GPR50 Antibody #13096

G-protein coupled receptor 50 (GPR50) is an orphan G-protein coupled receptor with high sequence homology to the melatonin receptors MT1 and MT2. While classified as a member of the melatonin receptor family and also known as melatonin-related receptor, GPR50 does not bind melatonin (1). GPR50 forms heterodimers with MT1 and MT2 and acts as a negative regulator of MT1 agonist binding and G protein coupling; inhibition of melatonin receptor activity is dependent on the long, proline-rich carboxy terminal tail of GPR50 (2). On a physiological level, GPR50 is involved in the regulation of adaptive thermoregulation in mammals and deletion of GPR50 in mice produces a profound effect on the response to fasting and facilitates entry into torpor (3). Polymorphisms in the corresponding GPR50 gene are associated with bipolar affective disorder and major depressive disorder in women, indicating that variation in GPR50 may be an important gender-specific risk factor for certain mental disorders (4,5).