title: Low-pH-induced membrane fusion mediated by human metapneumovirus F protein is a rare, strain-dependent phenomenon.
abstract: Membrane fusion promoted by human metapneumovirus (HMPV) fusion (F) protein was suggested to require low pH (R. M. Schowalter, S. E. Smith, and R. E. Dutch, J. Virol. 80:10931-10941, 2006). Using prototype F proteins representing the four HMPV genetic lineages, we detected low-pH-dependent fusion only with some lineage A proteins and not with lineage B proteins. A glycine at position 294 was found responsible for the low-pH requirement in lineage A proteins. Only 6% of all HMPV lineage A F sequences have 294G, and none of the lineage B sequences have 294G. Thus, acidic pH is not a general trigger of HMPV F proteins for activity.
authors.affiliation: Department of Virology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Sander
authors.initials: S
authors.lastname: Herfst
authors.forename: Vicente
authors.initials: V
authors.lastname: Mas
authors.forename: Lorena S
authors.initials: LS
authors.lastname: Ver
authors.forename: Rutger J
authors.initials: RJ
authors.lastname: Wierda
authors.forename: Albert D M E
authors.initials: AD
authors.lastname: Osterhaus
authors.forename: Ron A M
authors.initials: RA
authors.lastname: Fouchier
authors.forename: José A
authors.initials: JA
authors.lastname: Melero
mesh_terms: D000818:Animals; D002522:Chlorocebus aethiops; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008561:Membrane Fusion / Q000235:genetics / Q000502:physiology*; D029121:Metapneumovirus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D008958:Models, Molecular; D010802:Phylogeny; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D014709:Vero Cells; D014760:Viral Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D014760:Viral Fusion Proteins