文章基本信息

标题：Chemical reporters for fluorescent detection and identification of O-GlcNAc-modified proteins reveal glycosylation of the ubiquitin ligase NEDD4-1
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作者：Balyn W. Zaro ; Yu-Ying Yang ; Howard C. Hang 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2011
卷号：108
期号：20
页码：8146-8151
DOI：10.1073/pnas.1102458108
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The dynamic modification of nuclear and cytoplasmic proteins by the monosaccharide N-acetyl-glucosamine (GlcNAc) continues to emerge as an important regulator of many biological processes. Herein we describe the development of an alkynyl-modified GlcNAc analog (GlcNAlk) as a new chemical reporter of O-GlcNAc modification in living cells. This strategy is based on metabolic incorporation of reactive functionality into the GlcNAc biosynthetic pathway. When combined with the Cu(I)-catalyzed [3 + 2] azide-alkyne cycloaddition, this chemical reporter allowed for the robust in-gel fluorescent visualization of O-GlcNAc and affinity enrichment and identification of O-GlcNAc-modified proteins. Using in-gel fluorescence detection, we characterized the metabolic fates of GlcNAlk and the previously reported azido analog, GlcNAz. We confirmed previous results that GlcNAz can be metabolically interconverted to GalNAz, whereas GlcNAlk does not, thereby yielding a more specific metabolic reporter of O-GlcNAc modification. We also used GlcNAlk, in combination with a biotin affinity tag, to identify 374 proteins, 279 of which were not previously reported, and we subsequently confirmed the enrichment of three previously uncharacterized proteins. Finally we confirmed the O-GlcNAc modification of the ubiquitin ligase NEDD4-1, the first reported glycosylation of this protein.
关键词：click chemistry ; bioorthogonal labeling ; proteomics