YFLLRNP-induced Akt phosphorylation in human platelets. (A) Time-dependent phosphorylation (P) of Akt at Ser⁴⁷³ with YFLLRNP. Washed platelets were stimulated at 37°C for the time points indicated with YFLLRNP (500 μM) without stirring. (B) Washed platelets were incubated with different concentrations of YFLLRNP for 5 minutes at 37°C without stirring. The reaction was stopped by the addition of 3 × SDS sample buffer. Samples were separated by SDS-PAGE, transferred onto polyvinylidene difluoride membranes, and probed with anti-phospho-Akt (Ser⁴⁷³) antibody. Results are representative of 3 experiments.