Cellular mRNA export factor UAP56 recognizes nucleic acid binding site of influenza virus NP protein.
Influenza A virus nucleoprotein (NP) is a structural component that encapsulates the viral genome into the form of ribonucleoprotein complexes (vRNPs). Efficient assembly of vRNPs is critical for the virus life cycle. The assembly route from RNA-free NP to the NP-RNA polymer in vRNPs has been suggested to require a cellular factor UAP56, but the mechanism is poorly understood. Here, we characterized the interaction between NP and UAP56 using recombinant proteins and showed that UAP56 features two NP binding sites. In addition to the UAP56 core comprised of two RecA domains, we identified the N-terminal extension (NTE) of UAP56 as a previously unknown NP binding site. In particular, UAP56-NTE recognizes the nucleic acid binding region of NP. This corroborates our observation that binding of UAP56-NTE and RNA to NP is mutually exclusive. Collectively, our results reveal the molecular basis for how UAP56 acts on RNA-free NP, and provide new insights into NP-mediated influenza genome packaging.
['Morris|Andrew K|AK|', 'Wang|Zhen|Z|', 'Ivey|Austin L|AL|', 'Xie|Yihu|Y|', 'Hill|Pate S|PS|', 'Schey|Kevin L|KL|', 'Ren|Yi|Y|']
D001665:Binding Sites D053487:DEAD-box RNA Helicases D016679:Genome, Viral D054884:Host-Pathogen Interactions D006801:Humans D019590:Nucleocapsid Proteins D012333:RNA, Messenger D016601:RNA-Binding Proteins D012261:Ribonucleoproteins D014758:Viral Core Proteins D019065:Virus Assembly D014779:Virus Replication
Influenza A virus DEAD-Box ATPase Host-pathogen interaction RNA-Binding protein mRNA nuclear export