Fig. 1. Gastrin stimulates the phosphorylation and activity of JNK. CHO cells expressing the human CCKBR were stimulated for the times indicated with 10 nM gastrin. A, whole cell lysates were immunoblotted with an anti-phospho-Thr183 and -Tyr185 JNK antibody. B, after IP with an anti-JNK1 antibody, JNK activity using GST-c-Jun-(179) as an exogenous substrate was assayed as described in "Materials and Methods." As shown (bottom panels), comparable amounts of JNK1 proteins were detected in whole cell lysates or immunoprecipitates of all of the above-mentioned experiments. The autoradiograms were densitometrically analyzed, and the data from at least three separate autoradiograms were plotted as fold stimulation and presented as means ± SE.