FIG. 1.

ChIP analysis of NF-Y and p53 on G₂/M promoters. (A) ChIP was performed with NIH 3T3 mouse fibroblasts not treated (−) or treated (+) with adriamycin and the indicated antibodies (Ab). (B) (Upper panel) p53^−/− mouse embryo fibroblasts (MEF) were used in a similar ChIP analysis with the indicated antibodies. (Lower panel) NIH 3T3 cells arrested in G₀ by serum withdrawal were used in a ChIP analysis (6). (C) ChIP with NIH 3T3 cells stably transfected with a reporter construct containing the wild-type cyclin B2 promoter, a mutant lacking two CCAAT boxes (Y1-Y2m), or a mutant lacking all three CCAAT boxes (Y1-Y2-Y3m). Immunoprecipitated DNAs were amplified with oligonucleotides, revealing the luciferase (Luc) transgene as well as the respective endogenous cyclin B2 promoter. Ctl, control.