Figure 4

MMS22L depletion results in DNA double‐strand breaks‐independent p53 pathway activation, decreased level of chromatin‐bound H3.1, and increased genome‐wide H3K4me3 occupancy. (A) Volcano plot showing the differentially expressed genes (P < 0.05, log‐fold change >0.8) between transcriptionally defined shCTRL and shMMS22L MEPs. Genes associated with the TP53 pathway are shown in red. (B) Boxplots showing expression of the indicated genes in shCTRL and shMMS22L MEPs. Log₂‐transformed normalized expression values of selected genes were extracted from single‐cell RNA‐seq data. Boxplot centers, hinges, and whiskers represent median, first and third quartiles, and 1.5× interquartile range, respectively. P‐values from the Kolmogorov–Smirnov test are shown on the plot. (C) Western blot analysis showing the expression of p53, p21, and phosphorylated RB in shCTRL and shMMS22L‐transduced CD36‐positive cells. Protein levels were compared to actin. Data are representative of two independent experiments. (D) Comparative average metaprofiles of H3K4me3 Cut&Run enrichments from shCTRL and shMMS22L‐transduced UT‐7 cells. Dashed lines indicate standard deviation. (E) Violin plots showing that the H3K4me3 levels are equally increased at erythroid‐specific (“upregulated erythroid” and “stable erythroid”) and nonerythroid genes (“non erythroid”). Erythroid‐specific genes were defined based on their up‐regulation or constant expression throughout terminal differentiation (“upregulated erythroid” and “stable erythroid,” respectively). The “non‐erythroid” gene set was defined as genes being suppressed during differentiation. P‐values are determined by a two‐tailed t‐test. ns, not significant, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.