FGFRL1: Structure, Molecular Function, and Involvement in Human Disease.

FGFRL1 (fibroblast growth factor receptor-like 1) is a newly identified member of the FGFR family. Its extracellular domain resembles the four conventional FGFRs, while its intracellular part lacks the tyrosine kinase domain necessary for FGF-mediated signal transduction. At first, it was only considered a "decoy receptor". However, recent studies have demonstrated that FGFRL1 is a multifunctional molecule involved in prenatal and postnatal growth of cartilage and osteogenesis, the development of embryonic kidney and diaphragm, the modulation of cellular biological behaviors, and cell signal transduction. The functional abnormalities of FGFRL1 contribute to human diseases including congenital disease, hypertension, osteoporosis, degenerative diseases of the central nervous system, and different kinds of tumors. The present review summarizes the research progress of FGFRL1, especially its subcellular location, molecular function, and associated human disease. These data may offer valuable resources for further studying the molecular function of FGFRL1 and disclosing the mechanism of its related human diseases.