Activation of Akt during ER stress is independent of eIF2α phosphorylation and is correlated with activation of mTOR. (a) Western blot analysis for phospho-Ser473 Akt (pAkt) in eIF2α wild-type (wt) and eIF2αS51A knock-in fibroblasts following exposure of cells to tunicamycin (Tunic). (b) Activation of Akt in response to ER stress in NIH 3T3 cells coadministered with 10 nM wortmannin, 10 μM PIK-294, or 10 μM IC-87114 to inhibit endogenous PI3K activity. (c) Activation of Akt during ER stress in H1299 cells overexpressing p85α wt and p110α, p85α wt, and dominant negative (DN) p110α. (d) PERK+/+ or PERK−/− cells were treated with tunicamycin for the times indicated, and lysates were resolved by SDS-PAGE or utilized to pull down eIF4E complex with 7-Met-GTP-Sepharose. Arrows indicate relative positions of phosphorylated 4E-PB1 and CHOP.