Human TGFb-R2

Most cell types express three sizes of receptors for TGF-beta. These are designated type I (53 kDa), type II (70-85 kDa), and type III (250-350 kDa). The type II receptor is a membrane-bound serine/threonine kinase that binds TGF-beta 1 and TGF-beta 3 with high affinity and TGF-beta 2 with a much lower affinity. Current evidence suggests that signal transduction requires the cytoplasmic domains of both the type I and type II receptors. The recombinant soluble TGF-beta type II receptor is capable of binding TGF-beta 1, TGF-beta 3, and TGF-beta 5 with sufficient affinity to act as an inhibitor of these isoforms at high concentrations (1-5).