FIG 3.

Effects of HA ssNCRs on viral RNA synthesis and protein expression in an RNP reconstitution system derived from the WSN virus. (A) Effects of HA ssNCRs on viral RNA synthesis. 293T cells were transfected with four protein expression plasmids (pcDNA-PA, -PB1, -PB2, and -NP), together with a viral RNA expression plasmid (pPOLI-HA) in which the H1 ssNCR was replaced with other HA ssNCRs. The levels of mRNA, cRNA, and vRNA were detected by primer extension analyses. NC was the negative control, with only pPOLI-HA transfected. (B) Statistical analysis of the viral RNAs in panel A. The values of viral RNAs in the transfected 293T cells were standardized to the 5S rRNA level and then normalized to the levels of viral RNAs in the NC. The data represent the means and standard deviations (SD) of three independent experiments. (C) Effects of HA ssNCRs on viral protein expression. 293T cells were transfected as indicated for panel A. The levels of HA protein were analyzed by Western blotting. (D) Statistical analysis of HA protein expression levels in panel C. *, P < 0.05; **, P < 0.01; two-tailed Student's t test. The data represent the means and SD of three independent experiments.