receptor-regulated inositol lipid-signaling cascade have been identified recently. The G(q) family of G-protein alpha subunits is responsible for pertussis toxin-insensitive activation of a family of phospholipase C-beta isoenzymes. However, it also has been shown that G-protein betagamma subunits activate certain of these phospholipase C-beta isoenzymes, and that this novel activity may account for activation of phospholipase C by G proteins that are not members of the G(q) family, including those that account for pertussis-toxin-sensitive inositol lipid signaling.