TABLE 3.

Transcriptional and transdominant activity of Vpr mutants on Tat-stimulated HIV-1 LTR and dexamethasone-stimulated MMTV LTR in A204 cellsb

PromoterVpr mutantPromoter activity (mean ± SE)Transdominance against WT Vpr (mean ± SE)Mutant typea
HIV-1 LTRNone100.0 ± 2.2
WT397.2 ± 16.5100.0 ± 12.8
R80A259.5 ± 7.6140.0 ± 7.4A
L64A35.3 ± 5.94.3 ± 2.2T
L64, 67, 68A70.6 ± 1.320.0 ± 5.6T
F72A, R73A101.2 ± 3.290.2 ± 8.1I
174A, G75A94.1 ± 6.878.7 ± 12.8I
44-9682.2 ± 5.519.1 ± 6.0T
1-84111.8 ± 4.836.2 ± 4.1T
1-64117.6 ± 32.395.6 ± 3.2I
MMTV LTRNone100.0 ± 37.3
WT1,027.3 ± 112.5100.0 ± 15.9
R80A590.9 ± 12.6128.0 ± 13.1A
L64A50.9 ± 1.56.1 ± 1.3T
L64, 67, 68A72.3 ± 15.336.7 ± 4.3T
F72A, R73A96.3 ± 6.898.1 ± 5.1I
I74A, G75A90.1 ± 18.685.5 ± 11.0I
44-96114.1 ± 25.122.0 ± 4.3T
1-8463.4 ± 8.664.6 ± 7.3I
1-64102.6 ± 16.1107.1 ± 9.7I
  • a A, active mutant; T, transdominant mutant; I, inactive mutant.

  • b For the transactivation assay, A204 cells were transfected with the plasmid expressing the indicated Vpr mutants in the presence of L3-Luc or MMTV-LTR-Luc and pSV40-β-Gal. BS-Tat or 10−6 M dexamethasone was included to stimulate activities of HIV-1 LTR and MMTV LTR, respectively. Promoter activities in the presence of Tat or dexamethasone were assigned a value of 100. Shown are mean ± SE relative values of luciferase activity normalized for β-galactosidase activity. For the transdominance assay, A204 cells were transfected with 1.5 μg of plasmids/well expressing the indicated Vpr mutants in the presence of 0.3 μg of pCDNA3-VPR/well, together with L3-Luc or MMTV-LTR-Luc and pSV40-β-Gal. BS-Tat or 10−6 M dexamethasone were included to stimulate activities of the two promoters, respectively. Induced promoter activities in the presence of wild-type Vpr were assigned a value of 100. Mean ± SE values of relative luciferase activity normalized for β-galactosidase activity are shown. WT, wild type.