FIG. 2.

Reciprocal regulation of LEF-dependent reporters by HDAC1 and β-catenin. (A and B) Expression from the pTOPFLASH promoter was tested in the presence of different combinations of expression vectors encoding LEF1, β-catenin, and HDAC1 as indicated by the plus signs. (A) Cells were transfected with the amount (in micrograms) of HDAC expression plasmid indicated. A and R denote the combinations and amounts of expression vectors referred to as activation and repression conditions, respectively. (B) Cells were transfected with 0.4 or 5 μg of β-catenin expression plasmid in the presence or absence of 3 μg of HDAC1 expression plasmid as indicated. (C) Chromatin was immunoprecipitated using antiserum specific for acetylated amino-terminal tails of histone H4 from cells transfected under repression conditions and activation conditions. The pTOPFLASH and pFOPFLASH DNAs were detected by PCR using primers (see Materials and Methods) that spanned the wild-type or mutant LEF binding sites. “Lysate” represents 1:50 of the amount of lysate used in the immunoprecipitations and controls for DNA recovery. The data shown are representative of 4 independent experiments.