Vanitharani, R. and Mahalingam, S. and Rafaeli, Y. and Singh, S.P. and Srinivasan, A. and Weiner, D.B. and Ayyavoo, V. (2001) HIV-1 Vpr Transactivates LTR-Directed Expression through Sequences Present within −278 to −176 and Increases Virus Replication in Vitro. Virology, 289 (2). pp. 334-342. ISSN 0042-6822

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Abstract

Human immunodeficiency virus type 1 (HIV-1) Vpr, a 14-kDa virion-associated protein, plays an important role in the viral life cycle. Using a panel of truncated HIV-1 LTR-CAT constructs and Vpr expression plasmid, we have identified sequences from nucleotide −278 to −176 in LTR as Vpr-mediated transactivation domain. This region includes the glucocorticoid response element (GRE) in HIV-1 LTR. Transactivation by Vpr was noted with the HIV-1 LTR reporter constructs containing CAT or luciferase. A similar effect was also observed with a construct in which the GRE motif was linked to CAT. Studies involving Vpr mutants identified that helical domains I and III, and amino acid residues at G75 and C76, are responsible for GRE-mediated LTR transactivation. The transactivation function of Vpr is independent of its cell cycle arrest activity. Further, viral replication studies indicated that Vpr-mediated increase in viral replication is directly correlated with the ability of Vpr to transactivate HIV-1 LTR. The results presented here demonstrate that Vpr activates HIV-1 LTR through the host GR pathway and suggest that an intact GRE in the LTR is critical for Vpr activity.

Item Type:	Article
Subjects:	Molecular Biology
Depositing User:	Users 2 not found.
Date Deposited:	29 May 2015 07:42
Last Modified:	29 May 2015 07:42
URI:	http://cdfd.sciencecentral.in/id/eprint/108

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