Fig. 1.

FGF1/CPP-C reacts with all FGFR subtypes more weakly than FGF1. (A) The structure of the FGF1/CPP-C fusion protein is shown. (B) In addition to the signaling pathway of FGF through cell surface receptors, the cellular internalization of FGF induces other signaling pathways. The potential signaling pathways by FGF1/CPP-C are shown. (C) The BaF3 transfectant cell line expressing each FGFR subtype was cultured for 42 h with FGF1 or FGF1/CPP-C at the indicated concentrations in the presence of 5 μg/ml heparin. Cell numbers were estimated from optical absorbance at 450 nm (ABS450) using WST-1 reagent. All values are means ± SD (n = 4). ^*P < 0.05; ^***P < 0.001.