FIG. 6.

Transcriptional activation of the γHV68 gene 57 promoter by the γHV68 gene 50-encoded protein. A 565-bp fragment, spanning from bp 75218 to 75782 in the γHV68 genome and containing the gene 57 promoter (based on previous transcript mapping [20]), was cloned into pGL2 Basic (Promega). The 50-1 cDNA clone (see Fig. 2) was cloned into the NheI and KpnI sites of pBK-CMV (Stratagene). NIH 3T12 cells were cotransfected with 1 μg of either pGL2-Basic (pGLuc) or pGL2 Basic containing the gene 57 promoter (57pLuc) and 1 μg of either pBK-CMV (pBK) or pBK-CMV containing gene 50 (pBK50) with the lipid-based transfection reagent Superfect according to the manufacturer's protocol (Qiagen). Cell lysates were prepared 48 h posttransfection and assayed for luciferase activity (7). The data were compiled from four independent experiments, and the standard error of the mean is indicated.