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: Amino Acid Metabolism - tryptophan; EC 18.104.22.168; Oxidoreductase