FIG 9.

IFN-β promoter binding assay. HEK293 cells were cotransfected with plasmids encoding eGFP-IRF3 or eGFP or MAVS, as well as with increasing amounts of plasmids encoding 3×FLAG-tagged SFSV NSs, or the 3×FLAG-tagged control protein ΔMx, as indicated. Cell lysates were then incubated with an unlabeled, double-stranded DNA oligonucleotide comprising the IFN-β promoter or with a scrambled control oligonucleotide or were left untreated. Next, streptavidin-coated magnetic beads covered with biotinylated IFN-β promoter oligonucleotide were used to pull down activated IRF3. Bound proteins were eluted by boiling in Laemmli buffer and analyzed by immunoblotting.