Transmembrane O-methyltransferase (TOMT)

Transmembrane O-methyltransferase (TOMT) is a transmembrane enzyme localized primarily in the Golgi apparatus, and forms part of the auditory hair cell mechanotransduction (MET) complex responsible for converting acoustic mechanical signals into electrical activity within the cochlea. TOMT interacts directly with proteins such as TMC1 and TMC2 and is essential for trafficking and functional assembly of these channels at the stereocilia tips of hair cells. In contrast to classical catechol-O-methyltransferase (COMT), TOMT may lack significant catechol methyltransferase activity in vivo and appears to have evolved a unique, non-classical role specific to auditory physiology. Variants in the TOMT gene cause autosomal recessive nonsyndromic deafness, highlighting its essentiality for hearing but TOMT is currently not a recognized pharmacological target for approved drugs[1][2][5].

Other names

COMT2LRTOMTProtein LRTOMT2PP7517Catechol O-methyltransferase 2

For hair cell mechanotransduction: Facilitates TMC1 and TMC2 trafficking to stereocilia, independent of classic O-methyltransferase function. Enzymatic methylation of catechols is not physiologically significant in mammalian TOMT.