Endothelin receptor type B (ETRB) is a G protein-coupled receptor that activates a phosphatidylinoitol-calcium second messenger system. Its ligand, endothelin, consists of a family of three potent vasoactive peptides: ET1, ET2, and ET3. A splice variant (SVR), differing in the intracellular C terminal domain, has been described for this receptor. Both WT and the variant bind ET1. However, they exhibit different responses upon binding - suggesting that these two variants are functionally disti