MYBBP1A enhances p53 activation during anoikis. (A) Acetylation at lysine 382 residues of p53 induced under detached conditions requires MYBBP1A. MCF-7 cells were treated with siControl or siMYBBP1A for 48 h followed by culture under attached or detached conditions for 2 h. Cell lysates were analyzed by immunoblot using the indicated antibodies. (B) p53 recruitment to the Bax promoter under detached conditions requires MYBBP1A. MCF-7 cells were treated as shown in (A), and ChIP assay was performed using normal mouse IgG and anti-p53 antibodies. The p53-binding region of the Bax promoter was amplified and analyzed by RT–qPCR. (C) MYBBP1A translocates from the nucleolus to the nucleoplasm under detached conditions. MCF-7 cells were cultured under attached or detached conditions for 2 h, after which the localizations of MYBBP1A and p53 were visualized by immunofluorescence using anti-MYBBP1A and anti-p53 antibodies. (D) Endogenous MYBBP1A associates with p53 under detached conditions. MCF-7 cells were cultured under detached conditions for 2 h. The cell lysates were immunoprecipitated with normal rabbit IgG or anti-MYBBP1A antibodies and analyzed by immunoblot using antibodies against MYBBP1A and p53. Bars = mean + s.d. (n = 3).