Vercoutter-Edouart Anne-Sophie, El Yazidi-Belkoura Ikram, Guinez Céline, Baldini Steffi, Leturcq Maïté, Mortuaire Marlène, Mir Anne-Marie, Steenackers Agata, Dehennaut Vanessa, Pierce Annick, Lefebvre Tony
Unit of Structural and Functional Glycobiology, University of Lille 1, Villeneuve d'Ascq, France.
Proteomics. 2015 Mar;15(5-6):1039-50. doi: 10.1002/pmic.201400326. Epub 2015 Feb 3.
O-GlcNAcylation (O-linked beta-N-acetylglucosaminylation) is a widespread PTM confined within the nuclear, the cytosolic, and the mitochondrial compartments of eukaryotes. Recently, O-GlcNAcylation has been also detected in the close vicinity of plasma membranes particularly in lipid microdomains. The detection of this PTM can be easily done if appropriate controls and precautions are taken using a wide variety of tools including lectins, antibodies, or click-chemistry-based methods. In contrast, the identification of the proteins bearing O-GlcNAc moieties and the localization of the precise sites of O-GlcNAcylation remain challenging. This is due to the lability of the glycosidic bond between hydroxyl group of serine or threonine and N-acetylglucosamine using conventional fragmentation techniques such as CID. To tentatively overcome this technical limitation, electron-capture dissociation, or electron-transfer dissociation MS/MS are now used. Thanks to these breakthroughs, a large number of O-GlcNAc sites have been identified to date but these methodologies remain far from being used in routine.
O-连接的β-N-乙酰葡糖胺化修饰（O-GlcNAcylation）是一种广泛存在的蛋白质翻译后修饰，局限于真核生物的细胞核、细胞质和线粒体区室。最近，在质膜附近尤其是脂质微区中也检测到了O-GlcNAcylation修饰。如果采取适当的对照和预防措施，使用包括凝集素、抗体或基于点击化学的方法等多种工具，就可以轻松检测到这种翻译后修饰。相比之下，鉴定带有O-GlcNAc基团的蛋白质以及确定O-GlcNAcylation修饰的精确位点仍然具有挑战性。这是因为使用常规的裂解技术（如碰撞诱导解离，CID）时，丝氨酸或苏氨酸的羟基与N-乙酰葡糖胺之间的糖苷键不稳定。为了初步克服这一技术限制，目前使用电子捕获解离或电子转移解离串联质谱（MS/MS）。由于这些突破，迄今为止已经鉴定出大量的O-GlcNAc位点，但这些方法仍远未用于常规操作。
