Light-Activatable TET-Dioxygenases Reveal Dynamics of 5-Methylcytosine Oxidation and Transcriptome Reorganization

We report activation of TETs in mammalian cells by incorporation of genetically encoded 4,5-dimethoxy-2-nitrobenzyl-L-serine as transient active site block, and its subsequent deprotection with light. Our approach allows time-resolved monitoring of target gene activation and transcriptome reorganization. This sets a basis for dissecting the order and kinetics of chromatin-associated events triggered by TET catalysis, ranging from DNA demethylation to chromatin and transcription regulation. mRNA sequencing prior to deprotection, 4h, and 8h after activation of hTET2.