Effects and side-effects of viral RNA silencing suppressors on short RNAs.

In eukaryotes, short RNAs play a crucial regulatory role in many processes including development, maintenance of genome stability and antiviral responses. These different but overlapping RNA-guided pathways are collectively termed 'RNA silencing'. To counteract an antiviral RNA silencing response, plant viruses express silencing suppressor proteins. Recent results have shown that silencing suppressors operate by modifying the accumulation and/or activity of short RNAs involved in the antiviral response. Because RNA silencing pathways intersect, silencing suppressors can also inhibit other short-RNA-regulated pathways. Thus, suppressors contribute to viral symptoms. These findings fuel further research to test whether certain symptoms caused by animal viruses are also manifestations of altered RNA regulatory pathways.