Influenza Virus Nucleoprotein Interacts with Influenza Virus Polymerase Proteins

摘要: Influenza virus nucleoprotein (NP) is a critical factor in the viral infectious cycle switching influenza RNA synthesis from transcription mode to replication mode. In this study, we investigated interaction of NP with polymerase protein complex. Using coimmunoprecipitation monospecific or monoclonal antibodies, observed that interacted RNP-free complex virus-infected cells. addition, coexpression components (PB1, PB2, PA) either together pairwise revealed interacts PB1 and PB2 but not PA. Interaction was confirmed by both histidine tagging NP-PB1 NP-PB2 complexes. Further, it rather labile sensitive dissociation 0.1% sodium dodecyl sulfate stability regulated sequences present at COOH terminus NP. Analysis deletion mutants least three regions independently PB2. A detailed analysis mutation serine-to-alanine (SA) residues individually demonstrated SA mutations region did affect binding However, some drastically affected functional activity an vivo transcription-replication assay, whereas others exhibited temperature-sensitive phenotype still had no effect on RNA. These results suggest direct proteins may be involved regulating switch replication.