AUTHOR=Yin Ruoting , Wang Xin , Li Cheng , Gou Yuhan , Ma Xuecheng , Liu Yongzhao , Peng Jianfang , Wang Chao , Zhang Ying TITLE=Mass Spectrometry for O-GlcNAcylation JOURNAL=Frontiers in Chemistry VOLUME=Volume 9 - 2021 YEAR=2021 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.737093 DOI=10.3389/fchem.2021.737093 ISSN=2296-2646 ABSTRACT=O-linked β-N-acetylglucosamine modification (O-GlcNAcylation), one universal post-translational modification commonly found in nuclear and cytoplasmic proteins, shows regulatory roles in a variety of biological processes, such as signal transduction, transcriptional regulation, stress response, etc. Moreover, O-GlcNAcylations with abnormal expression levels have proven to be associated with many diseases including Alzheimer, diabetes and tumor. Therefore, sensitive O-GlcNAcylation profiling is of great importance for structure-function mechanism elucidating of low-abundance O-GlcNAcylated protein with high heterogeneity as required for glycomics. Mass spectrometry (MS) with high sensitivity and throughput properties has become widely used for comprehensive characterization of O-GlcNAcylation, enabling in-depth understanding of their biological roles these years. Herein, this review provides a comprehensive update of MS-based methodologies for quali-quantitative characterizing of O-GlcNAcylation.