tetano
Editor, Senior Moderator
Nucleic Acids Res. 2015 Sep 17. pii: gkv926. [Epub ahead of print]
[h=1]The novel influenza A virus protein PA-X and its naturally deleted variant show different enzymatic properties in comparison to the viral endonuclease PA.[/h] Bavagnoli L[SUP]1[/SUP], Cucuzza S[SUP]1[/SUP], Campanini G[SUP]2[/SUP], Rovida F[SUP]2[/SUP], Paolucci S[SUP]2[/SUP], Baldanti F[SUP]2[/SUP], Maga G[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] The PA protein of Influenza A virus (IAV) encoded by segment 3 acts as a specialized RNA endonuclease in the transcription of the viral genome. The same genomic segment encodes for a second shorter protein, termed PA-X, with the first 191 N-terminal aminoacids (aa) identical to PA, but with a completely different C-ter domain of 61 aa, due to a ribosomal frameshifting. In addition, it has been shown that several IAV isolates encode for a naturally truncated PA-X variant, PAXΔC20, missing the last 20 aa. The biochemical properties of PA-X and PAXΔC20 have been poorly investigated so far. Here, we have carried out an enzymatic characterization of PA-X and its naturally deleted form, in comparison with PA from the human IAV strain A/WSN/33 (H1N1). Our results showed, to the best of our knowledge for the first time, that PA-X possesses an endonucleolytic activity. Both PA and PA-X preferentially cut single stranded RNA regions, but with some differences. In addition, we showed that PAXΔC20 has severely reduced nuclease activity. These results point to a previously undetected role of the last C-ter 20 aa for the catalytic activity of PA-X and support distinct roles for these proteins in the viral life cycle.
? The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.
PMID: 26384413 [PubMed - as supplied by publisher] Free full text
[h=1]The novel influenza A virus protein PA-X and its naturally deleted variant show different enzymatic properties in comparison to the viral endonuclease PA.[/h] Bavagnoli L[SUP]1[/SUP], Cucuzza S[SUP]1[/SUP], Campanini G[SUP]2[/SUP], Rovida F[SUP]2[/SUP], Paolucci S[SUP]2[/SUP], Baldanti F[SUP]2[/SUP], Maga G[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] The PA protein of Influenza A virus (IAV) encoded by segment 3 acts as a specialized RNA endonuclease in the transcription of the viral genome. The same genomic segment encodes for a second shorter protein, termed PA-X, with the first 191 N-terminal aminoacids (aa) identical to PA, but with a completely different C-ter domain of 61 aa, due to a ribosomal frameshifting. In addition, it has been shown that several IAV isolates encode for a naturally truncated PA-X variant, PAXΔC20, missing the last 20 aa. The biochemical properties of PA-X and PAXΔC20 have been poorly investigated so far. Here, we have carried out an enzymatic characterization of PA-X and its naturally deleted form, in comparison with PA from the human IAV strain A/WSN/33 (H1N1). Our results showed, to the best of our knowledge for the first time, that PA-X possesses an endonucleolytic activity. Both PA and PA-X preferentially cut single stranded RNA regions, but with some differences. In addition, we showed that PAXΔC20 has severely reduced nuclease activity. These results point to a previously undetected role of the last C-ter 20 aa for the catalytic activity of PA-X and support distinct roles for these proteins in the viral life cycle.
? The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.
PMID: 26384413 [PubMed - as supplied by publisher] Free full text