PKD activation and COX-2 expression require the CDC25 domain of PLCϵ. A, PKD phosphorylation (p-PKDS916) was measured in PLCϵ KO astrocytes that were infected with WT PLCϵ or CDC25Δ adenovirus followed by vehicle or thrombin (5 nm) treatment for 1 h. The p-PKDS916 protein levels were normalized to total PKD and expressed relative to its own averaged control. Representative Western blots are shown and data quantitated as the mean ± S.E. (n = 9) of four independent experiments (control error bars are small but present). B, COX-2 protein levels were measured in PLCϵ KO astrocytes infected with WT PLCϵ or CDC25Δ adenovirus followed by thrombin (5 nm) treatment for 1 h and 6 h. COX-2 protein levels were normalized to GAPDH and expressed relative to its own control. Representative Western blots are shown and data quantitated at the 6 h time point as the mean ± S.E. (n = 6) of three independent experiments. *, p < .01 between control and thrombin treatment; #, p < .01 between thrombin treatments, one-way ANOVA.