Cell cycle regulated association of CBP and NPAT with the H2B promoter.

<p>(A) CBP and NPAT association with histone promoter in different phases of a cell cycle. HeLa cells were synchronized at G2/M, G1, G1/S and mid-S phases as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0022088#pone-0022088-g001" target="_blank">Figure 1</a>. ChIP assays were performed with rabbit anti-CBP or rabbit anti-NPAT antibodies with normal rabbit IgG as control. Enrichment of CBP or NPAT on H2B promoter at G1, G1/S or S phase was compared with that of G2/M phase, respectively, n = 5. (B) CBP and NPAT protein levels in different phases of a cell cycle. HeLa cells were synchronized with nocodazole and then released for different time points as indicated. Whole cells extracts were used for Western-Blot analyses. Membranes were blotted with mouse anti-CBP, rabbit anti-NPAT or mouse anti-tubulin. Tubulin was used as loading control.