Stretch-activated ion channel

Stretch-activated or stretch-gated ion channels are ion channels which open their pores in response to mechanical deformation of a neuron's plasma membrane. Stretch-activated channels were first observed in chick skeletal muscles by Falguni Guharay and Frederick Sachs in 1983 and the results were published in 1984.^[1] Since then strech-activated channels have been found in cells from bacteria to human as well as plants.

Mechanism

One of the three main types of ionotropic receptors or channel-linked receptor, which open by transmitting physical forces of stretch or pressure to the channels, causing them to undergo a conformational change to allow ions to pass through.^[2] The channels may also be pulled open due to tension on the membrane itself.^[2] Opening the channels allows ions to which they are permeable to flow down their electrochemical gradients into or out of the cell, causing a change in membrane potential.

This can also be referred to as the Stress-activated gate because the gate (protein receptor) responds to pressure or stress.

Functions

Such channels are of use in the initial formation of an action potential from a mechanical stimulus, for example by the mechanoreceptors in an animal's vibrissae (whiskers).

A possible role in myoblast development has been described.^[3]

Example

An example is "MID-1" (also known as "MCLC" or CLCC1.)^[4][5]

See also

• Mechanosensitive ion channel
• Large-conductance mechanosensitive channel
• Voltage-gated ion channels
• Ligand-gated ion channels

References

1. ^ . PMC 1193237. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1193237. 
2. ^ ^{a b} Kandel ER, Schwartz JH, Jessell TM. Principles of Neural Science, 4th ed., Pages 113-114. McGraw-Hill, New York (2000). ISBN 0-8385-7701-6
3. ^ Formigli L, Meacci E, Sassoli C et al. (May 2007). "Cytoskeleton/stretch-activated ion channel interaction regulates myogenic differentiation of skeletal myoblasts". J. Cell. Physiol. 211 (2): 296–306. doi:10.1002/jcp.20936. PMID 17295211. 
4. ^ Nagasawa M, Kanzaki M, Iino Y, Morishita Y, Kojima I (2001). "Identification of a novel chloride channel expressed in the endoplasmic reticulum, golgi apparatus, and nucleus". J. Biol. Chem. 276 (23): 20413–20418. doi:10.1074/jbc.M100366200. PMID 11279057. 
5. ^ Ozeki-Miyawaki C, Moriya Y, Tatsumi H, Iida H, Sokabe M (2005). "Identification of functional domains of Mid1, a stretch-activated channel component, necessary for localization to the plasma membrane and Ca2+ permeation". Exp. Cell Res. 311 (1): 84–95. doi:10.1016/j.yexcr.2005.08.014. PMID 16202999.