TSP-1 and CD36-binding peptides induce activatory signaling in platelets. (A) (i) Platelets (3 × 10⁸/mL) were incubated with either TSP-1 (10 μg/mL) or CD36 binding peptide (10μM) for 1-15 minutes. After lysis, platelet proteins were separated by SDS-PAGE and immunoblotted for phosphoSrc-Tyr⁴¹⁸, followed by stripping and reprobing for β-tubulin. (ii) Platelets (3 × 10⁸/mL) were treated with TSP-1 (10 μg/mL) in the presence of either PP1 (20μM), FA6-152 (1 μg/mL), or IgG control (1 μg/mL) and processed as described in panel A. (B) As in panel A, except membranes were probed for phospho-p38. (C) As in panel A, except membranes were probed for phosphoJNK. All immunoblots are representative of 4 to 6 independent experiments.