title: The putative alpha helix 2 of human immunodeficiency virus type 1 Vpr contains a determinant which is responsible for the nuclear translocation of proviral DNA in growth-arrested cells.
abstract: Several viral determinants were shown to play a role in the ability of human immunodeficiency virus type 1 (HIV-1) to infect nondividing cells. In particular, Vpr and Gag matrix (MA) were recognized to be involved in the nuclear transport of the viral preintegration complex. The goal of the present study was to evaluate the ability of isogenic HIV-1 viruses harboring different vpr and gag genes to infect nondividing cells. Surprisingly, our results reveal that the introduction of mutations in the MA nuclear localization signal marginally affected the ability of proviruses to establish infection in growth-arrested HeLa or MT4 cells. In contrast, we show that in our experimental system, the absence of Vpr expression leads to a reduction in viral infectivity and production which correlates with a decrease in the synthesis and nuclear transport of proviral DNA as determined by PCR analysis. Moreover, our data demonstrate that this reduction of viral replication is also observed with proviruses containing different mutated Vpr alleles. In particular, the Vpr Q65E mutant, which contains a substitution in the second predicted amphipathic alpha-helical structure located in the central region of the protein, is associated with an impairment of the protein nuclear localization and a concomitant reduction of the nuclear transport of proviral DNA. The results of this study provide evidence that a putative amphipathic alpha-helical structure in the central region of Vpr contains a determinant involved in the nuclear translocation of the preintegration complex in nondividing cells.
authors.affiliation: Département de Microbiologie et Immunologie, Faculté de Médecine, Université de Montréal, Québec, Canada.
authors.forename: Z
authors.initials: Z
authors.lastname: Nie
authors.forename: D
authors.initials: D
authors.lastname: Bergeron
authors.forename: R A
authors.initials: RA
authors.lastname: Subbramanian
authors.forename: X J
authors.initials: XJ
authors.lastname: Yao
authors.forename: F
authors.initials: F
authors.lastname: Checroune
authors.forename: N
authors.initials: N
authors.lastname: Rougeau
authors.forename: E A
authors.initials: EA
authors.lastname: Cohen
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001692:Biological Transport; D019556:COS Cells; D002455:Cell Division; D002461:Cell Line, Transformed; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D004247:DNA / Q000096:biosynthesis; D004279:DNA, Viral / Q000378:metabolism*; D016336:Gene Products, vpr / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015497:HIV-1 / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D016296:Mutagenesis; D019913:Nuclear Localization Signals; D010641:Phenotype; D011533:Proviruses / Q000235:genetics; D014763:Viral Matrix Proteins / Q000235:genetics; D014779:Virus Replication; D054325:vpr Gene Products, Human Immunodeficiency Virus
chemical_list: D004279:DNA, Viral; D016336:Gene Products, vpr; D019913:Nuclear Localization Signals; D014763:Viral Matrix Proteins; D054325:vpr Gene Products, Human Immunodeficiency Virus; D004247:DNA