FIGURE 6.

IRF3 and IRF8 regulate MyD88 degradation through ubiquitin–proteasome pathway. (A) HEK293 cells were seeded in 12-well plates and transfected with 0.4 μg of MyD88 and IRF3 plasmids or IRF8 plasmids for 24 h, and then the cells were treated with dimethyl sulfoxide (DMSO) or 30 μM of MG132 for 10 h. MyD88 was determined by immunoblot assays. (B) HEK293 cells were transfected with 0.4 μg of MyD88 and concentration gradient of IRF3 plasmids (0.2 or 0.4 μg) or concentration gradient of IRF8 plasmids (0.2 or 0.4 μg). At 24 h post transfection, the cells were treated with DMSO or 30 μM of MG132 for 12 h, and MyD88 was determined by immunoblot assays. (C) HEK293 cells were transfected with 0.4 μg of MyD88 and IRF3 plasmids or IRF8 plasmids. After 24-h transfection, the cells were treated with CHX (100 μg/ml), and the experiment group was treated with 30 μM of MG132 for different times. MyD88 was determined by immunoblot assays. All experiments were performed in at least three independent experiments.