tetano
Editor, Senior Moderator
J Virol. 2016 Oct 26. pii: JVI.01931-16. [Epub ahead of print]
[h=1]The dual roles of the HA segment-specific noncoding nucleotides in the extended duplex region of the influenza A virus RNA promoter.[/h] Wang J[SUP]1[/SUP], Li J[SUP]1[/SUP], Zhao L[SUP]1[/SUP], Cao M[SUP]1[/SUP], Deng T[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] We recently reported that the segment-specific noncoding regions (NCRs) of the HA and NA segments are subtype-specific, varying significantly in sequence and length at both the 3' and 5' ends. Interestingly, we found that nucleotides "CC" at positions 13-14 at the 3' end and "GUG" at positions 14' -16' at the 5' end are absolutely conserved among all HA subtype-specific NCRs. These HA segment-specific NCR nucleotides are located in the extended duplex region of the viral RNA promoter. In order to understand the significance of these highly conserved HA segment-specific NCR nucleotides in the virus life cycle, we performed extensive mutagenesis on the HA segment-specific NCR nucleotides and studied their functional significance in regulating influenza A virus replication in the context of the HA segment with both RNP reconstitution and virus infection systems. We found that the base-pairing at [SUP]3'[/SUP]13-[SUP]5'[/SUP]14' positions is critical for RNA promoter activity while the identity of the base pair is critical in determining HA segment packaging. Moreover, the identity of the residue at [SUP]3'[/SUP]14 is more functionally important in regulating virus genome packaging than in regulating viral RNA synthesis. Taken together, these results demonstrated that the HA segment-specific NCR nucleotides in the extended duplex region of the promoter not only form part of the promoter, but also play a key role in controlling virus selective genome packaging.
[h=4]IMPORTANCE:[/h] The segment-specific complementary nucleotides (13-15 in the 3' end and 14' -16' in the 5' end) in the extended duplex region of the influenza virus RNA promoter vary significantly among different segments and have rarely been studied. We here performed mutagenesis analysis of the highly conserved HA segment-specific nucleotides in the extended duplex region and examined their effects on virus replication in the context of the WSN virus infection. We found that these HA segment-specific nucleotides, not only act as a part of the RNA promoter, but also play a critical role in HA segment packaging. Therefore, we showed experimentally, for the first time, the requirement of the nucleotides in the extended duplex region for the RNA promoter, but also identified specific noncoding residues in regulating HA segment packaging. This work has implications for the development of attenuated vaccine strains and for elucidation the mechanisms of the virus genome packaging.
Copyright ? 2016, American Society for Microbiology. All Rights Reserved.
PMID: 27795444 DOI: 10.1128/JVI.01931-16
[PubMed - as supplied by publisher]
[h=1]The dual roles of the HA segment-specific noncoding nucleotides in the extended duplex region of the influenza A virus RNA promoter.[/h] Wang J[SUP]1[/SUP], Li J[SUP]1[/SUP], Zhao L[SUP]1[/SUP], Cao M[SUP]1[/SUP], Deng T[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] We recently reported that the segment-specific noncoding regions (NCRs) of the HA and NA segments are subtype-specific, varying significantly in sequence and length at both the 3' and 5' ends. Interestingly, we found that nucleotides "CC" at positions 13-14 at the 3' end and "GUG" at positions 14' -16' at the 5' end are absolutely conserved among all HA subtype-specific NCRs. These HA segment-specific NCR nucleotides are located in the extended duplex region of the viral RNA promoter. In order to understand the significance of these highly conserved HA segment-specific NCR nucleotides in the virus life cycle, we performed extensive mutagenesis on the HA segment-specific NCR nucleotides and studied their functional significance in regulating influenza A virus replication in the context of the HA segment with both RNP reconstitution and virus infection systems. We found that the base-pairing at [SUP]3'[/SUP]13-[SUP]5'[/SUP]14' positions is critical for RNA promoter activity while the identity of the base pair is critical in determining HA segment packaging. Moreover, the identity of the residue at [SUP]3'[/SUP]14 is more functionally important in regulating virus genome packaging than in regulating viral RNA synthesis. Taken together, these results demonstrated that the HA segment-specific NCR nucleotides in the extended duplex region of the promoter not only form part of the promoter, but also play a key role in controlling virus selective genome packaging.
[h=4]IMPORTANCE:[/h] The segment-specific complementary nucleotides (13-15 in the 3' end and 14' -16' in the 5' end) in the extended duplex region of the influenza virus RNA promoter vary significantly among different segments and have rarely been studied. We here performed mutagenesis analysis of the highly conserved HA segment-specific nucleotides in the extended duplex region and examined their effects on virus replication in the context of the WSN virus infection. We found that these HA segment-specific nucleotides, not only act as a part of the RNA promoter, but also play a critical role in HA segment packaging. Therefore, we showed experimentally, for the first time, the requirement of the nucleotides in the extended duplex region for the RNA promoter, but also identified specific noncoding residues in regulating HA segment packaging. This work has implications for the development of attenuated vaccine strains and for elucidation the mechanisms of the virus genome packaging.
Copyright ? 2016, American Society for Microbiology. All Rights Reserved.
PMID: 27795444 DOI: 10.1128/JVI.01931-16
[PubMed - as supplied by publisher]