Molecular characterization of endothelin receptors

Following the first report on the identification of endothelin (ET), an increasing body of work has accumulated on this endothelium-derived 21-amino acid vasoconstrictor peptide. Subsequently, the existence of three distinct isoforms of ET, designated ET-1, ET-2 and ET-3, was predicted from the finding of three separate genes. The differential potencies of the three isoforms of the ET family have opened up the possibility of the existence of multiple ET receptor subtypes. Recently, molecular biological techniques provided direct evidence of at least two distinct subtypes of ET receptor. This article discusses the functions of the ETs, focusing especially on the molecular characteristics of their receptors.