1. Structural Biology and Molecular Biophysics
  2. Computational and Systems Biology

Mechanism of allosteric regulation of β2-adrenergic receptor by cholesterol

  1. Moutusi Manna
  2. Miia Niemelä
  3. Joona Tynkkynen
  4. Matti Javanainen
  5. Waldemar Kulig
  6. Daniel J Müller
  7. Tomasz Rog
  8. Ilpo Vattulainen  Is a corresponding author
  1. Tampere University of Technology, Finland
  2. ETH Zürich, Switzerland
https://doi.org/10.7554/eLife.18432
Share this article
Cite this article
  1. Moutusi Manna
  2. Miia Niemelä
  3. Joona Tynkkynen
  4. Matti Javanainen
  5. Waldemar Kulig
  6. Daniel J Müller
  7. Tomasz Rog
  8. Ilpo Vattulainen
(2016)
Mechanism of allosteric regulation of β2-adrenergic receptor by cholesterol
eLife 5:e18432.
https://doi.org/10.7554/eLife.18432
  2. Download BibTeX
  3. Download .RIS

Abstract

There is evidence that lipids can be allosteric regulators of membrane protein structure and activation. However, there are no data showing how exactly the regulation emerges from specific lipid-protein interactions. Here we show in atomistic detail how the human β2-adrenergic receptor (β2AR) - a prototypical G protein-coupled receptor - is modulated by cholesterol in an allosteric fashion. Extensive atomistic simulations show that cholesterol regulates β2AR by limiting its conformational variability. The mechanism of action is based on the binding of cholesterol at specific high-affinity sites located near the transmembrane helices 5-7 of the receptor. The alternative mechanism, where the β2AR conformation would be modulated by membrane-mediated interactions, plays only a minor role. Cholesterol analogues also bind to cholesterol binding sites and impede the structural flexibility of β2AR, however cholesterol generates the strongest effect. The results highlight the capacity of lipids to regulate the conformation of membrane receptors through specific interactions.

Article and author information

Author details

  1. Moutusi Manna

    Department of Physics, Tampere University of Technology, Tampere, Finland
    Competing interests
    The authors declare that no competing interests exist.

  2. Miia Niemelä

    Department of Physics, Tampere University of Technology, Tampere, Finland
    Competing interests
    The authors declare that no competing interests exist.

  3. Joona Tynkkynen

    Department of Physics, Tampere University of Technology, Tampere, Finland
    Competing interests
    The authors declare that no competing interests exist.

  4. Matti Javanainen

    Department of Physics, Tampere University of Technology, Tampere, Finland
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4858-364X

  5. Waldemar Kulig

    Department of Physics, Tampere University of Technology, Tampere, Finland
    Competing interests
    The authors declare that no competing interests exist.

  6. Daniel J Müller

    Department of Biosystems Science and Engineering, ETH Zürich, Zürich, Switzerland
    Competing interests
    The authors declare that no competing interests exist.

  7. Tomasz Rog

    Department of Physics, Tampere University of Technology, Tampere, Finland
    Competing interests
    The authors declare that no competing interests exist.

  8. Ilpo Vattulainen

    Department of Physics, Tampere University of Technology, Tampere, Finland
    For correspondence
    Ilpo.Vattulainen@helsinki.fi
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7408-3214

Funding

European Research Council (290974)

  • Moutusi Manna
  • Waldemar Kulig
  • Tomasz Rog
  • Ilpo Vattulainen

Academy of Finland (272130)

  • Moutusi Manna
  • Joona Tynkkynen
  • Matti Javanainen
  • Waldemar Kulig
  • Tomasz Rog
  • Ilpo Vattulainen

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

Reviewing Editor

  1. Nir Ben-Tal, Tel Aviv University, Israel

Publication history

  1. Received: June 2, 2016
  2. Accepted: November 28, 2016
  3. Accepted Manuscript published: November 29, 2016 (version 1)
  4. Version of Record published: December 30, 2016 (version 2)

Copyright

© 2016, Manna 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

  • 3,807
    Page views
  • 851
    Downloads
  • 90
    Citations

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

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. Moutusi Manna
  2. Miia Niemelä
  3. Joona Tynkkynen
  4. Matti Javanainen
  5. Waldemar Kulig
  6. Daniel J Müller
  7. Tomasz Rog
  8. Ilpo Vattulainen
(2016)
Mechanism of allosteric regulation of β2-adrenergic receptor by cholesterol
eLife 5:e18432.
https://doi.org/10.7554/eLife.18432

Categories and tags

Research organism

Further reading

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

    Calcium and bicarbonate signaling pathways have pivotal, resonating roles in matching ATP production to demand

    Maura Greiser, Mariusz Karbowski ... Liron Boyman
    Research Article

    Mitochondrial ATP production in cardiac ventricular myocytes must be continually adjusted to rapidly replenish the ATP consumed by the working heart. Two systems are known to be critical in this regulation: mitochondrial matrix Ca2+ ([Ca2+]m) and blood flow that is tuned by local ventricular myocyte metabolic signaling. However, these two regulatory systems do not fully account for the physiological range of ATP consumption observed. We report here on the identity, location, and signaling cascade of a third regulatory system -- CO2/bicarbonate. CO2 is generated in the mitochondrial matrix as a metabolic waste product of the oxidation of nutrients that powers ATP production. It is a lipid soluble gas that rapidly permeates the inner mitochondrial membrane (IMM) and produces bicarbonate (HCO3-) in a reaction accelerated by carbonic anhydrase (CA). The bicarbonate level is tracked physiologically by a bicarbonate-activated adenylyl cyclase, soluble adenylyl cyclase (sAC). Using structural Airyscan super-resolution imaging and functional measurements we find that sAC is primarily inside the mitochondria of ventricular myocytes where it generates cAMP when activated by HCO3-. Our data strongly suggest that ATP production in these mitochondria is regulated by this cAMP signaling cascade operating within the inter-membrane space (IMS) by activating local EPAC1 (Exchange Protein directly Activated by cAMP) which turns on Rap1 (Ras-related protein 1). Thus, mitochondrial ATP production is shown to be increased by bicarbonate-triggered sAC signaling through Rap1. Additional evidence is presented indicating that the cAMP signaling itself does not occur directly in the matrix. We also show that this third signaling process involving bicarbonate and sAC activates the cardiac mitochondrial ATP production machinery by working independently of, yet in conjunction with, [Ca2+]m-dependent ATP production to meet the energy needs of cellular activity in both health and disease. We propose that the bicarbonate and calcium signaling arms function in a resonant or complementary manner to match mitochondrial ATP production to the full range of energy consumption in cardiac ventricular myocytes in health and disease.

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

    Drug Discovery: Decoding the mechanisms of allostery

    Saif Khan, Cornelius Gati
    Insight

    A complex interplay between structure, conformational dynamics and pharmacology defines distant regulation of G protein-coupled receptors.

    1. Structural Biology and Molecular Biophysics

    Biological condensates form percolated networks with molecular motion properties distinctly different from dilute solutions

    Zeyu Shen, Bowen Jia ... Mingjie Zhang
    Research Article

    Formation of membraneless organelles or biological condensates via phase separation and related processes hugely expands the cellular organelle repertoire. Biological condensates are dense and viscoelastic soft matters instead of canonical dilute solutions. To date, numerous different biological condensates have been discovered; but mechanistic understanding of biological condensates remains scarce. In this study, we developed an adaptive single molecule imaging method that allows simultaneous tracking of individual molecules and their motion trajectories in both condensed and dilute phases of various biological condensates. The method enables quantitative measurements of concentrations, phase boundary, motion behavior and speed of molecules in both condensed and dilute phases as well as the scale and speed of molecular exchanges between the two phases. Notably, molecules in the condensed phase do not undergo uniform Brownian motion, but instead constantly switch between a (class of) confined state(s) and a random diffusion-like motion state. Transient confinement is consistent with strong interactions associated with large molecular networks (i.e., percolation) in the condensed phase. In this way, molecules in biological condensates behave distinctly different from those in dilute solutions. The methods and findings described herein should be generally applicable for deciphering the molecular mechanisms underlying the assembly, dynamics and consequently functional implications of biological condensates.