Structure, function, and evolution of adenovirus virus-associated RNAs.

Abstract

One of the charms of adenovirus is its unique blend of orthodoxy and idiosyncrasy. Although the virus operates largely via host cell mechanisms, at least for transcriptional and translational purposes, it coopts these mechanisms by using a variety of viral products to modify cellular activities for its own benefit. Nowhere is this better illustrated than in the virus-associated (VA) RNA genes, which are transcribed by RNA polymerase III (pol III) while the rest of the viral genome is grist for pol II. More abundant in the infected cell than any messenger RNA, the VA RNAs encode no protein but are essential for efficient translation, a feat that is accomplished through a protein kinase that is regulated by highly structured RNA molecules. The protein kinase is a key element in the cellular antiviral defenses that are induced by interferon, and it is probable that one of the roles of the VA RNAs in natural infections is to spike the defensive guns.