Active N6-Methyladenine Demethylation by DMAD Regulates Gene Expression by Coordinating with Polycomb Protein in Neurons

A ten-eleven translocation (TET) ortholog exists as a DNA N6-methyladenine (6mA) demethylase (DMAD) in Drosophila. However, the molecular roles of 6mA and DMAD remain unexplored. Through genome-wide 6mA and transcriptome profiling in Drosophila brains and neuronal cells, we found that 6mA may epigenetically regulate a group of genes involved in neurodevelopment and neuronal functions. Mechanistically, DMAD interacts with the Trithorax-related complex protein Wds to maintain active transcription by dynamically demethylating intragenic 6mA. Accumulation of 6mA by depleting DMAD coordinates with Polycomb proteins and contributes to transcriptional repression of these genes. Our findings suggest that active 6mA demethylation by DMAD plays essential roles in fly CNS by orchestrating through added epigenetic mechanisms. [Display omitted] •DMAD is critical in Drosophila brain by actively demethylating 6mA•DMAD interacts with Trithorax-related protein Wds to regulate gene expression•6mA correlates with the binding of Polycomb proteins in Drosophila genome•DMAD and 6mA coordinate with Trithorax and Polycomb proteins for gene regulation A DNA N6-methyladenine (6mA) demethylase (DMAD) was found in Drosophila to actively remove 6mA. Yao et al. demonstrate that DMAD depletion in neurons leads to impaired neurodevelopment accompanied by 6mA accumulation. DMAD and 6mA epigenetically modulate a group of neuronal genes by coordinating with the Trithorax and Polycomb histone modifiers.