Inhibition of SARS-CoV-2 viral entry upon blocking N- and O-glycan elaboration
- State University of New York at Buffalo, United States
Abstract
The Spike protein of SARS-CoV-2, its receptor binding domain (RBD), and its primary receptor ACE2 are extensively glycosylated. The impact of this post-translational modification on viral entry is yet unestablished. We expressed different glycoforms of the Spike-protein and ACE2 in CRISPR-Cas9 glycoengineered cells, and developed corresponding SARS-CoV-2 pseudovirus. We observed that N- and O-glycans had only minor contribution to Spike-ACE2 binding. However, these carbohydrates played a major role in regulating viral entry. Blocking N-glycan biosynthesis at the oligomannose stage using both genetic approaches and the small molecule kifunensine dramatically reduced viral entry into ACE2 expressing HEK293T cells. Blocking O-glycan elaboration also partially blocked viral entry. Mechanistic studies suggest multiple roles for glycans during viral entry. Among them, inhibition of N-glycan biosynthesis enhanced Spike-protein proteolysis. This could reduce RBD presentation on virus, lowering binding to host ACE2 and decreasing viral entry. Overall, chemical inhibitors of glycosylation may be evaluated for COVID-19.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files. All plasmids generated by the authors will be deposited at Addgene.
Article and author information
Author details
Sriram Neelamegham
Funding
National Institutes of Health (HL103411)
- Sriram Neelamegham
National Institutes of Health (GM133195)
- Sriram Neelamegham
National Institutes of Health (GM126537)
- Sriram Neelamegham
National Institutes of Health (GM139160)
- Sheldon Park
- Sriram Neelamegham
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2020, Yang et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Inhibition of SARS-CoV-2 viral entry upon blocking N- and O-glycan elaboration
eLife 9:e61552.
https://doi.org/10.7554/eLife.61552
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