Abstract
Glycan biosynthesis relies on nucleotide sugars (NSs), abundant metabolites that serve as monosaccharide donors for glycosyltransferases.In vivo, signal-dependent fluctuations in NS levels are required to maintain normal cell physiology and are dysregulated in disease. However, how mammalian cells regulate NS levels and pathway flux remains largely uncharacterized. To address this knowledge gap, here we examined UDP-galactose 4′-epimerase (GALE), which interconverts two pairs of essential NSs. Using immunoblotting, flow cytometry, and LC-MS–based glycolipid and glycan profiling, we found that CRISPR/Cas9-mediatedGALEdeletion in human cells triggers major imbalances in NSs and dramatic changes in glycolipids and glycoproteins, including a subset of integrins and the cell-surface death receptor FS-7-associated surface antigen. In particular, we observed substantial decreases in total sialic acid, galactose, and GalNAc levels in glycans. These changes also directly impacted cell signaling, asGALE−/−cells exhibited FS-7-associated surface antigen ligand-induced apoptosis. Our results reveal a role of GALE-mediated NS regulation in death receptor signaling and may have implications for the molecular etiology of illnesses characterized by NS imbalances, including galactosemia and metabolic syndrome.
Funder
Rita Allen Foundation
HHS | NIH | National Institute of General Medical Sciences
HHS | NIH | National Eye Institute
Welch Foundation
German Academic Exchange Service
Subject
Cell Biology,Molecular Biology,Biochemistry
Reference97 articles.
1. Life is sweet: the cell biology of glycoconjugates
2. Freeze, H. , Hart, G. , and Schnaar, R. (2017) Glycosylation precursors. In Essentials of Glycobiology ( Varki, A. , Cummings, R. D. , Esko, J. D. , and Freeze, H. H. eds) 3rd Ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY
3. Cell migration—The role of integrin glycosylation
4. Sweet-talk: role of host glycosylation in bacterial pathogenesis of the gastrointestinal tract
5. O-GlcNAc modification of nucleocytoplasmic proteins and diabetes
Cited by
20 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献