Hair cell mechanoelectrical transducer channel (MET channel)

The hair cell mechanoelectrical transducer channel is an ion channel located at the tip of stereocilia on sensory hair cells in the inner ear. Mechanical deflection of stereocilia opens the channel, allowing cation influx (notably Ca²⁺ and K⁺), which depolarizes the cell and initiates the neural encoding of sound and vestibular stimuli. The channel is part of a complex structure that includes other proteins such as tip-link components (cadherin 23, protocadherin 15) and may contain TMC1/TMC2 as key subunits, although its molecular identity remains not fully established. Dysfunction or genetic mutations affecting the MET channel or its associated apparatus cause various forms of hereditary and acquired hearing loss, including syndromic deafness (Usher syndrome). The MET channel also exhibits permeability to large organic cations, such as choline and tetraethylammonium, and is blocked by several clinically relevant drugs, notably aminoglycoside antibiotics. Proper function of the MET channel is critical for auditory and vestibular signal transduction, and its dysregulation or pharmacological block is a major safety concern in hearing therapy and ototoxicity.

Other names

Mechanoelectrical transduction channelMET channelMechanotransducer channelHair cell mechanotransducer channel

Blockage of the MET channel by aminoglycosides leads to reduced Ca²⁺ and K⁺ influx, resulting in hair cell death and ototoxicity. FM1-43 permeates through the MET channel, visualizing its activity or blocking it.