Figure 3.

CtIP is a transcriptional repressor. C33A cells were transiently transfected with 1 μg of β-gal, 0.5 μg of the pSVECG reporter, and 2 μg of Gal4-p130 or 20 μg of Gal4-CtIP. Western blotting was performed to verify that transfected constructs expressed equal protein. As controls, C33A cells were transfected with 1 μg of β-gal, 0.5 μg of pSVECG reporter, and 2 μg of a vector encoding a Gal4 DNA binding domain (control vector). Cells were harvested 40 hours posttransfection, and CAT activity was assayed. β-gal values were used to normalize for transfection efficiency. Results of a typical experiment are shown.