(a) WT, WT-p150 KO, RNASEL KO, RNASEL-ADAR DKO, MAVS KO, MAVS-p150 DKO, MAVS-ADAR1 DKO; (PKR expression was induced 1.6–1.9 fold following IFN treatment in cells expressing ADAR1 and reduced 0.3–0.6 fold in cells deleted for ADAR1 or ADAR1 p150; Figure 2—source data 1.) (b) WT or RNASEL-MAVS DKO or (c) WT or PKR KO cells were treated or mock treated with 1000 U/ml IFN-α overnight, lysed and proteins analyzed by Western immunoblotting with antibodies as indicated. (d) WT and PKR KO cells were transfected with pIC (1 µg/ml). After 2 hr, proteins in cell lysates were separated by 12% SDS/PAGE, transferred to PVDF-membranes, and probed with antibodies to detect total eIF2α or phosphorylated eIF2α. Immunoblots (in a–c) were performed at least two times and one representative blot is shown. See Figure 2—figure supplement 1.