| Modification Notes |
A total of three members of the TGF∫ family, TGF∫1, TGF∫2 and TGF∫3, have been identified in mammals (1–3). Each is synthesized as a latent precursor that is subsequently cleaved forming the 112 amino acid growth factor which becomes active upon dimerization (2,3). TGF∫s mediate their activity by high affinity binding to the type II receptor transmembrane protein with a cytoplasmic serine-threonine kinase domain (4–6). TGF∫ RIII (transforming growth factor beta receptor type 3), also known as TGFBR3 or TGFR-3, is an 850 amino acid secreted and single-pass type I membrane protein that contains one ZP domain and may assist in capturing TGF∫ for presentation to signaling receptors. TGF∫ RIII undergoes post-translational modification by glycosaminoglycan groups (GAG) and is encoded by a gene that maps to human chromosome 1p22.2. |