an enzyme that is rate-limiting in the biosynthesis of serotonin. It catalyzes the biopterin dependent monooxygenation of tryptophan to 5-hydroxytryptophan (5HT), which is subsequently decarboxylated to form the neurotransmitter serotonin. Its expression is limited to a few specialized tissues: raphe neurons, pinealocytes, mast cells, mononuclear leukocytes, beta-cells of the islets of Langerhans, and intestinal and pancreatic enterochromaffin cells. Two alternatively spliced isoforms have been described. Note: This description may include information from UniProtKB.
Protein type: Oxidoreductase; Amino Acid Metabolism - tryptophan; EC 220.127.116.11
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.