GPR3

GPR3 is a member of the G protein-coupled receptor (GPCR) superfamily, officially named G protein-coupled receptor 3. It is also commonly referred to as MTR1 or GPR3_HUMAN. Functionally, GPR3 constitutively activates Gαs proteins, leading to sustained cAMP accumulation independent of exogenous ligands. This ligand-independent signaling plays a role in regulating cell cycle progression, particularly in oocyte maturation and neuronal survival by modulating downstream pathways like the PI3K-Akt and MAPK cascades.
Aberrant GPR3 expression or signaling has been linked to various pathological conditions, including ovarian disorders such as polycystic ovary syndrome (PCOS) and certain neurodegenerative diseases. Recent drug discovery efforts focus on developing selective modulators targeting GPR3, with small-molecule agonists and antagonists being explored for potential therapeutic applications in reproductive medicine and neurology, though clinical development remains in preclinical stages.