PINEAL SEROTONIN N-ACETYLTRANSFERASE - EXPRESSION CLONING AND MOLECULAR ANALYSIS

Pineal serotonin N-acetyltransferase (arylalkylamine N-acetyltransfera se, or AA-NAT) generates the large circadian rhythm in melatonin, the hormone that coordinates daily and seasonal physiology in some mammals . Complementary DNA encoding ovine AA-NAT was cloned. The abundance of AA-NAT messenger RNA (mRNA) during the day was high in the ovine pine al gland and somewhat lower in retina. AA-NAT mRNA was found unexpecte dly in the pituitary gland and in some brain regions. The night-to-day ratio of ovine pineal AA-NAT mRNA is less than 2. In contrast, the ra tio exceeds 150 in rats. AA-NAT represents a family within a large sup erfamily of acetyltransferases.