Indolethylamine-N-Methyltransferase (INMT)

Indolethylamine N-methyltransferase (INMT) catalyzes the N-methylation of tryptamine and structurally related compounds.The predicted 263-amino acid human INMT protein contains the signature sequences of methyltransferases, referred to as RI, RII, and RIII. Human INMT shares 88% amino acid sequence identity with rabbit INMT, 58% identity with mouse thioether methyltransferase, 53% identity with both human and mouse nicotinamide methyltransferase (NNMT), and 38% identity with human phenylethanolamine N-methyltransferase (PNMT). The INMT gene is 5,471 bp in length and contains 3 exons. Northern blot analysis detected an approximately 2.7-kb INMT transcript in most of the 35 human tissues tested, with highest expression in adult thyroid, adult adrenal gland, adult lung, and fetal lung.