Serine/threonine kinase receptors

Abstract

A new family of transmembrane receptors that contain intracellular serine/threonine kinase domains is emerging. Ligands for this class of receptors include members of the transforming growth factor-β (TGF-β) superfamily, e.g. TGF-βs and activins. TGF-βs exert their effects on target cells via formation of heteromeric serine/threonine kinase complexes (TGF-β type I and type II receptors). Other components, i.e. TGF-β type III receptor and endoglin, appear to have more indirect roles, e.g. to present ligands to the signalling receptors. Given the structural similarity between members of the TGF-β superfamily, other ligands in this family may act through structurally and functionally similar serine/threonine kinase receptors.