College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China.
State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, China.
FEBS Lett. 2019 May;593(10):1050-1060. doi: 10.1002/1873-3468.13381. Epub 2019 May 14.
O-GlcNAc transferase (OGT)-catalyzed protein O-GlcNAcylation is implicated in diverse cellular events. In the present study, we report the regulation of ogt transcription by the hepatocyte nuclear factor 1 homologue A (HNF1A) in HEK293T cells. We first identified a core ogt promoter (-150 to +200 bp) and confirmed its binding to the transcription factor HNF1A. We found that HNF1A regulates ogt transcription in a time-dependent manner and that O-GlcNAcylation of HNF1A represses ogt transcription. Electron-transfer dissociation based tandem mass spectrometry analysis revealed 14 O-GlcNAc sites on HNF1A, six of which are predominantly modified, including Ser , Ser , Ser and Thr . We further found that loss of O-GlcNAcylation at Ser or Thr significantly elevates ogt transcription. These findings highlight a negative feedback mechanism for ogt transcription, which partially explains the homeostasis of cellular O-GlcNAcylation.
O-GlcNAc 转移酶（OGT）催化的蛋白质 O-GlcNAc 化参与多种细胞事件。在本研究中，我们报告了 HNF1A 同源物 A（HNF1A）在 HEK293T 细胞中对 ogt 转录的调节。我们首先鉴定了一个核心的 ogt 启动子（-150 至+200bp），并证实其与转录因子 HNF1A 结合。我们发现 HNF1A 以时间依赖性方式调节 ogt 转录，并且 HNF1A 的 O-GlcNAc 化抑制 ogt 转录。基于电子转移解离的串联质谱分析显示 HNF1A 上有 14 个 O-GlcNAc 位点，其中 6 个主要被修饰，包括 Ser、Ser、Ser 和 Thr。我们进一步发现 Ser 或 Thr 上 O-GlcNAc 化的丧失显著增加了 ogt 转录。这些发现强调了 ogt 转录的负反馈机制，这部分解释了细胞内 O-GlcNAc 化的动态平衡。
