FIG. 5.

PKR activation by poly(I)-poly(C) in Huh7 cells. Huh7 cells were treated with 100 μg of poly(I)-poly(C) per ml for 2 h or with 1,000 U of IFN-α per ml for 16 h prior to harvest. PKR was immunoprecipitated from cell lysates, and kinase reactions were conducted with [γ-³²P]ATP with PKR still bound to the antibody beads. Phosphorylated PKR was analyzed by SDS-PAGE and autoradiography (top) or by phosphorimage analysis (bottom). Phosphorimage values are expressed as arbitrary units and represent the volume in individual PKR bands shown in the blot.