Function
Tryptophan hydroxylase (TPH; EC 1.14.16.4) catalyzes the biopterin-dependent monooxygenation of tryptophan to 5-hydroxytryptophan (5-HTP), which is subsequently decarboxylated to form the neurotransmitter serotonin (5-hydroxytryptamine or 5-HT). It is the rate-limiting enzyme in the biosynthesis of serotonin.
TPH 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.
Tph1 is not expressed in the mouse brain.
Read more about this topic: TPH1
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