Fig. 3.

JNK-1 interacts with and phosphorylates DAF-16. (A) Coimmunoprecipitation (IP) assay. After transfection with either Flag-DAF-16 alone or in combination with Xpress-JNK-1, cell lysates were immunoprecipitated with anti-Xpress antibody and immunoblotted with anti-Flag antibody. (B) In vitro kinase assay. Cells were transfected with Xpress-JNK-1 and activated by UV, followed by immunoprecipitation with anti-Xpress antibody and incubation with His-DAF-16 (N-terminal fragment) in kinase buffer. (Right) Loading of the substrates [His-DAF-16 (N-terminal fragment) and c-Jun] stained with Coomassie blue is shown. In both A and B, the expression of protein was confirmed by immunoblotting with anti-Flag or anti-Xpress antibody.