Fig. 3
From: p53-mediated adaptation to serine starvation is retained by a common tumour-derived mutant
MDM2 supports redox robustness and interacts with ATF4 in R248W cells undergoing serine and glycine (SG) deprivation. a Oxidative stress levels in the indicated cell lines treated with non-targeting control or MDM2 siRNA and cultured in SG-depleted or full medium for 3 days. Median fluorescent intensity of the CellRox Green probe in triplicate samples is presented as mean ± SEM per condition. Data analysed using a two-way ANOVA with Holm-Sidak’s multiple comparisons test and multiplicity-adjusted p values. b Oxidative stress levels in the indicated cell lines expressing HA-tagged MDM2 or a control vector (EV). c NADPH/NADP+ ratio in R248W cells with or without siRNA depletion of MDM2, or in p53 null cells expressing HA-MDM2 or empty vector (EV), and cultured in SG-depleted or full medium for 3 days. The NADPH/NADP+ ratio is shown as mean ± SEM from triplicate wells per condition. Data were analysed using a two-way ANOVA with Holm-Sidak’s multiple comparisons test and multiplicity-adjusted p values. d IP and Western blot of the indicated cell lines cultured in SG-depleted or full medium for 24 h. ATF4 was immunoprecipitated from each sample, then the imunoprecipitate (IP) or input lysate probed by Western blot for MDM2 and ATF4. e Oxidative stress levels in R248W cells treated with non-targeting control, MDM2, or ATF4 siRNA as in (a). f Total NADPH and NADP+ pools in R248W cells treated with non-targeting control (NT), MDM2, or ATF4 siRNA as in (c). BLQ: metabolite peak below quantitation/detection limit in the experiment. Stars indicate statistical significance.