title: Mutations in NA that induced low pH-stability and enhanced the replication of pandemic (H1N1) 2009 influenza A virus at an early stage of the pandemic.
abstract: An influenza A virus that originated in pigs caused a pandemic in 2009. The sialidase activity of the neuraminidase (NA) of previous pandemic influenza A viruses are stable at low pH (≤5). Here, we identified the amino acids responsible for this property. We found differences in low-pH stability at pH 5.0 among pandemic (H1N1) 2009 viruses, which enhanced the replication of these viruses. Low-pH-stable NA enhancement of virus replication may have contributed to the rapid worldwide spread and adaptation to humans of pandemic (H1N1) 2009 viruses during the early stages of the 2009 pandemic.
authors.affiliation: Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, United States of America.
authors.forename: Tadanobu
authors.initials: T
authors.lastname: Takahashi
authors.forename: Jiasheng
authors.initials: J
authors.lastname: Song
authors.forename: Takashi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kawaoka
mesh_terms: D002460:Cell Line; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009980:Influenza A virus / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity; D007251:Influenza, Human / Q000821:virology*; D009154:Mutation; D009439:Neuraminidase / Q000235:genetics*; D058873:Pandemics; D010802:Phylogeny; D014779:Virus Replication / Q000235:genetics / Q000502:physiology
chemical_list: D009439:Neuraminidase