title: Hsp40 facilitates nuclear import of the human immunodeficiency virus type 2 Vpx-mediated preintegration complex.
abstract: Human immunodeficiency virus type 2 (HIV-2) Vpx is required for nuclear translocation of the viral preintegration complex (PIC) in quiescent cells. In order to decipher the mechanism of action of Vpx, a cDNA library was screened with the yeast two-hybrid assay, resulting in the identification of heat shock protein 40, Hsp40/DnaJB6, as a Vpx-interactive protein. Interaction with Vpx was confirmed by glutathione S-transferase (GST) pull-down and coimmunoprecipitation assays. Overexpression of Hsp40/DnaJB6 enhanced Vpx nuclear import, whereas overexpression of a nuclear localization mutant of Hsp40/DnaJB6 (H31Q) or down-regulation of Hsp40/DnaJB6 by small interfering RNA (siRNA) reduced the nuclear import of Vpx. Hsp40/DnaJB6 competed with the Pr55(Gag) precursor protein for the binding of Vpx and incorporation into virus-like particles. Overexpression of Hsp40/DnaJB6 promoted viral PIC nuclear import, whereas siRNA down-regulation of Hsp40/DnaJB6 inhibited PIC nuclear import. These results demonstrate a role for Hsp40/DnaJB6 in the regulation of HIV-2 PIC nuclear transport.
authors.affiliation: Division of Molecular Oncology, Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Cheng
authors.forename: Michael
authors.initials: M
authors.lastname: Belshan
authors.forename: Lee
authors.initials: L
authors.lastname: Ratner
mesh_terms: D021581:Active Transport, Cell Nucleus; D002460:Cell Line; D002467:Cell Nucleus / Q000737:chemistry; D047369:Chromatin Immunoprecipitation; D015498:HIV-2 / Q000502:physiology*; D050956:HSP40 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D011485:Protein Binding; D020798:Two-Hybrid System Techniques; D054334:Viral Regulatory and Accessory Proteins / Q000378:metabolism*; D016662:Virus Integration / Q000502:physiology*
chemical_list: D050956:HSP40 Heat-Shock Proteins; C074286:VPX protein, Human immunodeficiency virus 2; D054334:Viral Regulatory and Accessory Proteins