FIG. 3.

Ability of wild-type Vhs and site-directed Vhs mutants to inhibit the expression of a cotransfected reporter gene. Triplicate cultures of Vero cells were transfected with 3 μg of the reporter plasmid pSV-β-galactosidase plus 0.73 pmol of pcDNA1.1amp (Vector) or UL41-containing effector plasmids encoding wild-type Vhs or the indicated mutant forms of Vhs. Transfection mixtures also contained enough salmon sperm carrier DNA to bring the total amount of DNA to 12 μg. Cell extracts were prepared 40 to 48 h after transfection and assayed for β-galactosidase activity as described in the text. For each transfection, the amount of β-galactosidase activity was expressed as a fraction of that observed in the transfection involving the vector pcDNA1.1amp. Errors bars indicate the standard error of the mean.