Conformational decoupling in acid-sensing ion channels uncovers mechanism and stoichiometry of PcTx1-mediated inhibition

被引:0
作者
Heusser, Stephanie A. [1 ]
Borg, Christian B. [1 ]
Colding, Janne M. [1 ]
Pless, Stephan A. [1 ]
机构
[1] Univ Copenhagen, Ctr Biopharmaceut, Dept Drug Design & Pharmacol, Copenhagen, Denmark
来源
ELIFE | 2022年 / 11卷
关键词
ion channels; toxins; pharmacology; protein engineering; fluorometry; stoichiometry; Xenopus; TARANTULA TOXIN PSALMOTOXIN-1; SYNAPTIC PLASTICITY; RECEPTOR; BINDING; SPIDER; NEUROPROTECTION; DYNORPHIN; STATE; SNAKE; 1A;
D O I
10.7554/eLife.73384; 10.7554/eLife.73384.sa0; 10.7554/eLife.73384.sa1; 10.7554/eLife.73384.sa2
中图分类号
Q [生物科学];
学科分类号
07 ; 0710 ; 09 ;
摘要
Acid-sensing ion channels (ASICs) are trimeric proton-gated cation channels involved in fast synaptic transmission. Pharmacological inhibition of ASIC1a reduces neurotoxicity and stroke infarct volumes, with the cysteine knot toxin psalmotoxin-1 (PcTx1) being one of the most potent and selective inhibitors. PcTx1 binds at the subunit interface in the extracellular domain (ECD), but the mechanism and conformational consequences of the interaction, as well as the number of toxin molecules required for inhibition, remain unknown. Here, we use voltage-clamp fluorometry and subunit concatenation to decipher the mechanism and stoichiometry of PcTx1 inhibition of ASIC1a. Besides the known inhibitory binding mode, we propose PcTx1 to have at least two additional binding modes that are decoupled from the pore. One of these modes induces a long-lived ECD conformation that reduces the activity of an endogenous neuropeptide. This long-lived conformational state is proton-dependent and can be destabilized by a mutation that decreases PcTx1 sensitivity. Lastly, the use of concatemeric channel constructs reveals that disruption of a single PcTx1 binding site is sufficient to destabilize the toxin-induced conformation, while functional inhibition is not impaired until two or more binding sites are mutated. Together, our work provides insight into the mechanism of PcTx1 inhibition of ASICs and uncovers a prolonged conformational change with possible pharmacological implications.
引用
收藏
页数:20
相关论文
共 48 条
  • [1] X-Ray Structure of Acid-Sensing Ion Channel 1-Snake Toxin Complex Reveals Open State of a Na+-Selective Channel
    Baconguis, Isabelle
    Bohlen, Christopher J.
    Goehring, April
    Julius, David
    Gouaux, Eric
    [J]. CELL, 2014, 156 (04) : 717 - 729
  • [2] Structural plasticity and dynamic selectivity of acid-sensing ion channel-spider toxin complexes
    Baconguis, Isabelle
    Gouaux, Eric
    [J]. NATURE, 2012, 489 (7416) : 400 - U86
  • [3] Bergh C, 2021, ELIFE, V10, DOI [10.7554/eLife.68369, 10.7554/eLife.68369.sa1, 10.7554/eLife.68369.sa2]
  • [4] Protonation controls ASIC1a activity via coordinated movements in multiple domains
    Bonifacio, Gaetano
    Lelli, Claudia Igutti Suenaga
    Kellenberger, Stephan
    [J]. JOURNAL OF GENERAL PHYSIOLOGY, 2014, 143 (01) : 105 - 118
  • [5] Mechanism and site of action of big dynorphin on ASIC1a
    Borg, Christian B.
    Braun, Nina
    Heusser, Stephanie A.
    Bay, Yasmin
    Weis, Daniel
    Galleano, Iacopo
    Lund, Camilla
    Tian, Weihua
    Haugaard-Kedstrom, Linda M.
    Bennett, Eric P.
    Lynagh, Timothy
    Stromgaard, Kristian
    Andersen, Jacob
    Pless, Stephan A.
    [J]. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (13) : 7447 - 7454
  • [6] High-throughput characterization of photocrosslinker-bearing ion channel variants to map residues critical for function and pharmacology
    Braun, Nina
    Friis, Soren
    Ihling, Christian
    Sinz, Andrea
    Andersen, Jacob
    Pless, Stephan A.
    [J]. PLOS BIOLOGY, 2021, 19 (09)
  • [7] Potent neuroprotection after stroke afforded by a double-knot spider-venom peptide that inhibits acid-sensing ion channel 1a
    Chassagnon, Irene R.
    McCarthy, Claudia A.
    Chin, Yanni K. -Y.
    Pineda, Sandy S.
    Keramidas, Angelo
    Mobli, Mehdi
    Pham, Vi
    De Silva, T. Michael
    Lynch, Joseph W.
    Widdop, Robert E.
    Rash, Lachlan D.
    King, Glenn F.
    [J]. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2017, 114 (14) : 3750 - 3755
  • [8] Interaction of acid-sensing ion channel (ASIC) 1 with the tarantula toxin psalmotoxin 1 is state dependent
    Chen, XM
    Kalbacher, H
    Gründer, S
    [J]. JOURNAL OF GENERAL PHYSIOLOGY, 2006, 127 (03) : 267 - 276
  • [9] The tarantula toxin psalmotoxin 1 inhibits acid-sensing ion channel (ASIC) 1a by increasing its apparent H+ affinity
    Chen, XM
    Kalbacher, H
    Gründer, S
    [J]. JOURNAL OF GENERAL PHYSIOLOGY, 2005, 126 (01) : 71 - 79
  • [10] The modulation of acid-sensing ion channel 1 by PcTx1 is pH-, subtype- and species-dependent: Importance of interactions at the channel subunit interface and potential for engineering selective analogues
    Cristofori-Armstrong, Ben
    Saez, Natalie J.
    Chassagnon, Irene R.
    King, Glenn F.
    Rash, Lachlan D.
    [J]. BIOCHEMICAL PHARMACOLOGY, 2019, 163 : 381 - 390