FGF-5

The FGF family is comprised of at least seven polypeptides that are potent regulators of cell proliferation, differentiation and function. All FGFs have two conserved cysteine residues and share 30-50% sequence homology at the amino acid level. FGF5 was originally identified as a transforming gene by the NIH3T3 focus formation assay using DNA derived from human tumors. FGF5 cDNA encodes a 267 amino acid residue protein with a putative 22 amino acid residue signal peptide. The murine homologue of FGF5 was cloned and found to be 84% homologous to the human protein at the amino acid sequence level. Human and murine FGF5 exhibit cross species activity. In vitro, recombinant human FGF5 is a mitogen for Balb/3T3 fibroblasts and bovine heart endothelial cells. FGF5 was also reported to be a major muscle-derived survival factor for cultured spinal moto-neurons.