Information on EC 2.1.1.4 - acetylserotonin O-methyltransferase

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The expected taxonomic range for this enzyme is: Eukaryota

EC NUMBER
COMMENTARY hide
2.1.1.4
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RECOMMENDED NAME
GeneOntology No.
acetylserotonin O-methyltransferase
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
S-adenosyl-L-methionine + N-acetylserotonin = S-adenosyl-L-homocysteine + melatonin
show the reaction diagram
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
methyl group transfer
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-
-
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O-methylation
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-
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PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
Metabolic pathways
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serotonin and melatonin biosynthesis
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Tryptophan metabolism
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SYSTEMATIC NAME
IUBMB Comments
S-adenosyl-L-methionine:N-acetylserotonin O-methyltransferase
Some other hydroxyindoles also act as acceptor, but more slowly.
CAS REGISTRY NUMBER
COMMENTARY hide
9029-77-0
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ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
gene At4g35160 or AtASMT; gene AtASMT
UniProt
Manually annotated by BRENDA team
gene At4g35160 or AtASMT; gene AtASMT
UniProt
Manually annotated by BRENDA team
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-
-
Manually annotated by BRENDA team
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-
-
Manually annotated by BRENDA team
black rhinoceros
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-
Manually annotated by BRENDA team
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Manually annotated by BRENDA team
Frog
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-
-
Manually annotated by BRENDA team
monkey
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-
Manually annotated by BRENDA team
rainbow trout
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-
Manually annotated by BRENDA team
Chinook salmon
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-
Manually annotated by BRENDA team
muskox
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-
Manually annotated by BRENDA team
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-
-
Manually annotated by BRENDA team
Wistar
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-
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
evolution
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the enzyme belongs to S-adenosyl-L-methionine dependent animal natural product O-methyltransferase
malfunction
metabolism
physiological function
additional information
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
4-hydroxy-N-acetyltryptamine + S-adenosyl-L-methionine
S-adenosyl-L-homocysteine + N-acetyl-4-methoxytryptamine
show the reaction diagram
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8% of the activity with N-acetylserotonin
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-
?
5-hydroxyindoleacetic acid + S-adenosyl-L-methionine
S-adenosyl-L-homocysteine + 5-methoxyindoleacetic acid
show the reaction diagram
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12% of the activity with N-acetylserotonin
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-
?
bufotenine + S-adenosyl-L-methionine
S-adenosyl-L-homocysteine + N,N-dimethyl-5-hydroxytryptamine
show the reaction diagram
N-acetylserotonin + S-adenosyl-L-methionine
S-adenosyl-L-homocysteine + N-acetyl-5-methoxytryptamine
show the reaction diagram
N-methylserotonin + S-adenosyl-L-methionine
S-adenosyl-L-homocysteine + N-methyl-5-methoxytryptamine
show the reaction diagram
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9% of the activity with N-acetylserotonin
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-
?
S-adenosyl-L-methionine + N-acetylserotonin
S-adenosyl-L-homocysteine + melatonin
show the reaction diagram
S-adenosyl-L-methionine + N-acetylserotonin
S-adenosyl-L-homocysteine + N-acetyl-5-methoxytryptamine
show the reaction diagram
S-adenosyl-L-methionine + serotonin
S-adenosyl-L-homocysteine + 5-methoxytryptamine
show the reaction diagram
serotonin + S-adenosyl-L-methionine
S-adenosyl-L-homocysteine + 5-methoxytryptamine
show the reaction diagram
additional information
?
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NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
N-acetylserotonin + S-adenosyl-L-methionine
S-adenosyl-L-homocysteine + N-acetyl-5-methoxytryptamine
show the reaction diagram
S-adenosyl-L-methionine + N-acetylserotonin
S-adenosyl-L-homocysteine + melatonin
show the reaction diagram
S-adenosyl-L-methionine + serotonin
S-adenosyl-L-homocysteine + 5-methoxytryptamine
show the reaction diagram
additional information
?
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COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
S-adenosyl-L-methionine
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information
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ASMT-specific activity is not altered by the addition of EDTA or the divalent cation Mg2+, suggesting that Oryza sativa ASMT is a cation-independent O-methyltransferase
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
Arginine vasotocin
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Ca2+
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caffeic acid
in vitro N-acetylserotonin methyltransferase activity is significantly and competitively inhibited by caffeic acid, a substrate of the caffeic acid O-methyltransferase, 73% inhibition at 0.01 mM, 93% at 0.1 mM
Cu2+
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cysteamine
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rat enzyme inhibited to 50% at 0.128 mM, bovine and ovine enzyme not
cysteic acid
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glutathione
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Homocysteic acid
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L-glutamate
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inhibition is reversible, dose-dependent, no inhibition of mRNA expression
Mg2+
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N-acetylserotonin
Oxytocin
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p-chloromercuribenzoate
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pyridoxal 5'-phosphate
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quercetin
in vitro N-acetylserotonin methyltransferase activity is significantly and competitively inhibited by quercetin, a substrate of the caffeic acid O-methyltransferase, in vivo production of melatonin is significantly inhibited by quercetin in 4-week-old detached rice leaves, 97% inhibition at 0.01 mM, complete inhibition at over 0.05 mM
S-adenosyl-L-homocysteine
S-adenosyl-L-methionine
Selenocysteamine
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50% inhibition at 0.013 mM
tryptophan
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about 30% inhibition
Vasopressin
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additional information
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
bicarbonate
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activation
N-acetylserotonin
oxaloacetate
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activation
S-adenosyl-L-methionine
tryptamine
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activates by 25%
additional information
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.005 - 0.864
N-acetylserotonin
0.00856 - 0.11
S-adenosyl-L-methionine
1.036
serotonin
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pH 8.8, 37C
additional information
additional information
Michaelis-Menten kinetics
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Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.042
N-acetylserotonin
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0.0059
pyridoxal 5'-phosphate
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S-adenosylmethionine
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
0.0000007
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purified recombinant enzyme, pH 7.8, 37C
0.000007
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purified GST-tagged recombinant enzyme, pH not specified in the publication, 30C
0.000013
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purified nontagged recombinant enzyme, pH not specified in the publication, 30C
0.00003
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purified nontagged recombinant enzyme, pH not specified in the publication, 30C, at 10 mM substrate N-acetylserotonin concentration
additional information
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
7.5 - 8.3
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7.9 - 8.4
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7.9
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assay at
8.8
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O-methylation of serotonin
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6.5 - 8.8
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both recombinant N- and C-terminal fusions of the enzyme, no activity at pH 5.4
7.8 - 8.4
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TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
45
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recombinant enzyme
TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information
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enzyme-associated melatonin levels increase as temperature increases, without effect on enzyme-encoding gene transcript levels. The melatonin levels in rice plants a 45C and 55C are 26% and 54% higher than that at 25C, showing a peak level at 55C
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
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dorsal portion
Manually annotated by BRENDA team
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fertile egg yolk
Manually annotated by BRENDA team
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postovulatory, no activity in preovulatory ovarian follicle
Manually annotated by BRENDA team
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CD19+ cell, CD14-CD4+ cell, CD56-CD8+ cell, CD56+ cell
Manually annotated by BRENDA team
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lowest activity in spleen
Manually annotated by BRENDA team
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mucosa from the ulcer margin
Manually annotated by BRENDA team
additional information
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
76000 - 78000
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SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
polymer
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x * 21800
Crystallization/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
enzyme crystal structure, PDB ID 4A6E, analysis and structure modeling
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STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
4C, 96 h, inactivated
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4C, 96 h, pineal enzyme stable
frozen, stable for several weeks
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Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
immobilized metal ion affinity chromatography (Ni2+)
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recombinant His6-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromatography
recombinant N-terminally His6-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromatography
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reombinant N-and C-terminally His-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromatograpy
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Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
expressed in HEK-293 cells
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expression analysis in eggs
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FreeStyle 293 expression system used for cellular expression, His-tagged protein synthesized in the Rapid translation system RTS500
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gene cloning, DNA and amino acid sequence determination and analysis, the At4g35160 gene exhibits the highest sequence identity (31%) to the rice ASMT gene, followed by the At1g76790 gene with 29% sequence identity, phylogenetic analysis. The recombinant proteins are recombinantly expressed from the two Arabidopsis genes. The At4g35160 recombinant protein exhibits ASMT enzyme activity, but the At1g76790 recombinant protein does not. Recombinant expression of N-terminally His6-tagged enzyme in Escherichia coli strain BL21(DE3)
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gene comt, recombinant expression in Escherichia coli strain BL21(DE3), the N-terminal His-tagged AtCOMT is more highly expressed in soluble form than the C-terminal His-tagged AtCOMT
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gene OsASMT, DNA and amino acid sequence determination and analysis, recombinant expression of GST-tagged and of nontagged enzyme in Escherichia coli strain BL21(DE3), expression of N- or C-terminally His-tagged enzyme is not successful
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gene OsCOMT, recombinant His6-tagged enzyme expression in Escherichia coli strain BL21(DE3), generation of transgenic Nicotiana benthamiana plants and Oryza sativa plants expressing the enzyme using the Agrobacterium tumefaciens strains GV2260 and LBA4404 transfection method
gene sequenced
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EXPRESSION
ORGANISM
UNIPROT
LITERATURE
AtASMT transcripts are induced by cadmium treatment in Arabidopsis thaliana followed by increased melatonin synthesis
enzyme-associated melatonin levels increase as temperature increases when rice seedlings are exposed to various temperatures for 1 hr, but temperature-dependent increase in melatonin synthesis is only closely associated with an increase in both SNAT and ASMT activities, but not with transcript levels of melatonin biosynthetic genes. The relative melatonin levels are higher in the dark, exposure of rice seedlings to 1 hr darkness at 55C results in a melatonin yield of 4.9 ng/g fresh weight, compared with 2.95 ng/g fresh weight under light conditions
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In retinal cells the mutation of the YY1-binding site decreases the HIOMT promoter activity by 70%
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significant daily rhythms of mRNA in pineal gland, liver and hindgut
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the expression level in submandibular gland is higher in the dark period compared with the light period
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the mRNA expression for HIOMT is only slightly increased at day 0 upon ulcer induction when compared with that in the intact mucosa, but at day 8 after ulcer formation, this expression of HIOMT is significantly enhanced, particularly at the ulcer areas in rats treated with melatonin or L-tryptophan
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the rat Crx transcription factor is able to activate the HIOMT promoter in transfected HEK-293 cells
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there is an age-related decline in rat extrapineal melatonin synthesis with a consequent HIOMT functionality decrease in spleen, liver and heart during physiological aging, in the thymus HIOMT expression reveals no significant alterations with age
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ENGINEERING
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information