A novel fibroblast growth factor receptor-5 preferentially expressed in the pancreas

Using the polymerase chain reaction on human embryonic cDNAs, we isolated a cDNA encoding a novel 504 amino acid protein, termed fibroblast growth fac tor receptor (FGFR)-5, which is highly homologous to known FGFRs. The NH2-t erminal portion of FGFR5 contains a putative secretory signal sequence, thr ee typical immunoglobulin-like domains, six cysteines, and an acidic box, b ut no HAV motif. The COOH-terminal portion of FGFR5 contains one transmembr ane domain but no intracellular kinase domain. Recombinant FGFR5 expressed in COS-7 cells is not secreted. but recombinant truncated FGFR5 lacking the predicted transmembrane domain is secreted. Acidic fibroblast growth facto r (aFGF) and basic fibroblast growth factor (bFGF) do not bind to FGFR5. Am ong 23 adult human tissues, FGFR5 mRNA is preferentially expressed in the p ancreas. These results suggest that FGFR5 may provide a binding site for so me other fibroblast growth factors and may regulate some pancreatic functio n. (C) 2001 Elsevier Science B.V. All rights reserved.