Association of phospho-SHIP-1 with PKC-δ. Washed aspirin-treated human platelets were stimulated with 500 μM AYPGKF or 100 ng/mL CVX for 60 seconds at 37°C under stirring conditions, and then the samples were immunoprecipitated with total PKC-δ and immunoblotted for phospho-SHIP-1 (A) as described in “Immunoprecipitation and Western blotting.” Reverse immunoprecipitation experiments were carried out by immunoprecipitating total SHIP-1 and immunoblotting for total PKC-δ (B). Rabbit IgG served as a negative control for all our immunoprecipitation experiments.