Description
Nicotinamide N-Methyltransferase (NNMT) methylates nicotinamide and other pyridine containing compounds. NNMT transfers a methyl group from S-adenosylmethionine (SAM) to nitrogen N1 of nicotinamide to produce 1-methylnicotinamide (MNA) and S-adenosylhomocysteine. MNA is a messenger molecule that increases neurite branching, serves as an anti-thrombotic, and has anti-inflammatory properties. The role of NNMT overexpression in cancers may be to alter epigenetic methylation patterns in two ways: by lowering the intracellular concentration of SAM, required by methyltransferase enzymes, and by depleting the available NAD+ by transforming nicotinamide to MNA. Sirtuins use NAD+ as a substrate to alter protein acetylation and ribosylation, including histone targets