FIG 3.

Effect of Prp18 on primary transcription. (A) HeLa cells were transfected with control siRNA or siPrp18. At 48 h posttransfection, cells were transfected with the pCAGGS-rPrp18-Myc (containing a silent mutation within the siRNA target sequence) and pCAGGS-empty plasmids. After 24 h posttransfection, cells were superinfected with influenza virus at an MOI of 3 and incubated for 4 h in the presence of cycloheximide (CHX). Total RNAs were subjected to quantitative RT-PCR with a primer set specific for segment 5 mRNA. The results are normalized to the level of 18S rRNA. The averages and standard deviations determined from three independent experiments are shown. The level of significance was determined by Student's t test (*, P < 0.01). (B) Western blotting was conducted by using infected cells prepared as described above for panel A. Cell lysates were loaded onto a 10% SDS-PAGE gel and subjected to Western blotting with anti-Prp18 antibody.