Hemagglutinin of influenza A virus binds specifically to cell surface nucleolin and plays a role in virus internalization

• Published in: Virology (New York, N.Y.) Vol. 494; pp. 78 - 88
• Main Authors: Chan, Che-Man, Chu, Hin, Zhang, Anna Jinxia, Leung, Lai-Han, Sze, Kong-Hung, Kao, Richard Yi-Tsun, Chik, Kenn Ka-Heng, To, Kelvin Kai-Wang, Chan, Jasper Fuk-Woo, Chen, Honglin, Jin, Dong-Yan, Liu, Liang, Yuen, Kwok-Yung
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.2016
• Subjects: Amino Acid Sequence; Animals; Cell Line; Cell surface; Cells, Cultured; Chromatography, Liquid; Clathrin - metabolism; Endocytosis; Entry; Gene Knockdown Techniques; Hemagglutinin; Hemagglutinin Glycoproteins, Influenza Virus - metabolism; Humans; Infectious Disease; Influenza A virus; Influenza A virus - physiology; Influenza virus; Internalization; Ligands; Mass Spectrometry; Membrane Proteins - metabolism; Nucleolin; Phosphoproteins - chemistry; Phosphoproteins - genetics; Phosphoproteins - metabolism; Protein Binding; Protein Interaction Mapping; RNA-Binding Proteins - chemistry; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; Virus Attachment; Virus Internalization; VOPBA; Entry; Influenza virus; Hemagglutinin; Internalization; VOPBA; Nucleolin; Cell surface
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/j.virol.2016.04.008

Abstract The hemagglutinin (HA) protein of influenza A virus initiates cell entry by binding to sialic acids on target cells. In the current study, we demonstrated that in addition to sialic acids, influenza A/Puerto Rico/8/34 H1N1 (PR8) virus HA specifically binds to cell surface nucleolin (NCL). The interaction between HA and NCL was initially revealed with virus overlay protein binding assay (VOPBA) and subsequently verified with co-immunoprecipitation. Importantly, inhibiting cell surface NCL with NCL antibody, blocking PR8 viruses with purified NCL protein, or depleting endogenous NCL with siRNA all substantially reduced influenza virus internalization. We further demonstrated that NCL was a conserved cellular factor required for the entry of multiple influenza A viruses, including H1N1, H3N2, H5N1, and H7N9. Overall, our findings identified a novel role of NCL in influenza virus life cycle and established NCL as one of the host cell surface proteins for the entry of influenza A virus.