title: Neuraminidase amino acids 149 and 347 determine the infectivity and oseltamivir sensitivity of pandemic influenza A/H1N1 (2009) and avian influenza A/H5N1.
abstract: Pandemic influenza A/H1N1 (2009) and avian influenza A/H5N1 neuraminidase (NA) differ at two critical residues, positions 149 and 347. Recombinant influenza A viruses were constructed in which these two residues in pandemic influenza A/H1N1 (2009) NA were changed to the corresponding amino acids of avian influenza A/H5N1 NA, and vice versa. Recombinant viruses bearing N1 NA with the oseltamivir resistance mutation H274Y in combination with mutations at residues 149 and 347 were also constructed. Recombinant viruses grew normally in allantoic fluid and were subsequently studied for viral infectivity (TCID50), substrate binding (Km) and sensitivity to oseltamivir (Ki). The data demonstrated that infectivity of mutant viruses in Madin Darby canine kidney cells was comparable to, or even greater than, the infectivity of the parental viruses harboring wild-type N1 NA. Furthermore, mutations at NA residues 149 and 347 altered Km and Ki values, and thus modulated oseltamivir sensitivity. Although these mutants have yet to be observed among natural isolates, the minimal costs to the growth of recombinant viruses indicate their possible viability. Reassortment between pandemic influenza A/H1N1 (2009) and avian influenza A/H5N1 viruses may therefore generate new influenza A viruses with increased infectivity and oseltamivir resistance, and continued surveillance will be crucial for public health preparedness.
authors: Protein-Ligand Engineering and Molecular Biology Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Thailand Science Park, Pathumthani 12120, Thailand. suganya.yon@biotec.or.th
authors: Suganya
authors: S
authors: Yongkiettrakul
authors: Tarangsri
authors: T
authors: Nivitchanyong
authors: Supitcha
authors: S
authors: Pannengpetch
authors: Asawin
authors: A
authors: Wanitchang
authors: Anan
authors: A
authors: Jongkaewwattana
authors: Potjanee
authors: P
authors: Srimanote
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002460:Cell Line; D004285:Dogs; D024882:Drug Resistance, Viral; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D053124:Influenza A Virus, H5N1 Subtype / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D016297:Mutagenesis, Site-Directed; D009439:Neuraminidase / Q000235:genetics* / Q000378:metabolism; D053139:Oseltamivir / Q000494:pharmacology*; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D000998:Antiviral Agents; D014764:Viral Proteins; D037521:Virulence Factors; D053139:Oseltamivir; C487630:NA protein, influenza A virus; D009439:Neuraminidase