FIG. 6.

Prevention of PKR activation late in the viral life cycle requires the Us11 gene product. (A) S10 extracts from infected or mock-infected U373 cells were prepared at 18 h postinfection. After the extracts were incubated in the presence of [γ-³²P]ATP, PKR activation was assessed by immunoprecipitating PKR. Immune complexes were fractionated by SDS-polyacrylamide gel electrophoresis, and the fixed, dried gel was exposed to Kodak XAR film. (B) U373 cells were infected and processed as described in the legend to Fig. 3A. The abundances of total eIF2α (bottom) and eIF2α phosphorylated on Ser 51 (top) were evaluated by immunoblotting.