Conformational decoupling in acidsensing ion channels uncovers mechanism and stoichiometry of PcTx1mediated inhibition

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Conformational decoupling in acidsensing ion channels uncovers mechanism and stoichiometry of PcTx1mediated inhibition. / Heusser, Stephanie A.; Borg, Christian B.; Colding, Janne M.; Pless, Stephan A.

In: eLife, Vol. 11, e73384, 2022.

Research output: Contribution to journalJournal articleResearchpeer-review

Harvard

Heusser, SA, Borg, CB, Colding, JM & Pless, SA 2022, 'Conformational decoupling in acidsensing ion channels uncovers mechanism and stoichiometry of PcTx1mediated inhibition', eLife, vol. 11, e73384. https://doi.org/10.7554/ELIFE.73384

APA

Heusser, S. A., Borg, C. B., Colding, J. M., & Pless, S. A. (2022). Conformational decoupling in acidsensing ion channels uncovers mechanism and stoichiometry of PcTx1mediated inhibition. eLife, 11, [e73384]. https://doi.org/10.7554/ELIFE.73384

Vancouver

Heusser SA, Borg CB, Colding JM, Pless SA. Conformational decoupling in acidsensing ion channels uncovers mechanism and stoichiometry of PcTx1mediated inhibition. eLife. 2022;11. e73384. https://doi.org/10.7554/ELIFE.73384

Author

Heusser, Stephanie A. ; Borg, Christian B. ; Colding, Janne M. ; Pless, Stephan A. / Conformational decoupling in acidsensing ion channels uncovers mechanism and stoichiometry of PcTx1mediated inhibition. In: eLife. 2022 ; Vol. 11.

Bibtex

@article{a6cf2c3b53fc49828784561f11ce2058,
title = "Conformational decoupling in acidsensing ion channels uncovers mechanism and stoichiometry of PcTx1mediated inhibition",
abstract = "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.",
author = "Heusser, {Stephanie A.} and Borg, {Christian B.} and Colding, {Janne M.} and Pless, {Stephan A.}",
note = "Funding Information: We acknowledge funding from the Lundbeck Foundation (R303-2018-3030 to SAH and R313-2019-571 to SAP), the Br{\o}drene Hartmanns Fond, and the European Union{\textquoteright}s Horizon 2020 research and innovation program under the Marie Sk{\l}odowska-Curie grant agreement no. 834274 (to SAH). We thank Drs. Han Chow Chua and Samuel G Usher for comments on the manuscript. Funding Information: We acknowledge funding from the Lundbeck Foundation (R303-2018-3030 to SAH and R313-2019-571 to SAP), the Br?drene Hartmanns Fond, and the European Union?s Horizon 2020 research and innovation program under the Marie Sk?odowska-Curie grant agreement no. 834274 (to SAH). ",
year = "2022",
doi = "10.7554/ELIFE.73384",
language = "English",
volume = "11",
journal = "eLife",
issn = "2050-084X",
publisher = "eLife Sciences Publications Ltd.",

}

RIS

TY - JOUR

T1 - Conformational decoupling in acidsensing ion channels uncovers mechanism and stoichiometry of PcTx1mediated inhibition

AU - Heusser, Stephanie A.

AU - Borg, Christian B.

AU - Colding, Janne M.

AU - Pless, Stephan A.

N1 - Funding Information: We acknowledge funding from the Lundbeck Foundation (R303-2018-3030 to SAH and R313-2019-571 to SAP), the Brødrene Hartmanns Fond, and the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 834274 (to SAH). We thank Drs. Han Chow Chua and Samuel G Usher for comments on the manuscript. Funding Information: We acknowledge funding from the Lundbeck Foundation (R303-2018-3030 to SAH and R313-2019-571 to SAP), the Br?drene Hartmanns Fond, and the European Union?s Horizon 2020 research and innovation program under the Marie Sk?odowska-Curie grant agreement no. 834274 (to SAH).

PY - 2022

Y1 - 2022

N2 - 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.

AB - 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.

U2 - 10.7554/ELIFE.73384

DO - 10.7554/ELIFE.73384

M3 - Journal article

C2 - 35156612

AN - SCOPUS:85125289639

VL - 11

JO - eLife

JF - eLife

SN - 2050-084X

M1 - e73384

ER -

ID: 300064899