Identification and isolation from bovine epithelial lens cells of two basic fibroblast growth factor receptors that possess bFGF-enhanced phosphorylation activities

Cross-linking of bound 125I-basic fibroblast growth factor (bFGF) to bovine epithelial lens cells identified two labelled species whose apparent molecular weights were identical with those of two phosphorylated proteins. The bFGF-stimulated phosphorylation of these proteins was shown to be rapid, suggesting an autophosphorylation process. To demonstrate that the phosphorylated proteins were indeed the bFGF-binding molecules, the two components were purified to homogeneity and their bFGF-binding activity was examined. We conclude that bFGF stimulates the phosphorylation of two receptors of 130 and 160 kDa in bovine epithelial lens cells.