FIG. 11.

p130 renders the dhfr promoter insensitive to TSA. CHOC 400 cells were transfected with 0.5 μg of DHFR-GAL4, a luciferase reporter plasmid in which the E2F sites were replaced with a GAL4 DNA binding site, per plate and pCMV-β-gal (1 μg) as the control, with or without expression plasmids for GAL4-CBP (20 μg) (A) or GAL4-pRB (2 μg) and GAL4-p130 (2 μg) (B). After removal of DNA, cells were incubated for 24 h in fresh medium containing 10% FBS or 10% FBS with 100 nM TSA as indicated. Luciferase activity was determined in cell extracts, was normalized to expression of β-galactosidase, and is expressed in relative light units (RLU) as averages of duplicate samples. Error bars, standard errors of the means. GAL4-CBP, GAL4-pRb, and GAL4-p130 influenced expression of pCMV-β-gal less than 5% under all conditions tested.