PDK1 deficiency abolished agonist-induced phosphorylation of Akt Thr308 and Gsk3β Ser9 in platelets, and the Akt Ser473 phosphorylation did not contribute to thrombin-induced platelets activation. (A) The expression levels of downstream molecules of PDK1. The phosphorylation of Akt at Ser473 and Thr308, Gsk3β at Ser9, and S6k at Thr229 in PDK1^f/f and PDK1^−/− platelets in response to low doses of (B) thrombin, (C) ADP, and (D) U46619. (E) The phosphorylation of Akt Ser473, Akt Thr308, and Gsk3β Ser9 in PDK1^f/f platelets in response to a low dose of thrombin in the presence of dimethylsulfoxide, the PI3K inhibitor Wortmannin (Wort), and the Akt inhibitor SH6, respectively. (F) mTOR inhibitor PP242 (100nM) did not affect the aggregation of PDK1^f/f and PDK1^−/− platelets, respectively, in response to 0.05 U/mL of α-thrombin. (G) mTORC2 inhibitor PP242 inhibited most, but not all, the phosphorylation of Akt residue Ser473 in thrombin-treated PDK1^f/f platelets, but totally inhibited Akt Ser473 phosphorylation in PDK1^−/− platelets treated with α-thrombin. On the contrary, PP242 has no obvious effect on the phosphorylation of Akt Thr308 in PDK1^f/f and PDK1^−/− platelets in response to thrombin.