FIG 5.
Detection of STAT1/STAT2 heterodimer formation in HeLa cells after IFN-β treatment. (A) Cells were transfected with empty vector pXJ41 or pXJ41-3C. At 24 h posttransfection, cells were either left untreated (−) or treated (+) with 1,000 U/ml of IFN-β for 1 h and lysed for IP and Western blotting (WB), as indicated on the figure. Expression of 3Cpro is also shown. β-Actin was used as a loading control. The data presented here were results from one experiment of three IP and Western blotting experiments. (B) Densitometry analysis of the digital image from three independent experiments. The band intensities are shown as relative protein expression levels. Error bars indicate the standard deviations of three experiments.