STRUCTURE AND EXPRESSION OF HUMAN FIBROBLAST GROWTH FACTOR-10

We isolated the cDNA encoding a novel member of the human fibroblast g rowth factor (FGF) family from the lung. The cDNA encodes a protein of 208 amino acids with high sequence homology (95.6%) to rat FGF-10, in dicating that the protein is human FGF-10. Human FGF-10 as well as ra t FGF-10 has a hydrophobic amino terminus (similar to 40 amino acids), which may serve as a signal sequence. The apparent evolutionary relat ionships of human FGFs indicate that FGF-10 is closest to FGF-7. Chrom osomal localization of the human FGF-IO gene was examined by in situ h ybridization. The gene was found to map to the 5p12-p13 region. Human FGF-10 (amino acids 40 to 208 with a methionine residue at the amino t erminus) was produced in Escherichia coil and purified from the cell l ysate. Recombinant human FGF-10 (similar to 19 kDa) showed mitogenic a ctivity for fetal rat keratinizing epidermal cells, but essentially no activity for NIH/3T3 cells, fibroblasts. The specificity of mitogenic activity of FGF-10 is similar to that of FGF-7 but distinct from that of bFGF, In structure and biological activity, FGF-10 is similar to F GF-7.