title: Influence of residue 44 on the activity of the M2 proton channel of influenza A virus.
abstract: The influenza A virus M2 proton channel plays a role in two stages of virus replication. The proteins of two closely related strains of the avian H7 subtype of influenza A virus, Rostock and Weybridge, were found to differ in their pH-modulating activities and activation characteristics. Of three amino acid differences at residues 27, 38 and 44 within the membrane-spanning domain, substitution at residue 44 was necessary and sufficient to account for differences in trans-Golgi pH-modulating activity, whereas changes in all three were required to switch the activation characteristics of the Weybridge M2 to those of the Rostock M2. These results not only separate the two phenomena genetically, but also indicate that the 'unique' activation characteristics of the Rostock M2 channel were selected specifically. In addition, they point to the importance of functional complementarity between the activation characteristics of the M2 channel and the pH of membrane fusion by haemagglutinin during virus entry.
authors.affiliation: Institute of Virology, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovakia.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Betakova
authors.affiliation: Institute of Virology, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovakia.
authors.forename: Fedor
authors.initials: F
authors.lastname: Ciampor
authors.affiliation: National Institute for Medical Research, The Ridgeway, London NW7 1AA, UK.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Hay
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D006056:Golgi Apparatus / Q000737:chemistry / Q000378:metabolism; D006389:Hemagglutinins, Viral / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D009980:Influenza A virus / Q000378:metabolism*; D007473:Ion Channels / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D011522:Protons; D016415:Sequence Alignment; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000378:metabolism*; D014779:Virus Replication; D000086082:Viroporin Proteins
chemical_list: D006389:Hemagglutinins, Viral; D007473:Ion Channels; D011522:Protons; D014763:Viral Matrix Proteins; C488937:M2 protein, Influenza A virus; D000086082:Viroporin Proteins