Endothelin receptor type B, (ET-B) is a protein that in humans is encoded by the EDNRB gene.[5]
Endothelin receptor type B is a G protein-coupled receptor which activates a phosphatidylinositol-calcium second messenger system. Its ligand, endothelin, consists of a family of three potent vasoactive peptides: ET1, ET2, and ET3. 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.[6]
In melanocytic cells the EDNRB gene is regulated by the microphthalmia-associated transcription factor. Mutations in either gene are links to Waardenburg syndrome.[7][8]
The multigenic disorder, Hirschsprung disease type 2, is due to mutation in endothelin receptor type B gene.[9]
In horses, a mutation in the middle of the EDNRB gene, Ile118Lys, when homozygous, causes Lethal White Syndrome.[10] In this mutation, a mismatch in the DNA replication causes lysine to be made instead of isoleucine.[10] The resulting EDNRB protein is unable to fulfill its role in the development of the embryo, limiting the migration of the melanocyte and enteric neuron precursors. A single copy of the EDNRB mutation, the heterozygous state, produces an identifiable and completely benign spotted coat color called frame overo.[11]
Endothelin receptor type B has been shown to interact with Caveolin 1.[12]
AG mutation, which changed isoleucine to lysine in the predicted first transmembrane domain of the EDNRB protein. This was associated with LWFS when homozygous and with the overo phenotype when heterozygous. -->
This article incorporates text from the United States National Library of Medicine, which is in the public domain.
