Glycine N-Methyltransferase/GNMT Proteins and Enzymes

Glycine N-methyltransferase (GNMT) is a cytoplasmic homotetramer of 32 kDa units that converts S-adenosylmethionine to N-methylglycine (sarcosine), also producing S-adenosylhomocysteine. It is abundant in liver, but has also been found in the pancreas and prostate, and is downregulated in hepatocellular carcinoma. GNMT adjusts liver methyl group synthesis for dietary methionine, influencing DNA methylation. The 5-methyltetrahydrofolate form of folic acid binds and inhibits GNMT activity.