FIG. 3.

Influence of kinase inhibitors on PKC-ι's tyrosine phosphorylation state and activity. (A) Cells were pretreated with genistein (0 to 20 μM), PP2 (0 to 40 μM), or K252a (0 to 300 nM) for 1 h prior to stimulation with 100 ng of NGF/ml for 15 min. Tyrosine phosphorylation of PKC-ι was determined by immunoprecipitation (IP) with 4G10 followed by PKC-ι Western blotting (WB). (B) Activity of PKC-ι was assayed in triplicate by immune complex kinase assay. PKC activity was normalized after adjusting NGF-induced activity to 100%. Values are means ± SEM (n = 3).