FIG. 5.

PTB knockdown inhibits accumulation of gene products and replication of EMCV. (A) Western blot analysis demonstrates knockdown of endogenous PTB in HeLa S3 cells transfected with C2 (control) siRNA compared to P9 (PTB) siRNA (left panel). A cross-reacting protein, which is seen in HeLa S3 cells, is not affected by P9 treatment. Western blot analysis of lysates collected from HeLa S3 cells treated with either C2 or P9 siRNAs and infected with EMCV. Blots were probed for the EMCV 3D protein; the asterisk marks a cross-reacting protein indicating equal loading (right panel). (B) EMCV progeny after infection of HeLa S3 as determined by plaque assay from lysates shown in A. (C) One-step growth kinetics in EMCV-infected HeLa S3 cells treated with either C2 or P9 siRNAs. It should be noted that while the results of the one-step growth kinetics represent the average of duplicate samples, the Western blot results show levels of EMCV 3D for only one of these samples. In the few cases where the samples had large variance (e.g., the 6-h p.i. samples), it is not possible to make direct comparisons between levels of 3D and viral progeny.