Insulin-like growth factor binding protein-1 : isolation of the gene and characterization of the protein

Fetal and postnatal growth is the ultitnate result of a delicate balance between processes of proliferation, differentiation and death of cells. Proliferation and differentiation are strictly controlled by growth factors and hormones. A large number of growth factors has been characterized thus far; among them are the Insulin-like Growth Factors I and II (IGF-I,-ll). IGFs were identified originally as mediators of Growth Hormone (GH) action (Salmon and Daughaday, 1957). Both IGFs are small, single chain polypeptides, with structural and functional similarity to insulin. They display insulin-like mitogenic and differentiation stimulating activities (Froesch et al, 1963; Rinderknecht and Humbel, 1976; Rinderknecht and Humbel, 1978a; Rinderknecht and Humbel ,1978b). The biological response of the IGFs is mediated by specific receptors (Recbler et al, 1980; Recbler and Nissley, 1986).