title: Host Cell Copper Transporters CTR1 and ATP7A are important for Influenza A virus replication.
abstract: The essential role of copper in eukaryotic cellular physiology is known, but has not been recognized as important in the context of influenza A virus infection. In this study, we investigated the effect of cellular copper on influenza A virus replication.
  
  
  
  Influenza A/WSN/33 (H1N1) virus growth and macromolecule syntheses were assessed in cultured human lung cells (A549) where the copper concentration of the growth medium was modified, or expression of host genes involved in copper homeostasis was targeted by RNA interference.
  
  
  
  Exogenously increasing copper concentration, or chelating copper, resulted in moderate defects in viral growth. Nucleoprotein (NP) localization, neuraminidase activity assays and transmission electron microscopy did not reveal significant defects in virion assembly, morphology or release under these conditions. However, RNAi knockdown of the high-affinity copper importer CTR1 resulted in significant viral growth defects (7.3-fold reduced titer at 24 hours post-infection, p = 0.04). Knockdown of CTR1 or the trans-Golgi copper transporter ATP7A significantly reduced polymerase activity in a minigenome assay. Both copper transporters were required for authentic viral RNA synthesis and NP and matrix (M1) protein accumulation in the infected cell.
  
  
  
  These results demonstrate that intracellular copper regulates the influenza virus life cycle, with potentially distinct mechanisms in specific cellular compartments. These observations provide a new avenue for drug development and studies of influenza virus pathogenesis.
authors.affiliation: Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, USA.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Rupp
authors.affiliation: Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, USA.|Present address: Institute Albert Bonniot - INSERM U1209, Université Grenoble Alpes, Grenoble, France.
authors.forename: Manon
authors.initials: M
authors.lastname: Locatelli
authors.affiliation: Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, USA.
authors.forename: Alexis
authors.initials: A
authors.lastname: Grieser
authors.affiliation: Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, USA.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ramos
authors.affiliation: Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Campbell
authors.affiliation: Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Hong
authors.initials: H
authors.lastname: Yi
authors.affiliation: Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: John
authors.initials: J
authors.lastname: Steel
authors.affiliation: Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, USA. jlburkhead@uaa.alaska.edu.
authors.forename: Jason L
authors.initials: JL
authors.lastname: Burkhead
authors.affiliation: Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, USA. ebortz@uaa.alaska.edu.
authors.forename: Eric
authors.identifier: 0000-0002-1376-0012
authors.initials: E
authors.lastname: Bortz
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000378:metabolism*; D002460:Cell Line; D003300:Copper / Q000378:metabolism*; D000079923:Copper Transporter 1; D000073840:Copper-Transporting ATPases; D003470:Culture Media / Q000737:chemistry; D004847:Epithelial Cells / Q000378:metabolism / Q000821:virology*; D054884:Host-Pathogen Interactions; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000502:physiology*; D014779:Virus Replication
chemical_list: D027682:Cation Transport Proteins; D000079923:Copper Transporter 1; D003470:Culture Media; C490079:SLC31A1 protein, human; D003300:Copper; D000251:Adenosine Triphosphatases; C081184:ATP7A protein, human; D000073840:Copper-Transporting ATPases
keywords: ATP7A; CTR1; Cell metabolism; Copper; Copper transport; Influenza virus