O-GlcNAcylation regulates EZH2 protein stability and function
Resource
Proc. Natl. Acad. Sci. U. S. A., 111(4), 1355-1360
Journal
Proceedings of the National Academy of Sciences
Pages
1355-1360
Date Issued
2014
Date
2014
Author(s)
Chu, Chi-Shuen
Lo, Pei-Wen
Yeh, Yi-Hsien
Hsu, Pang-Hung
Peng, Shih-Huan
Teng, Yu-Ching
Kang, Ming-Lun
Wong, Chi-Huey
Juan, Li-Jung
Abstract
O-linked N-acetylglucosamine (GlcNAc) transferase (OGT) is the only known enzyme that catalyzes the O-GlcNAcylation of proteins at the Ser or Thr side chain hydroxyl group. OGT participates in transcriptional and epigenetic regulation, and dysregulation of OGT has been implicated in diseases such as cancer. However, the underlying mechanism is largely unknown. Here we show that OGT is required for the trimethylation of histone 3 at K27 to form the product H3K27me3, a process catalyzed by the histone methyltransferase enhancer of zeste homolog 2 (EZH2) in the polycomb repressive complex 2 (PRC2). H3K27me3 is one of the most important histone modifications to mark the transcriptionally silenced chromatin. We found that the level of H3K27me3, but not other H3 methylation products, was greatly reduced upon OGT depletion. OGT knockdown specifically down-regulated the protein stability of EZH2, without altering the levels of H3K27 demethylases UTX and JMJD3, and disrupted the integrity of the PRC2 complex. Furthermore, the interaction of OGT and EZH2/PRC2 was detected by coimmunoprecipitation and cosedimentation experiments. Importantly, we identified that serine 75 is the site for EZH2 O-GlcNAcylation, and the EZH2 mutant S75A exhibited reduction in stability. Finally, microarray and ChIP analysis have characterized a specific subset of potential tumor suppressor genes subject to repression via the OGT-EZH2 axis. Together these results indicate that OGT-mediated O-GlcNAcylation at S75 stabilizes EZH2 and hence facilitates the formation of H3K27me3. The study not only uncovers a functional posttranslational modification of EZH2 but also reveals a unique epigenetic role of OGT in regulating histone methylation.
SDGs
Other Subjects
histone H3; n acetylglucosamine; o acetylglucosamine; transcription factor EZH2; unclassified drug; acylation; article; cancer cell; controlled study; down regulation; histone modification; human; human cell; immunoprecipitation; methylation; priority journal; protein depletion; protein expression; protein function; protein protein interaction; protein stability; protein synthesis; real time polymerase chain reaction; reverse transcription polymerase chain reaction; sedimentation; transcription initiation; tumor suppressor gene; Western blotting; Acetylglucosamine; DNA Methylation; Down-Regulation; Gene Knockdown Techniques; Genes, Tumor Suppressor; Humans; N-Acetylglucosaminyltransferases; Polycomb Repressive Complex 2; Protein Stability