FIGURE 6.

S287A-STAT2 is protected from IFN-α desensitization. U6A cells stably expressing WT-STAT2 or S287A-STAT2 were treated with IFN-α (1000 units/ml) for 10 h, followed by two washes with PBS, and addition of regular DMEM for 14 h. Cells were then restimulated with IFN-α for the indicated times. Naïve cells indicate U6A WT-STAT2 or S287A-STAT2 that have been treated with IFN-α for 0.5 h without prior desensitization. Tyrosine phosphorylation of STAT2 (pSTAT2) and STAT1 (pSTAT1) were evaluated by immunoblot analysis. Immunoblots shown are one representative experiment of three performed.