G protein-coupled receptor 143 (GPR143)

G protein-coupled receptor 143 (GPR143), also called OA1, is an intracellular orphan GPCR found primarily in pigment-producing cells such as melanocytes and cells of the retinal pigment epithelium[1][2][4]. It regulates the size, maturation, and trafficking of melanosomes, organelles essential for producing and storing melanin, the pigment responsible for skin, hair, and eye color[1][3][5]. Mutations in the GPR143 gene cause ocular albinism type 1 (OA1), resulting in hypopigmentation and visual defects[5]. Endogenous ligands include L-DOPA, tyrosine, and dopamine; upon ligand binding, GPR143 activates calcium influx and can influence secretion of neurotrophic factors[6][8]. While its complete physiological role is still under investigation, GPR143 is considered a therapeutic and research target for pigmentary and visual disorders, with possible broader implications in cancer and cardiovascular regulation as suggested by recent studies[1][3].

Other names

OA1ocular albinism type 1 proteinocular albinism 1 (Nettleship-Falls)GP143_HUMAN[2][4][5]

Ligand binding (L-DOPA, dopamine) stimulates Ca^{2+} influx and secretion of neurotrophic factors; signal transduction via G proteins