FIGURE 12.

Effects of DGKη1(K74A) and DGKη1(R85A) on EGF-dependent activation of ERK. COS-7 cells were transfected with pAcGFP vector, pAcGFP-DGKη1, pAcGFP-DGKη1(K74A), or pAcGFP-DGKη1(R85A). After 24 h, the cells were serum-starved for 5 h and then stimulated with 100 ng/ml EGF for 5 min. ERK1/2 phosphorylation (p-ERK) and total ERK2 in the cell lysates were analyzed by Western blotting. A, representative results of Western blotting analysis are shown. B, the phospho-ERK levels (phosphorylated ERK/total ERK) were quantified by densitometry. Phospho-ERK levels in cells that were transfected with pAcGFP vector alone and stimulated with EGF for 5 min were set to 100. The data are shown as means ± S.D. of four independent experiments. The statistical significance was determined using analysis of variance followed by Tukey's post hoc test (*, p < 0.05; **, p < 0.01; ***, p < 0.005). Error bars represent S.E.