Figure 1. E1A-ER fusion protein activates c-Jun through JNK.

(A) Histogram showing c-Jun-GAL4 reporter assay. Luciferase activity was determined for the indicated periods of time of incubation with 1 μM E₂ and then normalized with Renilla. (B) JNK inhibitor SP600125 (10 μM) significantly blocked E1A-induced c-Jun-GAL4 reporter expression. Cells were incubated with E₂ for 7 h. (C) E1A induced transient JNK activation. In vitro protein kinase assay of total JNK was performed with E1A-ER stably transfected cells using KinaseSTAR JNK activity assay kit (see Materials and Methods). In all histograms: one-tailed p-values were calculated by Student's t-test; error bars represent s.d.