ASMT
Function
Isoform 1
Catalyzes the transfer of a methyl group onto N-acetylserotonin, producing melatonin (N-acetyl-5-methoxytryptamine).
Isoform 2
Does not show Acetylserotonin O-methyltransferase activity.
Isoform 3
Does not show Acetylserotonin O-methyltransferase activity.
Pathway
Aromatic compound metabolism; melatonin biosynthesis; melatonin from serotonin: step 1/2.
Sequence Similarities
Belongs to the class I-like SAM-binding methyltransferase superfamily. Cation-independent O-methyltransferase family.
Tissue Specificity
Expressed in the pineal gland (at protein level). In the retina, very low expression is found at the mRNA level (PubMed:7989373), and not at the protein level (PubMed:8574683).
Alternative names
Acetylserotonin O-methyltransferase, Hydroxyindole O-methyltransferase, HIOMT, ASMT