Figure 6.

Notch activation recruits p300 to the pS2 promoter. (a) ChIP on the pS2 promoter from MCF-7 cells treated with 5 nm E₂ for 1 h after 3 days charcoal stripping. (b) ChIP on the pS2 promoter from MCF-7 cells co-cultured with LTK–JAG1 or LTK–PAR fibroblasts for 3 h after 3 days charcoal stripping. Data in panels a and b are expressed as relative fold increase of specific antibody over IgG control, after normalization to human-specific internal control RPL13a. (c) ChIP on the pS2 promoter from MCF-7 cells grown in charcoal-stripped medium for a total of 3 days, transfected with IKKα siRNA or scrambled control, and co-cultured with LTK–JAG1 or LTK–PAR fibroblasts for 3 h. Data are expressed as relative fold induction by LTK–JAG1 over LTK–PAR after normalization to IgG control and internal control RPL13a. (d) Right: Co-IP experiments on MCF-7 cells, charcoal-stripped for 3 days and transfected with IKKα siRNA or scrambled control. Left: IKKα knockdown was confirmed by western blotting. (e) Co-IP of ERα and p300 on MCF-7 cells, charcoal-stripped for 3 days and transfected with either wild-type or DN-MAML1, or the empty vector control; *P ⩽ 0.05. ChIP, chromatin immunoprecipitation; DN-MAML1, the dominant-negative form of MAML1; LTK–JAG1, mouse LTK fibro-blasts expressing Notched ligand Jagged-1; LTK–PAR, control vector-transduced parental fibroblast; siRNA, short interfering RNA.