Figure 3.

E1A represses β-catenin–mediated transcriptional activation. A, The reporter plasmid pTOPFLASH (1 μg) was transfected into HeLa cells with or without 1 μg of pt β-catenin–encoding plasmid. The expression vector encoding E1A or E1A mutCBP (100 or 500 ng) were cotransfected as indicated. B, SW480 cells were cotransfected with 100 ng of the pTOPFLASH reporter, and increasing amounts (100 or 400 ng) of CBP expression plasmid, 5 ng each of the plasmids encoding E1A WT, E1A mutRB, or E1A mutCBP, or 50 ng of dnLEF-1 expression plasmid as indicated. The activity of the pTOPFLASH reporter in the absence of exogenous CBP, E1A, or dnLEF-1 was set at 100%.