G Protein Coupled Receptor 50 (GPR50)

GPR50 is a member of the G protein-coupled receptor family of integral membrane proteins and is most closely related to the melatonin receptor. GPR50 is able to heterodimerize with both the MT₁ and MT₂ melatonin receptor subtypes. While GPR50 has no effect on MT₂ function, GPR50 prevented MT₁ from both binding melatonin and coupling to G proteins.

Certain polymorphisms of the GPR50 gene in females are associated with increased risk of developing bipolar affective disorder, major depressive disorder, and schizophrenia. Other GPR50 gene polymorphism are associated with higher fasting circulating triglyceride levels and lower circulating High-density lipoprotein levels.