Studies On The Interaction Of Avian Influenza Virus NS1 Protein With Host Protein NOLC1

Avian influenza that is caused by Avian influenza virus(AIV)is a highly contagious acute infectious disease from respiratory system pathological changes to septicaemic of total body. NS1 protein is the only non-structural protein encoded by the influenza A virus, as the causative agent of the virus, NS1 protein of influenza virus can interact with a variety of host proteins in cells, by enhancing the expression of viral proteins or changes in the redistribution of host proteins, thereby enhancing virus pathogenicity and virulence. In order to study the avian influenza virus NS1 protein in the process of replication and pathogenesis,in the previous study, we have used T7-phage display technology,highly pathogenic (H5N1 type) avian influenza virus NS1 protein as bait to screen host proteins that can interacts with NS1 protein, it is called human nucleolar and coiled-body phosphoprotein 1(NOLC1). Both mammalian two-hybrid experiments and immunoprecipitation experiments in vivo identified specified interaction of avian influenza virus NS1 protein with NOLC1. The screen and identification of protein that interacts with NS1 is used to further reveal mechanism of pathopoiesis and provide insights into the therapy of Avian influenza.Human nucleolar and coiled-body phosphoprotein 1(NOLC1) is a highly phosphorylated protein and exists in the interphase nuclei nucleolus. It can distribute uniformly into cytoplasm, bind to RNA polymerase I and regulate the transcription of rRNA during cell mitotic division, so it plays an important role in regulation of cell growth, inflammation genesis and hepatoma development.In order to penetrating research of biological functions NS1 protein interaction with NOLC1 protein, on the base of pre-screened host protein NOLC1 that interact with NS1 protein , His-pull down technology in vitro to further verify the interaction between NS1 and NOLC1. In addition, NS1 green fluorescent protein and NOLC1 red fluorescent protein were co-expressed in Hela cell lines, fluorescence localization indicated both of them were co-localized in the nucleus. On this basis, truncated gene experiments revealed that the effector domain of NS1 were sufficiently able to interact with NOLC1, the effector domain of NS1 is main domain of protein interaction. This study provided us a good foundation for further studying the biological function of NS1 interacting with the host cells and the replication of H5N1 subtype avian influenza virus in the host cells. Given the numerous roles of NS1 during virus replication, one potential target for anti-influenza drug design may be to disrupt interactions of NS1 with NOLC1. This may be particularly relevant for prophylaxis and treatment in the event of an emerging influenza A virus outbreak.