title: RNA packaging signal of human immunodeficiency virus type 1.
abstract: Cells infected with a recombinant vaccinia virus carrying the gag and pol regions of the human immunodeficiency virus type 1 genome (Vac-gag/pol) released human immunodeficiency virus (HIV)-like particles containing HIV-specific RNA. However, cells infected with another recombinant vaccinia, Vac-gag/pol-dP, derived through the deletion of an 85-base region (nucleotide positions 679-763) of the HIV genome between the primer binding site and the gag initiation codon of Vac-gag/pol, produced HIV-like particles devoid of the HIV-specific RNA. This 85-base deletion was suggested to cause the collapse of a stable stem-loop structure of 46 bases (751-796) around the gag initiation codon. To examine the role of the stem-loop structure in the packaging of RNAs, we constructed a vaccinia vector plasmid that carried this 46-base sequence followed by the Sendai virus nucleocapsid (NP) gene. When both Vac-gag/pol-dP and this plasmid were introduced into cells, HIV-like particles released from the cells contained the NP gene RNA. However, another vaccinia vector plasmid, which carried the 46-base sequence in the midst of the NP gene, could not supply RNA for incorporation into HIV-like particles. Computer analysis of this plasmid sequence suggested that the 46-base sequence cannot form the stem-loop structure. These findings suggest that the stem-loop structure formed by the 46-base sequence is crucial as a packaging signal.
authors.affiliation: Department of Viral Infection, University of Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hayashi
authors.forename: T
authors.initials: T
authors.lastname: Shioda
authors.forename: Y
authors.initials: Y
authors.lastname: Iwakura
authors.forename: H
authors.initials: H
authors.lastname: Shibuta
mesh_terms: D001483:Base Sequence; D004274:DNA, Recombinant; D015683:Gene Products, gag / Q000502:physiology*; D015750:Genes, gag; D015497:HIV-1 / Q000235:genetics* / Q000254:growth & development / Q000648:ultrastructure; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011485:Protein Binding; D012367:RNA, Viral / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D014779:Virus Replication
chemical_list: D004274:DNA, Recombinant; D015683:Gene Products, gag; D009838:Oligodeoxyribonucleotides; D012367:RNA, Viral