N-linked Glycan Micro-heterogeneity in Glycoproteins of Arabidopsis

作者:Zeng, Wei; Ford, Kristina L.; Bacic, Antony; Heazlewood, Joshua L.*
来源:MOLECULAR & CELLULAR PROTEOMICS, 2018, 17(3): 413-421.
DOI:10.1074/mcp.RA117.000165

摘要

N-glycosylation is one of the most common protein posttranslational modifications in eukaryotes and has a relatively conserved core structure between fungi, animals and plants. In plants, the biosynthesis of N-glycans has been extensively studied with all the major biosynthetic enzymes characterized. However, few studies have applied advanced mass spectrometry to profile intact plant N-glycopeptides. In this study, we use hydrophilic enrichment, high-resolution tandem mass spectrometry with complementary and triggered fragmentation to profile Arabidopsis N-glycopeptides from microsomal membranes of aerial tissues. A total of 492 N-glycosites were identified from 324 Arabidopsis proteins with extensive N-glycan structural heterogeneity revealed through 1110 N-glycopeptides. To demonstrate the precision of the approach, we also profiled N-glycopeptides from the mutant (xylt) of beta-1,2-xylosyltransferase, an enzyme in the N-glycan biosynthetic pathway. This analysis represents the most comprehensive and unbiased collection of Arabidopsis N-glycopeptides revealing an unsurpassed level of detail on the micro-heterogeneity present in N-glycoproteins of Arabidopsis. Data are available via Proteome-Xchange with identifier PXD006270.