YEATS2 O-GlcNAcylation promotes chromatin association of the ATAC complex and lung cancer tumorigenesis

The intracellular O-linked β-N-acetylglucosamine (O-GlcNAc) modification is known to be enriched in the nucleus and on chromatin, but many of its chromatin targets remain to be identified. Herein, we demonstrate the O-GlcNAcylation of Yaf9, ENL, AF9, Taf14, Sas5 (YEATS) domain-containing 2 (YEATS2), a subunit of the chromatin Ada-two-A-containing (ATAC) complex and a reader of H3K27 acetylation levels. We show that YEATS2 interacts with the O-GlcNAc transferase and further pinpoint its major O-GlcNAcylation site to be Thr604 using electron transfer dissociation mass spectrometry. O-GlcNAcylation promotes the chromatin association of YEATS2, and the affinity between YEATS2 and other ATAC components on chromatin, such as ZZZ3, GCN5, and PCAF. Downstream, YEATS2-T604A mutants attenuated the ATAC-dependent H3K9 acetylation levels and inactivated the expression of essential ribosomal genes as shown in chromatin immunoprecipitation assays. Furthermore, xenograft experiments show that YEATS2 O-GlcNAcylation promotes lung cancer tumorigenesis. Our work reveals the critical role of YEATS2 O-GlcNAcylation in stabilizing the ATAC complex on chromatin and expands the chromatin substrates of O-GlcNAc transferase.