Stretch-activated Ion Channel - Examples

Examples

TRP channels are typically non-selective, although a few are selective for calcium or hydrated magnesium ions, and are composed of integral membrane proteins. Although many TRP channels are activated by voltage change, ligand binding, or temperature change, some TRP channels have been hypothesized to be involved in mechanotransduction. Some examples are TRPV4, which mediates mechanical load in a variety of tissues, including the liver, heart, lung, trachea, testis, spleen, salivary glands, cochlea, and vascular endothelial cells, as well as TRPC1 and TRPC6, which are involved in muscle mechanosensation. TRPC1 is expressed in the myocytes of the heart, arteries, and skeletal muscle. TRPC1 is widely considered to be a non-selective “store-operated ion channel” (SOC) involved in the calcium influx following calcium depletion of the endoplasmic reticulum of the cell. TRPC6 is a calcium-permeable non-selective cation channel expressed in the cardiovascular system. TRPC6 is potentially a sensor of mechanically and osmotically induced membrane stretch, and is possibly directly gated by membrane tension. Other examples include TREK-1 and TRAAK which are found in mammalian neurons and are classified as potassium channels in the tandem pore domain class and "MID-1" (also known as "MCLC" or CLCC1.)

The six K2P channel subfamilies are regulated by various physical, cellular, and pharmacological stimulants, including membrane stretch, heat, pH change, calcium flux, and protein kinases.