G protein-coupled receptor 143 (GPR143) is a receptor for tyrosine, L-DOPA and dopamine. After binding to L-DOPA, it stimulates Ca2+ influx into the cytoplasm, increases secretion of the neurotrophic factor SERPINF1 and relocalizes beta arrestin at the plasma membrane; this ligand-dependent signaling occurs through a G(q)-mediated pathway in melanocytic cells. GPR143 activity is mediated by G proteins which activate the phosphoinositide signaling pathway. It also plays a role as an intracellular G protein-coupled receptor involved in melanosome biogenesis, organization and transport. References: The UniProt Consortium. Nucleic Acids Res. 47: D506-515 (2019); Nucleic Acids Res. 2016 Jan 4;44(D1):D733-45, PMID:26553804