The influenza A virus NS1 protein binds small interfering RNAs and suppresses RNA silencing in plants.
RNA silencing comprises a set of sequence-specific RNA degradation pathways that occur in a wide range of eukaryotes, including animals, fungi and plants. A hallmark of RNA silencing is the presence of small interfering RNA molecules (siRNAs). The siRNAs are generated by cleavage of larger double-stranded RNAs (dsRNAs) and provide the sequence specificity for degradation of cognate RNA molecules. In plants, RNA silencing plays a key role in developmental processes and in control of virus replication. It has been shown that many plant viruses encode proteins, denoted RNA silencing suppressors, that interfere with this antiviral response. Although RNA silencing has been shown to occur in vertebrates, no relationship with inhibition of virus replication has been demonstrated to date. Here we show that the NS1 protein of human influenza A virus has an RNA silencing suppression activity in plants, similar to established RNA silencing suppressor proteins of plant viruses. In addition, NS1 was shown to be capable of binding siRNAs. The data presented here fit with a potential role for NS1 in counteracting innate antiviral responses in vertebrates by sequestering siRNAs.
Bucher
Etienne
E
Laboratory of Virology, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands.
Hemmes
Hans
H
Laboratory of Virology, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands.
de Haan
Peter
P
Viruvation BV, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands.
Goldbach
Rob
R
Laboratory of Virology, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands.
Prins
Marcel
M
Laboratory of Virology, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands.
D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D006801:Humans; D066298:In Vitro Techniques; D009980:Influenza A virus / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D010942:Plant Viruses / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology; D010944:Plants / Q000235:genetics* / Q000821:virology*; D030821:Plants, Genetically Modified; D017863:Potexvirus / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000821:virology; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000502:physiology*; D014774:Virulence
D004279:DNA, Viral; C085820:INS1 protein, influenza virus; D012330:RNA, Double-Stranded; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins; D017361:Viral Nonstructural Proteins