Research Article Downregulation of host NOLC1 protein during influenza A
virus H1N1 infection negatively affects virus replication
Introduction: The influenza A virus nonstructural protein NS1 is crucial
for the virus infection process. By interacting with various host RNAs
or proteins, NS1 regulates both host and viral activities. Nucleolar and
coiled-body phosphoprotein 1 (NOLC1), a protein involved in cell cycle
regulation, may be involved in host viral resistance. The purpose of
this study was to elucidate the changes in host NOLC1 during virus
infection and the effect of these changes on virviral replication.
Methods: We used co-immunoprecipitation to confirm that H1N1 NS1 can
interact with NOLC1 in host cells. Results: We found that the D125 and
R200 residues in H1N1 NS1 are crucial for the interaction. Real-time PCR
and western blotting revealed changes in host NOLC1 during viral
infection. Constructing a lentiviral vector, and then overexpressing and
knocking down NOLC1 in A549 cells, enabled us to demonstrate how
NOLC1 affects viral replication. We found that H1N1 NS1 interacts with
host NOLC1 and that NOLC1 is inhibited during H1N1 infection. In
NOLC1-knockdown A549 cells, viral replication was inhibited.
Conclusion: The current study revealed that viral replication is
negatively affected by a decrease in NOLC1 level in host cells. This
research lays the foundation for a deeper comprehension of the
mechanisms underlying the complex host–influenza virus interactions, as
well as for the prevention and management of influenza viruses.