FIGURE 5.

Inhibition of the ISR does not prevent caspase‐8 activation. (A) Casp9 ^−/− MEFs were treated with brefeldin A (BFA), etoposide or paclitaxel for the indicated times. Whole cell lysates were immunoblotted for p‐eIF2α, eIF2α, ATF4, CHOP and ACTIN. (b‐d) Casp9 ^−/− MEFs were treated with 200 nM integrated stress response inhibitor (ISRIB) (B) or transfected with non‐coding (NC) and Atf4 siRNA (C) or Ddit3 siRNA (D) followed by treatment with BFA, etoposide or paclitaxel for 24–72 h. Immunoblots show (B and C) ATF4, cleaved caspase‐8, cleaved caspase‐3 or (D) CHOP, cleaved caspase‐8 and caspase‐3. ACTIN was used as loading control