Figure 4.

DNA-PK affects kinetics of IRF-3 degradation. (A) Immunoprecipitation-Western blot showing total levels of IRF-3 in M059J (DNA-PK−) and M059J with a chromosomal copy of DNA-PK (DNA-PK+) cells that had been infected with virus for indicated amounts of time. Immunoprecipitations were carried out by using the α-IRF-3 (SL-12) antibody covalently crosslinked to protein A/G beads. Immunoblotting was performed with the same antibody. (B) Immunofluorescence experiment showing the time course of nuclear IRF-3 staining in the same cell lines. After infection, cells were fixed in 2% paraformaldehyde and permeabilized with −20°C methanol to reveal almost exclusively nuclear IRF-3 staining. Cells were stained with the SL-12 antibody and counterstained with 4′,6-diamidino-2-phenylindole (DAPI). Subsequently, low-magnification confocal images were generated.