FIG 8.
FMDV 3Cpro induces KPNA1 degradation. (A) FMDV 3Cpro had no effects on KPNA2, KPNA3, or KPNA4. HeLa cells were cotransfected with pXJ41-3C and FLAG-tagged KPNA1, KPNA2, KPNA3, or KPNA4 plasmids. pXJ41 empty vector was used as a control. At 24 h posttransfection, cells were lysed with the cell lysis buffer supplemented with PMSF. Western blotting was done individually with antibody against FLAG, HA, or β-actin. The data presented here are results from one experiment of three Western blotting experiments. (B) Densitometry analysis of the digital image of FLAG-tagged KPNA1, KPNA2, KPNA3, or KPNA4 from three independent experiments. The band intensities of blotting with FLAG antibody are shown as the relative protein expression levels, normalized with β-actin. Error bars indicate the standard deviations of three experiments. (C) KPNA1 degradation in 3Cpro-expressing cells was independent of the proteasome and caspase pathways. HeLa cells were transfected with pXJ41 empty vector or pXJ41-3C. At 18 h posttransfection, MG132 or zVAD-FMK was added. Six hours later, the cells were harvested, and the endogenous KPNA1 was analyzed by Western blotting using antibody against KPNA1, HA, or β-actin. The data presented here are the results from one experiment of three Western blotting experiments. (D) Densitometry analysis of the digital image of KPNA1 from three independent experiments. The band intensities of blotting with KPNA1 antibody are shown as the relative protein expression levels, normalized with β-actin. Data represent the means ± the standard deviations (error bars) of three experiments.