UniProt: Q13585 GPR50 or melatonin-related receptor is a 617 amino acid protein that belongs to the G-protein coupled receptor 1 family, containing one disulfide bond. GPR50 does not bind melatonin and its endogenous ligand is still unknown. Nevertheless, this receptor has been shown to behave as an antagonist of the melatonin receptor MT1. GPR50 has been identified as a genetic risk factor for bipolar disorder and major depression in women, and it has been linked to neurite outgrowth, lipid metabolism, stress response and energy homeostasis and torpor. Its expression seems to be limited to brain, particularly the hypothalamus and pituitary. Application: IHC (p)