Regulates G protein-coupled receptor signaling cascades. Inhibits signal transduction by increasing the GTPase activity of G protein alpha subunits, thereby driving them into their inactive GDP-bound form. The RGS7/GNB5 dimer enhances GNAO1 GTPase activity. May play a role in synaptic vesicle exocytosis. Modulates the activity of potassium channels that are activated by GNAO1 in response to muscarinic acetylcholine receptor M2/CHRM2 signaling (PubMed:10092682). Interacts with PKD1; this prevents rapid proteasomal degradation. Interacts with GNB5. Interacts with RGS7BP, leading to regulate the subcellular location of the heterodimer formed with GNB5. Interacts (phosphorylated form) with 14-3-3 protein YWHAQ. Interacts with SNAPIN. Interacts with GNAI1 (By similarity). Interacts with GNAO1, GNAI3 and GNAZ (PubMed:10092682). Interaction with PKD1 promotes location at the cell membrane. Interaction with RGS7BP promotes location at the cell membrane. Brain-specific. Predominantly cerebellar granule cells. Palmitoylated. Ubiquitinated, leading to rapid proteasomal degradation. Phosphorylation and subsequent interaction with 14-3-3 proteins inhibits GAP activity.