Long double-stranded RNAs (dsRNAs) may undergo extensive modification (hyperediting) by adenosine deaminases that act on RNA (ADARs), where up to 50% of adenosine (A) residues are changed to inosine (I). Traditionally, consequences of A-to-I editing were thought to be limited to modified RNA itself. We show here, however, that hyperedited dsRNA (I-dsRNA) is able to downregulate gene expression ...

BACKGROUND RNA interference (RNAi) is a phenomenon in which introduced double-stranded RNAs (dsRNAs) silence gene expression through specific degradation of their cognate mRNAs. Recent analyses in vitro suggest that dsRNAs may be copied, or converted, into 21-23 nucleotide (nt) guide RNAs that direct the nucleases responsible for RNAi to their homologous mRNA targets. Such small RNAs are also a...

In plants, SGS3 and RNA-dependent RNA polymerase 6 (RDR6) are required to convert single- to double-stranded RNA (dsRNA) in the innate RNAi-based antiviral response and to produce both exogenous and endogenous short-interfering RNAs. Although a role for RDR6-catalysed RNA-dependent RNA polymerisation in these processes seems clear, the function of SGS3 is unknown. Here, we show that SGS3 is a d...

Eukaryotic RNA quality control (RQC) uses both endonucleolytic and exonucleolytic degradation to eliminate dysfunctional RNAs. In addition, endogenous and exogenous RNAs are degraded through post-transcriptional gene silencing (PTGS), which is triggered by the production of double-stranded (ds)RNAs and proceeds through short-interfering (si)RNA-directed ARGONAUTE-mediated endonucleolytic cleava...

The double-stranded RNA (dsRNA)-binding domain of the human p68 kinase has been localized to the N-terminal half of the enzyme by using progressive deletion analysis and in vitro binding assays. To further define the domains responsible for binding to dsRNA, we cloned the mouse dsRNA-activated p65 kinase and used sequence alignment to identify conserved domains in the N-terminal region. Deletio...

In Neurospora crassa, sequence-specific inhibition of endogenous genes can be induced by the introduction of transgenic DNA homologous to the target gene, through the mechanism of post-transcriptional gene silencing (PTGS) known as quelling. The application of this strategy to inactivate genes in N. crassa has, to date, been restricted by a limited silencing efficiency and instability of the si...

Abstract Citrus tristeza virus (CTV) is found worldwide wherever citrus cultivated, causing disease resulting in significant yield losses and sometimes the death of plant. Transgenic plants encoding CTV gene sequences have shown to exhibit pathogen-derived resistance CTV. Exogenous application double-stranded RNA (dsRNA) an established strategy for plant control, making this method attractive a...

Two distinct gene-silencing phenomena are observed in plants: transcriptional gene silencing (TGS), which involves decreased RNA synthesis because of promoter methylation, and posttranscriptional gene silencing (PTGS), which involves sequence-specific RNA degradation. PTGS is induced by deliberate [1-4] or fortuitous production (R.v.B., unpublished data) of double-stranded RNA (dsRNA). TGS coul...

RNA interference (RNAi) is a post-transcriptional gene silencing mechanism that widely exists in eukaryotes. RNAi is initiated by double-stranded RNA (dsRNA) or microRNA (miRNA) and degrades specific messenger RNAs (mRNAs) by RNA-induced silencing complex (RISC), and then it specifically impairs the expression of target genes [1,2]. Therefore, RNAi has been becoming an effective tool to explore...

The production of aberrant RNA (aRNA) is the initial step in several RNAi pathways. How aRNA is produced and specifically recognized by RNA-dependent RNA polymerases (RdRPs) to generate double-stranded RNA (dsRNA) is not clear. We previously showed that in the filamentous fungus Neurospora, the RdRP QDE-1 is required for rDNA-specific aRNA production, suggesting that QDE-1 may be important in a...