• FGFR4 (Fibroblast Growth Factor Receptor 4), is a member of the FGFR family of receptor tyrosine kinases. This family regulates a host of cellular functions including angiogenesis, mitogenesis, osteogenesis, myogenesis, carcinogenesis, cellular differentiation, and tissue repair after injury. The FGFR4 protein is a tyrosine-protein kinase that acts as a cell-surface receptor for fibroblast growth factors and plays a role in the regulation of cell proliferation, differentiation, migration, and in the regulation of lipid metabolism, bile acid biosynthesis, glucose uptake, vitamin D metabolism, and phosphate homeostasis. FGFR4 is required for normal down-regulation of the expression of CYP7A1, the rate-limiting enzyme in bile acid synthesis, in response to FGF19. FGFR4 plays a role in postnatal lung development and may be involved in the development of skeletal muscle cell lineages.

Western blot analysis of FGFR4 protein expression in homozygous B-hFGFR4 mice. Various tissue lysates were collected from wild-type C57BL/6N mice (+/+)  and homozygous B-hFGFR4 mice (H/H), and then analyzed by western blot with anti-FGFR4 antibody(Santa Cruz, sc-136988). 40 μg total proteins were loaded for western blotting analysis. FGFR4 was detectable in liver, lung, kidney, stomach, small intestine and testis. 

Strain specific analysis of FGFR4 mRNA expression in wild-type C57BL/6N mice and B-hFGFR4 mice by RT-PCR. Liver RNA were isolated from wild-type C57BL/6N mice (+/+) and homozygous B-hFGFR4 mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human FGFR4 primers. Mouse Fgfr4 mRNA were detectable only in wild-type C57BL/6 mice. Human FGFR4 mRNA was detectable only in homozygous B-hFGFR4 mice but not in wild-type mice.