Figure 3

Mutation of crucial DPV UL41 residues rescued UL41 protein expression and IFN-β signalling. A HEK293T cells were transfected with the pcaggs-UL41-HA, pcaggs-mUL41-HA or empty vector. The cells were then harvested and subjected to RT-qPCR. B DEF cells were transfected with pcaggs-UL41-HA, pcaggs-mUL41-HA or empty vector and then treated with DMSO, 10 μM MG132, or 20 mM NH4Cl. C HEK293T cells were transfected with the pcaggs-UL41-HA, pcaggs-mUL41-HA or empty vector. Immunofluorescence analysis revealed that the fluorescence (green) was significantly stronger in the mUL41 group than in the UL41 group. D DEF cells were transfected with the UL41 or mUL41 expression plasmid or empty vector and then stimulated with 50 µg/mL poly(I:C) at 12 hpt. The cells were harvested and subjected to RT-qPCR after 24 h of stimulation. E DEF cells were co-transfected with IFN-β-Luc, pRL-TK, and 1 μg/well pcaggs-UL41-HA, 2 μg/well pcaggs-UL41-HA, 2 μg/well pcaggs-mUL41-HA or empty vector and then stimulated with 50 μg/mL poly(I:C) at 12 hpt. The cells were harvested and detected by the dual-luciferase assay at 24 hpt. Protein expression was confirmed by Western blotting. The data were analysed by one-way ANOVA. *p < 0.05, **p < 0.01.