ATP-Sensitive Potassium Channels Exhibit Variance in the Number of Open Channels below the Limit Predicted for Identical and Independent Gating
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Choi-2012-ATP-Sensitive Potass.pdf
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Author(s)
Choi, Kee-Hyun
Licht, Stuart
Date Issued
May 2012
Journal
PLoS ONE
Publisher
Public Library of Science
Citation
Choi, Kee-Hyun, and Stuart Licht. “ATP-Sensitive Potassium Channels Exhibit Variance in the Number of Open Channels Below the Limit Predicted for Identical and Independent Gating.” Ed. Floyd Romesberg. PLoS ONE 7.5 (2012): e37399.
Version
Final published version
Abstract
In small cells containing small numbers of ion channels, noise due to stochastic channel opening and closing can introduce a substantial level of variability into the cell's membrane potential. Negatively cooperative interactions that couple a channel's gating conformational change to the conformation of its neighbor(s) provide a potential mechanism for mitigating this variability, but such interactions have not previously been directly observed. Here we show that heterologously expressed ATP-sensitive potassium channels generate noise (i.e., variance in the number of open channels) below the level possible for identical and independent channels. Kinetic analysis with single-molecule resolution supports the interpretation that interchannel negative cooperativity (specifically, the presence of an open channel making a closed channel less likely to open) contributes to the decrease in noise. Functional coupling between channels may be important in modulating stochastic fluctuations in cellular signaling pathways.
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
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Creative Commons Attribution
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DOI of Published Version
https://doi.org/10.1371/journal.pone.0037399
