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Structural Divergence in O-GlcNAc Glycans Displayed on Epidermal Growth Factor-like Repeats of Mammalian Notch1
Extracellular O-GlcNAc is a novel class of modification catalyzed by epidermal growth factor-like (EGF)-domain specific O-GlcNAc transferase (EOGT). In mammals, EOGT is required for ligand-mediated Notch signaling for vascular development. Previous studies have revealed that O-GlcNAc in mammalian cu...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6099671/ https://www.ncbi.nlm.nih.gov/pubmed/30018219 http://dx.doi.org/10.3390/molecules23071745 |
Sumario: | Extracellular O-GlcNAc is a novel class of modification catalyzed by epidermal growth factor-like (EGF)-domain specific O-GlcNAc transferase (EOGT). In mammals, EOGT is required for ligand-mediated Notch signaling for vascular development. Previous studies have revealed that O-GlcNAc in mammalian cultured cells is subject to subsequent glycosylation, which may impose additional layers of regulation. This study aimed to analyze the O-GlcNAc glycans of Drosophila EGF20 as model substrates and mouse Notch1 EGF repeats by mass-spectrometry. The analysis of Drosophila EGF20 expressed in HEK293T cells revealed that the majority of the proteins are modified with an elongated form of O-GlcNAc glycan comprising terminal galactose or sialic acid residues. In contrast, recombinant Notch1 EGF repeats isolated from HEK293T cells revealed structural divergence of O-GlcNAc glycans among the different EGF domains. Although the majority of Notch1 EGF2 and EGF20 domains contained the extended forms of the glycan, the O-GlcNAc in many other domains mostly existed as a monosaccharide irrespective of the exogenous EOGT expression. Our results raised a hypothesis that an array of O-GlcNAc monosaccharides may impact the structure and function of Notch receptors. |
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