Fibroblast Growth Factor-4 (FGF4) is a 19 kDa protein, belonging to the FGF family of proteins. Fibroblast growth factors (FGF) are glycoproteins concealed in the extracellular matrix and cell surface. There are around 22 different types of FGFs known. These factors weigh in the range of 17 to 34 kDa and they possess a conserved sequence of 120 amino acids. The FGF4 gene is mapped to human chromosome 11q13.3.
Fibroblast growth factor-4 (FGF-4) is identified in NIH-3T3 cell assays as a transforming gene from DNA derived from human tumors, including stomach (hst) and colon cancers, Kaposi′s sarcoma, and hepatocellular carcinoma. FGF-4 includes a secretory signal sequence and shares 42% sequence identity with FGF-Basic at the amino acid level. Both FGF-4 and FGF-Basic bind to the same receptors. Mouse and human FGF-4 shares 82% homology with species cross-reactivity. FGF-4 does not appear to be expressed in normal adult tissues, but during embryogenesis, the gene is spatially and temporally regulated. FGF-4 is a mitogen for fibroblasts and endothelial cells and a potent promoter of angiogenesis. It is believed to be critical in embryonic limb development. FGF-4 participates in cell differentiation and cell migration.
