Journal article
Mechanism of activation at the selectivity filter of the KcsA K+ channel
- Heer, Florian T Biozentrum, University of Basel, Basel, Switzerland
- Posson, David J ORCID Department of Physiology and Biophysics, Weill Cornell Medical College, New York, United States
- Wojtas-Niziurski, Wojciech Biozentrum, University of Basel, Basel, Switzerland
- Nimigean, Crina M ORCID Department of Biochemistry, Weill Cornell Medical College, New York, United States
- Bernèche, Simon ORCID Biozentrum, University of Basel, Basel, Switzerland
- 2017-10-10
Published in:
- eLife. - eLife Sciences Publications, Ltd. - 2017, vol. 6
English
Potassium channels are opened by ligands and/or membrane potential. In voltage-gated K+ channels and the prokaryotic KcsA channel, conduction is believed to result from opening of an intracellular constriction that prevents ion entry into the pore. On the other hand, numerous ligand-gated K+ channels lack such gate, suggesting that they may be activated by a change within the selectivity filter, a narrow region at the extracellular side of the pore. Using molecular dynamics simulations and electrophysiology measurements, we show that ligand-induced conformational changes in the KcsA channel removes steric restraints at the selectivity filter, thus resulting in structural fluctuations, reduced K+ affinity, and increased ion permeation. Such activation of the selectivity filter may be a universal gating mechanism within K+ channels. The occlusion of the pore at the level of the intracellular gate appears to be secondary.
- Language
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- English
- Open access status
- gold
- Identifiers
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- DOI 10.7554/elife.25844
- ISSN 2050-084X
- Persistent URL
- https://sonar.ch/global/documents/232054
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