FIGURE 6.
Dual functions of VA RNAIin vivo. VA RNAI is processed by Dicer to produce short single-stranded RNAs from the TS that are incorporated into RISC, and an apical stem-central domain (AS-CD) RNA, equivalent to TSΔ21 RNA, that remains fully active against PKR. Thus, each transcript from the VA RNAI gene is able to both saturate cellular RNA interference mechanisms and block the PKR-mediated down-regulation of general translation of cellular and viral proteins via eIF2α phosphorylation. Abbreviations used for proteins are as follows: PKR, dsRNA binding motifs (1 and 2); KD, kinase domain.