This gene encodes a member of the G-protein coupled receptor family. It encodes a receptor for endothelins, peptides that are involved in vasocontriction. The encoded protein activates a phosphatidylinositol-calcium second messenger system and is required for the development of enteric neurons and melanocytes. Gene disruption causes pigmentation anomalies, deafness, and abnormal dilation of the colon due to defects of neural crest-derived cells. Mutations in this gene are found in the piebald mouse, and mouse models of Hirschsprung's disease and Waardenburg syndrome type 4. Renal collecting duct-specific gene deletion causes sodium retention and hypertension. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2013]