Catalyzes N-acetylation of tryptamine, tyramine, dopamine, serotonin and octopamine (PubMed:7498465, PubMed:8901578, PubMed:25406072). In astrocytes, regulates sleep homeostasis by limiting the accumulation of serotonin and dopamine in the brain upon sleep deprivation (PubMed:10710313, PubMed:32955431). Is not essential for sclerotization (PubMed:9703021). 2-arylethylamine + acetyl-CoA = CoA + H(+) + N-acetyl-2-arylethylamine acetyl-CoA + serotonin = CoA + H(+) + N-acetylserotonin acetyl-CoA + dopamine = CoA + H(+) + N-acetyl-dopamine acetyl-CoA + tyramine = CoA + H(+) + N-acetyltyramine acetyl-CoA + octopamine = CoA + H(+) + N-acetyloctopamine 5-methoxytryptamine + acetyl-CoA = CoA + H(+) + melatonin 2-phenylethylamine + acetyl-CoA = CoA + H(+) + N-(2-phenylethyl)acetamide acetyl-CoA + noradrenaline = CoA + H(+) + N-acetylnoradrenaline butanoyl-CoA + tyramine = CoA + H(+) + N-butanoyltyramine hexanoyl-CoA + tyramine = CoA + H(+) + N-hexanoyltyramine acetyl-CoA + tryptamine = CoA + H(+) + N-acetyltryptamine dopamine + hexadecanoyl-CoA = CoA + H(+) + N-hexadecanoyl-dopamine (9Z)-octadecenoyl-CoA + dopamine = CoA + H(+) + N-(9Z-octadecanoyl)-dopamine hexadecanoyl-CoA + serotonin = CoA + H(+) + N-hexadecanoyl-serotonin (9Z)-octadecenoyl-CoA + serotonin = CoA + H(+) + N-(9Z-octadecenoyl)-serotonin octadecanoyl-CoA + serotonin = CoA + H(+) + N-octadecanoyl-serotonin (5Z,8Z,11Z,14Z)-eicosatetraenoyl-CoA + serotonin = CoA + H(+) + N-[(5Z,8Z,11Z,14Z)-eicosatetraenoyl]-serotonin Inhibited by long-chain acyl-CoA thioesters, oleoyl-CoA (an analog of acetyl-CoA) and tyrosol (an analog of tyramine). kcat is 21.9 sec(-1) with tryptamine and acetyl-CoA as substrate (at pH 7.2). Optimum temperature is 37 degrees Celsius. Retains 84% of activity when incubated at 4 degrees Celsius for 3 days. kcat is 19 sec(-1) for tyramine (at pH 8 and with acetyl-CoA as cosubstrate) (PubMed:25406072). kcat is 13 sec(-1) for octapamine (at pH 8 and with acetyl-CoA as cosubstrate) (PubMed:25406072). kcat is 17.6 sec(-1) for dopamine (at pH 8 and with acetyl-CoA as cosubstrate) (PubMed:25406072). kcat is 22 sec(-1) for tryptamine (at pH 8 and with acetyl-CoA as cosubstrate) (PubMed:25406072). kcat is 35 sec(-1) for 5-methoxytryptamine (at pH 8 and with acetyl-CoA as cosubstrate) (PubMed:25406072). kcat is 20 sec(-1) for noradrenaline (at pH 8 and with acetyl-CoA as cosubstrate) (PubMed:25406072). kcat is 30 sec(-1) for 2-phenylethylamine (at pH 8 and with acetyl-CoA as cosubstrate). kcat is 29.7 sec(-1) for serotonine (at pH 8 and with acetyl-CoA as cosubstrate) (PubMed:25406072). Aromatic compound metabolism; melatonin biosynthesis; melatonin from serotonin: step 1/2. In astrocytes, is primarily cytoplasmic, but in neurons is also nuclear. In the adult, expressed in the midgut portion of the thoracic segments and the frontal half of the abdomen (at protein level) (PubMed:9703021). Expressed in the epithelial cell layer facing the lumen of the gut (at protein level) (PubMed:9703021). In the brain, expressed in a sub-populations of neurons and astrocytes, and in a set of distinct stripes in the optic lobes (at protein level) (PubMed:9703021, PubMed:32955431). Expressed mainly in serotonergic neurons but also in subsets of glutamatergic, GABAergic and cholinergic neurons (at protein level) (PubMed:32955431). Detected in late pupal stages and in adult (at protein level). Detected from 8h up to the adult stage at relatively constant levels (at protein level) (PubMed:9703021). From 16 hours embryo, detected in cells of the brain, the ventral nerve cord, and the midgut (PubMed:9703021). Expressed in the embryonic central nervous system (at protein level) (PubMed:32955431). First detected in stage 14 embryos in cells of the future proventriculus (PubMed:8901578). From stage 15 onwards, strongly expressed in the proventriculus as well as in endodermal cells of the anterior and posterior midgut, whereas the remainder of the midgut shows only very weak expression (PubMed:8901578). No expression is observed in the cells of the developing gastric caeca (PubMed:8901578). Expression in the ventral cord and the brain is nonsegmental (PubMed:8901578). Expression at the transcriptional or the translational level is not regulated in a circadian fashion. Has a darker body color (PubMed:32709620). Shows ectopic pigmentation in the wing hinge, the posterior pupal case, leg joints and cuticular sutures (PubMed:32709620). RNAi-mediated knockdown in astrocytes, does not affect numbers of astrocytes present in the brain (PubMed:32955431). Shows normal baseline patterns and amounts of daytime and nighttime sleep, but while awake are less active (PubMed:32955431). Upon overnight mechanical sleep deprivation, results in increased recovery sleep next day (PubMed:32955431). RNAi-mediated knockdown in neurons results in normal patterns of baseline sleep (PubMed:32955431). Shows lower levels of activity while awake during daytime (PubMed:32955431). During the night, increases duration of sleep bouts and decrease their numbers, suggesting improved sleep consolidation at night (PubMed:32955431). Do not display enhanced recovery sleep the next day following overnight mechanical sleep deprivation (PubMed:32955431). Does not affect the percentage or circadian distribution of rest and waking (PubMed:10710313, PubMed:32955431). Shows normal amounts and pattern of activity (PubMed:10710313, PubMed:32955431). Increases homeostatic sleep following deprivation (PubMed:10710313, PubMed:32955431). Reduces catabolism of serotonin and dopamine in the brains in response to sleep deprivation, leading to inappropriate accumulation of these monoamines (PubMed:32955431). Belongs to the acetyltransferase family. AANAT subfamily.