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Information on EC 2.1.1.129 - inositol 4-methyltransferase
for references in articles please use BRENDA:EC2.1.1.129
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EC Tree 2 Transferases
2.1 Transferring one-carbon groups
2.1.1 Methyltransferases
2.1.1.129 inositol 4-methyltransferase
IUBMB Comments
The enzyme from the rice bean Vigna umbellata (Fabaceae) is highly specific for S-adenosyl-L-methionine. The enzyme also methylates 1L-1,2,4/3,5-cyclohexanepentol, 2,4,6/3,5-pentahydroxycyclohexanone, D,L-2,3,4,6/5-pentacyclohexanone and 2,2′-anhydro-2-C-hydroxymethyl-myo-inositol, but at lower rates than that of myo-inositol.
The enzyme appears in viruses and cellular organisms
- 2.1.1.129
-
carotid
-
intima-media
- artery
- atherosclerosis
- cardiovascular
-
ultrasound
- plaque
- women
- cholesterol
-
ultrasonography
-
systolic
-
b-mode
- coronary
- hypertension
-
subclinical
-
smoking
- lipoprotein
-
intima
-
smoke
- myofibroblastic
- triglyceride
-
stiffness
-
wave
-
brachial
-
thicken
-
c-reactive
-
diastolic
- endothelial
-
dilation
-
low-density
-
inspiratory
-
middle-aged
- femoral
- stenosis
- hdl
- waist
-
doppler
-
flow-mediated
-
distensibility
-
brachial-ankle
-
tertile
-
tonometry
- alk
-
framingham
-
ankle-brachial
-
alk-positive
-
hypertensives
-
pseudotumors
-
hscrp
-
ldl-cholesterol
Reaction Schemes
showSynonyms
imt, pcimt1, myo-inositol o-methyltransferase, inositol methyl transferase, myo-inositol 6-o-methyltransferase, more
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SYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
EC 2.1.1.134
-
-
formerly
-
IMT
Imt1
IMT1 protein
-
-
-
-
inositol 6-O-methyltransferase
-
-
-
-
m6OMT
-
-
-
-
methyltransferase, inositol 6-O
-
-
-
-
methyltransferase, inositol L-1- (Mesembryanthemum crystallinum clone Imt1 reduced)
-
-
-
-
myo-inositol 4-O-methyltransferase
-
-
-
-
myo-inositol 6-O-methyltransferase
-
-
-
-
myo-inositol O-methyltransferase
S-adenosyl-L-methionine:myo-inositol 6-O-methyltransferase
-
-
-
-
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REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
S-adenosyl-L-methionine + myo-inositol = S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
-
-
-
-
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REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
methyl group transfer
-
-
-
-
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PATHWAY SOURCE
PATHWAYS
MetaCyc
pinitol biosynthesis I
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SYSTEMATIC NAME
IUBMB Comments
S-adenosyl-L-methionine:1D-myo-inositol 4-methyltransferase
The enzyme from the rice bean Vigna umbellata (Fabaceae) is highly specific for S-adenosyl-L-methionine. The enzyme also methylates 1L-1,2,4/3,5-cyclohexanepentol, 2,4,6/3,5-pentahydroxycyclohexanone, D,L-2,3,4,6/5-pentacyclohexanone and 2,2'-anhydro-2-C-hydroxymethyl-myo-inositol, but at lower rates than that of myo-inositol.
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CAS REGISTRY NUMBER
COMMENTARY
146048-86-4
-
169277-48-9
formerly EC 2.1.1.134
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SUBSTRATE
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
LITERATURE
COMMENTARY
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
S-adenosyl-L-methionine + 1L-1,3,4/2,5-cyclohexanepentol
?
-
Substrates: i.e. L-viburnitol
Products: -
Products: -
?
S-adenosyl-L-methionine + 2,4,6/3,5-pentahydroxy-cyclohexanone
?
-
Substrates: i.e. myo-inosose-2
Products: -
Products: -
?
S-adenosyl-L-methionine + D,L-2,3,4,6/5-pentahydroxy-cyclohexanone
?
-
Substrates: i.e. myo-inosose-4
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + 4-methyl-myo-inositol
-
Substrates: -
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
?
-
Substrates: the enzyme catalyzes the first step in the biosynthesis of the cyclic sugar alcohol pinitol. The presence of high levels of sugar alcohols correlates with osmotolerance
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
?
-
Substrates: the product 1D-4-O-methyl-myo-inositol is accumulated in response to abiotic stress
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
Substrates: during normal growth IMT is repressed, after salinity stress IMT is induced. By inducing expression of IMT and increasing myo-inositol synthesis, metabolic end products accumulate, facilitating sodium sequestration and protecting photosynthesis
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
Substrates: involved in the biosynthesis of pinitol, which is important for osmotic stress response
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
Substrates: -
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
-
Substrates: -
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
-
Substrates: accumulation of methylated inositol in plants under salt-stress
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
-
Substrates: -
Products: 1D-4-O-methyl-myo-inositol is accumulated in response to abiotic stresses
Products: 1D-4-O-methyl-myo-inositol is accumulated in response to abiotic stresses
?
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + D-ononitol
Substrates: -
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + D-ononitol
-
Substrates: -
Products: D-ononitol is 1-D-4-O-methyl-myo-inositol
Products: D-ononitol is 1-D-4-O-methyl-myo-inositol
?
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NATURAL SUBSTRATE
NATURAL PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
LITERATURE
COMMENTARY
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
S-adenosyl-L-methionine + myo-inositol
?
-
Substrates: the enzyme catalyzes the first step in the biosynthesis of the cyclic sugar alcohol pinitol. The presence of high levels of sugar alcohols correlates with osmotolerance
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
?
-
Substrates: the product 1D-4-O-methyl-myo-inositol is accumulated in response to abiotic stress
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
Substrates: during normal growth IMT is repressed, after salinity stress IMT is induced. By inducing expression of IMT and increasing myo-inositol synthesis, metabolic end products accumulate, facilitating sodium sequestration and protecting photosynthesis
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
Substrates: involved in the biosynthesis of pinitol, which is important for osmotic stress response
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
Substrates: -
Products: -
Products: -
?
S-adenosyl-L-methionine + myo-inositol
S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
-
Substrates: -
Products: -
Products: -
?
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COFACTOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
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METALS and IONS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
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INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
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ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
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KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
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SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
additional information
additional information
-
proteome profile during salt-stress, up-regulation of RNA and protein expression following exposure to salinity, profiling of reaction product by gas chromatography, functional characterization of recombinant protein, regulation of pinitol synthesis pathway under different abiotic stresses, different plant species known to produce pinitol in response to stress listed, accumulation of D-pinitol via inositol is a stress-regulated pathway, presence of D-pinitol synthesizing protein/gene in a wild halophytic rice, absence in domesticated rice, adaptive feature in salt tolerance
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pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
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pH RANGE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
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TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
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TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
30 - 55
-
30°C: about 40% of maximal activity, 55°C: about 30% of maximal activity
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ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
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SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE
during normal growth IMT is repressed, after salinity stress IMT is induced
brenda
during normal growth IMT is repressed, after salinity stress IMT is induced
brenda
Highest Expressing Human Cell Lines
Cell Line LinksPlease wait a moment until the data is sorted. This message will disappear when the data is sorted.
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
metabolism
exogenous myo-inositol increases salt tolerance and accelerates Crassulacean acid metabolism (CAM) induction in the early juvenile stage of the facultative halophyte Mesembryanthemum crystallinum (ice plant) but not in the late juvenile stage. Ice plants develop salt tolerance during the transition from the juvenile to the adult stage. Myo-inositol is the precursor for the synthesis of compatible solute D-pinitol and promotes Na+ transport in ice plants. Treatment combining high salt and myo-inositol synergistically induces the expression of myo-inositol phosphate synthase (INPS), myo-inositol O-methyltransferase (IMT), and inositol transporters (INTs), which modulate root-to-shoot Na/K ratio and increase leaf D-pinitol content. Sufficient myo-inositol is a prerequisite for high salt tolerance in ice plant
physiological function
physiological function
-
after cold stress, the Imt1 transgenic Arabidopsis plants exhibit stronger growth than the wild type plants
physiological function
tobacco plants transformed with the IMT gene produce up to 2.38 mg of D-ononitol per gram dry weight of leaves. Introduction of IMT, OEPA displaying NAD+-dependent D-ononitol dehydrogenase activity, and OEPB having NADP+-dependent D-pinitol dehydrogenase activity into tobacco plants results in production of D-ononitol and D-pinitol in transformants
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UNIPROT
ENTRY NAME
ORGANISM
NO. OF AA
NO. OF TRANSM. HELICES
MOLECULAR WEIGHT[Da]
SOURCE
SEQUENCE
LOCALIZATION PREDICTION
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable).
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable). Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
additional information
-
40 kDa immunoreactive protein under stressed and unstressed conditions in wild rice, an about 60 kDa major band detected by antibodies in domesticated and in wild rice
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SUBUNIT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
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pH STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
5.5
-
3 h, at room temperature, about 45% loss of activity compared to maximal stability at pH 7.0-7.6
6.5
-
3 h, at room temperature, about 10% loss of activity compared to maximal stability at pH 7.0-7.6
8
-
3 h, at room temperature, about 30% loss of activity compared to maximal stability at pH 7.0-7.6
9
-
3 h, at room temperature, about 70% loss of activity compared to maximal stability at pH 7.0-7.6
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TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
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GENERAL STABILITY
ORGANISM
UNIPROT
LITERATURE
activity is lost within a week, when the enzyme is frozen or kept at 4°C without glycerol
-
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STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
-30°C, 25 mM Tris-HCl, pH 7.6, 2 mM dithiothreitol, 2 mM MgCl2, 0.25 mM ammonium sulfate, 50% glycerol, half-life: 300 d
-
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PURIFICATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
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CLONED (Commentary)
ORGANISM
UNIPROT
LITERATURE
expression in Escherichia coli
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REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Vernon, D.M.; Bohnert, H.J.
A novel methyl transferase induced by osmotic stress in the facultative halophyte Mesembryanthemum crystallinum
EMBO J.
11
2077-2085
1992
Mesembryanthemum crystallinum
brenda
Wanek, W.; Richter, A.
Purification and characterization of myo-inositol 6-O-methyltransferase from Vigna umbellata Ohwi et Ohashi
Planta
197
427-434
1995
Vigna umbellata
-
brenda
Nelson, D.E.; Rammesmayer, G.; Bohnert, H.J.
Regulation of cell-specific inositol metabolism and transport in plant salinity tolerance
Plant Cell
10
753-764
1998
Mesembryanthemum crystallinum (P45986)
brenda
Chiera, J.M.; Streeter, J.G.; Finer, J.J.
Ononitol and pinitol production in transgenic soybean containing the inositol methyl transferase gene from Mesembryanthemum crystallinum
Plant Sci.
171
647-654
2006
Mesembryanthemum crystallinum (P45986)
-
brenda
Sengupta, S.; Patra, B.; Ray, S.; Majumder, A.L.
Inositol methyl tranferase from a halophytic wild rice, Porteresia coarctata Roxb. (Tateoka): regulation of pinitol synthesis under abiotic stress
Plant Cell Environ.
31
1442-1459
2008
Oryza coarctata, no activity in Oryza sativa
brenda
Zhu, B.; Peng, R.; Xiong, A.; Xu, J.; Fu, X.; Zhao, W.; Jin, X.; Meng, X.; Gao, J.; Cai, R.; Yao, Q.
Transformation with a gene for myo-inositol O-methyltransferase enhances the cold tolerance of Arabidopsis thaliana
Biol. Plant.
56
135-139
2012
Mesembryanthemum crystallinum
-
brenda
Pupel, P.; Szablinska-Piernik, J.; Lahuta, L.B.
Two-step D-ononitol epimerization pathway in Medicago truncatula
Plant J.
100
237-250
2019
Medicago truncatula (G7JTH4), Medicago truncatula
brenda
Li, C.H.; Tu, Y.C.; Wen, M.F.; Tien, H.J.; Yen, H.E.
Exogenous myo-inositol increases salt tolerance and accelerates CAM induction in the early juvenile stage of the facultative halophyte Mesembryanthemum crystallinum but not in the late juvenile stage
Funct. Plant Biol.
50
363-377
2023
Mesembryanthemum crystallinum (P45986)
brenda
EXTERNAL LINKS (specific for EC-Number 2.1.1.129)
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