Figure 8: The presence of nucleoplasmic NPM1 is a prerequisite for stress-induced p53 activation.
From: A redox mechanism underlying nucleolar stress sensing by nucleophosmin
(a) FLAG-NPM1 WT and the mutants WW and C275S were added back to NPM1-silenced cells before treatment with Act.D. Co-IP assays were performed using antibody against HDM2 and western blottings were performed using antibodies as indicated. (b) Localization of exogenous HA-ARF and endogenous NPM1 after Act.D treatment, from respective cells on same coverslip. Nucleolar/nucleoplasmic RFI ratio of NPM1 (n=29) and ARF (n=41) were displayed. Mean±s.e.m. Unpaired t-test. ***P<0.001. (c) p53 accumulation in HA-ARF-transfected normal and NPM1-silenced cells (left) or in FLAG-NPM1 WT or the mutant C275S added back NPM1-silenced cells (right), with or without Act.D treatment as indicated. (d) HA-ARF was co-transfected with FLAG-NPM1 WT or the mutant C275S in NPM1-silenced cells before treatment with Act.D. Co-IP assays were performed using IgG or antibody against HDM2, and western blottings were performed using antibodies as indicated. Scale bars, 10 μm. WW, W280/290A. All of the experiments were performed in U2OS cells.
