Figure 1.

Effect of MEK inhibition on AA release, ERK inhibition, and cPLA₂ Ser⁵⁰⁵ phosphorylation (A) EGFP-cPLA₂-transfected cells were incubated with the indicated concentrations of U0126 for 15 min prior to stimulation with 100 μM ATP, 1 μM IONO, or 10 μM IONO. AA release was assayed at 3 min. Results show the average ± SD of 3 experiments (error bars are down for ATP for clarity). Protein extracts from EGFP-cPLA₂-transfected cells incubated with the indicated concentrations of U0126 for 15 min prior to stimulation with 100 μM ATP, 1 μM IONO, or 10 μM IONO for 3 min were subjected to immunoblotting using (B) anti-phospho-ERK and (C) anti-cPLA₂ polyclonal antibodies. Results are from 3 to 5 independent experiments.