PLSCR1 inhibits influenza virus transcription and replication.
(A) HEK293T cells were transfected with siRNA targeting PLSCR1 or with scrambled siRNA for 48 h. The knockdown of PLSCR1 expression was confirmed by western blotting. (B) HEK293T cells treated with siRNA were transfected with the four RNP protein expression constructs (PB2, PB1, PA and, NP) derived from WSN virus, together with pHH21-SC09NS F-Luc, which encodes NS vRNA possessing a reporter firefly luciferase gene. At 48 h post-transfection, a dual-luciferase assay was performed in which the relative firefly luciferase activity was normalized to the internal control, Renilla luciferase activity. **, P < 0.01. (C, D) The PLSCR1-overexpressing or empty retrovirus-transduced control A549 cells were infected with WSN virus at an MOI of 5. Total RNA was harvested at 6 h (C) and 10 h (D) p.i. NP-specific vRNA, cRNA, and mRNA were analyzed by RT-qPCR and then normalized to GAPDH mRNA. The values shown are standardized to the corresponding RNA expression level in the control A549 cells (100%). **, P < 0.01.