OGT binds a conserved C-terminal domain of TET1 to regulate TET1 activity and function in development

TET enzymes convert 5-methylcytosine to 5-hydroxymethylcytosine and higher oxidized derivatives. TETs stably associate with and are post-translationally modified by the nutrient-sensing enzyme OGT, suggesting a connection between metabolism and the epigenome. Here, we show for the first time that modification by OGT enhances TET1 activity in vitro. We identify a a domain of TET1 domain that is responsible necessary and sufficient for binding to OGT and report a point mutation that disrupts the TET1-OGT interaction. We show that the TET1-OGTthis interaction is necessary for TET1 to rescue hematopoetic stem cell production in tet mutant zebrafish embryos, suggesting that OGT promotes TET1’s function during development. Finally, we show that disrupting the TET1-OGT interaction in mouse embryonic stem cells changes the abundance of TET-containing high molecular weight complexesTET2 and 5-methylcytosine, which is accompanied by alterations in gene expression and causes widespread gene expression changes. These results link metabolism and epigenetic control, which may be relevant to the developmental and disease processes regulated by these two enzymes.