title: Extracellular addition of a domain of HIV-1 Vpr containing the amino acid sequence motif H(S/F)RIG causes cell membrane permeabilization and death.
abstract: Vpr is a virion-associated protein of human immunodeficiency virus type 1 (HIV-1) whose function in acquired immune deficiency syndrome (AIDS) has been uncertain. We previously employed yeast as a model to examine the effects of Vpr on basic cellular functions; intracellular Vpr was shown to cause cell-growth arrest and structural defects, and these effects were caused by a region of Vpr containing the sequence HFRIGCRHSRIG. Here we show that peptides containing the H(S/F)RIG amino acid sequence motif cause death when added externally to a variety of yeast including Saccharomyces cerevisiae, Kluyveromyces lactis, Candida glabrata, Candida albicans and Schizosaccharomyces pombe. Such peptides rapidly entered the cell from the time of addition, resulting in cell death. Elevated levels of ions, particularly magnesium and calcium ions, abrogated the cytotoxic effect by preventing the Vpr peptides from entering the cells. Extracellular Vpr found in the serum, or breakdown products of extracellular Vpr, may have similar effects to the Vpr peptides described here and could explain the death of uninfected bystander cells during AIDS.
authors.affiliation: Biomolecular Research Institute, Division of Biomolecular Engineering, Parkville, Victoria, Australia. ianm@mel.dbe.csiro.au
authors.forename: I G
authors.initials: IG
authors.lastname: Macreadie
authors.forename: C K
authors.initials: CK
authors.lastname: Arunagiri
authors.forename: D R
authors.initials: DR
authors.lastname: Hewish
authors.forename: J F
authors.initials: JF
authors.lastname: White
authors.forename: A A
authors.initials: AA
authors.lastname: Azad
mesh_terms: D000595:Amino Acid Sequence; D002455:Cell Division / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects; D016336:Gene Products, vpr / Q000235:genetics* / Q000502:physiology; D015497:HIV-1 / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics / Q000494:pharmacology; D015003:Yeasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D054325:vpr Gene Products, Human Immunodeficiency Virus
chemical_list: D016336:Gene Products, vpr; D010446:Peptide Fragments; D054325:vpr Gene Products, Human Immunodeficiency Virus