University of Massachusetts Medical School Faculty Publications

UMMS Affiliation

Department of Biochemistry and Molecular Pharmacology

Publication Date

6-1-2017

Document Type

Article Preprint

Disciplines

Amino Acids, Peptides, and Proteins | Cells | Enzymes and Coenzymes | Genetic Phenomena | Virology | Virus Diseases | Viruses

Abstract

Dengue virus (DENV) is the most common arboviral infection globally, infecting an estimated 390 million people each year. We employed a genome-wide CRISPR screen to identify host dependency factors required for DENV propagation, and identified the oligosaccharyltransferase (OST) complex as an essential host factor for DENV infection. Mammalian cells express two OSTs containing either STT3A or STT3B. We found that the canonical catalytic function of the OSTs as oligosaccharyltransferases is not necessary for DENV infection, as cells expressing catalytically inactive STT3A or STT3B are able to support DENV propagation. However, the OST subunit MAGT1, which associates with STT3B, is also required for DENV propagation. MAGT1 expression requires STT3B, and a catalytically inactive STT3B also rescues MAGT1 expression, supporting the hypothesis that STT3B serves to stabilize MAGT1 in the context of DENV infection. We found that the oxidoreductase CxxC active site motif of MAGT1 was necessary for DENV propagation as cells expressing an AxxA MAGT1 mutant were unable to support DENV infection. Interestingly, cells expressing single-cysteine CxxA or AxxC mutants of MAGT1 were able to support DENV propagation. Utilizing the engineered peroxidase APEX2, we demonstrate the close proximity between MAGT1 and NS1 or NS4B during DENV infection. These results reveal that the oxidoreductase activity of the STT3B-containing OST is necessary for DENV infection, which may guide the development of antivirals targeting DENV.

Keywords

microbiology, Dengue virus, CRISPR, STT3B, MAGT1, oligosaccharyltransferase

Rights and Permissions

The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It is made available under a CC-BY 4.0 International license.

DOI of Published Version

10.1101/130914

Source

bioRxiv 130914; doi: https://doi.org/10.1101/130914. Link to preprint on bioRxiv service.

Related Resources

Now published in mBio doi: 10.1128/mBio.00939-17.

Journal/Book/Conference Title

bioRxiv

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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