title: Identification of polymerase gene mutations that affect viral replication in H5N1 influenza viruses isolated from pigeons.
abstract: Highly pathogenic avian influenza virus H5N1 infects a wide range of host species, with a few cases of sporadic pigeon infections reported in the Middle East and Asia. However, the role of pigeons in the ecology and evolution of H5N1 viruses remains unclear. We previously reported two H5N1 virus strains, isolated from naturally infected pigeons in Egypt, that have several unique mutations in their viral polymerase genes. Here, we investigated the effect of these mutations on H5N1 polymerase activity and viral growth and identified three mutations that affected viral polymerase activity. The results showed that the PB1-V3D mutation significantly decreased polymerase activity and viral growth in both mammalian and avian cells. In contrast, the PB2-K627E and PA-K158R mutations had moderate effects: PB2-K627E decreased and PA-K158R increased polymerase activity. Structural homology modelling indicated that the PB1-V3D residue was located in the PB1 core region that interacts with PA, predicting that the PB1 mutation would produce a stronger interaction between PB1 and PA that results in decreased replication of pigeon-derived H5N1 viruses. Our results identified several unique mutations responsible for changes in polymerase activity in H5N1 virus strains isolated from infected pigeons, emphasizing the importance of avian influenza surveillance in pigeons and in studying the possible role of pigeon-derived H5N1 viruses in avian influenza virus evolution.
authors.affiliation: Department of Microbiology, Faculty of Veterinary Medicine, Damanhour University, Damanhur, Egypt.|Department of Infectious Diseases, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Emad Mohamed
authors.initials: EM
authors.lastname: Elgendy
authors.affiliation: Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.|Department of Infectious Diseases, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Yasuha
authors.initials: Y
authors.lastname: Arai
authors.affiliation: Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.|Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.
authors.forename: Norihito
authors.initials: N
authors.lastname: Kawashita
authors.affiliation: Department of Infectious Diseases, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Tomo
authors.initials: T
authors.lastname: Daidoji
authors.affiliation: Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.|Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Takagi
authors.affiliation: Department of Microbiology, Faculty of Veterinary Medicine, Damanhour University, Damanhur, Egypt.|Department of Infectious Diseases, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Madiha Salah
authors.initials: MS
authors.lastname: Ibrahim
authors.affiliation: Department of Infectious Diseases, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Nakaya
authors.affiliation: Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.|Department of Infectious Diseases, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D002460:Cell Line; D010856:Columbidae / Q000821:virology*; D004534:Egypt; D053124:Influenza A Virus, H5N1 Subtype / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D008958:Models, Molecular; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D020125:Mutation, Missense; D011487:Protein Conformation; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics* / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication
chemical_list: D050505:Mutant Proteins; C061290:PA protein, influenza viruses; C057027:PB2 protein, Influenzavirus A; D014764:Viral Proteins; C077346:influenza virus polymerase basic protein 1; D012324:RNA-Dependent RNA Polymerase