Cell type and tissue distribution of the fibroblast growth factor receptor

✍ Scribed by Bradley B. Olwin; Stephen D. Hauschka

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 718 KB
• Volume: 39
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.240390410

✦ Synopsis

A receptor for fibroblast growth factor (aFGF, bFGF) was partially characterized in intact cell cultures, cell plasma membranes, and tissue plasma membrane preparations. Analysis of 24 different cell types from four species identified a 165-kDa FGF receptor present on the cell surface of most mesodermal and neuroectodermal cells. Chemical crosslinking of '"I-aFGF to its cell surface recep tor was specifically blocked by a 100-fold molar excess of either aFGF or bFGF. In contrast to the similar molecular weight of FGF receptors, different cell types exhibited significant variations in binding of '251-aFGF to intact cultures with low values of 8 pM and 700, to high values of 60 pM and 30,000, for the K,, and receptor number per cell, respectively. A binding assay was developed for quantitation of '251-aFGF binding to cell-and tissue-derived membrane preparations.

Membranes prepared from baby hamster kidney cells exhibited a & of 55 pM, while a similar K,, of 67 pM was determined for intact baby hamster kidney cells. Although ten different adult bovine tissue membrane preparations and human term placental membranes exhibited no specific binding of lZ5I-aFGF, FGF receptor was detected in embryonic murine tissues (1 7 days gestation). These results support the existence, in a variety of cells, of either a common FGF receptor that binds both aFGF and bFGF or closely related FGF receptors that cannot be distinguished by molecular weight. The differential binding of FGF to its receptor in embryonic vs. adult tissues suggests a potentially broad role for FGF in embryonic development and a more restrictive role in the adult.