Department of Laboratory Medicine, School of Medicine, University of Pécs, Ifjúság str. 13, Pécs 7624, Hungary.
János Szentágothai Research Centre, University of Pécs, Ifjúság str. 13, Pécs 7624, Hungary.
Oxid Med Cell Longev. 2017;2017:1308692. doi: 10.1155/2017/1308692. Epub 2017 Dec 31.
O-linked N-acetylglucosamine (O-GlcNAc) is a posttranslational modification that is increasingly recognized as a signal transduction mechanism. Unlike other glycans, O-GlcNAc is a highly dynamic and reversible process that involves the addition and removal of a single N-acetylglucosamine molecule to Ser/Thr residues of proteins. UDP-GlcNAc-the direct substrate for O-GlcNAc modification-is controlled by the rate of cellular metabolism, and thus O-GlcNAc is dependent on substrate availability. Serving as a feedback mechanism, O-GlcNAc influences the regulation of insulin signaling and glucose transport. Besides nutrient sensing, O-GlcNAc was also implicated in the regulation of various physiological and pathophysiological processes. Due to improvements of mass spectrometry techniques, more than one thousand proteins were detected to carry the O-GlcNAc moiety; many of them are known to participate in the regulation of metabolites, ions, or protein transport across biological membranes. Recent studies also indicated that O-GlcNAc is involved in stress adaptation; overwhelming evidences suggest that O-GlcNAc levels increase upon stress. O-GlcNAc elevation is generally considered to be beneficial during stress, although the exact nature of its protective effect is not understood. In this review, we summarize the current data regarding the oxidative stress-related changes of O-GlcNAc levels and discuss the implications related to membrane trafficking.
O-连接的 N-乙酰葡萄糖胺（O-GlcNAc）是一种越来越被认为是信号转导机制的翻译后修饰。与其他聚糖不同，O-GlcNAc 是一个高度动态和可逆的过程，涉及到单个 N-乙酰葡萄糖胺分子的添加和去除到蛋白质的 Ser/Thr 残基上。UDP-GlcNAc-是 O-GlcNAc 修饰的直接底物-受细胞代谢率的控制，因此 O-GlcNAc 取决于底物的可用性。作为一种反馈机制，O-GlcNAc 影响胰岛素信号和葡萄糖转运的调节。除了营养感应外，O-GlcNAc 还参与了各种生理和病理生理过程的调节。由于质谱技术的改进，已经检测到超过一千种蛋白质携带 O-GlcNAc 部分；其中许多已知参与代谢物、离子或蛋白质在生物膜中的运输调节。最近的研究还表明，O-GlcNAc 参与应激适应；大量证据表明，应激时 O-GlcNAc 水平增加。O-GlcNAc 的升高通常被认为在应激期间是有益的，尽管其保护作用的确切性质尚不清楚。在这篇综述中，我们总结了关于 O-GlcNAc 水平与氧化应激相关变化的最新数据，并讨论了与膜运输相关的意义。
