FIG. 3.
Activated forms of IRF-3 and IRF-7/3 chimeric proteins but not IRF-7 are associated with histone acetyltransferases. 293 cells were transfected with Flag-tagged IRF-3, IRF-7, or IRF-7/3 expression plasmids, as indicated above the lanes. At 24 h posttransfection, cells were infected with Sendai virus for 12 h (+) or left uninfected (−), as indicated. Whole-cell extracts (WCE) (200 μg for CBP and 500 μg for p300, PCAF, and TAFIII250) were immunoprecipitated with anti-CBP antibody A-22 (A), anti-p300 antibody N-15 (B), anti-PCAF antibody (C), or anti-TAFIIp250 antibody 6B3 (D). Immunoprecipitated complexes (upper panel) or 20 μg of whole-cell extracts (middle panel) was analyzed by SDS–8% PAGE and subsequently probed with anti-Flag antibody M2. The membranes shown in the upper panel were reprobed with anti-CBP antibody A-22 (A), anti-p300 antibody N-15 (B), anti-PCAF antibody (C), or anti-TAFIIp250 antibody 6B3 (D) (lower panel). IP, immunoprecipitation; IB, immunoblotting.