Endothelin Receptor B (ETRB)

Endothelin receptor type B is a G protein-coupled receptor which activates a phosphatidylinoitol-calcium second messenger system. Its ligand, endothelin, consists of a family of three potent vasoactive peptides: ET₁, ET₂, and ET₃. Studies suggest that the multigenic disorder, Hirschsprung disease type 2, is due to mutation in endothelin receptor type B gene. A splice variant, named SVR, has been described; the sequence of the ETB-SVR receptor is identical to ETRB except for the intracellular C-terminal domain. While both splice variants bind ET₁, they exhibit different responses upon binding which suggests that they may be functionally distinct.In melanocytic cells the EDNRB gene is regulated by the microphthalmia-associated transcription factor. Mutations in either gene are links to Waardenburg syndrome.