tetano
Editor, Senior Moderator
Nucleic Acids Res
. 2025 Jan 24;53(3):gkaf027.
doi: 10.1093/nar/gkaf027. Influenza A virus NS2 protein acts on vRNA-resident polymerase to drive the transcription to replication switch
Lei Zhang[SUP] 1 2 [/SUP], Qiuxian Yang[SUP] 1 3 [/SUP], Yuekun Shao[SUP] 1 4 [/SUP], Shenyang Ding[SUP] 1 4 [/SUP], Jiamei Guo[SUP] 1 [/SUP], George F Gao[SUP] 1 4 [/SUP], Tao Deng[SUP] 1 4 [/SUP]
Affiliations
The heterotrimeric RNA-dependent RNA polymerase (RdRp) of influenza A virus catalyzes viral RNA transcription (vRNA→mRNA) and replication (vRNA→cRNA→vRNA) by adopting different conformations. A switch from transcription to replication occurs at a relatively late stage of infection. We recently reported that the viral NS2 protein, expressed at later stages from a spliced transcript of the NS segment messenger RNA (mRNA), inhibits transcription, promotes replication and plays a key role in the transcription-to-replication switch. In this study, we performed comprehensive functional analyses to elucidate how NS2 promotes viral genome replication. Using a cell-based single-step RNP reconstitution assay, we found that NS2 specifically promotes the first-step vRNA-to-cRNA synthesis. Further investigation revealed that this promotion is tightly associated with the intrinsic properties of the 3'-vRNA promoter. Employing a highly sensitive complementation reporter assay, we demonstrated that NS2 associates more strongly with the vRNA-resident RdRp than the cRNA-resident RdRp. These findings were further validated through in vitro replication analyses. We, therefore, propose that influenza A virus NS2 protein targets vRNA-resident RdRp to drive the transcription-to-replication switch during infection.
. 2025 Jan 24;53(3):gkaf027.
doi: 10.1093/nar/gkaf027. Influenza A virus NS2 protein acts on vRNA-resident polymerase to drive the transcription to replication switch
Lei Zhang[SUP] 1 2 [/SUP], Qiuxian Yang[SUP] 1 3 [/SUP], Yuekun Shao[SUP] 1 4 [/SUP], Shenyang Ding[SUP] 1 4 [/SUP], Jiamei Guo[SUP] 1 [/SUP], George F Gao[SUP] 1 4 [/SUP], Tao Deng[SUP] 1 4 [/SUP]
Affiliations
- PMID: 39878213
- PMCID: PMC11775585
- DOI: 10.1093/nar/gkaf027
The heterotrimeric RNA-dependent RNA polymerase (RdRp) of influenza A virus catalyzes viral RNA transcription (vRNA→mRNA) and replication (vRNA→cRNA→vRNA) by adopting different conformations. A switch from transcription to replication occurs at a relatively late stage of infection. We recently reported that the viral NS2 protein, expressed at later stages from a spliced transcript of the NS segment messenger RNA (mRNA), inhibits transcription, promotes replication and plays a key role in the transcription-to-replication switch. In this study, we performed comprehensive functional analyses to elucidate how NS2 promotes viral genome replication. Using a cell-based single-step RNP reconstitution assay, we found that NS2 specifically promotes the first-step vRNA-to-cRNA synthesis. Further investigation revealed that this promotion is tightly associated with the intrinsic properties of the 3'-vRNA promoter. Employing a highly sensitive complementation reporter assay, we demonstrated that NS2 associates more strongly with the vRNA-resident RdRp than the cRNA-resident RdRp. These findings were further validated through in vitro replication analyses. We, therefore, propose that influenza A virus NS2 protein targets vRNA-resident RdRp to drive the transcription-to-replication switch during infection.