How small-molecule inhibitors of dengue-virus infection interfere with viral membrane fusion

  1. Luke H Chao
  2. Jaebong Jang
  3. Adam Johnson
  4. Anthony Nguyen
  5. Nathanael Gray
  6. Priscilla L Yang
  7. Stephen C Harrison  Is a corresponding author
  1. Harvard Medical School, United States
  2. Dana-Farber Cancer Institute, United States

Abstract

Dengue virus (DV) is a compact, icosahedrally symmetric, enveloped particle, covered by 90 dimers of envelope protein (E), which mediates viral attachment and membrane fusion. Fusion requires a dimer-to-trimer transition and membrane engagement of hydrophobic 'fusion loops'. We previously characterized the steps in membrane fusion for the related West Nile virus (WNV), using recombinant, WNV virus-like particles (VLPs) for single-particle experiments (Chao et al., 2014). Trimerization and membrane engagement are rate-limiting; fusion requires at least two adjacent trimers; availability of competent monomers within the contact zone between virus and target membrane creates a trimerization bottleneck. We now report an extension of that work to dengue VLPs, from all four serotypes, finding an essentially similar mechanism. Small-molecule inhibitors of dengue virus infection that target E block its fusion-inducing conformational change. We show that ~12-14 bound molecules per particle (~20-25% occupancy) completely prevent fusion, consistent with the proposed mechanism.

Data availability

Simulation software deposited at Gihub.

The following data sets were generated

Article and author information

Author details

  1. Luke H Chao

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4849-4148
  2. Jaebong Jang

    Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Adam Johnson

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Anthony Nguyen

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Nathanael Gray

    Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5354-7403
  6. Priscilla L Yang

    Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7456-2557
  7. Stephen C Harrison

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
    For correspondence
    harrison@crystal.harvard.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7215-9393

Funding

National Cancer Institute (CA13202)

  • Stephen C Harrison

National Institute of Allergy and Infectious Diseases (AI109740)

  • Stephen C Harrison

Howard Hughes Medical Institute

  • Stephen C Harrison

Charles A. King Trust

  • Luke H Chao

Jane Coffin Childs Memorial Fund for Medical Research

  • Luke H Chao

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Reinhard Jahn, Max Planck Institute for Biophysical Chemistry, Germany

Publication history

  1. Received: March 9, 2018
  2. Accepted: July 10, 2018
  3. Accepted Manuscript published: July 12, 2018 (version 1)
  4. Version of Record published: July 23, 2018 (version 2)

Copyright

© 2018, Chao 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.

Metrics

  • 2,330
    Page views
  • 457
    Downloads
  • 13
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, Scopus, PubMed Central.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Luke H Chao
  2. Jaebong Jang
  3. Adam Johnson
  4. Anthony Nguyen
  5. Nathanael Gray
  6. Priscilla L Yang
  7. Stephen C Harrison
(2018)
How small-molecule inhibitors of dengue-virus infection interfere with viral membrane fusion
eLife 7:e36461.
https://doi.org/10.7554/eLife.36461

Further reading

    1. Structural Biology and Molecular Biophysics
    2. Cell Biology
    Peter R Strege, Luke M Cowan ... Arthur Beyder
    Research Article Updated

    Voltage-gated ion channels (VGICs) orchestrate electrical activities that drive mechanical functions in contractile tissues such as the heart and gut. In turn, contractions change membrane tension and impact ion channels. VGICs are mechanosensitive, but the mechanisms of mechanosensitivity remain poorly understood. Here, we leverage the relative simplicity of NaChBac, a prokaryotic voltage-gated sodium channel from Bacillus halodurans, to investigate mechanosensitivity. In whole-cell experiments on heterologously transfected HEK293 cells, shear stress reversibly altered the kinetic properties of NaChBac and increased its maximum current, comparably to the mechanosensitive eukaryotic sodium channel NaV1.5. In single-channel experiments, patch suction reversibly increased the open probability of a NaChBac mutant with inactivation removed. A simple kinetic mechanism featuring a mechanosensitive pore opening transition explained the overall response to force, whereas an alternative model with mechanosensitive voltage sensor activation diverged from the data. Structural analysis of NaChBac identified a large displacement of the hinged intracellular gate, and mutagenesis near the hinge diminished NaChBac mechanosensitivity, further supporting the proposed mechanism. Our results suggest that NaChBac is overall mechanosensitive due to the mechanosensitivity of a voltage-insensitive gating step associated with the pore opening. This mechanism may apply to eukaryotic VGICs, including NaV1.5.

    1. Structural Biology and Molecular Biophysics
    Meng Shi, Jiaqi Zhao ... Song Xiang
    Research Article Updated

    The mono-ubiquitination of the histone protein H2B (H2Bub1) is a highly conserved histone post-translational modification that plays critical roles in many fundamental processes. In yeast, this modification is catalyzed by the conserved Bre1–Rad6 complex. Bre1 contains a unique N-terminal Rad6-binding domain (RBD), how it interacts with Rad6 and contributes to the H2Bub1 catalysis is unclear. Here, we present crystal structure of the Bre1 RBD–Rad6 complex and structure-guided functional studies. Our structure provides a detailed picture of the interaction between the dimeric Bre1 RBD and a single Rad6 molecule. We further found that the interaction stimulates Rad6’s enzymatic activity by allosterically increasing its active site accessibility and likely contribute to the H2Bub1 catalysis through additional mechanisms. In line with these important functions, we found that the interaction is crucial for multiple H2Bub1-regulated processes. Our study provides molecular insights into the H2Bub1 catalysis.