| Modification Notes |
Melatonin is a natually occurring secreted hormone that exhibits antioxidant capabilities and is crucial in the proper regulation of the circadian rhythm. ASMT (acetylserotonin O-methyltransferase), also known as HIOMT (hydroxyindole O-methyltransferase), is a 345 amino acid protein that belongs to the methyltransferase superfamily and is involved in melatonin biosynthesis. Expressed in brain, retina and pineal gland, ASMT functions to catalyze the final reaction in the synthesis of melatonin, specifically the conversion of S-adenosyl-L-methionine and N-acetylserotonin to S-adenosyl-L-homocysteine and melatonin. Multiple isoforms of ASMT exist due to alternative splicing events. The gene encoding ASMT maps to the pseudoautosomal region of chromosomes X and Y. |