A constricted opening in Kir channels does not impede potassium conduction

Katrina A. Black, Sitong He, Ruitao Jin, David M. Miller, Jani R. Bolla, Oliver B. Clarke, Paul Johnson, Monique Windley, Christopher J. Burns, Adam P. Hill, Derek Laver, Carol V. Robinson, Brian J. Smith () and Jacqueline M. Gulbis ()
Additional contact information
Katrina A. Black: The Walter and Eliza Hall Institute of Medical Research
Sitong He: La Trobe University
Ruitao Jin: La Trobe University
David M. Miller: The Walter and Eliza Hall Institute of Medical Research
Jani R. Bolla: University of Oxford
Oliver B. Clarke: Columbia University
Paul Johnson: The University of Newcastle
Monique Windley: Victor Chang Cardiac Research Institute
Christopher J. Burns: The University of Melbourne
Adam P. Hill: Victor Chang Cardiac Research Institute
Derek Laver: The University of Newcastle
Carol V. Robinson: University of Oxford
Brian J. Smith: La Trobe University
Jacqueline M. Gulbis: The Walter and Eliza Hall Institute of Medical Research

Nature Communications, 2020, vol. 11, issue 1, 1-13

Abstract: Abstract The canonical mechanistic model explaining potassium channel gating is of a conformational change that alternately dilates and constricts a collar-like intracellular entrance to the pore. It is based on the premise that K+ ions maintain a complete hydration shell while passing between the transmembrane cavity and cytosol, which must be accommodated. To put the canonical model to the test, we locked the conformation of a Kir K+ channel to prevent widening of the narrow collar. Unexpectedly, conduction was unimpaired in the locked channels. In parallel, we employed all-atom molecular dynamics to simulate K+ ions moving along the conduction pathway between the lower cavity and cytosol. During simulations, the constriction did not significantly widen. Instead, transient loss of some water molecules facilitated K+ permeation through the collar. The low free energy barrier to partial dehydration in the absence of conformational change indicates Kir channels are not gated by the canonical mechanism.

Date: 2020
References: Add references at CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
https://www.nature.com/articles/s41467-020-16842-0 Abstract (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:natcom:v:11:y:2020:i:1:d:10.1038_s41467-020-16842-0

Ordering information: This journal article can be ordered from
https://www.nature.com/ncomms/

DOI: 10.1038/s41467-020-16842-0

Access Statistics for this article

Nature Communications is currently edited by Nathalie Le Bot, Enda Bergin and Fiona Gillespie

More articles in Nature Communications from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().