FIG 6.

Function of the NSs binding-deficient STAT2 chimera. The reporter plasmids were cotransfected into HEK293T cells with the expression plasmids for NSs and each STAT2 chimera. Twenty-four h after transfection, cells were treated with IFN-αA/D (500 U/ml) for 18 h or left untreated and then were lysed to measure luciferase activity (upper) or detect protein expression using immunoblotting (lower). The ISRE activity was calculated by dividing RLU in IFN-αA/D-treated cells by the units of cells not treated with IFN-αA/D. The ISRE activity in the absence of NSs was set as 100%. The assays were independently performed in triplicate. The data represent averages with SDs. **, P < 0.05 versus hSTAT2.