Inhibits signal transduction by increasing the GTPase activity of G protein alpha subunit egl-30 (G-alpha(q)), thereby driving it into its inactive GDP-bound form. May organize egl-30 into a stable multiprotein signaling complex, and thereby persistently inhibit egl-30 when triggered by calcium or phospholipids. Interacts with egl-30. The C2 and the RGS domains are both required for its inhibitory effect on G-protein signaling.