Structural plasticity and dynamic selectivity of acid-sensing ion channelspider toxin complexes

Isabelle Baconguis, Eric Gouaux

Research output: Contribution to journalArticle

174 Scopus citations

Abstract

Acid-sensing ion channels (ASICs) are voltage-independent, amiloride-sensitive channels involved in diverse physiological processes ranging from nociception to taste. Despite the importance of ASICs in physiology, we know little about the mechanism of channel activation. Here we show that psalmotoxin activates non-selective and Na +-selective currents in chicken ASIC1a at pH 7.25 and 5.5, respectively. Crystal structures of ASIC1apsalmotoxin complexes map the toxin binding site to the extracellular domain and show how toxin binding triggers an expansion of the extracellular vestibule and stabilization of the open channel pore. At pH 7.25 the pore is approximately 10 Å in diameter, whereas at pH 5.5 the pore is largely hydrophobic and elliptical in cross-section with dimensions of approximately 5 by 7 Å, consistent with a barrier mechanism for ion selectivity. These studies define mechanisms for activation of ASICs, illuminate the basis for dynamic ion selectivity and provide the blueprints for new therapeutic agents.

Original languageEnglish (US)
Pages (from-to)400-405
Number of pages6
JournalNature
Volume489
Issue number7416
DOIs
StatePublished - Sep 20 2012

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Structural plasticity and dynamic selectivity of acid-sensing ion channelspider toxin complexes'. Together they form a unique fingerprint.

  • Cite this