Fig. (2) E1 represses UPR activation of BiP. Huh-7 cells were
co-transfected with the BiP reporter gene plasmid and the
respective plasmids as indicated together with the internal control
plasmid encoding β-galactosidase for 32 h and then treated with 1
µg/ml of tunicamycin (Tm) or the dimethylsulphoxide (DMSO)
solvent control for 16 h. The BiP promoter luciferase activity was
normalized against β-galactosidase activity and expressed relative
to the solvent controls, which are set as 1. The values obtained
represent the mean ± SEM of three independent experiments
performed in triplicate. *Significance of the difference (P<0.05).