Endothelin receptor type B, also known as ET
B is a
protein that in humans is encoded by the ''EDNRB''
gene.
Function
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: ET
1, ET
2, and ET
3. 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 ET
1, they exhibit different responses upon binding which suggests that they may be functionally distinct.
Regulation
In
melanocytic
Melanocytes are melanin-producing neural crest-derived cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea),
the inner ear,
vaginal epithelium, meninges,
bones,
and heart.
...
cells the EDNRB gene is regulated by the
microphthalmia-associated transcription factor
Microphthalmia-associated transcription factor also known as class E basic helix-loop-helix protein 32 or bHLHe32 is a protein that in humans is encoded by the ''MITF'' gene.
MITF is a basic helix-loop-helix leucine zipper transcription factor ...
. Mutations in either gene are links to
Waardenburg syndrome.
Clinical significance
The multigenic disorder,
Hirschsprung disease type 2, is due to mutation in endothelin receptor type B gene.
Animals
In
horses, a mutation in the middle of the EDNRB gene, Ile118Lys, when
homozygous, causes
Lethal White Syndrome.
In this mutation, a mismatch in the
DNA replication causes
lysine
Lysine (symbol Lys or K) is an α-amino acid that is a precursor to many proteins. It contains an α-amino group (which is in the protonated form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −C ...
to be made instead of
isoleucine
Isoleucine (symbol Ile or I) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH form under biological conditions), an α-carboxylic acid group (which is in the deprot ...
.
[ 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
Lethal white syndrome (LWS), also called overo lethal white syndrome (OLWS), lethal white overo (LWO), and overo lethal white foal syndrome (OLWFS), is an autosomal genetic disorder most prevalent in the American Paint Horse. Affected foals are bor ...
.
Interactions
Endothelin receptor type B has been shown to interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with Caveolin 1.
Ligands
; Agonists
* IRL-1620
See also
* Endothelin receptor
There are at least four known endothelin receptors, ETA, ETB1, ETB2 and ETC, all of which are G protein-coupled receptors whose activation result in elevation of intracellular-free calcium, which constricts the smooth muscles of the blood vessels ...
References
Further reading
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External links
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{{DEFAULTSORT:Endothelin Receptor Type B
G protein-coupled receptors