Adenosine deaminases that act on RNA (ADARs) are RNA-editing enzymes that deaminate adenosines to create inosines in double-stranded RNA (dsRNA). Here we demonstrate that ADARs are not required for RNA interference (RNAi) and that they do not antagonize the pathway to a detectable level when RNAi is initiated by injecting dsRNA. We find, however, that transgenes expressed in the somatic tissues...

Plants and invertebrates can suppress viral infection through RNA silencing, mediated by RNA-induced silencing complex (RISC). Trans-activation response RNA-binding protein (TRBP), consisting of three double-stranded RNA-binding domains, is a component of the RISC. In our previous paper, a TRBP homologue in Fenneropenaeus chinensis (Fc-TRBP) was reported to directly bind to eukaryotic initiatio...

Exogenous nucleic acids induce an innate immune response in mammalian host cells through activation of the retinoic acid-inducible gene I (RIG-I). We evaluated RIG-I protein for RNA binding and ATPase stimulation with RNA ligands to investigate the correlation with the extent of immune response through RIG-I activation in cells. RIG-I protein favored blunt-ended, double-stranded RNA (dsRNA) lig...

Ribonuclease III (RNase III) represents a family of double-stranded RNA (dsRNA) endonucleases. The simplest bacterial enzyme contains an endonuclease domain (endoND) and a dsRNA binding domain (dsRBD). RNase III can affect RNA structure and gene expression in either of two ways: as a dsRNA-processing enzyme that cleaves dsRNA, or as a dsRNA binding protein that binds but does not cleave dsRNA. ...

Protein kinase R (PKR) is a central component of the innate immunity antiviral pathway and is activated by dsRNA. PKR contains a C-terminal kinase domain and two tandem dsRNA binding domains. In the canonical activation model, binding of multiple PKR monomers to dsRNA enhances dimerization of the kinase domain, leading to enzymatic activation. A minimal dsRNA of 30 bp is required for activation...

Virus-induced secretion of proinflammatory chemokines (e.g., regulated on activation, normal T cells expressed and secreted [RANTES], interleukin [IL]-8) by airway epithelial cells helps to initiate antiviral responses and airway inflammation by enhancing inflammatory cell recruitment. To define mechanisms for virus-induced chemokine secretion, monolayers of nontransformed bronchial epithelial ...

All types of double-stranded RNA (DSRNA) tested inhibit protein synthesis in rabbit reticulocyte lysates. The inhibition is characterized by its strongly biphasic kinetics, and can be enhanced by preincubation of the lysate with dsRNA in the absence of protein synthesis. Only properly and extensively matched dsRNA (greater than about 50 base pairs) has this property; no form of DNA, single-stra...

Bacterial ribonuclease III (RNase III) can affect RNA structure and gene expression in either of two ways: as a processing enzyme that cleaves double-stranded (ds) RNA, or as a binding protein that binds but does not cleave dsRNA. We previously proposed a model of the catalytic complex of RNase III with dsRNA based on three crystal structures, including the endonuclease domain of RNase III with...

RNA interference (RNAi) or RNA silencing is a gene regulatory system, widely conserved in eukaryotes, that represses gene expression through a homology-dependent mechanism. This repressive effect is mediated by small non-coding RNAs (sRNAs) of about 20–30 nucleotides, derived from double-stranded RNA (dsRNA) precursors that are recognized and processed by the RNaseIII Dicer. These sRNAs are loa...

The occurrence of high molecular weight double-stranded RNA (dsRNA) in plants is associated with the presence of RNA viruses. DsRNA is stable, can be extracted easily from the majority of plant species and provides an excellent tool for characterization of novel viruses that are recalcitrant to purification. Several protocols have been developed for dsRNA purification, the majority of which are...