When it comes to viruses, those that transiently infect their hosts and cause the most damage get a lot of attention. Hollywood makes movies about Ebola, or about fictional viruses that resemble souped-up versions of the 1918 pandemic flu.
RNA (ribonucleic acid) has come a long way in just a few short years. Once the ugly stepchild of the nucleic acids, it was thought to be a boring and simple intermediary that only decoded DNA into proteins. That’s an important role, but only a sliver of its diverse set of functions.
In antiviral RNA interference (RNAi), virus-derived double-stranded RNA is processed by the endoribonuclease DICER into 21–23 nucleotide small interfering RNAs (siRNAs) that guide ARGONAUTE proteins to silence complementary viral RNA. As a counter-strategy, viruses express viral suppressors of RNAi (VSRs).
