title: Circadian clocks, clock networks, arylalkylamine N-acetyltransferase, and melatonin in the retina.
abstract: 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 turnover, and visual sensitivity. This review focuses on recent progress in understanding how clocks and light control arylalkylamine N-acetyltransferase (AANAT), which is thought to drive the daily rhythm in melatonin production in those retinas that synthesize the neurohormone; AANAT is also thought to detoxify arylalkylamines through N-acetylation. The review will cover evidence that cAMP is a major output of the circadian clock in photoreceptor cells; and recent advances indicating that clocks and clock networks occur in multiple cell types of the retina.
authors.affiliation: Department of Pharmacology, Emory University School of Medicine, 1510 Clifton Road, rm. 5107, Atlanta, GA 30322, USA. miuvone@pharm.emory.edu
authors.forename: P Michael
authors.initials: PM
authors.lastname: Iuvone
authors.forename: Gianluca
authors.initials: G
authors.lastname: Tosini
authors.forename: Nikita
authors.initials: N
authors.lastname: Pozdeyev
authors.forename: Rashidul
authors.initials: R
authors.lastname: Haque
authors.forename: David C
authors.initials: DC
authors.lastname: Klein
authors.forename: Shyam S
authors.initials: SS
authors.lastname: Chaurasia
mesh_terms: D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000378:metabolism*; D001683:Biological Clocks / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D000242:Cyclic AMP / Q000378:metabolism; D006801:Humans; D008027:Light; D008550:Melatonin / Q000096:biosynthesis*; D012160:Retina / Q000378:metabolism*
chemical_list: D000242:Cyclic AMP; D001191:Arylamine N-Acetyltransferase; D008550:Melatonin