Fig. 2: p53 regulates ASNS transcript and asparagine metabolism.
a Schematic diagram describing the reaction catalysed by ASNS. b Quantitative RT-PCR analysis of ASNS expression in p53+/+ and p53−/− HCT116 cells or in shCtrl and shp53 U2OS cells. c Protein expression in p53+/+ and p53−/− HCT116 cells and in U2OS cells stably expressing control or p53 shRNA. Relative ASNS/Actin ratios are shown. d ASNS protein expression in p53+/+ and p53−/− HCT116 cells treated with 0, 5 or 10 μM Nutlin-3 for 36 hours. e Protein expression in EL4 cells treated with the indicated chemical compounds for 24 h. f ASNS mRNA levels in the brain, liver, pancreas and bone marrow (BM) from p53+/+ and p53−/− mice. g Binding of p53 to the ASNS genomic locus in HCT116 cells was analysed by chromatin immunoprecipitation assay using anti-p53 antibody. Isotype mouse IgG was used as a control. Three potential p53 response elements (REs) were individually amplified by PCR. h, i ASNS activity (h) and intracellular amount of Asn (i) in p53+/+ and p53−/− HCT116 cells and in shCtrl and shp53 U2OS cells. j Asn levels in EL4 cells treated as in e. k Asp levels within and outside p53+/+ and p53−/− HCT116 cells. l Intracellular and extracellular labelling fraction of Asn after 24 h of incubation with 15N-aspartate. m Labelling fraction of Asn after 48 h of incubation with 15N-aspartate in p53+/+ and p53−/− HCT116 cells. n, o Intracellular and extracellular labelling fraction of Asp or Asn after 24 h of incubation with [U-13C5]glutamine in p53+/+ and p53−/− HCT116 cells. p Levels of Asn in liver and pancreas tissues from p53+/+ and p53−/− mice. Data are mean ± s.d., unpaired two-tailed Student’s t-test, *p < 0.05, **p < 0.01, ***p < 0.001, NS not significant. Source data are provided as a Source Data file.
