title: Homeobox genes and melatonin synthesis: regulatory roles of the cone-rod homeobox transcription factor in the rodent pineal gland.
abstract: Nocturnal synthesis of melatonin in the pineal gland is controlled by a circadian rhythm in arylalkylamine N-acetyltransferase (AANAT) enzyme activity. In the rodent, Aanat gene expression displays a marked circadian rhythm; release of norepinephrine in the gland at night causes a cAMP-based induction of Aanat transcription. However, additional transcriptional control mechanisms exist. Homeobox genes, which are generally known to encode transcription factors controlling developmental processes, are also expressed in the mature rodent pineal gland. Among these, the cone-rod homeobox (CRX) transcription factor is believed to control pineal-specific Aanat expression. Based on recent advances in our understanding of Crx in the rodent pineal gland, we here suggest that homeobox genes play a role in adult pineal physiology both by ensuring pineal-specific Aanat expression and by facilitating cAMP response element-based circadian melatonin production.
authors.affiliation: Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Rigshospitalet 6102, Blegdamsvej 9, 2100 Copenhagen, Denmark.
authors.forename: Kristian
authors.identifier: 0000-0002-5077-0607
authors.initials: K
authors.lastname: Rohde
authors.affiliation: Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Rigshospitalet 6102, Blegdamsvej 9, 2100 Copenhagen, Denmark.
authors.forename: Morten
authors.identifier: 0000-0002-3263-7482
authors.initials: M
authors.lastname: Møller
authors.affiliation: Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Rigshospitalet 6102, Blegdamsvej 9, 2100 Copenhagen, Denmark.
authors.forename: Martin Fredensborg
authors.initials: MF
authors.lastname: Rath
mesh_terms: D000818:Animals; D047068:Arylalkylamine N-Acetyltransferase / Q000096:biosynthesis* / Q000235:genetics; D002940:Circadian Rhythm / Q000502:physiology*; D000242:Cyclic AMP / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D008550:Melatonin / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D010870:Pineal Gland / Q000378:metabolism*; D051381:Rats; D020218:Response Elements / Q000502:physiology; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
chemical_list: D018398:Homeodomain Proteins; D015534:Trans-Activators; C109288:cone rod homeobox protein; D000242:Cyclic AMP; C520223:Aanat protein, rat; D047068:Arylalkylamine N-Acetyltransferase; D008550:Melatonin