| RNA silencing is a eukaryotic RNA degradation mechanism that protects the genome against the invasion of foreign nucleic acids, such as viruses, transposons, and transgenes. The process is triggered by double-stranded RNA and culminates with the sequence-specific destruction of target RNAs. Similar gene requirements and common RNA intermediates in the pathway, reveal that this ancient RNA degradation mechanism occurs in a diverse array of eukaryotes including plants, fungi, worms, flies, algae and mammals. In plants, RNA silencing is induced by both transgene transcription and virus replication and, not surprisingly, many plant viruses encode proteins that are capable of inhibiting RNA silencing. Here we attempt to elucidate how the potyviral protein Helper Component-Proteinase (HC-Pro) suppresses RNA silencing in Nicotiana tabacum with the goals of gaining new insight into the mechanism of RNA silencing and providing new technology to improve genetic manipulation of important agricultural crops. |
