FIG. 5.
vIRF-2 binds to PKR in vitro. (A) In vitro-translated, 35S-labeled PKR was incubated with GST-tagged vIRF-2 or vIRF-1 coupled to glutathione-agarose beads as described in Materials and Methods. Lane 1 represents 10% of the input volume of in vitro-translated PKR (p68) used for the binding reactions. (B) Absence of binding of in vitro-translated, 35S-labeled luciferase (Lucif) or IRF-3 to GST/vIRF-2 beads. (C) Whole-cell lysates from IFN (500 U/ml, 16 h)-treated or untreated HeLa cells were incubated with GST-tagged vIRF-2 or vIRF-1 coupled to glutathione-agarose beads. Bound proteins were separated by SDS-PAGE and subjected to immunoblot analysis with anti-PKR antiserum. Lanes 1 and 2 show the presence of p68 in 10% of the input volume of cell lysates used for the binding reactions.