Fibroblast growth factor receptor-like 1 (FGFRL1)

Fibroblast growth factor receptor-like 1 (FGFRL1) is the fifth and most recently characterized member of the fibroblast growth factor receptor family. Unlike the classical FGFR1–4, FGFRL1 has three extracellular immunoglobulin-like domains enabling it to bind fibroblast growth factor (FGF) ligands and heparin with high affinity, but it lacks the intracellular protein tyrosine kinase domain typical of other FGFRs; instead, it contains only a short intracellular tail with a histidine-rich motif[1][2]. FGFRL1 functions mainly as a cell adhesion molecule and is not capable of classical receptor tyrosine kinase signaling, though it can bind FGFs, possibly acting as a decoy receptor or modulator for FGF pathway activity[1][2]. It plays crucial roles in cell differentiation, cell–cell fusion, kidney development, and bone formation; deficiency or mutations in FGFRL1 can cause perinatal lethality in mice (due to diaphragm and kidney defects) and developmental disorders in humans, including craniosynostosis[1][2]. No approved drugs are known to interact with this receptor, and its deficiency or blockade presents significant safety concerns due to its importance in developmental processes[1][2]. Key points are drawn from primary review literature for maximal accuracy[1][2].

Other names

FGFRL1FGFR5FHFRUNQ480/PRO943FGF receptor-like protein 1FGFR-5FGF homologous factor receptorFGFR-like proteinFibroblast growth factor receptor 5fibroblast growth factor receptor 5fibroblast growth factor receptor-like 1

Not a classical signaling receptor; presumed to function as a decoy receptor for FGFs or as a cell adhesion molecule. No known mechanism for pharmacological modulation.