The function of GPR143 (G protein-coupled receptor 143, Ensembl gene identifier ENSG00000101850) is as follows. Receptor for tyrosine, L-DOPA and dopamine. After binding to L-DOPA, stimulates Ca(2+) 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. Its activity is mediated by G proteins which activate the phosphoinositide signaling pathway. Also plays a role as an intracellular G protein-coupled receptor involved in melanosome biogenesis, organization and transport. {ECO:0000269|PubMed:10471510, ECO:0000269|PubMed:16524428, ECO:0000269|PubMed:18697795, ECO:0000269|PubMed:18828673, ECO:0000269|PubMed:19717472}.