FIG. 1.

DNA binding of in vivo-phosphorylated IRF-3. Whole-cell extracts were prepared from 2fTGH and 2fTGH/IRF-7 (clone 7/9) cells infected with Sendai virus 4 h after infection and incubated (200 μg) with magnetic beads containing either IFNA1 or IFNA2 VRE for 2 h at 4°C as described previously (Au et al., submitted). After extensive washing, proteins retained on the beads were separated on SDS–10% polyacrylamide gels and transferred to membranes, and IRF-2, IRF-3, and IRF-7 were identified by immunoblotting with specific antibodies. The relative levels of IRF-2, IRF-3, and IRF-7 in total cellular lysates were determined by Western blotting.