Role of PKC-θ on thromboxane generation and ERK phosphorylation. (A) Non–aspirin-treated mouse platelets separated from PKC-θ^−/− mice (■) and WT littermates (□) were stimulated with collagen (10 μg/mL) and CRP (10 μg/mL) as well as AYPGKF (100 μM) and thrombin (0.05 U/mL) for 3.5 minutes at 37°C in stirring condition. Reactions were terminated and the generated TXB₂ levels were measured. Data are presented as maximal percentage of TXB₂ generated in the WT controls. Each bar is the average ( ± SD) of 3 experiments from 3 different donors. (B) Stimulated washed mouse samples were also analyzed by Western blotting using antibodies against antiphospho-ERK and total ERK as lane loading control. The phenotype of the mice was assured by probing the mice samples with total PKC-θ antibody. The Western blot shown is representative of results from 3 different donors. Phosphorylation data were quantified and analyzed in fold increase over control.