ArticleThe Journal of general physiology2004
External barium affects the gating of KCNQ1 potassium channels and produces a pore block via two discrete sites.
Article in The Journal of general physiology, 2004. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 20 papers.
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Who cites it
20 citing papers in PubMed, 31 citations in OpenAlex.
- Barium senses subtle pore changes in a voltage-gated KScience advances · 2026Article
- Secondary structure transitions and dual PIP2 binding define cardiac KCNQ1-KCNE1 channel gating.Cell research · 2025Article
- Barium and psoriasis: a mini-review and hypothesis linking environmental exposures to ion channel modulation.Frontiers in medicine · 2025Review
- Membrane pools of phosphatidylinositol-4-phosphate regulate KCNQ1/KCNE1 membrane expression.Communications biology · 2021Article
- The activation gate controls steady-state inactivation and recovery from inactivation in Shaker.The Journal of general physiology · 2020Article
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- Oxygen and Glucose Deprivation Induces Bergmann Glia Membrane Depolarization and CaFrontiers in cellular neuroscience · 2017Article
- Appearance of fast astrocytic component in voltage-sensitive dye imaging of neural activity.Molecular brain · 2015Article
- Capturing distinct KCNQ2 channel resting states by metal ion bridges in the voltage-sensor domain.The Journal of general physiology · 2014Article
- Article
- External Ba2+ block of the two-pore domain potassium channel TREK-1 defines conformational transition in its selectivity filter.The Journal of biological chemistry · 2011Article
- Extracellular potassium inhibits Kv7.1 potassium channels by stabilizing an inactivated state.Biophysical journal · 2011Article
- Article
- Intracellular domains interactions and gated motions of I(KS) potassium channel subunits.The EMBO journal · 2009Article
- Determinants within the turret and pore-loop domains of KCNQ3 K+ channels governing functional activity.Biophysical journal · 2008Article
- Article
- An inactivation gate in the selectivity filter of KCNQ1 potassium channels.Biophysical journal · 2007Article
- Dopaminergic regulation of neuronal excitability through modulation of Ih in layer V entorhinal cortex.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2006Article
- Pore conformations and gating mechanism of a Cys-loop receptor.Proceedings of the National Academy of Sciences of the United States of America · 2005Article
- Antagonistic regulation of swelling-activated Cl- current in rabbit ventricle by Src and EGFR protein tyrosine kinases.American journal of physiology. Heart and circulatory physiology · 2005Article
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Authors and funding
4 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The pore properties and the reciprocal interactions between permeant ions and the gating of KCNQ channels are poorly understood. Here we used external barium to investigate the permeation characteristics of homomeric KCNQ1 channels. We assessed the Ba(2+) binding kinetics and the concentration and voltage dependence of Ba(2+) steady-state block. Our results indicate that extracellular Ba(2+) exerts a series of complex effects, including a voltage-dependent pore blockade as well as unique gating alterations. External barium interacts with the permeation pathway of KCNQ1 at two discrete and nonsequential sites. (a) A slow deep Ba(2+) site that occludes the channel pore and could be simulated by a model of voltage-dependent block. (b) A fast superficial Ba(2+) site that barely contributes to channel block and mostly affects channel gating by shifting rightward the voltage dependence of activation, slowing activation, speeding up deactivation kinetics, and inhibiting channel inactivation. A model of voltage-dependent block cannot predict the complex impact of Ba(2+) on channel gating in low external K(+) solutions. Ba(2+) binding to this superficial site likely modifies the gating transitions states of KCNQ1. Both sites appear to reside in the permeation pathway as high external K(+) attenuates Ba(2+) inhibition of channel conductance and abolishes its impact on channel gating. Our data suggest that despite the high degree of homology of the pore region among the various K(+) channels, KCNQ1 channels display significant structural and functional uniqueness.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.