1. Biochemistry and Chemical Biology
  2. Structural Biology and Molecular Biophysics

Mechanism of B-box 2 domain-mediated higher-order assembly of the retroviral restriction factor TRIM5α

  1. Jonathan M Wagner
  2. Marcin D Roganowicz
  3. Katarzyna Skorupka
  4. Steven L Alam
  5. Devin E Christensen
  6. Ginna L Doss
  7. Yueping Wan
  8. Gabriel A Frank
  9. Barbie K Ganser-Pornillos
  10. Wesley I Sundquist
  11. Owen Pornillos  Is a corresponding author
  1. University of Virginia, United States
  2. University of Utah, United States
  3. Ben-Gurion University, Israel
https://doi.org/10.7554/eLife.16309
Share this article
Cite this article
  1. Jonathan M Wagner
  2. Marcin D Roganowicz
  3. Katarzyna Skorupka
  4. Steven L Alam
  5. Devin E Christensen
  6. Ginna L Doss
  7. Yueping Wan
  8. Gabriel A Frank
  9. Barbie K Ganser-Pornillos
  10. Wesley I Sundquist
  11. Owen Pornillos
(2016)
Mechanism of B-box 2 domain-mediated higher-order assembly of the retroviral restriction factor TRIM5α
eLife 5:e16309.
https://doi.org/10.7554/eLife.16309
  2. Download BibTeX
  3. Download .RIS

Abstract

Restriction factors and pattern recognition receptors are important components of intrinsic cellular defenses against viral infection. Mammalian TRIM5α proteins are restriction factors and receptors that target the capsid cores of retroviruses and activate ubiquitin-dependent antiviral responses upon capsid recognition. Here, we report crystallographic and functional studies of the TRIM5α B-box 2 domain, which mediates higher-order assembly of TRIM5 proteins. The B-box can form both dimers and trimers, and the trimers can link multiple TRIM5α proteins into a hexagonal net that matches the lattice arrangement of capsid subunits and enables avid capsid binding. Two modes of conformational flexibility allow TRIM5α to accommodate the variable curvature of retroviral capsids. B-box mediated interactions also modulate TRIM5α's E3 ubiquitin ligase activity, by stereochemically restricting how the N-terminal RING domain can dimerize. Overall, these studies define important molecular details of cellular recognition of retroviruses, and how recognition links to downstream processes to disable the virus.

Article and author information

Author details

  1. Jonathan M Wagner

    Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, United States
    Competing interests
    No competing interests declared.

  2. Marcin D Roganowicz

    Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, United States
    Competing interests
    No competing interests declared.

  3. Katarzyna Skorupka

    Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, United States
    Competing interests
    No competing interests declared.

  4. Steven L Alam

    Department of Biochemistry, University of Utah, Salt Lake City, United States
    Competing interests
    No competing interests declared.

  5. Devin E Christensen

    Department of Biochemistry, University of Utah, Salt Lake City, United States
    Competing interests
    No competing interests declared.

  6. Ginna L Doss

    Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, United States
    Competing interests
    No competing interests declared.

  7. Yueping Wan

    Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
    Competing interests
    No competing interests declared.

  8. Gabriel A Frank

    Department of Life Sciences and National Institute for Biotechnology in the Negev, Ben-Gurion University, Beer-Sheeva, Israel
    Competing interests
    No competing interests declared.

  9. Barbie K Ganser-Pornillos

    Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, United States
    Competing interests
    No competing interests declared.

  10. Wesley I Sundquist

    Department of Biochemistry, University of Utah, Salt Lake City, United States
    Competing interests
    Wesley I Sundquist, Reviewing editor, eLife.

  11. Owen Pornillos

    Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, United States
    For correspondence
    owp3a@eservices.virginia.edu
    Competing interests
    No competing interests declared.

Reviewing Editor

  1. Stephen P Goff, Howard Hughes Medical Institute, Columbia University, United States

Version history

  1. Received: March 23, 2016
  2. Accepted: May 20, 2016
  3. Accepted Manuscript published: June 2, 2016 (version 1)
  4. Version of Record published: July 7, 2016 (version 2)

Copyright

© 2016, Wagner 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

  • 2,771
    views
  • 590
    downloads
  • 78
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

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. Jonathan M Wagner
  2. Marcin D Roganowicz
  3. Katarzyna Skorupka
  4. Steven L Alam
  5. Devin E Christensen
  6. Ginna L Doss
  7. Yueping Wan
  8. Gabriel A Frank
  9. Barbie K Ganser-Pornillos
  10. Wesley I Sundquist
  11. Owen Pornillos
(2016)
Mechanism of B-box 2 domain-mediated higher-order assembly of the retroviral restriction factor TRIM5α
eLife 5:e16309.
https://doi.org/10.7554/eLife.16309

Share this article

https://doi.org/10.7554/eLife.16309

Categories and tags

Research organism

Further reading

    1. Immunology and Inflammation
    2. Microbiology and Infectious Disease

    Primate TRIM5 proteins form hexagonal nets on HIV-1 capsids

    Yen-Li Li, Viswanathan Chandrasekaran ... Wesley I Sundquist
    Research Article Updated

    TRIM5 proteins are restriction factors that block retroviral infections by binding viral capsids and preventing reverse transcription. Capsid recognition is mediated by C-terminal domains on TRIM5α (SPRY) or TRIMCyp (cyclophilin A), which interact weakly with capsids. Efficient capsid recognition also requires the conserved N-terminal tripartite motifs (TRIM), which mediate oligomerization and create avidity effects. To characterize how TRIM5 proteins recognize viral capsids, we developed methods for isolating native recombinant TRIM5 proteins and purifying stable HIV-1 capsids. Biochemical and EM analyses revealed that TRIM5 proteins assembled into hexagonal nets, both alone and on capsid surfaces. These nets comprised open hexameric rings, with the SPRY domains centered on the edges and the B-box and RING domains at the vertices. Thus, the principles of hexagonal TRIM5 assembly and capsid pattern recognition are conserved across primates, allowing TRIM5 assemblies to maintain the conformational plasticity necessary to recognize divergent and pleomorphic retroviral capsids.

    1. Structural Biology and Molecular Biophysics
    2. Microbiology and Infectious Disease

    Host-virus Interactions: Closing the net on retroviruses

    Jeremy Luban
    Insight

    Structural studies reveal how an antiviral factor forms a molecular net to restrict retroviruses including HIV-1.

    1. Biochemistry and Chemical Biology
    2. Cell Biology

    Remodeling of skeletal muscle myosin metabolic states in hibernating mammals

    Christopher TA Lewis, Elise G Melhedegaard ... Julien Ochala
    Research Article

    Hibernation is a period of metabolic suppression utilized by many small and large mammal species to survive during winter periods. As the underlying cellular and molecular mechanisms remain incompletely understood, our study aimed to determine whether skeletal muscle myosin and its metabolic efficiency undergo alterations during hibernation to optimize energy utilization. We isolated muscle fibers from small hibernators, Ictidomys tridecemlineatus and Eliomys quercinus and larger hibernators, Ursus arctos and Ursus americanus. We then conducted loaded Mant-ATP chase experiments alongside X-ray diffraction to measure resting myosin dynamics and its ATP demand. In parallel, we performed multiple proteomics analyses. Our results showed a preservation of myosin structure in U. arctos and U. americanus during hibernation, whilst in I. tridecemlineatus and E. quercinus, changes in myosin metabolic states during torpor unexpectedly led to higher levels in energy expenditure of type II, fast-twitch muscle fibers at ambient lab temperatures (20 °C). Upon repeating loaded Mant-ATP chase experiments at 8 °C (near the body temperature of torpid animals), we found that myosin ATP consumption in type II muscle fibers was reduced by 77–107% during torpor compared to active periods. Additionally, we observed Myh2 hyper-phosphorylation during torpor in I. tridecemilineatus, which was predicted to stabilize the myosin molecule. This may act as a potential molecular mechanism mitigating myosin-associated increases in skeletal muscle energy expenditure during periods of torpor in response to cold exposure. Altogether, we demonstrate that resting myosin is altered in hibernating mammals, contributing to significant changes to the ATP consumption of skeletal muscle. Additionally, we observe that it is further altered in response to cold exposure and highlight myosin as a potentially contributor to skeletal muscle non-shivering thermogenesis.