Molecular rhythms in the pineal gland.
Recent findings have clarified the mechanisms regulating the night- and pineal-specific transcription of serotonin N-acetyltransferase, the rate-limiting enzyme in melatonin formation. Norepinephrine, acting via beta-adrenoceptors and cAMP at night, stimulates the cAMP response element binding protein, which turns on the transcription of N-acetyltransferase and inducible cAMP early repressor, the major inhibitor of N-acetyltransferase transcription. The tissue-specific gene expression within the pineal gland and retina derives, in part, from a pineal/retina-specific transcription factor, cone-rod homeobox protein, which binds to a pineal regulatory element. This regulatory element is present in promoters of pineal-selective enzymes, such as N-acetyltransferase, hydroxyindole-O-methyl transferase, and pineal night-specific ATPase.
Li
X
X
Johns Hopkins University School of Medicine, Department of Neuroscience, Baltimore, Maryland 21205, USA. xl@welchlink.jhu.edu
Borjigin
J
J
Snyder
S H
SH
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D001191:Arylamine N-Acetyltransferase / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology*; D006801:Humans; D008550:Melatonin / Q000378:metabolism*; D010870:Pineal Gland / Q000201:enzymology*
D001191:Arylamine N-Acetyltransferase; D000251:Adenosine Triphosphatases; D008550:Melatonin