Differential site accessibility mechanistically explains subcellular-specific N-glycosylation determinants
Autor: | Nicolle H. Packer, Morten Thaysen-Andersen, Chi-Hung Lin, Susan Fanayan, Ling Y. Lee |
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Jazyk: | angličtina |
Rok vydání: | 2014 |
Předmět: |
glycoprotein
solvent accessibility lcsh:Immunologic diseases. Allergy Glycan Glycosylation Immunology subcellular location N-glycosylation glycosylation site Glycomics chemistry.chemical_compound N-linked glycosylation Immunology and Allergy Original Research chemistry.chemical_classification biology Glycobiology Lectin Glycome carbohydrates (lipids) chemistry Biochemistry N-glycan N-glycome biology.protein glycoproteome Glycoprotein lcsh:RC581-607 |
Zdroj: | Frontiers in Immunology, Vol 5 (2014) Frontiers in Immunology |
ISSN: | 1664-3224 |
Popis: | Glycoproteins perform extra- and intracellular functions in innate and adaptive immunity by lectin-based interactions to exposed glyco-determinants. Herein, we document and mechanistically explain the formation of subcellular-specific N-glycosylation determinants on glycoproteins trafficking through the shared biosynthetic machinery of human cells. LC-MS/MS-based quantitative glycomics showed that the secreted glycoproteins of eight human breast epithelial cells displaying diverse geno- and phenotypes consistently displayed more processed, primarily complex type, N-glycans than the high-mannose-rich microsomal glycoproteins. Detailed subcellular glycome profiling of proteins derived from three breast cell lines (MCF7/MDA468/MCF10A) demonstrated that secreted glycoproteins displayed significantly more α-sialylation and α1,6-fucosylation, but less α-mannosylation, than both the intermediately glycan-processed cell-surface glycoproteomes and the under-processed microsomal glycoproteomes. Subcellular proteomics and gene ontology revealed substantial presence of endoplasmic reticulum resident glycoproteins in the microsomes and confirmed significant enrichment of secreted and cell-surface glycoproteins in the respective subcellular fractions. The solvent accessibility of the glycosylation sites on maturely folded proteins of the 100 most abundant putative N-glycoproteins observed uniquely in the three subcellular glycoproteomes correlated with the glycan type processing thereby mechanistically explaining the formation of subcellular-specific N-glycosylation. In conclusion, human cells have developed mechanisms to simultaneously and reproducibly generate subcellular-specific N-glycosylation using a shared biosynthetic machinery. This aspect of protein-specific glycosylation is important for structural and functional glycobiology and discussed here in the context of the spatio-temporal interaction of glyco-determinants with lectins central to infection and immunity. |
Databáze: | OpenAIRE |
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