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The ER membrane protein complex is required to ensure correct topology and stable expression of flavivirus polyproteins
Flaviviruses translate their genomes as multi-pass transmembrane proteins at the endoplasmic reticulum (ER) membrane. Here, we show that the ER membrane protein complex (EMC) is indispensable for the expression of viral polyproteins. We demonstrated that EMC was essential for accurate folding and po...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
eLife Sciences Publications, Ltd
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6756788/ https://www.ncbi.nlm.nih.gov/pubmed/31516121 http://dx.doi.org/10.7554/eLife.48469 |
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author | Ngo, Ashley M Shurtleff, Matthew J Popova, Katerina D Kulsuptrakul, Jessie Weissman, Jonathan S Puschnik, Andreas S |
author_facet | Ngo, Ashley M Shurtleff, Matthew J Popova, Katerina D Kulsuptrakul, Jessie Weissman, Jonathan S Puschnik, Andreas S |
author_sort | Ngo, Ashley M |
collection | PubMed |
description | Flaviviruses translate their genomes as multi-pass transmembrane proteins at the endoplasmic reticulum (ER) membrane. Here, we show that the ER membrane protein complex (EMC) is indispensable for the expression of viral polyproteins. We demonstrated that EMC was essential for accurate folding and post-translational stability rather than translation efficiency. Specifically, we revealed degradation of NS4A-NS4B, a region rich in transmembrane domains, in absence of EMC. Orthogonally, by serial passaging of virus on EMC-deficient cells, we identified two non-synonymous point mutations in NS4A and NS4B, which rescued viral replication. Finally, we showed a physical interaction between EMC and viral NS4B and that the NS4A-4B region adopts an aberrant topology in the absence of the EMC leading to degradation. Together, our data highlight how flaviviruses hijack the EMC for transmembrane protein biogenesis to achieve optimal expression of their polyproteins, which reinforces a role for the EMC in stabilizing challenging transmembrane proteins during synthesis. |
format | Online Article Text |
id | pubmed-6756788 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | eLife Sciences Publications, Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-67567882019-09-25 The ER membrane protein complex is required to ensure correct topology and stable expression of flavivirus polyproteins Ngo, Ashley M Shurtleff, Matthew J Popova, Katerina D Kulsuptrakul, Jessie Weissman, Jonathan S Puschnik, Andreas S eLife Microbiology and Infectious Disease Flaviviruses translate their genomes as multi-pass transmembrane proteins at the endoplasmic reticulum (ER) membrane. Here, we show that the ER membrane protein complex (EMC) is indispensable for the expression of viral polyproteins. We demonstrated that EMC was essential for accurate folding and post-translational stability rather than translation efficiency. Specifically, we revealed degradation of NS4A-NS4B, a region rich in transmembrane domains, in absence of EMC. Orthogonally, by serial passaging of virus on EMC-deficient cells, we identified two non-synonymous point mutations in NS4A and NS4B, which rescued viral replication. Finally, we showed a physical interaction between EMC and viral NS4B and that the NS4A-4B region adopts an aberrant topology in the absence of the EMC leading to degradation. Together, our data highlight how flaviviruses hijack the EMC for transmembrane protein biogenesis to achieve optimal expression of their polyproteins, which reinforces a role for the EMC in stabilizing challenging transmembrane proteins during synthesis. eLife Sciences Publications, Ltd 2019-09-13 /pmc/articles/PMC6756788/ /pubmed/31516121 http://dx.doi.org/10.7554/eLife.48469 Text en © 2019, Ngo et al http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited. |
spellingShingle | Microbiology and Infectious Disease Ngo, Ashley M Shurtleff, Matthew J Popova, Katerina D Kulsuptrakul, Jessie Weissman, Jonathan S Puschnik, Andreas S The ER membrane protein complex is required to ensure correct topology and stable expression of flavivirus polyproteins |
title | The ER membrane protein complex is required to ensure correct topology and stable expression of flavivirus polyproteins |
title_full | The ER membrane protein complex is required to ensure correct topology and stable expression of flavivirus polyproteins |
title_fullStr | The ER membrane protein complex is required to ensure correct topology and stable expression of flavivirus polyproteins |
title_full_unstemmed | The ER membrane protein complex is required to ensure correct topology and stable expression of flavivirus polyproteins |
title_short | The ER membrane protein complex is required to ensure correct topology and stable expression of flavivirus polyproteins |
title_sort | er membrane protein complex is required to ensure correct topology and stable expression of flavivirus polyproteins |
topic | Microbiology and Infectious Disease |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6756788/ https://www.ncbi.nlm.nih.gov/pubmed/31516121 http://dx.doi.org/10.7554/eLife.48469 |
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