Identification of a novel antiviral micro-RNA targeting the NS1 protein of the H1N1 pandemic human influenza virus and a corresponding viral escape mutation.
Host-range restriction of vaccinia virus E3L deletion mutant can be overcome in vitro, but not in vivo, by expression of the influenza virus NS1 protein.
Thus, DP<sub>92-93</sub> in the NS1 protein may confer a disadvantage to Influenza B viruses circulating in the human population and interestingly the low frequency of DP<sub>92-93</sub>detection in the NS1 protein since 2004 is consistent with this suggestion.
As a consequence, influenzaNS1 gene knockout virus delNS1 (an influenza A virus lacking the NS1 open reading frame) fails to replicate in normal cells but produces infectious particles in PKR-deficient cells.
ADAR1 editing activity was enhanced by both viruses through dengue virus NS3 and influenza virus NS1 proteins, suggesting a similar virus-host co-evolution.
Viral proteins such as the NS1 protein of Influenza virus A act upstream of the pathway while other viral proteins such as Theiler's virus L* protein act downstream.
This phenomenon occurs with multiple strains of IAV, is dependent on influenzaNS1 protein, and can be modulated by SUMOylation of an intrinsically disordered region (IDR) of NS1 expressed by the 1918 pandemic IAV strain.
NS1 mutations D189N and V194I impaired the ability of the NS1 protein to inhibit general gene expression, and recombinant viruses harboring these mutations were attenuated in a mouse model of influenza infection.
The C-terminal tail of influenza virus NS1 protein constitutes a nucleolar localization signal (NoLS) and is the binding domain of the cellular pre-mRNA processing protein, poly(A)-binding protein II (PABII).
This study aims at improving our understanding on the pathogenic mechanism of influenza viruses, in particular the role of non-structural (NS1) protein in inducing pro-inflammatory and apoptotic responses.
Unlike other influenza viruses, engineering truncations hypothesized to reduce interferon antagonism into the NS1 protein didn't attenuate bat-influenza.
InfluenzaNS1 protein is among the most promising novel druggable anti-influenza target, based on its structure; multiple interactions; and global function in influenza replication and pathogenesis.
Our results show that the lack of functional PKR permits the delNS1 virus to replicate in otherwise nonpermissive hosts, suggesting that the major function of the influenza virus NS1 protein is to counteract or prevent the PKR-mediated antiviral response.
In conclusion, our results indicate that influenzaNS1 protein targets TRIM25 and Riplet ubiquitin E3 ligases in a species-specific manner for the inhibition of RIG-I ubiquitination and antiviral IFN production.