FIG. 3.

Δ3-103-EBNA2 cannot transactivate an LMP-1 promoter reporter plasmid. (A) A 0.5-μg aliquot of an LMP-1 promoter-luciferase reporter plasmid was cotransfected into DG75 cells with the indicated amounts of wild-type EBNA2 (WT) or Δ3-103-EBNA2 (Δ3-103) expression plasmids. The amount of expression plasmid in each transfection reaction was equilibrated with the empty SG5 expression plasmid. The results are presented as fold activation of the promoter in the presence of an effector. Average transactivation efficiencies representing three independent experiments are presented. Standard error bars are shown. (B) Representative Western blot analysis of wild-type and Δ3-103-EBNA2 expression in samples from the transient-transfection experiments described in the legend for panel A. At 48 h after transfection, cells transfected with the SG5 plasmid alone (lane 1), the indicated amounts of Δ3-103-EBNA2 (Δ3-103; lanes 2 and 3), or wild-type EBNA2 (WT; lanes 4 and 5) expression plasmids were subjected to SDS-PAGE and Western blot analysis using an anti-HA monoclonal antibody. Cell lysate aliquots containing equal amounts of total cellular protein were analyzed in each lane. Molecular mass markers are shown in kilodaltons on the left. Arrows on the right indicate migrations of WT and Δ3-103 proteins.