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

Conformational fingerprinting of allosteric modulators in metabotropic glutamate receptor 2

  1. Brandon Wey-Hung Liauw
  2. Arash Foroutan
  3. Michael R Schamber
  4. Weifeng Lu
  5. Hamid Samareh Afsari  Is a corresponding author
  6. Reza Vafabakhsh  Is a corresponding author
  1. Northwestern University, United States
  2. Boehringer Ingelheim Pharmaceuticals, Inc, United States
https://doi.org/10.7554/eLife.78982
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  1. Brandon Wey-Hung Liauw
  2. Arash Foroutan
  3. Michael R Schamber
  4. Weifeng Lu
  5. Hamid Samareh Afsari
  6. Reza Vafabakhsh
(2022)
Conformational fingerprinting of allosteric modulators in metabotropic glutamate receptor 2
eLife 11:e78982.
https://doi.org/10.7554/eLife.78982
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Abstract

Activation of G protein-coupled receptors (GPCRs) is an allosteric process. It involves conformational coupling between the orthosteric ligand binding site and the G protein binding site. Factors that bind at non-cognate ligand binding sites to alter the allosteric activation process are classified as allosteric modulators and represent a promising class of therapeutics with distinct modes of binding and action. For many receptors, how modulation of signaling is represented at the structural level is unclear. Here, we developed FRET sensors to quantify receptor modulation at each of the three structural domains of metabotropic glutamate receptor 2 (mGluR2). We identified the conformational fingerprint for several allosteric modulators in live cells. This approach enabled us to derive a receptor-centric representation of allosteric modulation and to correlate structural modulation to the standard signaling modulation metrics. Single-molecule FRET analysis revealed that a NAM increases the occupancy of one of the intermediate states while a PAM increases the occupancy of the active state. Moreover, we found that the effect of allosteric modulators on the receptor dynamics is complex and depend on the orthosteric ligand. Collectively, our findings provide a structural mechanism of allosteric modulation in mGluR2 and suggest possible strategies for design of future modulators.

Data availability

All data generated or analyzed during this study are included in the manuscript and supporting files. Accompanying source data is provided for figures 1-4 and tables 1-3. The PDB accession codes for human mGluR2 structures used are 7MTS, 7MTR, 7E9G, 7EPE, and 7EPF.

The following previously published data sets were used

Article and author information

Author details

  1. Brandon Wey-Hung Liauw

    Department of Molecular Biosciences, Northwestern University, Evanston, United States
    Competing interests
    No competing interests declared.

  2. Arash Foroutan

    Department of Molecular Biosciences, Northwestern University, Evanston, United States
    Competing interests
    No competing interests declared.

  3. Michael R Schamber

    Department of Molecular Biosciences, Northwestern University, Evanston, United States
    Competing interests
    No competing interests declared.

  4. Weifeng Lu

    Department of Molecular Biosciences, Northwestern University, Evanston, United States
    Competing interests
    No competing interests declared.

  5. Hamid Samareh Afsari

    Boehringer Ingelheim Pharmaceuticals, Inc, Ridgefield, United States
    For correspondence
    hamid.samareh_afsari@boehringer-ingelheim.com
    Competing interests
    Hamid Samareh Afsari, is affiliated with Boehringer Ingelheim Pharma GmbH & Co. The author has no financial interests to declare..
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5839-4765

  6. Reza Vafabakhsh

    Department of Molecular Biosciences, Northwestern University, Evanston, United States
    For correspondence
    reza.vafabakhsh@northwestern.edu
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-8384-3203

Funding

NIGMS (R01GM140272)

  • Reza Vafabakhsh

NIGMS (T32GM-008061)

  • Brandon Wey-Hung Liauw

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

Reviewing Editor

  1. Marcel P Goldschen-Ohm, University of Texas at Austin, United States

Publication history

  1. Received: March 26, 2022
  2. Preprint posted: April 28, 2022 (view preprint)
  3. Accepted: June 30, 2022
  4. Accepted Manuscript published: July 1, 2022 (version 1)
  5. Version of Record published: July 20, 2022 (version 2)

Copyright

© 2022, Liauw 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. Brandon Wey-Hung Liauw
  2. Arash Foroutan
  3. Michael R Schamber
  4. Weifeng Lu
  5. Hamid Samareh Afsari
  6. Reza Vafabakhsh
(2022)
Conformational fingerprinting of allosteric modulators in metabotropic glutamate receptor 2
eLife 11:e78982.
https://doi.org/10.7554/eLife.78982

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