Choi, Kee-Hyun Licht, Stuart 2024-01-20T14:34:39Z 2024-01-20T14:34:39Z 2021-09-05 2012-05-30 1932-6203 https://pubs.kist.re.kr/handle/201004/129239 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. English PUBLIC LIBRARY SCIENCE ION CHANNELS MEDIATED PHOSPHORYLATION SUPERPOSITION PROPERTIES ACETYLCHOLINE-RECEPTORS NEGATIVE COOPERATIVITY QUANTAL VARIABILITY CELLS MEMBRANE CONDUCTANCE PROTEINS ATP-Sensitive Potassium Channels Exhibit Variance in the Number of Open Channels below the Limit Predicted for Identical and Independent Gating Article 10.1371/journal.pone.0037399 1 PLOS ONE, v.7, no.5 PLOS ONE 7 5 scie scopus 000305353400026 2-s2.0-84861601595 Multidisciplinary Sciences Science & Technology - Other Topics Article ION CHANNELS MEDIATED PHOSPHORYLATION SUPERPOSITION PROPERTIES ACETYLCHOLINE-RECEPTORS NEGATIVE COOPERATIVITY QUANTAL VARIABILITY CELLS MEMBRANE CONDUCTANCE PROTEINS