TGF-ß1 (transforming growth factor beta 1) is one of three closely related mammalian members of the large TGF-ß1 superfamily that share a characteristic cystine knot structure. TGF-ß1, -2 and -3 are highly pleiotropic cytokines that act as cellular switches to regulate processes such as immune function, proliferation and epithelial-mesenchymal transition. Each TGF-ß isoform has some non-redundant function; for TGF-ß1, mice with targeted deletion show defects in hematopoiesis and endothelial differentiation and died of overwhelming inflammation. TGF-ß1 signaling begins with high-affinity binding to a type II ser/thr kinase receptor termed TGF-ß RII. This receptor then phosphorylates and activates a second ser/thr kinase receptor, TGF-ß RI (also called activin receptor-like kinase (ALK)-5), or alternatively, ALK-1. This complex phosphorylates and activates Smad proteins that regulate transcription.
Recombinant Human TGF-ß1 produced in CHO cells is a polypeptide chain containing 112 amino acids. A fully biologically active molecule, rhTGF-ß1 has a molecular mass of 12 kDa, analyzed by reducing SDS-PAGE and is obtained by chromatographic techniques at GenScript.