Vpr, an accessory protein of human immunodeficiency virus type 1, is a multifunctional protein that plays an important role in viral replication. We have previously shown that the region between residues 17 and 74 of Vpr (Vpr(N17C74)) contained a bona fide nuclear localization signal and it is targeted Vpr(N17C74) to the nuclear envelope and then imported into the nucleus by importin α (Impα) a...

HIV-1 Vpr promotes nuclear entry of viral nucleic acids in nondividing macrophages and also causes a G2 cell-cycle arrest. Consistent with its role in nuclear transport, we show Vpr localizes to the nuclear envelope in both human and yeast cells. Like the importin-beta subunit of the nuclear import receptor, Vpr also interacts with the yeast importin-alpha subunit and nucleoporins. Moreover, ov...

The human immunodeficiency virus type 1 (HIV-1) Vpr protein affects cell morphology and prevents proliferation of human cells by induction of cell cycle G2 arrest. In this study, we used the fission yeast Schizosaccharomyces pombe as a model system to investigate the cellular effects of HIV-1 vpr gene expression. The vpr gene was cloned into an inducible fission yeast gene expression vector and...

Vpr is an accessory protein of human immunodeficiency virus type 1 (HIV-1) with multiple functions. The induction of G2 arrest by Vpr plays a particularly important role in efficient viral replication because the transcriptional activity of the HIV-1 long terminal repeat is most active in G2 phase. The regulation of apoptosis by Vpr is also important for immune suppression and pathogenesis duri...

BACKGROUND The HIV1 protein Vpr assembles with and acts through an ubiquitin ligase complex that includes DDB1 and cullin 4 (CRL4) to cause G2 cell cycle arrest and to promote degradation of both uracil DNA glycosylase 2 (UNG2) and single-strand selective mono-functional uracil DNA glycosylase 1 (SMUG1). DCAF1, an adaptor protein, is required for Vpr-mediated G2 arrest through the ubiquitin lig...

BACKGROUND The hallmark of HIV-1 pathogenesis is the progressive CD4(+) T cell depletion and high propensity of CD4(+) T cells to apoptosis. HIV-1 viral protein R (Vpr) is a major pro-apoptotic gene product. A first Vpr-mediated apoptotic mechanism that requires a physical interaction of HIV-1 Vpr(71-82) mitochondriotoxic domain containing the conserved sequence (71-)HFRIGCRHSRIG(-82) with the ...

The human immunodeficiency virus (HIV) Vpr protein plays a critical role in AIDS pathogenesis, especially by allowing viral replication within nondividing cells such as mononuclear phagocytes. Most of the data obtained so far have been in experiments with endogenous Vpr protein; therefore the effects of extracellular Vpr protein remain largely unknown. We used synthetic Vpr protein to activate ...

Viral protein R (Vpr) of human immunodeficiency virus type 1 (HIV-1) is an accessory protein that plays an important role in viral pathogenesis. This pathogenic activity of Vpr is related in part to its capacity to induce cell cycle G2 arrest and apoptosis of target T cells. A screening for multicopy suppressors of these Vpr activities in fission yeast identified heat shock protein 70 (Hsp70) a...