5'-Triphosphate RNA Is the Ligand for RIG-I

@article{Hornung20065TriphosphateRI,
  title={5'-Triphosphate RNA Is the Ligand for RIG-I},
  author={Veit Hornung and Jana M. Ellegast and Sarah Kim and Krzysztof Brzózka and Andreas Jung and Hiroki Kato and Hendrik Poeck and Shizuo Akira and Karl-Klaus Conzelmann and Martin Schlee and Stefan Endres and Gunther Hartmann},
  journal={Science},
  year={2006},
  volume={314},
  pages={994 - 997}
}
The structural basis for the distinction of viral RNA from abundant self RNA in the cytoplasm of virally infected cells is largely unknown. We demonstrated that the 5′-triphosphate end of RNA generated by viral polymerases is responsible for retinoic acid–inducible protein I (RIG-I)–mediated detection of RNA molecules. Detection of 5′-triphosphate RNA is abrogated by capping of the 5′-triphosphate end or by nucleoside modification of RNA, both occurring during posttranscriptional RNA processing… 
5′-triphosphate RNA requires base-paired structures to activate antiviral signaling via RIG-I
TLDR
It is shown that RIG-I ligands require base-paired structures in conjunction with a free 5′-triphosphate to trigger antiviral signaling, and accurately defines a minimal molecular pattern sufficient to activate Rig-I that can be found in viral genomes or transcripts.
Cytosolic 5′-Triphosphate Ended Viral Leader Transcript of Measles Virus as Activator of the RIG I-Mediated Interferon Response
TLDR
RIG-I is proposed to recognize Mononegavirales transcription, which occurs in the cytosol, while scanning cytosolic RNAs, and to trigger an IFN response when encountering a free 5′-triphosphate RNA resulting from a mislocated transcription activity, which is therefore considered as the hallmark of a foreign invader.
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TLDR
Using single-molecule protein-induced fluorescence enhancement, a robust adenosine 5′-triphosphate–powered dsRNA translocation activity of RIG-I is discovered and may provide a means to specifically sense and counteract replicating viruses.
Viral unmasking of cellular 5S rRNA pseudogene transcripts induces RIG-I mediated immunity
TLDR
The findings reveal that antiviral immunity can be triggered by host RNAs that are unshielded following depletion of their respective binding proteins by the virus.
5'-Triphosphate-Dependent Activation of PKR by RNAs with Short Stem-Loops
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It is reported that RNAs with very limited secondary structures activate PKR in a 5′-triphosphate–dependent fashion in vitro and in vivo, and this form of RNA-based discrimination may be a critical step in mounting an early immune response.
Differential recognition of viral RNA by RIG-I
TLDR
It is shown that in Sendai virus infected cells, RIG-I specifically and preferentially associated with the copy-back defective interfering (DI) particle RNA and not with the full-length Sendai viruses genome or Sendaiirus encoded mRNAs.
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