FIG. 4.

Inhibitory effect of Ubc9 on HIV-1 LTR promoter transactivation by HHV-6A IE2. Molt-3 cells were transfected as described in Materials and Methods with 2 μg pLTR-Luc reporter construct, 4 μg pcDNA4-IE2, and 0, 4, 8, or 12 μg of either pcDNA3.1-Ubc9 (A) or pcDNA3.1-Ubc9 C93S (B). Cells were lysed 48 h after electroporation. Transactivation of the pLTR-Luc reporter was quantified by measurement of luciferase activity, expressed as transactivation (n-fold) relative to control (pcDNA-transfected cells). Results are means ± standard deviations (SD) from four distinct experiments and were normalized for protein content in each sample. *, P < 0.05 compared with IE2-transfected cells.