Flg-2, a new member of the family of fibroblast growth factor receptors.

Two genes, flg and bek, have been recently shown to encode receptors for fibroblast growth factors (FGF). Here we report the molecular cloning and sequence of a new member of the FGF receptor family, denoted flg-2, which was isolated from a human keratinocyte cDNA library. The cDNA sequence predicts an extracellular region possessing three immunoglobulin-like domains, a single transmembrane region and a cytoplasmic portion containing the tyrosine kinase domain split by a short inter-kinase segment. The amino acid sequence of flg-2 shows 68% and 64% identity with bek and flg, respectively. The most variable domain among the three genes is the amino-terminal immunoglobulin-like domain. Comparison with the chicken FGF receptor genes suggests that flg-2 is homologous to cek-2, whereas flg and bek are homologous to cek-1 and cek-3, respectively. Analysis of mRNA from various tissues shows that flg-2 is expressed predominantly in skin, brain and lung.