E2F1 methylation by SETD6 disrupts BRD4-E2F1 binding and modulates gene regulation in prostate cancer cells

The SETD6 protein lysine methyltransferase has a role in the regulation of various cellular processes including cancer initiation and progression. It methylates several cellular proteins including K117 of the E2F1 transcription factor, but the functional consequences of this methylation event are unknown. In this study, the role of SETD6 mediated E2F1 methylation on the progression of prostate cancer was investigated. We identified distinct sets of genes that are bound and upregulated by methylated and unmethylated E2F1. Genes upregulated by methylated E2F1 lead to the negative regulation of cell migration, while genes upregulated by unmethylated E2F1 have roles in cell proliferation and apoptosis. BRD4 is known to bind E2F1 acetylated at K117 and K120. Here, we demonstrate that methylation of E2F1 at K117 prevents E2F1-BRD4 binding of in vitro and in cells establishing the molecular mechanism of the differential gene regulation by methylated and unmethylated E2F1 that depends on SETD6 activity. Overall design: The DU145 human prostate cancer cell line was used in experiment. SETD6 knock-out cells was generated by CRISPR/Cas9 system. Cells had stable expression of Flag-E2F1 WT and E2F1 K117R.