title: Reassortment between seasonal H1N1 and pandemic (H1N1) 2009 influenza viruses is restricted by limited compatibility among polymerase subunits.
abstract: Reassortment is important for influenza virus evolution and the generation of novel viruses with pandemic potential; however, the factors influencing reassortment are still poorly understood. Here, using reverse genetics and a replicon assay, we demonstrated that a mixed polymerase complex containing a pandemic (H1N1) 2009 influenza virus PB2 on a seasonal H1N1 virus background has reduced polymerase activity, leading to impaired virus viability. Adaptation of viruses containing the mixed polymerase complex resulted in compensatory mutations in PB1. Taken together, our results identify the cooperation between PB2 and PB1 as an important restricting factor for reassortment of influenza viruses.
authors.affiliation: Division of Virology, Department of Microbiology and Immunology, The University of Tokyo, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan. kawaoka@ims.u-tokyo.ac.jp
authors.forename: Cássio Pontes
authors.initials: CP
authors.lastname: Octaviani
authors.forename: Hideo
authors.initials: H
authors.lastname: Goto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kawaoka
mesh_terms: D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000201:enzymology* / Q000235:genetics*; D007251:Influenza, Human / Q000821:virology; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics / Q000378:metabolism*; D016865:Reassortant Viruses / Q000201:enzymology / Q000235:genetics*; D012261:Ribonucleoproteins / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C502893:PB2 protein, influenza virus; D012261:Ribonucleoproteins; D014764:Viral Proteins; C077346:influenza virus polymerase basic protein 1; D012324:RNA-Dependent RNA Polymerase