title: Role of HIV-1 RNA and protein determinants for the selective packaging of spliced and unspliced viral RNA and host U6 and 7SL RNA in virus particles.
abstract: HIV-1 particles contain RNA species other than the unspliced viral RNA genome. For instance, viral spliced RNAs and host 7SL and U6 RNAs are natural components that are non-randomly incorporated. To understand the mechanism of packaging selectivity, we analyzed the content of a large panel of HIV-1 variants mutated either in the 5'UTR structures of the viral RNA or in the Gag-nucleocapsid protein (GagNC). In parallel, we determined whether the selection of host 7SL and U6 RNAs is dependent or not on viral RNA and/or GagNC. Our results reveal that the polyA hairpin in the 5'UTR is a major packaging determinant for both spliced and unspliced viral RNAs. In contrast, 5'UTR RNA structures have little influence on the U6 and 7SL RNAs, indicating that packaging of these host RNAs is independent of viral RNA packaging. Experiments with GagNC mutants indicated that the two zinc-fingers and N-terminal basic residues restrict the incorporation of the spliced RNAs, while favoring unspliced RNA packaging. GagNC through the zinc-finger motifs also restricts the packaging of 7SL and U6 RNAs. Thus, GagNC is a major contributor to the packaging selectivity. Altogether our results provide new molecular insight on how HIV selects distinct RNA species for incorporation into particles.
authors.affiliation: UMR5236 CNRS, UMI&II, CPBS, 1919 Rte de Mende, Montpellier, France.
authors.forename: L
authors.initials: L
authors.lastname: Didierlaurent
authors.forename: P J
authors.initials: PJ
authors.lastname: Racine
authors.forename: L
authors.initials: L
authors.lastname: Houzet
authors.forename: C
authors.initials: C
authors.lastname: Chamontin
authors.forename: B
authors.initials: B
authors.lastname: Berkhout
authors.forename: M
authors.initials: M
authors.lastname: Mougel
mesh_terms: D020121:5' Untranslated Regions; D000595:Amino Acid Sequence; D057809:HEK293 Cells; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009154:Mutation; D017434:Protein Structure, Tertiary; D012326:RNA Splicing; D020733:RNA, Small Cytoplasmic / Q000378:metabolism*; D012342:RNA, Small Nuclear / Q000378:metabolism*; D012367:RNA, Viral / Q000737:chemistry* / Q000378:metabolism; D018271:Signal Recognition Particle / Q000378:metabolism*; D014771:Virion / Q000378:metabolism*; D019065:Virus Assembly; D016335:Zinc Fingers; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000737:chemistry* / Q000235:genetics
chemical_list: D020121:5' Untranslated Regions; C115990:7SL RNA; D020733:RNA, Small Cytoplasmic; D012342:RNA, Small Nuclear; D012367:RNA, Viral; D018271:Signal Recognition Particle; C405486:U6 small nuclear RNA; D054301:gag Gene Products, Human Immunodeficiency Virus