Site-specific N-glycan profiles of α 5 β 1 integrin from rat liver.

Autor: Mirgorodskaya E; Proteomics Core Facility, Sahlgrenska Academy, University of Gothenburg, Sweden., Dransart E; Institut Curie, Université PSL, Paris, France., Shafaq-Zadah M; Institut Curie, Université PSL, Paris, France., Roderer D; Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany., Sihlbom C; Proteomics Core Facility, Sahlgrenska Academy, University of Gothenburg, Sweden., Leffler H; Section MIG (Microbiology, Immunology, Glycobiology), Department of Laboratory Medicine, Lund University, Sweden., Johannes L; Institut Curie, Université PSL, Paris, France.
Jazyk: angličtina
Zdroj: Biology of the cell [Biol Cell] 2022 Jun; Vol. 114 (6), pp. 160-176. Date of Electronic Publication: 2022 Mar 31.
DOI: 10.1111/boc.202200017
Abstrakt: Background Information: Like most other cell surface proteins, α 5 β 1 integrin is glycosylated, which is required for its various activities in ways that mostly remain to be determined.
Results: Here, we have established the first comprehensive site-specific glycan map of α 5 β 1 integrin that was purified from a natural source, that is, rat liver. This analysis revealed striking site selective variations in glycan composition. Complex bi, tri, or tetraantennary N-glycans were predominant at various proportions at most potential N-glycosylation sites. A few of these sites were nonglycosylated or contained high mannose or hybrid glycans, indicating that early N-glycan processing was hindered. Almost all complex N-glycans had fully galactosylated and sialylated antennae. Moderate levels of core fucosylation and high levels of O-acetylation of NeuAc residues were observed at certain sites. An O-linked HexNAc was found in an EGF-like domain of β 1 integrin. The extensive glycan information that results from our study was projected onto a map of α 5 β 1 integrin that was obtained by homology modeling. We have used this model for the discussion of how glycosylation might be used in the functional cycle of α 5 β 1 integrin. A striking example concerns the involvement of glycan-binding galectins in the regulation of the molecular homeostasis of glycoproteins at the cell surface through the formation of lattices or endocytic pits according to the glycolipid-lectin (GL-Lect) hypothesis.
Conclusion: We expect that the glycoproteomics data of the current study will serve as a resource for the exploration of structural mechanisms by which glycans control α 5 β 1 integrin activity and endocytic trafficking.
Significance: Glycosylation of α 5 β 1 integrin has been implicated in multiple aspects of integrin function and structure. Yet, detailed knowledge of its glycosylation, notably the specific sites of glycosylation, is lacking. Furthermore, the α 5 β 1 integrin preparation that was analyzed here is from a natural source, which is of importance as there is not a lot of literature in the field about the glycosylation of "native" glycoproteins.
(© 2022 The Authors. Biology of the Cell published by Wiley-VCH GmbH on behalf of Société Française des Microscopies and Société de Biologie Cellulaire de France.)
Databáze: MEDLINE
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