Influenza A virus-generated small RNAs regulate the switch from transcription to replication.
The discovery of regulatory small RNAs continues to reshape paradigms in both molecular biology and virology. Here we describe examples of influenza A virus-derived small viral RNAs (svRNAs). svRNAs are 22-27 nt in length and correspond to the 5' end of each of the viral genomic RNA (vRNA) segments. Expression of svRNA correlates with the accumulation of vRNA and a bias in RNA-dependent RNA polymerase (RdRp) activity from transcription toward genome replication. Synthesis of svRNA requires the RdRp, nucleoprotein and the nuclear export protein NS2. In addition, svRNA is detectable during replication of various influenza A virus subtypes across multiple host species and associates physically with the RdRp. We demonstrate that depletion of svRNA has a minimal impact on mRNA and complementary vRNA (cRNA) but results in a dramatic loss of vRNA in a segment-specific manner. We propose that svRNA triggers the viral switch from transcription to replication through interactions with the viral polymerase machinery. Taken together, the discovery of svRNA redefines the mechanistic switch of influenza virus transcription/replication and provides a potential target for broad-range, anti-influenza virus-based therapeutics.
Microbiology Graduate School Training Program, Department of Microbiology, Mount Sinai School of Medicine, New York, NY 10029, USA.
Jasmine T
JT
Perez
Andrew
A
Varble
Ravi
R
Sachidanandam
Ivan
I
Zlatev
Muthiah
M
Manoharan
Adolfo
A
García-Sastre
Benjamin R
BR
tenOever
D021581:Active Transport, Cell Nucleus; D045744:Cell Line, Tumor; D004261:DNA Replication; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D006801:Humans; D009980:Influenza A virus / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics; D008957:Models, Genetic; D009841:Oligonucleotides / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic
D035683:MicroRNAs; D009841:Oligonucleotides; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012367:RNA, Viral; D012324:RNA-Dependent RNA Polymerase; D012321:DNA-Directed RNA Polymerases