MRGPRX4

G protein-coupled receptor for bile acids, which is specifically expressed in sensory neurons of dorsal root ganglion and is involved in itch perception. Activated by bile acids, such as deoxycholate, chenodeoxycholate, taurocholate, taurodeoxycholate and taurodeoxycholate. Has a preference for 3-sulfated bile acids, such as deoxycholate 3-sulfate, glycoursodeoxycholate 3-sulfate and tauroursodeoxycholate 3-sulfate, which are present at high level in cholestatic patients with itch symptoms. Bile acid-binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of downstream effectors. MRGPRX4 is coupled to G(q)/G(11) G alpha proteins and activates phospholipase C-beta, releasing diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) second messengers that modulate the activity of phosphatidylinositol 3-kinase and promote the release of Ca2+ ions from intracellular stores, respectively..

Function from UniProtKB (Q96LA9), read 2026-09-23. CC BY 4.0.