Figure 10.

FGF-2-activated shedding is blocked by an FGF receptor tyrosine kinase inhibitor. CHO cells were placed in serum-free media in the presence of FGF-2 and the FGF receptor tyrosine kinase inhibitor SU5402, or the PKC inhibitor G₀6983. Conditioned media and cell extracts were collected after two hours. The shed FGFR-1 ectodomain was precipitated with WGA-Sepharose. The cells were extracted directly into SDS-PAGE sample buffer. The samples were analyzed by SDS-PAGE and immunoblotting with Mab6 (A) or antibodies to phospho-ERK and total ERK (B) to test for the inhibition of FGFR-1 activation by SU5402.