Fig 3.

Protein expression of subgenomic Rev reporters. 293T cells were transfected with the SA6-rev-luc reporter constructs (A) or with the SA5-rev-luc reporter constructs (B). Both constructs encode the firefly luciferase gene. Cells were cultured for 2 days, and the intracellular firefly luciferase level (relative light units [RLU]) was measured to quantify luciferase production, using renilla luciferase produced from the cotransfected pRL-CMV plasmid as an internal control. The ratio between firefly and renilla luciferase was calculated, and the results of 14 measurements (means ± standard errors of the means [SEM]) are shown. The mean value is shown next to each bar. Statistical analysis performed by one-way analysis of variance (ANOVA) demonstrated that luciferase production differed significantly between SA6-rev-luc (wt) and mutants 4 and 4a (A; ***, P < 0.0001); luciferase production differed significantly between SA5-rev-luc (wt) and mutants 4, 4a, and 1234 (B; *, P < 0.05). Control, cells transfected with pGL3-control; mock, cells transfected with pBluescript plasmid instead of firefly luciferase-encoding plasmid.