FIG 5.

SMRT associates with p53 binding sites on the p21 gene. (A) Schematic representation of the upstream region of the p21 gene, and the positions of the primers used in qPCR to target the 5′ and 3′ p53 binding and nonspecific sites are indicated by arrows. TSS, transcription start site. (B) Chromatin immunoprecipitation assays showing doxorubicin-induced recruitment of SMRT to p53 binding sites of the p21 gene promoter, as well as the upstream nonspecific (NS; p53 response element-deficient) site (inset). MCF-7 cells were treated with vehicle (Veh; PBS) or doxorubicin (Dox; 1 μM) for 6 h, followed by chromatin isolation and immunoprecipitation using antibodies for SMRT or p53 in parallel with the appropriate IgG negative control. Immunoprecipitated DNA was quantitated by qPCR using the indicated primers. Data represent the averages ± SEMs of three independent experiments.