Send to

Choose Destination
Channels (Austin). 2012 Nov-Dec;6(6):409-13. doi: 10.4161/chan.22154. Epub 2012 Sep 18.

Toxin binding reveals two open state structures for one acid-sensing ion channel.

Author information

Institute of Physiology, RWTH Aachen University, Aachen, Germany.


Of the three principal conformations of acid-sensing ion channels (ASICs)--closed, open and desensitized--only the atomic structure of the desensitized conformation had been known. Two recent papers report the crystal structure of chicken ASIC1 in complex with the spider toxin psalmotoxin 1, and one of these studies finds that, depending on the pH, channels are in two different open conformations. Compared with the desensitized conformation, toxin binding induces only subtle structural changes in the lower part of the large extracellular domain but a complete rearrangement of the two transmembrane domains (TMDs), suggesting that desensitization gating (the transition from open to desensitized) is mainly associated with conformational rearrangements of the TMDs. Moreover, the study reveals how two different arrangements of the TMDs in the open state give rise to ion pores with different selectivity for monovalent cations.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Taylor & Francis Icon for PubMed Central
Loading ...
Support Center