- transforming growth factor
Proteins secreted by transformed cells that can stimulate growth of normal cells. Unfortunate misnomer, since they induce aspects of transformed phenotype, such as growth in semi-solid agar, but do not actually transform. TGF- a, a 50 amino acid polypeptide originally isolated from viral-transformed rodent cells, contains EGF-like domain and binds to EGF receptor. Stimulates growth of microvascular endothelial cells, ie. is angiogenic. TGF- b polypeptide, a homodimer of two 112 chains, is secreted by many different cell types, stimulates wound healing but in vitro is also a growth inhibitor for certain cell types. The TGF family includes many of the bone morphogenetic proteins (BMPs).
Dictionary of molecular biology. 2004.