G-protein-mediated regulation of phospholipase C Involvement of βγ 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 α subunits is responsible for pertussis toxin-insensitive activation of a family of phospholipase C-β isoenzymes. However, it also has been shown that G-protein βγ subunits activate certain of these phospholipase C-β 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.