Ligand binding by fibroblast growth factor receptors investigated using chimeric receptor molecules.
In order to map in detail the ligand binding sites of fibroblast growth factor receptor 2 (FGFR2) and keratinocyte growth factor receptor (KGFR), we have generated receptor molecules that are chimeric within the membrane proximal sequence that varies between them. The chimeric molecules are found to bind aFGF with a greater than 5-fold difference in affinity, indicating that there is coupling between the chimeric regions with respect to aFGF binding. Further, binding of bFGF and KGF is abolished in the chimeras, showing that the binding site for these ligands requires the whole of the 48- or 50- amino acid variable sequence to be intact. Direct interactions between the different regions exchanged in the chimeras are most probably involved in forming KGF or bFGF binding sites.
Department of Chemical Immunology, Weizmann Institute of Science, Rehovot, Israel.
A
A
Yayon
T E
TE
Gray
Y
Y
Zimmer
M
M
Eisenstein
D
D
Givol
D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D003432:Cross-Linking Reagents; D017931:DNA Primers / Q000235:genetics; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008024:Ligands; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016133:Polymerase Chain Reaction; D051497:Receptor, Fibroblast Growth Factor, Type 2; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics / Q000378:metabolism*; D017978:Receptors, Growth Factor / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection
D003432:Cross-Linking Reagents; D017931:DNA Primers; D008024:Ligands; D017468:Receptors, Fibroblast Growth Factor; D017978:Receptors, Growth Factor; D011993:Recombinant Fusion Proteins; D016222:Fibroblast Growth Factor 2; D051497:Receptor, Fibroblast Growth Factor, Type 2; C065104:keratinocyte growth factor receptor