Recognition of virus presence via RIG-I (retinoic acid inducible gene I) and/or MDA5 (melanoma differentiation-associated protein 5) initiates a signaling cascade that culminates in transcription of innate response genes such as those encoding the alpha/beta interferon (IFN-alpha/beta) cytokines. It is generally assumed that MDA5 is activated by long molecules of double-stranded RNA (dsRNA) pro...

Processive transcription antitermination requires the assembly of the complete antitermination complex, which is initiated by the formation of the ternary NusB-NusE-BoxA RNA complex. We have elucidated the crystal structure of this complex, demonstrating that the BoxA RNA is composed of 8 nt that are recognized by the NusB-NusE heterodimer. Functional biologic and biophysical data support the s...

Abstract RNA interference (RNAi) represents one of the most conserved pathways evolved by eukaryotic cells for regulating gene expression. RNAi utilises non-translatable double-stranded (dsRNA) molecules to sequester or degrade mRNA gene. In RNAi, specifically designed exogenous dsRNA delivered cell can silence a target gene, phenomenon that has been exploited in many functional studies and exp...

The natural occurrence of fully double-stranded RNA (dsRNA) of high molecular weight in viruses, virus-like particles in fungi, as intermediates in the replication of RNA and DNA viruses has suggested some possible biological role for such molecules [ 11. Interest in dsRNA as a possible regulatory signal has been generated by the observations that dsRNA is a potent interferon inducer [2] and a ...

Double-stranded RNA (dsRNA) inhibits expression of homologous genes by a process involving messenger RNA degradation. To gain insight into the mechanism of degradation, we examined how RNA interference is affected by mutations in the smg genes, which are required for nonsense-mediated decay. For three of six smg genes tested, mutations resulted in animals that were initially silenced by dsRNA b...

RNA interference (RNAi) has a range of physiological functions including as a defence mechanism against viruses. To protect uninfected cells in a multicellular organism, not only a cell-autonomous RNAi response is required but also a systemic one. However, the route of RNA spread in systemic RNAi remains unclear. Here we show that phagocytosis can be a route for double-stranded RNA uptake. Doub...

When a cell is exposed to double-stranded RNA (dsRNA), mRNA from the homologous gene is selectively degraded by a process called RNA interference (RNAi). Here, we provide evidence that dsRNA is amplified in Caenorhabditis elegans to ensure a robust RNAi response. Our data suggest a model in which mRNA targeted by RNAi functions as a template for 5' to 3' synthesis of new dsRNA (termed transitiv...

Lepidopteran insects are highly refractory to oral RNA interference (RNAi). Degradation, impaired cellular uptake and intracellular transport of double-stranded (dsRNA) considered the major factors responsible for reduced RNAi efficiency in these insects. In this study, potential lectins improve dsRNA delivery efficacy was evaluated. First, a fusion protein consisting Galanthus nivalis agglutin...

Double-stranded (ds) RNA is a key player in numerous biological activities in cells, including RNA interference, anti-viral immunity and mRNA transport. The class of proteins responsible for recognizing dsRNA is termed double-stranded RNA binding proteins (dsRBP). However, little is known about the molecular mechanisms underlying the interaction between dsRBPs and dsRNA. Here we examined four h...

RNA interference (RNAi) is the phenomenon that double-stranded RNA (dsRNA) induces post-transcriptional sequence-specific gene silencing in eukaryote."2] During the process of RNAi, long dsRNA is cleaved into -21 nt small interfering RNAs (siRNAs), and the siRNAs then guide sequencespecific mRNA degradation. Since the discovery in Caenorhabditis etegans,3] RNAi has been shown to eccur in many e...