Fig. 6. EphB1/Fc stimulates phosphorylation of p46 JNK. (A) Kinetics of EphB1/Fc-induced JNK activation. CHO cells stably expressing ephrin-B1 were serum-starved overnight and stimulated with EphB1/Fc following a time course as indicated. Cells were lysed and 30 µg of protein was subjected to western blot analysis as described in the Materials and Methods. (B) Concentration dependence of EphB1/Fc-induced JNK activation. CHO cells stably expressing ephrin-B1 were treated with EphB1/Fc from 0 to 4 µg/ml for 20 minutes, and cell lysates were subjected to western blot analysis. (C) Ephrin-B1 C-terminal deletion mutants block EphB1/Fc-induced JNK activation. CHO cells transfected with vector (MOCK), full-length wild-type human ephrin-B1, ephrin-B1Cy or ephrin-B1PDZbd were serum starved and stimulated with EphB1/Fc, and cell lysates were subjected to western blot analysis. The data are representative of three independent experiments.