Phosphorylation of TET2 by AMPK is indispensable in myogenic differentiation [RNA-seq]

TET-mediated oxidation of 5-mC participates in both passive and active DNA demethylation, which exerts a significant influence on diverse biological processes. Mass spectrometry has identified multiple phosphorylation sites of TET2. However, the functions of these phosphosites and their corresponding kinases are mostly unknown. Here we showed that AMP-activated protein kinase (AMPK) phosphorylates murine TET2 at the serine residue 97 (S97), enhances TET2 stability through promoting its binding to 14-3-3ß. AMPK ablation resulted in decreased global 5-hmC levels at the myotube stages, severe differentiation defects of C2C12 cells and, significantly, total loss of expression of Pax7. Genome-wide analyses revealed increased DNA methylation at genic and enhancer regions of AMPK-null myoblasts and myotubes. Using CRISPR/Cas9 technology, we showed that a novel enhancer, which is hypermethylated in AMPK-null cells, regulates Pax7 expression. The phospho-mimicking mutant, TET2-S97E, could partly rescue the differentiation defect in AMPK ablated C2C12 cells. Together, our data demonstrated that AMPK is a critical regulator of myogenesis, partly through phosphorylating TET2. Overall design: RNA sequencing of C2C12 cells with wildtype and AMPK knockout at day 0 and day 8 of differentiation. RNA sequencing of AMPK knockout C2C12 cells with WT and S97E mutation FLAGBirA-TET2 knockin (2 clones per condition). All experiments were conducted in duplicate.