Viral Protein R (Vpr), an accessory gene of human immunodeficiency virus type 1 (HIV-1), encodes a virion-associated nuclear protein with a variety of biological functions. Forced expression of Vpr induces abnormalities in the cell cycle at the G2/M phase, macrophage infection, apoptosis and nuclear transportation of the pre-integration complex. Vpr is a transacting factor and exogenously added Vpr can also induce apoptosis. It has been reported that Vpr is present in blood and cerebrospinal fluids of HIV-1 positive patients. Vpr may also be linked with functional abnormality of the central nervous system. Recently, it was reported that Vpr induces DNA double-strand breaks (DSBs) and activates ATM and H2AX. ATM is considered a major physiological mediator of H2AX mobilization in response to DSB formation. Foci of ATM phosphorylated at serine 1981 (ATM-p) and H2AX were observed in cells with Vpr expression.
Feature and Advantages
• Vpr is detected in the blood of about 40% of HIV-positive individuals.
• Vpr in the blood of HIV-positive individuals is detected in the nM-pM range.
• Useful in western blotting, FACS, immunoprecipitation and also in neutralizing activity.
• High-purity recombinant Vpr (rVpr) can be purified by affinity chromatography.
References:
1) Daiki Taneichi, et al, Identification of SNF2h, a Chromatin-Remodeling Factor, as a Novel Binding Protein of Vpr of Human Immunodeficiency Virus Type 1 J Neuroimmune Pharmacol (2011) 6:177.187. PMID: 21519849
2) Mari Shimura, et al, Epigenetic displacement of HP1 from heterochromatin by HIV-1 Vpr causes premature sister chromatid separation J Cell Biol. 2011 Sep 5; 194(5):721-35. Epub 2011 Aug 29. PMID: 21875947
3) Tram N. Q. Pham, et al, Modulation of NKG2D-Mediated Cytotoxic Functions of Natural Killer Cells by Viral Protein R from HIV-1 Primary Isolates: J.Virol. 85: 12254-12261 (2011). PMID: 21957298
4) Shigeki Hoshino, et al, HIV-1 Vpr induces TLR4/MyD88-mediated IL-6 production and reactivates viral production from latency. J. Leukoc Biol. 87:1133-1143 (2010). PMID: 20145198
5) Hoshino, S., et al, Vpr in plasma of HIV-1-positive patients is correlated with the HIV-1 RNA titers. AIDS Res. Hum. Retrovir. 23, 391-397 (2007). PMID: 17411372
6) Nakai-Murakami C, et al, HIV-1 Vpr induces ATM-dependent cellular signal with enhanced homologous recombination. Oncogene. 2007 Jan 25;26(4):477-86. PMID: 16983346
