Ion channel

Article By:

Nichols, Colin G. Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri.

Flagg, Thomas P. Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri.

Last reviewed:May 2022

DOI:https://doi.org/10.1036/1097-8542.351555

Show previous versions

• Ion channel, published December 2021:Download PDF Get Adobe Acrobat Reader
• Ion channels (genetics), published 2008:Download PDF Get Adobe Acrobat Reader

A protein that spans cellular membranes and mediates the passage of electrolytes across the hydrophobic barrier that maintains the integrity of the cell and interior compartments. Ion channels are found in both prokaryotes and eukaryotes and their structures are highly conserved. Ion channels come in a variety of types. Some are selective for cations, while others favor anions. Some are regulated by membrane voltage, while others are controlled by binding of ligands (Fig. 1). Hundreds of genes encode for human ion channels, and some genes encode multiple functionally distinct variants as a result of alternative splicing [a process in gene expression that enables the production of multiple forms of messenger ribonucleic acid (mRNA) from a single RNA transcript, thus enabling the production of multiple forms of protein from one gene]. Regulated and coordinated actions of ion channels are required to generate and transmit the electrical signals necessary for a myriad of operations that are essential for normal physiological function. See also: Biopotentials and ionic currents; Cell membrane; Ion; Protein

The content above is only an excerpt.