Fig. 2: The MED15 T603 dephosphorylated mutation confers resistance to cellular senescence.

a β-Galactosidase activity was determined by β-gal staining in cultured WT and MED15 T603A mutant HaCaT cells treated without or with 5 ng/mL TGFβ for different periods. b Statistical analysis of the senescent cells in (a). The values are presented as means ± SD. **P < 0.01 and ***P < 0.001. c Immunoblot analysis with the indicated antibodies in WT and MED15 T603A mutant HaCaT cells treated without or with 2 ng/mL TGFβ. β-Actin was blotted as a loading control. The pMED15 antibody specifically targeted the phosphorylated T603 site of MED15. d qRT-PCR assays were performed to determine the mRNA levels of SASP genes in WT and MED15 T603A mutant HaCaT cells. The values are presented as means ± SD. **P < 0.01 and ***P < 0.001. e Heatmap of the RNA-seq analysis of DEGs in WT and MED15 T603A mutant HaCaT cells treated without or with 2 ng/mL TGFβ for 3 h. f, g Scatter plot of DEGs (fragments per kilobase of transcript per million mapped reads (FPKM), fold change ≥ 1.5, P < 0.05) identified by RNA-seq in WT and MED15 T603A mutant HaCaT cells treated without or with 2 ng/mL TGFβ for 3 h. h Venn diagram showing the 722 overlapping genes among the downregulated DEGs identified by RNA-seq in the MED15 T603A mutant cells. i GO analysis of 722 genes downstream of MED15 pT603. j GSEA enrichment plot of the indicated gene sets. NES normalized enrichment score.