Stretch-Activated Ion Channels: What Are They?

• Published in: Physiology (Bethesda, Md.) Vol. 25; no. 1; pp. 50 - 56
• Main Author: Sachs, Frederick
• Format: Journal Article
• Language: English
• Published: United States Am Physiological Soc 01.02.2010
• Subjects: Animals; Cytoskeleton - metabolism; Extracellular Matrix - metabolism; Humans; Ion Channels - drug effects; Ion Channels - metabolism; Lipid Bilayers - metabolism; Mechanoreceptors - drug effects; Mechanoreceptors - metabolism; Mechanotransduction, Cellular - drug effects; Models, Biological; Stress, Mechanical
• ISSN: 1548-9213; 1548-9221
• DOI: 10.1152/physiol.00042.2009

Frederick Sachs State University of New York, Buffalo, New York, sachs{at}buffalo.edu Mechanosensitive ion channels (MSCs) exist in all cells, but mechanosensitivity is a phenotype not a genotype. Specialized mechanoreceptors such as the hair cells of the cochlea require elaborate mechanical impedance matching to couple the channels to the external stress. In contrast, MSCs in nonspecialized cells appear activated by stress in the bilayer local to the channel—within about three lipids. Local mechanical stress can be produced by far-field tension, amphipaths, phase separations, the cytoskeleton, the extracellular matrix, and the adhesion energy between the membrane and a patch pipette. Understanding MSC function requires under standing the stimulus.