Figure 3.

Exogenously expressed p28, but not Δp28 results in dose-dependent repression of Tax-mediated transcription. 293 T cells (2 × 10⁵) were co-transfected with 1 μg of wtHTLV-2 proviral clone or negative control DNA, 0.1 μg of LTR-2-Luc and 0.01 μg of TK-Renilla, and varying concentrations (0.2–0.4 μg) of CMVp28AU1 or CMVΔp28AU1 expression vectors as indicated. (A) Tax function was measured as firefly luciferase activity from LTR-2-Luc normalized to Renilla luciferase activity. RLU, relative light units. (B) Western blot analysis was performed on lysates to confirm expression of p28 (AU1 antibody) or β-actin as a loading control. As expected, results indicated that the Δp28 mutation disrupts p28 protein expression.