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The daily rhythm in melatonin levels is controlled by cAMP through actions on the penultimate enzyme in melatonin synthesis, arylalkylamine N-acetyltransferase (AANAT; serotonin N-acetyltransferase, EC ). Results presented here describe a regulatory/binding sequence in AANAT that encodes a cAMP-operated binding switch through which cAMP-regulated protein(More)
A remarkably constant feature of vertebrate physiology is a daily rhythm of melatonin in the circulation, which serves as the hormonal signal of the daily light/dark cycle: melatonin levels are always elevated at night. The biochemical basis of this hormonal rhythm is one of the enzymes involved in melatonin synthesis in the pineal gland-the melatonin(More)
In vertebrates, the circadian rhythm in the activity of serotonin N-acetyltransferase [arylalkylamine N-acetyltransferase (AA-NAT); EC] drives the daily rhythm in circulating melatonin. We have discovered that expression of the AA-NAT gene in the rat pineal gland is essentially turned off during the day and turned on at night, resulting in a more(More)
A 10-100-fold rhythm in the activity of arylalkylamine N-acetyltransferase (AA-NAT; EC controls the rhythm in melatonin synthesis in the pineal gland. In some mammals, including the rat, the high nocturnal level of AA-NAT activity is preceded by an approximately 100-fold increase in AA-NAT mRNA. The increase in AA-NAT mRNA is generated by(More)
The nocturnal increase in circulating melatonin in vertebrates is regulated by 10- to 100-fold increases in pineal serotonin N-acetyltransferase (AA-NAT) activity. Changes in the amount of AA-NAT protein were shown to parallel changes in AA-NAT activity. When neural stimulation was switched off by either light exposure or L-propranolol-induced(More)
Circadian clocks are self-sustaining genetically based molecular machines that impose approximately 24h rhythmicity on physiology and behavior that synchronize these functions with the solar day-night cycle. Circadian clocks in the vertebrate retina optimize retinal function by driving rhythms in gene expression, photoreceptor outer segment membrane(More)
Mammalian pineal function appears to be controlled primarily through the release of noradrenaline from the terminals of nerves whose cell bodies lie in the superior cervical ganglia. This is the final segment of the following neural pathway: retina----retinohypothalamic projection----suprachiasmatic nuclei----paraventricular nuclei----intermediolateral cell(More)
The abundance of serotonin N-acetyltransferase (arylalkylamine N-acetyltransferase, AANAT) mRNA in the chicken pineal gland exhibits a circadian rhythm, which is translated into a circadian rhythm in melatonin production. Here we have started to elucidate the molecular basis of the circadian rhythm in chicken AANAT (cAANAT). The 5'-flanking region of the(More)
Serotonin N-acetyltransferase (arylalkylamine N-acetyltransferase, AA-NAT, HGMW-approved symbol AANAT; EC is the penultimate enzyme in melatonin synthesis and controls the night/day rhythm in melatonin production in the vertebrate pineal gland. We have found that the human AA-NAT gene spans approximately 2.5 kb, contains four exons, and is located(More)
Complete melatonin rhythm generating systems, including photodetector, circadian clock and melatonin synthesis machinery, are located within individual photoreceptor cells in two sites in Teleost fish: the pineal organ and retina. In both, light regulates daily variations in melatonin secretion by controlling the activity of arylalkylamine(More)