Activation of JNK activity by VRP treatment. Cell lysates were immunoprecipitated with JNK antibody. The immune complexes were washed twice with RIPA buffer and once in kinase buffer. The complex was then incubated in a kinase buffer containing recombinant GST c-Jun 0.2 μg/μL (1-79 amino acids) and 5 μCi γ³²P-ATP for 30 minutes at RT. The reaction was terminated by adding 2× SDS sample buffer and boiling the sample for 5 minutes at 100°C. Proteins were separated on 12% SDS-PAGE and detected by autoradiography. Normal rabbit IgG was used as a negative control for the immunoprecipitations. The increase in the activation of JNK is indicated (by fold increase).