Targeted protein O-GlcNAc reveals transcriptional functions for O-GlcNAc

O-Linked β-N-acetylglucosamine (O-GlcNAc) is an essential nucleocytoplasmic post-translational modification (PTM) installed on many substrates by a single O-GlcNAc transferase (OGT), although functional outcomes for most of these modifications are unknown. Induced proximity methods to write and erase PTMs from desired targets can accelerate functional annotation and identify therapeutic opportunities for PTMs like O-GlcNAc. Here, we report an induced-proximity method with a destabilized nanobody-OGT fusion and demonstrate its general utility for targeted protein O-GlcNAc against 21 substrates followed by annotation of the direct effects of O-GlcNAc on transcription factors in cells. Deeper investigation of AP-1 transcriptional activation reveals an inhibitory nutrient-sensing event regulated by O-GlcNAc on transcription factors c-Fos and c-Jun. Collectively, these data illustrate the rapid investigation of O-GlcNAc functions in cells enabled by a generalizable induced proximity method for targeted protein O-GlcNAc.