Fig 4.

ORF2 negatively regulates NYMV polymerase activity. (A) BSR-T7 cells were transfected with the NYMV minigenome encoding Gaussia luciferase and the indicated pCA expression vectors. To normalize for transfection efficiency, a plasmid encoding firefly luciferase was cotransfected. At 72 h posttransfection, Gaussia and firefly luciferase-mediated light emissions were quantified. The normalized value obtained for the positive control (containing pCA-N, -ORF3, and -L only) was arbitrarily set to 1. Bars represent the average values of three independent experiments. Standard deviations are shown. (B) The inhibitory effect of ORF2 on viral polymerase activity is dose dependent. BSR-T7 cells were transfected as in panel A but with increasing amounts of the ORF2-encoding plasmid. The analysis was performed as described for panel A. The normalized value obtained for the positive control (containing pCA-N, -ORF3, and -L only) was arbitrarily set to 100%. Bars show the average values of three independent experiments. Standard deviations are shown. RLU = relative light units.