DHPG-induced regulation of eIF4F requires PI3K/mTOR signaling. A, The PI3K inhibitors did not significantly alter the DHPG-induced activation of either ERK2 or Mnk1. B, The mTOR inhibitor rapamycin (20 nm, 30 min) did not significantly alter the DHPG-induced activation of either ERK2 or Mnk1. C, The PI3K inhibitors LY294002 (50 μm, 30 min) and wortmannin (100 nm, 30 min) blocked the DHPG-induced increase in eIF4E phosphorylation. D, The mTOR inhibitor rapamycin (20 nm, 30 min) blocked the DHPG-induced increase in eIF4E phosphorylation. E, DHPG-induced increase in eIF4E phosphorylation occurs in 4E-BP2 knock-out mice but is not sensitive to rapamycin (20 nm, 30 min). Representative Western blots are shown in each panel. The cumulative data represent mean + SEM, and the number is indicated in the bars. *p < 0.05, statistical significance determined by Student’s t test. CTL, Control; LY, LY294002; wort, wortmannin; rap, rapamycin.