Transmembrane channel-like protein 2
Developmental stage
Expressed at low, constant levels in temporal bone from embryonic day 14 to day 1 after birth. Increases by 8 to 16-fold at day 5, 10 and 20.
Function
Pore-forming subunit of the mechanotransducer (MET) non-selective cation channel complex located at the tips of stereocilia of cochlear hair cells and that mediates sensory transduction in the auditory system (PubMed:11850618, PubMed:23871232). The MET complex is composed of two dimeric pore-forming ion-conducting transmembrane TMC (TMC1 or TMC2) subunits, several auxiliary proteins including LHFPL5, TMIE, CIB2/3 and TOMT, the tip-link PCDH15, and possibly the PIEZO subunits (By similarity). MET channel is activated by tension in the tip-link extending from the side wall of one stereocilium to the tip of the adjacent shorter stereocilium, where the channel is located (By similarity). TMC2 MET channel is highly permeable to calcium and likely transports monovalent cations (PubMed:23871232). Also involved in vestibular hair cell transduction current of the mammalian inner ear (PubMed:23871232).
Sequence Similarities
Belongs to the TMC family.
Tissue Specificity
Inner ear and testis. Expressed in cochlear inner and outer hair cells and vestibular organ hair cells (PubMed:38228630).
Cellular localization
- Cell membrane
- Multi-pass membrane protein
- Localized to the stereocilia tips of the cochlear hair cells and plasma membranes of cuticular plates.
Alternative names
Transmembrane channel-like protein 2, Transmembrane cochlear-expressed protein 2, Tmc2