Description
Activin receptor type-2B (ACVR2B) is also known as ActR-IIB and MGC116908, ACVR2B is an activin type 2 receptor.
Activins are dimeric growth and differentiation factors which belong to the transforming growth factor-beta (TGF-beta) superfamily of structurally related signaling proteins.
Activins signal through a heteromeric complex of receptor serine kinases which include at least two type I (I and IB) and two type II (II and IIB) receptors.
These receptors are all transmembrane proteins, composed of a ligand-binding extracellular domain with cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine specificity.
Type I receptors are essential for signaling; and type II receptors are required for binding ligands and for expression of type I receptors.
Type I and II receptors form a stable complex after ligand binding, resulting in phosphorylation of type I receptors by type II receptors.
Type II receptors are considered to be constitutively active kinases.
This gene encodes activin A type IIB receptor, which displays a 3- to 4-fold higher affinity for the ligand than activin A type II receptor.
Defects in ACVR2B are the cause of visceral heterotaxy autosomal type 4 (HTX4)