FIG. 4.

Intracellular forms of NOTCH1 repress the larger −2350 LMP1 promoter element lacking the RBP-Jκ binding sites in Jurkat cells. Activity on the larger wild-type −2350 LMP1 promoter element (A) and activity of intracellular NOTCH1 on the −2350 (lacking the RBP-Jκ binding site) promoter construct (B) are shown. The effect of ICNW and EBNA2 on the −2350 LMP1 element lacking the RBP-Jκ binding sites (C) is shown. Ten million Jurkat cells were transfected with the appropriate amounts of DNA, and the cells were harvested after 22 h. Lysates were then used for CAT reporter assays, and the results were obtained with a PhosphorImager from Molecular Dynamics. Only ΔE transactivated this LMP1 promoter, lacking RBP-Jκ binding sites, slightly above background. All other forms of NOTCH1 repressed this promoter in this assay.