Z-REX uncovers a bifurcation in function of Keap1 paralogs

  1. Alexandra Van Hall-Beauvais
  2. Jesse R Poganik
  3. Kuan-Ting Huang
  4. Saba Parvez
  5. Yi Zhao
  6. Hong-Yu Lin
  7. Xuyu Liu
  8. Marcus John Curtis Long  Is a corresponding author
  9. Yimon Aye  Is a corresponding author
  1. École Polytechnique Fédérale de Lausanne, Switzerland
  2. Brigham and Women's Hospital, United States
  3. University of Utah, United States
  4. Xiamen University, China
  5. University of Sydney, Australia
  6. University of Lausanne, Switzerland

Abstract

Studying electrophile signaling is marred by difficulties in parsing changes in pathway flux attributable to on-target, vis-à-vis off-target, modifications. By combining bolus dosing, knockdown, and Z-REX-a tool investigating on-target/on-pathway electrophile signaling, we document that electrophile labeling of one zebrafish-Keap1-paralog (zKeap1b) stimulates Nrf2- driven antioxidant response (AR) signaling (like the human-ortholog). Conversely, zKeap1a is a dominant-negative regulator of electrophile-promoted Nrf2-signaling, and itself is nonpermissive for electrophile-induced Nrf2-upregulation. This behavior is recapitulated in human cells, wherein following electrophile treatment: (1) zKeap1b-transfected cells are permissive for augmented AR-signaling through reduced zKeap1b-Nrf2 binding; (2) zKeap1a-transfected cells are non-permissive for AR-upregulation, as zKeap1a-Nrf2 binding capacity remains unaltered; (3) 1:1 ZKeap1a:zKeap1b-transfected cells show no Nrf2-release from the Keap1-complex, rendering these cells unable to upregulate AR. We identified a zKeap1a-specific point-mutation (C273I) responsible for zKeap1a's behavior. Human-Keap1(C273I), of known diminished Nrf2-regulatory capacity, dominantly muted electrophile-induced Nrf2-signaling. These studies highlight divergent and interdependent electrophile signaling behaviors, despite conserved electrophile sensing.

Data availability

The data generated in this study using these materials are provided in Main Figure 1-8, accompanied by 17 associated Figure Supplements, and the Source Data Files associated with Main Figure 1-8 and 17 associated Figure Supplements.

Article and author information

Author details

  1. Alexandra Van Hall-Beauvais

    École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-2515-5191
  2. Jesse R Poganik

    Department of Medicine, Brigham and Women's Hospital, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Kuan-Ting Huang

    École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
  4. Saba Parvez

    Department of Pharmacology and Toxicology, University of Utah, Salt lake City, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Yi Zhao

    École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-6049-1943
  6. Hong-Yu Lin

    Department of Chemical Biology, Xiamen University, Xiamen, China
    Competing interests
    The authors declare that no competing interests exist.
  7. Xuyu Liu

    School of Chemistry, University of Sydney, New South Wales, Australia
    Competing interests
    The authors declare that no competing interests exist.
  8. Marcus John Curtis Long

    Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
    For correspondence
    marcusjohncurtis.long@unil.ch
    Competing interests
    The authors declare that no competing interests exist.
  9. Yimon Aye

    École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
    For correspondence
    yimon.aye@epfl.ch
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1256-4159

Funding

Novartis FreeNovation

  • Yimon Aye

European Research Council

  • Yimon Aye

Swiss Federal Institute od Technology

  • Yimon Aye

National Institutes of Health (NIH T32GM008500)

  • Jesse R Poganik

AHA predoctoral Fellowship (17PRE33670395)

  • Jesse R Poganik

HHMI International Fellow

  • Saba Parvez

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

Ethics

Animal experimentation: All procedures performed at Cornell (2017-2018) and EPFL (2018-present) conform to the animal care, maintenance, and experimentation procedures followed by Cornell University's and EPFL's Institutional Animal Care and Use Committee (IACUC) guidelines and approved by the respective institutional committees. All experiments with zebrafish performed at EPFL (2018-present) have been performed in accordance with the Swiss regulations on Animal Experimentation (Animal Welfare Act SR 455 and Animal Welfare Ordinance SR 455.1), in the EPFL zebrafish unit, cantonal veterinary authorization VD-H23).

Copyright

© 2022, Van Hall-Beauvais 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

  • 940
    views
  • 155
    downloads
  • 7
    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. Alexandra Van Hall-Beauvais
  2. Jesse R Poganik
  3. Kuan-Ting Huang
  4. Saba Parvez
  5. Yi Zhao
  6. Hong-Yu Lin
  7. Xuyu Liu
  8. Marcus John Curtis Long
  9. Yimon Aye
(2022)
Z-REX uncovers a bifurcation in function of Keap1 paralogs
eLife 11:e83373.
https://doi.org/10.7554/eLife.83373

Share this article

https://doi.org/10.7554/eLife.83373

Further reading

    1. Biochemistry and Chemical Biology
    2. Microbiology and Infectious Disease
    Mai Nguyen, Elda Bauda ... Cecile Morlot
    Research Article

    Teichoic acids (TA) are linear phospho-saccharidic polymers and important constituents of the cell envelope of Gram-positive bacteria, either bound to the peptidoglycan as wall teichoic acids (WTA) or to the membrane as lipoteichoic acids (LTA). The composition of TA varies greatly but the presence of both WTA and LTA is highly conserved, hinting at an underlying fundamental function that is distinct from their specific roles in diverse organisms. We report the observation of a periplasmic space in Streptococcus pneumoniae by cryo-electron microscopy of vitreous sections. The thickness and appearance of this region change upon deletion of genes involved in the attachment of TA, supporting their role in the maintenance of a periplasmic space in Gram-positive bacteria as a possible universal function. Consequences of these mutations were further examined by super-resolved microscopy, following metabolic labeling and fluorophore coupling by click chemistry. This novel labeling method also enabled in-gel analysis of cell fractions. With this approach, we were able to titrate the actual amount of TA per cell and to determine the ratio of WTA to LTA. In addition, we followed the change of TA length during growth phases, and discovered that a mutant devoid of LTA accumulates the membrane-bound polymerized TA precursor.

    1. Biochemistry and Chemical Biology
    2. Computational and Systems Biology
    Shinichi Kawaguchi, Xin Xu ... Toshie Kai
    Research Article

    Protein–protein interactions are fundamental to understanding the molecular functions and regulation of proteins. Despite the availability of extensive databases, many interactions remain uncharacterized due to the labor-intensive nature of experimental validation. In this study, we utilized the AlphaFold2 program to predict interactions among proteins localized in the nuage, a germline-specific non-membrane organelle essential for piRNA biogenesis in Drosophila. We screened 20 nuage proteins for 1:1 interactions and predicted dimer structures. Among these, five represented novel interaction candidates. Three pairs, including Spn-E_Squ, were verified by co-immunoprecipitation. Disruption of the salt bridges at the Spn-E_Squ interface confirmed their functional importance, underscoring the predictive model’s accuracy. We extended our analysis to include interactions between three representative nuage components—Vas, Squ, and Tej—and approximately 430 oogenesis-related proteins. Co-immunoprecipitation verified interactions for three pairs: Mei-W68_Squ, CSN3_Squ, and Pka-C1_Tej. Furthermore, we screened the majority of Drosophila proteins (~12,000) for potential interaction with the Piwi protein, a central player in the piRNA pathway, identifying 164 pairs as potential binding partners. This in silico approach not only efficiently identifies potential interaction partners but also significantly bridges the gap by facilitating the integration of bioinformatics and experimental biology.