Identification and Localization of Two Hydroxysteroid Sulfotransferases in the Human Brain

Hydroxysteroid sulfotransferase (SULT2) is thought to be a key enzyme in the synthesis of neurosteroid sulfates, which are known to act as potent regulators of neuronal activity within the brain. We detected two SULT2 mRNAs (SULT2A1 and SULT2B1b) in the human brain. We isolated their cDNAs, and determined the location of their expression in the brain by Northern blot hybridization. Exclusive SULT2A1 expression was detected in the thalamus and hypothalamus, whereas SULT2B1b expression was detected throughout the brain in varying amounts, reaching levels two to three times greater in some regions than in others. These findings further our understanding of the physiological role of SULT2 enzymes within the human brain, particularly how they affect neurosteroid metabolism, and thus, modulate neuronal activity within the brain.