Figure 4. Recruitment of ER-α and NF-Y to the UBC9 promoter in vivo.

(A) Schematic representation of the UBC9 gene including the proximal promoter with the putative transcription factor binding sites and the negative control region (UBC9 exon 7). Primer pairs are indicated by arrows. (B) ChIP assays using anti-ER-α, NF-YA or IgG control antibodies were performed on chromatin isolated from cells cultured in phenol red-free medium in the absence (white bars) or the presence (black bars) of E₂ for 48 hours. The equivalent fraction of the sonicated chromatin was set aside as 'input' DNA (non-immunoprecipitated) before the antibody affinity manipulations. Data were presented as relative amount of immunoprecipitated DNA normalized to input as measured by quantitative PCR assay, and were given as mean ±SD obtained in four separate experiments. **P<0.01 (Student’s t-test). (C) Ethidium bromide staining of the PCR products of the UBC9 promoter region (upper panel) and UBC9 exon 7 control region (lower panel).