Serotonin N-acetyltransferase

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Serotonin N-acetyltransferase
Properties of human protein
Mass / length primary structure 207 amino acids
Secondary to quaternary structure Monomer
Identifier
Gene name AANAT
External IDs
Enzyme classification
EC, category 2.3.1.87 ,  acetyltransferase
Response type N- acetylation
Substrate 2-arylethylamine + acetyl-CoA
Products N-acetyl-2-arylethylamine + CoA
Occurrence
Homology family Aryl-CoA acyltransferase
Parent taxon Bilateral animals

Serotonin-N-acetyltransferase (AANAT) is the enzyme that catalyzes the transfer of an acetic acid residue to serotonin . This reaction is the first and rate-limiting of two steps in the biosynthesis of melatonin . AANAT occurs in bilateral animals . In humans, it is mainly located in the pineal gland , the upper digestive tract, and the retina . Their activity is indirectly dependent on daylight.

Catalyzed reaction

CH 3 CO-S-CoA + HS-CoA +Serotonin Acetylserotonin

Serotonin is converted to N-acetylserotonin. Other 2-arylethylamines are also accepted as substrates.

regulation

The activity of the AANAT increases ten to one hundred times at night. The time to double the activity is about 15 minutes and the time it takes to halve the activity in the morning is about 3.5 minutes. This enormous effect is achieved by activating the enzyme by means of phosphorylation and complexation to 14-3-3 proteins , which is dependent on the intracellular cAMP level. This in turn is regulated via a signal cascade by the hormone noradrenaline , which is released from the suprachiasmatic nucleus depending on daylight .

The production of AANAT is linked to the pineal endocannabinoid system , which was first discovered in rats in 2008. The nocturnal amplification of AANAT translation is genetically regulated by the protein hnRNP Q.

Individual evidence

  1. ↑ UniProt Q16613
  2. ↑ Konturek SJ, Konturek PC, Brzozowski T, Bubenik GA: Role of melatonin in upper gastrointestinal tract . In: J. Physiol. Pharmacol. . 58 Suppl 6, December 2007, pp. 23-52. PMID 18212399 .
  3. ↑ Ichihara N, Okada M, Takeda M: Characterization and purification of polymorphic arylalkylamine N-acetyltransferase from the American cockroach, Periplaneta americana . In: Insect Biochem. Mol. Biol . 32, No. 1, December 2001, pp. 15-22. PMID 11719065 .
  4. ↑ Aisien SO, Hellmund C, Walter RD: Characterization of the arylalkylamine N-acetyltransferase in Onchocerca volvulus . In: Parasitol. Res. . 82, No. 4, 1996, pp. 369-71. PMID 8740555 .
  5. ↑ Klein DC: Arylalkylamine N-acetyltransferase: "the Timezyme" . In: J. Biol. Chem. . 282, No. 7, February 2007, pp. 4233-7. doi : 10.1074 / jbc.R600036200 . PMID 17164235 .
  6. ↑ Koch M, Habazettl I, Dehghani F, Korf HW: The rat pineal gland comprises an endocannabinoid system . In: J. Pineal Res . 45, No. 4, November 2008, pp. 351-60. doi : 10.1111 / j.1600-079X.2008.00597.x . PMID 18554250 .
  7. ↑ Kim TD, Woo KC, Cho S, Ha DC, Jang SK, Kim KT: Rhythmic control of AANAT translation by hnRNP Q in circadian melatonin production . In: Genes Dev. . 21, No. 7, April 2007, pp. 797-810. doi : 10.1101 / gad.1519507 . PMID 17403780 . PMC 1838531 (free full text).

Web links

Wikibooks: Biochemistry and Pathobiochemistry: Tyrosine Metabolism  - Learning and Teaching Materials