Figure 5.

PHE decreases PKCζ activity in rat-1 fibroblasts. A, Cells were treated with 2 μM PHE for 0, 2, 5, 10 and 15 min, lysed and immunoprecipitated with PKCζ antibody for a kinase assay using [γ-³²P]ATP and a selective peptide substrate as described in Methods. Relative PKCζ activity was expressed as the fold (increase or decrease) of basal. Values are the mean ± S.E. of four independent experiments. * Value significantly different from the basal, p < .05. B, Effect of myristoylated PSζ on PKCζ activity. Cells were pretreated with 50 μM PSζ for 1 hour followed by a 5 min treatment with 2 μM PHE or its vehicle. PKCζ activity was measured as previously described. Values are the mean ± S.E. of four independent experiments. * Value significantly different from vehicle, p < .001. †, Value significantly different from PHE alone, p < .01.