title: Hemagglutinin of influenza A virus binds specifically to cell surface nucleolin and plays a role in virus internalization.
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.
authors.affiliation: State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.
authors.forename: Che-Man
authors.initials: CM
authors.lastname: Chan
authors.affiliation: State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.
authors.forename: Hin
authors.initials: H
authors.lastname: Chu
authors.affiliation: State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.
authors.forename: Anna Jinxia
authors.initials: AJ
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine and Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Macau, China.
authors.forename: Lai-Han
authors.initials: LH
authors.lastname: Leung
authors.affiliation: State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.
authors.forename: Kong-Hung
authors.initials: KH
authors.lastname: Sze
authors.affiliation: State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.
authors.forename: Richard Yi-Tsun
authors.initials: RY
authors.lastname: Kao
authors.affiliation: Department of Microbiology, The University of Hong Kong, Hong Kong, China.
authors.forename: Kenn Ka-Heng
authors.initials: KK
authors.lastname: Chik
authors.affiliation: State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.
authors.forename: Kelvin Kai-Wang
authors.initials: KK
authors.lastname: To
authors.affiliation: State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.
authors.forename: Jasper Fuk-Woo
authors.initials: JF
authors.lastname: Chan
authors.affiliation: State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.
authors.forename: Honglin
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Biochemistry, The University of Hong Kong, Hong Kong, China.
authors.forename: Dong-Yan
authors.initials: DY
authors.lastname: Jin
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine and Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Macau, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China. Electronic address: kyyuen@hku.hk.
authors.forename: Kwok-Yung
authors.initials: KY
authors.lastname: Yuen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D002853:Chromatography, Liquid; D002966:Clathrin / Q000378:metabolism; D004705:Endocytosis; D055785:Gene Knockdown Techniques; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000378:metabolism*; D006801:Humans; D009980:Influenza A virus / Q000502:physiology*; D008024:Ligands; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D053585:Virus Attachment; D053586:Virus Internalization; D000097796:Nucleolin
chemical_list: D002966:Clathrin; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D008024:Ligands; D008565:Membrane Proteins; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; D000097796:Nucleolin
keywords: Cell surface; Entry; Hemagglutinin; Influenza virus; Internalization; Nucleolin; VOPBA