Abstract

Immune cells activate in binary, switch-like fashion via large protein assemblies known as signalosomes, but the molecular mechanism of the switch is not yet understood. Here, we employed an in-cell biophysical approach to dissect the assembly mechanism of the CARD-BCL10-MALT1 (CBM) signalosome, which governs NF-κB activation in both innate and adaptive immunity. We found that the switch consists of a sequence-encoded and deeply conserved nucleation barrier to ordered polymerization by the adaptor protein BCL10. The particular structure of the BCL10 polymers did not matter for activity. Using optogenetic tools and single-cell transcriptional reporters, we discovered that endogenous BCL10 is functionally supersaturated even in unstimulated human cells, and this results in a predetermined response to stimulation upon nucleation by activated CARD multimers. Our findings may inform on the progressive nature of age-associated inflammation, and suggest that signalosome structure has evolved via selection for kinetic rather than equilibrium properties of the proteins.

Data availability

Original data underlying this manuscript can be accessed from the Stowers Original Data Repository at http://www.stowers.org/research/publications/libpb-1675

Article and author information

Author details

  1. Alejandro Rodriguez Gama

    Stowers Institute for Medical Research, Kansas City, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-3257-5549
  2. Tayla Miller

    Stowers Institute for Medical Research, Kansas City, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Jeffrey J Lange

    Stowers Institute for Medical Research, Kansas City, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Jay R Unruh

    Stowers Institute for Medical Research, Kansas City, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-3077-4990
  5. Randal Halfmann

    Stowers Institute for Medical Research, Kansas City, United States
    For correspondence
    rhn@stowers.org
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-6592-1471

Funding

National Institutes of Health (R01GM130927)

  • Randal Halfmann

National Institutes of Health (F99AG068511)

  • Alejandro Rodriguez Gama

American Cancer Society (RSG-19-217-01-CCG)

  • Randal Halfmann

Stowers Institute for Medical Research

  • Jay R Unruh
  • Randal Halfmann

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

Reviewing Editor

  1. Jungsan Sohn, Johns Hopkins University School of Medicine, United States

Version history

  1. Preprint posted: January 29, 2022 (view preprint)
  2. Received: April 28, 2022
  3. Accepted: June 20, 2022
  4. Accepted Manuscript published: June 21, 2022 (version 1)
  5. Version of Record published: August 1, 2022 (version 2)

Copyright

© 2022, Rodriguez Gama 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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  1. Alejandro Rodriguez Gama
  2. Tayla Miller
  3. Jeffrey J Lange
  4. Jay R Unruh
  5. Randal Halfmann
(2022)
A nucleation barrier spring-loads the CBM signalosome for binary activation
eLife 11:e79826.
https://doi.org/10.7554/eLife.79826

Share this article

https://doi.org/10.7554/eLife.79826

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