FIG. 6.

TATA box requirement for Vpr-mediated stimulation of the HIV-1 LTR. Jurkat cells were transfected with either the 141-bp fragment of the LTR (−161 to −20), containing the NF-κB and Sp1 transcription factor binding sites, and the TATA box or the 61-bp fragment of the LTR (−81 to −20), containing the Sp1 transcription factor binding sites and the TATA box, in the presence or absence of expression plasmid pCMV-Vpr. In all transfections, the empty CMV expression plasmid was cotransfected with each reporter plasmid as a control. The values of all transfections performed in the absence of Vpr are normalized to 1, and results are reported as fold increase in luciferase activity (indicated above the histograms) obtained in the presence of Vpr for each reporter plasmid (y axis). Reported values are means of at least three independent transfections, each performed in triplicate, and error bars represent standard errors of mean. wt, wild type.