Potassium Channels

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Potassium Channels

William A Coetzee, New York University School of Medicine, New York, USA
Bernardo Rudy, New York University School of Medicine, New York, USA

Published online: January 2006

DOI: 10.1038/npg.els.0005670

Full Article on Wiley Online Library

Abstract
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References

Potassium channels constitute a highly diverse class of ion channel and thus participate in multiple modulatory functions. There are several functional types of K⁺ channel, including voltage-gated K⁺ channels, Ca²⁺-activated K⁺ channels, inward rectifiers, leak K⁺ channels and Na⁺-activated K⁺ channels. Principal or pore-forming subunits of at least the first four types have been identified and are classified into three groups of proteins on the basis of their structural properties.

Keywords: potassium channels; ion channels; electrophysiology; membrane proteins; transport proteins

Figure 1. Functional K⁺ channels in mammalian cells can be divided into those that are activated by Ca²⁺ (Ca²⁺-activated K⁺ channels) or membrane voltage (voltage-activated K⁺ channels). The K⁺ channels not gated by voltage either exhibit the property of inward rectification (inward rectifier K⁺ channels) or behave as simple K⁺-permeable ‘holes’ in the membrane (‘leak’ K⁺ channels). Na⁺-activated K⁺ channels are not shown here.

Figure 2. Classification of K⁺ channel principal subunits into those having two, four or six transmembrane domains (TMDs) in a continuous polypeptide. Transmembrane segments are shown as cylinders spanning the membrane (the intra- and extracellular side is indicated). The schematic views from the top illustrate the dimeric (in the case of four-TMD channels) or tetrameric (in the case of two-TMD or six-TMD channels structure). The darker shading represents one of the principal subunits in the channel complex.

References
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Further Reading
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Web Links
	ePath Molecular Diversity of K+ Channels http://k-channels.med.nyu.edu/
	ePath Mammalian 2P domain and background K+ channels (K2P) http://www.ipmc.cnrs.fr/~duprat/2p/index.htm
	ePath Permeation of Ions Across the Potassium Channel http://anusf.anu.edu.au/Vizlab/viz_showcase/shinho_chung/
	ePath Ion Channels, Transmitters, Receptors and Disease http://www.neuro.wustl.edu/neuromuscular/mother/chan.html
	ePath Neurotoxins http://faculty.washington.edu/chudler/toxin1.html
	ePath Ion Channel Slides http://www.sigma-aldrich.com/saws.nsf/Pages/sg_ls_cs_ionchannelslide_home

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How to Cite

Coetzee, William A, and Rudy, Bernardo(Jan 2006) Potassium Channels. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0005670]