FGF-6

Fibroblast Growth Factor-6 (FGF-6), also known as HST2, is a 25-28 kDa member of the FGF family of heparin binding polypeptides which are potent regulators of cell proliferation, differentiation, and function. FGF proteins contain a 120 amino acid (aa) core FGF domain that exhibits a β-trefoil structure. Mature human FGF6 is a 171 aa protein that shares 94% aa sequence identity with mouse and rat FGF6. It binds and signals primarily through FGF R1c, 2c, and 4. FGF6 functions as a mitogen for fibroblasts, vascular endothelial cells, and prostate carcinoma cells, and N-linked glycosylation is required for the full mitogenic effect. FGF6 expression is restricted to skeletal muscle during development although it can be upregulated in prostate cancer and Kaposi sarcoma. In the adult, FGF6 is upregulated in injured skeletal muscle and is required for muscle regeneration. FGF6 inhibits the terminal differentiation of myoblasts and also cooperates with TGFβ-2 to promote chondrogenesis in embryonic somites.