LRTOMT transfers Met to DA, forming 3MT

Transmembrane O-methyltransferase (LRTOMT aka COMT2) catalyses the O-methylation of catecholamine neurotransmitters, thereby inactivating them (Du et al. 2008). LRTOMT is highly expressed in sensory hair cells of the inner ear. Defects in LRTOMT can cause autosomal recessive deafness 63 (DFNB63), a form of non-syndromic sensorineural hearing loss (Ahmed et al. 2008, Du et al. 2008). In this example, dopamine (DA) is O-methylated using S-adenosyl-L-methionine (AdoMet) as the methyl donor to form 3-methyltyramine (3MT) and S-adenosyl-L-homocysteine (AdoHcy).

跨膜O-甲基转移酶（LRTOMT，亦称COMT2）催化儿茶酚胺神经递质的O-甲基化反应，从而使其失活（Du等，2008年）。LRTOMT在内耳的感觉毛细胞中高度表达。LRTOMT的缺陷可导致常染色体隐性聋病63（DFNB63），这是一种非综合征性感音神经性听力丧失的表型（Ahmed等，2008年，Du等，2008年）。在本例中，通过使用S-腺苷-L-蛋氨酸（AdoMet）作为甲基供体，将多巴胺（DA）O-甲基化，生成3-甲基酪胺（3MT）和S-腺苷-L-高半胱氨酸（AdoHcy）。