CHD8 depletion increases P53 protein stability. (A) CHD8 interacts with P53 protein in hematopoietic progenitor–like HPC7 cells. IgG immunoprecipitation as a negative control. (B) Representative CHD8 and H3K4me3 CUT&RUN tracks of Cdkn1a, Ccng1, and Bax in WT and Chd8^−/− LSK cells. WT represents Chd8^F/F mice. (C) Protein level of P53 and its targets in sorted LSKs. β-Actin was the loading control. (D) Western blot of P53 in cKit⁺ cells of WT, Chd8^−/−, and Chd8^−/−P53^+/− mice. β-Actin was the loading control. (E) Comparison of P53 protein level in WT and Chd8^−/− cKit⁺ cells after 4 hours of MG132 treatment. Final MG132 concentration, 10 µM. (F) CHX treatment of cKit⁺ cells to determine the degradation rate of P53 protein in WT and Chd8^−/− mice. β-Actin was the loading control. Ratio of P53 protein level compared with 0 minutes of treatment with CHX. Final CHX concentration, 10 µg/mL. The exposure times of P53 between WT and Chd8^−/− cells varied because of different P53 expression levels and were normalized to that before CHX treatment. Statistical analysis was made with 3 biological replicates. **P < .01. (G) Western blot of ubiquitination of P53 in WT and Chd8^−/− low-density BM cells after 10 µM MG132 block for 4 hours.