Viral Suppressors of Gene Silencing

Verchot-Lubicz, J.; Carr, J.P.

Virus-induced gene silencing and viral suppression of gene silencing was first described in plants using plant poty- and potexviruses. This research began by a few laboratories has burgeoned into a larger field of study surrounding the role of small 21–25 nt RNAs in modulating disease and development. Gene silencing is often referred to as an antiviral defense mechanism producing siRNAs which target viral genomes for degradation. Many viruses encode silencing suppressor proteins which function to block production of siRNAs or the ability of siRNAs to reach their targets. miRNAs are small RNAs which regulate development and nuclear gene expression. Recent studies have shown that viruses manipulate the miRNA pathway in a manner that alters host gene expression, sometimes causes developmental defects, and modulates disease symptoms.