TGF beta (transforming growth factor beta) is a superfamily of cytokines that participate in a variety of cellular processes including growth, proliferation, differentiation, and apoptosis. There are 3 classes of receptors for TGF beta cytokines and they are known as type I, II, and III. TGF beta receptor type III (TGF beta-RIII) is a high affinity receptor for TGF beta-I and TGF beta-II and binds other TGF beta ligands with lower affinities. It is a 250-300 kDa protein that can exist as a single pass transmembrane protein or in its soluble/secreted form.
Transforming growth factor-beta receptor III (TGF-beta RIII) is one of three receptors for the secreted growth factor TGF-beta. Unlike type I and type II TGF-beta receptors, TGF-beta RIII does not participate directly in the propagation of intracellular signaling in response to TGF-beta binding (1). TGF-beta RIII typically functions as a coreceptor for TGF-beta by binding the ligand with high affinity in order to regulate signaling. TGF-beta RIII contains a large glycosylated extracellular domain and a small intracellular domain.
