FIGURE 2.

PRL treatment induces chromatin decompaction and promotes binding of the transcriptional machinery. A–F, ChIP-qPCR analysis of the CISH promoter following a time course of PRL treatment. Nuclear lysates were precipitated with antibodies against H3 (A), H4 (B), H1 (C), RNAPII (D), phosphorylated (p-) RNAPII (E), or STAT5 (F). Normal IgG served as a control for nonspecific binding. For all histones and STAT5, primers amplify the region of the CISH promoter from −81 to −9 bp relative to the TSS, which includes STAT5 consensus elements. For RNAPII and phospho-RNAPII, primers amplify the region from +46 to +132 bp of the CISH TSS. See Fig. 3B for a map of the CISH promoter. The amount of DNA recovered was calculated relative to the input control and is graphed as a percentage of input. Results are presented as the mean ± S.E. (error bars), n ≥ 3 independent experiments. Statistical significance was determined by a two-sided ratio paired t test, comparing PRL treatment time points with the untreated sample. STAT5 ChIP was analyzed by two-sided paired differences t test. p > 0.05; *, p ≤ 0.05; **, p ≤ 0.01; ***, p ≤ 0.001.