GTPase activator component of the RGS7-GNB5 complex that regulates G protein-coupled receptor signaling cascades ( ). The RGS7-GNB5 complex acts as an inhibitor signal transduction by promoting the GTPase activity of G protein alpha subunits, such as GNAO1, thereby driving them into their inactive GDP-bound form (, ). May play a role in synaptic vesicle exocytosis  (Probable). Glycine-dependent regulation of the RGS7-GNB5 complex by GPR158 affects mood and cognition via its ability to regulate neuronal excitability in L2/L3 pyramidal neurons of the prefrontal cortex (By similarity). Modulates the activity of potassium channels that are activated by GNAO1 in response to muscarinic acetylcholine receptor M2/CHRM2 signaling .
Subcellular locations: Cytoplasm, Cytosol, Cytoplasm, Cell membrane, Membrane
Interaction with PKD1 promotes location at the cell membrane . Interaction with RGS7BP promotes location at the cell membrane .