Fig 2: RSK2 maintains genome stability in response to genotoxic stress.RSK2 is phosphorylated at both Ser227 and Thr577 in response to DNA damage. Activated RSK2 translocates to the nucleus and interacts with Atm, thus activating the Atm/p53-dependent DNA damage pathway, as well as p53-controlled cellular events. RSK2 KO relieves AD-induced cell cycle arrest at the G2/M check point and subsequently inhibited the DNA repair process, as indicated by the increased formation of ?H2AX foci.

Fig 3: Growth arrest of human GBM via CG500354-mediated p53 overexpression.(A) Cell cycle analysis shows that the percent of cells in G1 phase was increased after CG500354 treatment. (B–C) Quantitative RT-PCR analysis shows that the cell cycle regulators cyclin A1, B1, D1 and D3 were significantly down-regulated and that the Cdks p21 and p27 were significantly up-regulated in the presence of CG500354. (D) Western blot analysis shows that p53 expression was increased by treating the cells with 1 µM or 3 µM CG500354. The full-length blots are included in the supplementary information (Suppl. Fig. S5). (E–F) GBM-derived cells treated with CG500354 were stained with a p53 antibody. The number of p53-expressing cells (green) were significantly increased after CG500354 treatment at both concentrations (1 µM and 3 µM). Nuclei (blue) were counterstained with DAPI. Scale bar = 0.5 mm.

Fig 4: IFNß reduces mutant p53 mRNA levels by inhibiting its RNA stabiliser WIG1 (ZMAT3).Cells were treated with IFNß for the designated time points, fixed and sorted by an “Image stream” FACS. (A) Representative images from each condition and (B) a graph representing the mean pixel intensity of mutant p53 positive cells for the entire population. (C) Cells were treated with the designated IFNs for 24 h and mutant p53 and GAPDH levels were measured by western blot. Cells were treated with IFNß for 24 h and mutant p53 (D) and WIG1 (E) RNA levels were determined by QRT-PCR. * P<0.05. (F) HepG2 cells were introduced with mut175 plasmid and treated with IFNß. RNA levels were determined by QRT-PCR. * P<0.05. (G) H1299 cell harbouring a TS form of mutant p53 (Wild type form at 32°C and mutant form at 37°C) were treated with IFNß for 30 h. p53 and GAPDH levels were measured by western blot, shown in the lower panel a is normalized quantification of the bands.

Fig 5: RNASE4 and ANG interact with p53 in the cytoplasm in response to stress.a Experimental set-up to assess interactions between p53 and Myc-Flag-tagged RNASE4 or ANG after senescence-inducing stress. b Immunoblots of cell fractions in indicated conditions and timepoints post-irradiation. C, cytoplasmic fraction marked by Tubulin levels; M membrane fraction indicated by EGFR levels; N, nuclear fraction marked by HDAC2 levels. One experiment was performed. c, d Proximity ligation assay (PLA) on MEFs at indicated timepoints post-irradiation. PLA was assessed between endogenous p53 and Myc-Flag-tagged RNASE4 or ANG. Scale bars, 10 µm. Data represent means ± SEM. n = 3 independent MEF lines from 1 experiment in c, d. Statistics: one-way ANOVA with Sidak’s correction in c, d. Source data are provided as a Source Data file.