title: Cooperation between different RNA virus genomes produces a new phenotype.
abstract: An RNA virus population generally evolves rapidly under selection pressure, because of high error rates of the viral RNA polymerase. Measles virus, an enveloped RNA virus, has a fusion protein mediating fusion of the viral envelope with the cell membrane. Here we observe that a non-fusogenic recombinant measles virus evolves, after passages, into mutant viruses which regain the ability to induce membrane fusion. Unexpectedly, we identify a mutant virus possessing two types of genomes within a single virion: one genome encoding the wild-type fusion protein, the other a mutant version with a single amino-acid substitution. Neither the wild-type nor mutant protein by itself is able to mediate membrane fusion, but both together exhibit enhanced fusion activity through hetero-oligomer formation. Our results reveal a molecular mechanism for the 'cooperation' between different RNA virus genomes, which may have implications in viral evolution and in the evolution of other macromolecules.
authors.affiliation: Department of Virology, Faculty of Medicine, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. yuuta@virology.med.kyushu-u.ac.jp
authors.forename: Yuta
authors.initials: Y
authors.lastname: Shirogane
authors.forename: Shumpei
authors.initials: S
authors.lastname: Watanabe
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Yanagi
mesh_terms: D000818:Animals; D002522:Chlorocebus aethiops; D019143:Evolution, Molecular; D016679:Genome, Viral / Q000235:genetics* / Q000502:physiology; D008459:Measles virus / Q000235:genetics / Q000502:physiology; D008561:Membrane Fusion / Q000235:genetics / Q000502:physiology; D010641:Phenotype; D012328:RNA Viruses / Q000235:genetics* / Q000502:physiology; D016865:Reassortant Viruses / Q000235:genetics / Q000502:physiology; D012641:Selection, Genetic / Q000235:genetics / Q000502:physiology; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000235:genetics / Q000502:physiology; D014760:Viral Fusion Proteins / Q000235:genetics / Q000502:physiology
chemical_list: D014759:Viral Envelope Proteins; D014760:Viral Fusion Proteins