Enhanced ER proteostasis and temperature differentially impact the mutational tolerance of influenza hemagglutinin
- Massachusetts Institute of Technology, United States
- Fred Hutchinson Cancer Research Center, United States
- Tufts University, United States
Abstract
Herein, we systematically and quantitatively evaluate whether endoplasmic reticulum (ER) proteostasis factors impact the mutational tolerance of secretory pathway proteins. We focus on influenza hemagluttinin (HA), a viral membrane protein that folds in the host's ER via a complex pathway. By integrating chemical methods to modulate ER proteostasis with deep mutational scanning to assess mutational tolerance, we discover that upregulation of ER proteostasis factors broadly enhances HA mutational tolerance across diverse structural elements. Remarkably, this proteostasis network-enhanced mutational tolerance occurs at the same sites where mutational tolerance is most reduced by propagation at fever-like temperature. These findings have important implications for influenza evolution, because influenza immune escape is contingent on HA possessing sufficient mutational tolerance to evade antibodies while maintaining the capacity to fold and function. More broadly, this work provides the first experimental evidence that ER proteostasis mechanisms define the mutational tolerance and, therefore, the evolution of secretory pathway proteins.
Data availability
FASTQ files for DMS sequencing are available in the Sequence Read Archive under accession number SRP149672. The deep mutational scanning data analysis will be available upon publication at https://github.com/amphilli/HA_DMS_2018, and is also available in Dataset 1. All differential selection values from deep mutational scanning (pre- and post-filtering) are available in Figure 5-source data 1. The complete RNAseq data are available from GEO under accession number GSE115168.
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ER proteostasis and temperature differentially impact the mutational tolerance of influenza hemagglutininPublicly available at the NCBI Gene Expression Omnibus (accession no: GSE115168).
Article and author information
Author details
Matthew D Shoulders
Funding
National Science Foundation (CAREER Award 1652390)
- Matthew D Shoulders
National Science Foundation (Graduate Research Fellowship)
- Angela M Phillips
Richard and Susan Smith Family Foundation (Award for Excellence in Biomedical Research)
- Matthew D Shoulders
Massachusetts Institute of Technology
- Matthew D Shoulders
Tufts University
- Yu-Shan Lin
National Cancer Institute (Koch Institute Support (core) Grant P30-CA14051)
- Vincent L Butty
- Matthew D Shoulders
National Institutes of Health (Al127893)
- Jesse D Bloom
Howard Hughes Medical Institute (Faculty Scholars grant)
- Jesse D Bloom
Simons Foundation (Faculty Scholars grant)
- Jesse D Bloom
National Institute of Environmental Health Sciences (MIT Center for Environmental Health Sciences (core) Grant P30-ES002109)
- Vincent L Butty
- Matthew D Shoulders
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2018, Phillips 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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Enhanced ER proteostasis and temperature differentially impact the mutational tolerance of influenza hemagglutinin
eLife 7:e38795.
https://doi.org/10.7554/eLife.38795
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