P19: Difference between revisions

==Plant Viral Protein p19 Suppression of RNA Silencing==

==Background==

[http://en.wikipedia.org/wiki/RNA_Silencing RNA silencing] is a gene inactivation system in many eukaryotes that relies on tiny RNAs as the targeting molecules. One function of RNA silencing, which is also called [http://en.wikipedia.org/wiki/Post-transcriptional_gene_silencing post-transcriptional gene silencing (PTGS)] or [[RNA Interference|RNA interference]] (RNAi), is to act in surveillance against molecular parasites, such as viruses. Double-stranded RNA triggers the RNA silencing pathway and most plant viruses use a double-stranded RNA to replicate their genome. Various plant viruses have developed evasion techniques to circumvent this surveillance system. In one such evasion strategy, the plant viral protein p19 suppresses a plant's anti-viral RNA silencing response. p19 binds with high affinity to the double-stranded RNA silencing mediator, called [http://en.wikipedia.org/wiki/Small_interfering_RNA siRNA], and this binding sequesters the siRNA, preventing its participation in later steps of RNA silencing.