Figure 4
From: BAC transgenic mice provide evidence that p53 expression is highly regulated in vivo
Disrupting c-Myc binding on the conserved E-box in p53 promoter downregulated p53 expression. (a) RT-PCR results of LacZ mRNA expression as normalized to p53 mRNA in embryos at 10.5 day from PZU and PMZU mice. (b) RT-PCR results of LacZ mRNA expression as normalized to p53 mRNA in small intestine, skin and kidney from PZU and PMZU mice. (c) RT-PCR results of lacZ mRNA expression normalized to 18 s RNA in a time course upon serum stimulation in MEFs from PZU and PMZU mice with the same BAC copy number. (d) ChIP analysis on c-Myc binding on the endogenous p53 promoter (wild-type E-box) or p53 promoter in transgenic BAC (mutant E-box) in the E11.5 embryo of the PMZU mice. (e) ChIP analysis on c-Myc and USF binding on the endogenous p53 promoter (wild type E-box) or p53 promoter in transgenic BAC (mutant E-box) in small intestine and liver of 2-month-old PMZU mice. (f) ChIP analysis on c-Myc binding on the endogenous p53 promoter (wild-type E-box) or p53 promoter in transgenic BAC (mutant E-box) in the MEFs from the PMZU mice under the treatment of Myc inhibitor 10058-F4 for 6 h (upper panel) and ChIP analysis on c-Myc binding on the p53 promoter (wild-type E-box) in the MEFs from the PZU mice under the treatment of Myc inhibitor 10058-F4 for 6 h (lower panel). (g)RT-PCR results of LacZ and p53 mRNA expressions normalized to β-actin in MEFs from PZU and PMZU mice under the treatment of 10058-F4 for 8 h. (h) β-gal staining of MEFs from the PZU and PMZU mice under the treatment of 10058-F4 for 10 h. MEFs were stained in 1 mg/ml X-gal staining solution at 37 °C for 10 h. Scale bar=200 μm. Values are means±S.E.M.s. *P<0.05; **P<0.01; ***P<0.001 (t-test)
