Tgfb1 (transforming growth factor-β1 human) is a 25kDa peptide encoded by the gene mapped to human chromosome 19q13.2. TGF-β1 polypeptide is produced as a precursor with hydrophobic signal sequence, pro-region and mature peptide. Cleavage of the precursor at tetrabasic cleavage site results in monomers of carboxy-terminal 112 amino acids. The biologically active form of Tgfb1 exists as a disulphide-linked homodimer. In mammals, three isoforms of TGF-β has been identified : TGF-β1, TGF-β2 and TGF-β3.
TGF-β1 is a multifunctional peptide capable of influencing cell proliferation, tissue growth, differentiation, and other functions in a wide range of cell types. TGF-β1 plays a fundamental role in differentiation by involvement in adipogenesis, myogenesis, chondrogenesis, osteogenesis, epithelial cell differentiation and immune cell function. All cells possess a specific TGF-β1 receptor. Both transformed and non-neoplastic tissues release transforming growth factors.The multi-modal nature of TGF-β1 is seen in its ability to stimulate or inhibit cellular proliferation. TGF-β1 is associated with the developmental and metastasis of colorectal cancer.
Transforming growth factor-β1 (TGF-β1) is produced by many cell types, but is reported to be most concentrated in mammalian platelets, where it is present at approximately four times the level of TGF-β2.