Structural Insights into Human Acid-sensing Ion Channel 1a Inhibition by Snake Toxin Mambalgin1

  1. Changlin Tian  Is a corresponding author
  2. Demeng Sun
  3. Sanling Liu
  4. Siyu Li
  5. Mengge Zhang
  6. Fan Yang
  7. Ming Wen
  8. Pan Shi
  9. Tao Wang
  10. Man Pan
  11. Shenghai Chang
  12. Xing Zhang
  13. Longhua Zhang
  14. Lei Liu
  1. University of Science and Tehnology of China, China
  2. University of Science and Technology of China, China
  3. Chinese Academy of Sciences, China
  4. Tsinghua University, China
  5. Zhejiang University, China

Abstract

Acid-sensing ion channels (ASICs) are proton-gated cation channels that are involved in diverse neuronal processes including pain sensing. Peptide toxin Mambalgin1 (Mamba1) from black mamba snake venom can reversibly inhibit the conductance of ASICs, showing an analgesic effect. However, the detailed inhibitory mechanism of Mamba1 on ASIC1s, especially how Mamba1 binding to extracellular domain affects the conformational changes of the transmembrane domain of ASICs remains elusive. Here, we present single-particle cryo-EM structures of human ASIC1a (hASIC1a) and hASIC1a-Mamba1 complex at resolutions of 3.56 and 3.90 Å, respectively. The structures revealed the inhibited conformation of hASIC1a upon Mamba1 binding. The combination of the structural and physiological data indicates that Mamba1 prefers to bind hASIC1a in a closed state and reduces the proton sensitivity of the channel, representing a closed-state trapping mechanism.

Data availability

The EM maps for hASIC1a and hASIC1a-Mamba1 complex have been deposited in EMDB (www.ebi.ac.uk/pdbe/emdb/) with accession codes EMD-30346 and EMD-30347. The atomic coordinates for hASIC1a and hASIC1a-Mamba1 complex have been deposited in the Protein Data Bank (www.rcsb.org) with accession codes 7CFS and 7CFT respectively

The following previously published data sets were used

Article and author information

Author details

  1. Changlin Tian

    School of Life Science, University of Science and Tehnology of China, Hefei, China
    For correspondence
    cltian@ustc.edu.cn
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-9315-900X
  2. Demeng Sun

    School of Life Sciences, University of Science and Technology of China, Hefei, China
    Competing interests
    The authors declare that no competing interests exist.
  3. Sanling Liu

    School of Life Science, University of Science and Tehnology of China, Hefei, China
    Competing interests
    The authors declare that no competing interests exist.
  4. Siyu Li

    School of Life Science, University of Science and Tehnology of China, Hefei, China
    Competing interests
    The authors declare that no competing interests exist.
  5. Mengge Zhang

    School of Life Science, University of Science and Tehnology of China, Hefei, China
    Competing interests
    The authors declare that no competing interests exist.
  6. Fan Yang

    School of Life Science, University of Science and Tehnology of China, Hefei, China
    Competing interests
    The authors declare that no competing interests exist.
  7. Ming Wen

    School of Life Science, University of Science and Tehnology of China, Hefei, China
    Competing interests
    The authors declare that no competing interests exist.
  8. Pan Shi

    School of Life Science, University of Science and Tehnology of China, Hefei, China
    Competing interests
    The authors declare that no competing interests exist.
  9. Tao Wang

    High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China
    Competing interests
    The authors declare that no competing interests exist.
  10. Man Pan

    Department of Chemistry, Tsinghua University, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  11. Shenghai Chang

    School of Medicine, Zhejiang University, Hangzhou, China
    Competing interests
    The authors declare that no competing interests exist.
  12. Xing Zhang

    School of Medicine, Zhejiang University, Hangzhou, China
    Competing interests
    The authors declare that no competing interests exist.
  13. Longhua Zhang

    School of Life Science, University of Science and Tehnology of China, Hefei, China
    Competing interests
    The authors declare that no competing interests exist.
  14. Lei Liu

    Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.

Funding

Ministry of Science and Technology of the People's Republic of China (National Key Research and Development Project,2017YFA0505201,2017YFA0505403 and 2016YFA0400903)

  • Changlin Tian

Chinese Academy of Sciences (Queensland-Chinese Academy of Sciences (Q-CAS) Collaborative Science Fund,GJHZ201946)

  • Changlin Tian

Ministry of Science and Technology of the People's Republic of China (National Key Research and Development Project,2017YFA0505200)

  • Lei Liu

National Natural Science Foundation of China (31600601,21778051)

  • Demeng Sun

National Natural Science Foundation of China (91753205,21532004)

  • Lei Liu

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

Copyright

© 2020, Tian 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

  • 3,873
    views
  • 696
    downloads
  • 44
    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. Changlin Tian
  2. Demeng Sun
  3. Sanling Liu
  4. Siyu Li
  5. Mengge Zhang
  6. Fan Yang
  7. Ming Wen
  8. Pan Shi
  9. Tao Wang
  10. Man Pan
  11. Shenghai Chang
  12. Xing Zhang
  13. Longhua Zhang
  14. Lei Liu
(2020)
Structural Insights into Human Acid-sensing Ion Channel 1a Inhibition by Snake Toxin Mambalgin1
eLife 9:e57096.
https://doi.org/10.7554/eLife.57096

Share this article

https://doi.org/10.7554/eLife.57096

Further reading

    1. Biochemistry and Chemical Biology
    2. Structural Biology and Molecular Biophysics
    Yamato Niitani, Kohei Matsuzaki ... Michio Tomishige
    Research Article

    The two identical motor domains (heads) of dimeric kinesin-1 move in a hand-over-hand process along a microtubule, coordinating their ATPase cycles such that each ATP hydrolysis is tightly coupled to a step and enabling the motor to take many steps without dissociating. The neck linker, a structural element that connects the two heads, has been shown to be essential for head–head coordination; however, which kinetic step(s) in the chemomechanical cycle is ‘gated’ by the neck linker remains unresolved. Here, we employed pre-steady-state kinetics and single-molecule assays to investigate how the neck-linker conformation affects kinesin’s motility cycle. We show that the backward-pointing configuration of the neck linker in the front kinesin head confers higher affinity for microtubule, but does not change ATP binding and dissociation rates. In contrast, the forward-pointing configuration of the neck linker in the rear kinesin head decreases the ATP dissociation rate but has little effect on microtubule dissociation. In combination, these conformation-specific effects of the neck linker favor ATP hydrolysis and dissociation of the rear head prior to microtubule detachment of the front head, thereby providing a kinetic explanation for the coordinated walking mechanism of dimeric kinesin.

    1. Structural Biology and Molecular Biophysics
    Christopher T Schafer, Raymond F Pauszek III ... David P Millar
    Research Article

    The canonical chemokine receptor CXCR4 and atypical receptor ACKR3 both respond to CXCL12 but induce different effector responses to regulate cell migration. While CXCR4 couples to G proteins and directly promotes cell migration, ACKR3 is G-protein-independent and scavenges CXCL12 to regulate extracellular chemokine levels and maintain CXCR4 responsiveness, thereby indirectly influencing migration. The receptors also have distinct activation requirements. CXCR4 only responds to wild-type CXCL12 and is sensitive to mutation of the chemokine. By contrast, ACKR3 recruits GPCR kinases (GRKs) and β-arrestins and promiscuously responds to CXCL12, CXCL12 variants, other peptides and proteins, and is relatively insensitive to mutation. To investigate the role of conformational dynamics in the distinct pharmacological behaviors of CXCR4 and ACKR3, we employed single-molecule FRET to track discrete conformational states of the receptors in real-time. The data revealed that apo-CXCR4 preferentially populates a high-FRET inactive state, while apo-ACKR3 shows little conformational preference and high transition probabilities among multiple inactive, intermediate and active conformations, consistent with its propensity for activation. Multiple active-like ACKR3 conformations are populated in response to agonists, compared to the single CXCR4 active-state. This and the markedly different conformational landscapes of the receptors suggest that activation of ACKR3 may be achieved by a broader distribution of conformational states than CXCR4. Much of the conformational heterogeneity of ACKR3 is linked to a single residue that differs between ACKR3 and CXCR4. The dynamic properties of ACKR3 may underly its inability to form productive interactions with G proteins that would drive canonical GPCR signaling.