FIG. 3.

(A) Time course of the CNF1-induced activation of JNK. HeLa cells were incubated for 0 to 5 h with 500 ng of GST-CNF1 per ml. After lysis, the endogenous JNK was immunoprecipitated from the clear lysates. The activity of the JNK was determined in a kinase assay, in which the immunocomplexed JNK was incubated for 30 min at 30°C with [γ-³²P]ATP and GST–c-Jun as substrates. The samples were subjected to SDS-PAGE and Western blotting. Phosphorylation of GST–c-Jun was quantified by the Image Quant program of the Phosphorimager (Molecular Dynamics). (B) The amount of precipitated JNK was determined by enhanced chemiluminescence.