Information on EC 2.3.1.50 - serine C-palmitoyltransferase

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The enzyme appears in viruses and cellular organisms

EC NUMBER
COMMENTARY hide
2.3.1.50
-
RECOMMENDED NAME
GeneOntology No.
serine C-palmitoyltransferase
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
palmitoyl-CoA + L-serine = CoA + 3-dehydro-D-sphinganine + CO2
show the reaction diagram
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
Acyl group transfer
-
-
-
-
Claisen condensation
-
-
condensation
decarboxylation
-
-
-
-
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
ceramide de novo biosynthesis
-
-
sphingolipid biosynthesis (plants)
-
-
sphingolipid biosynthesis (yeast)
-
-
ceramide biosynthesis
-
-
Sphingolipid metabolism
-
-
Metabolic pathways
-
-
SYSTEMATIC NAME
IUBMB Comments
palmitoyl-CoA:L-serine C-palmitoyltransferase (decarboxylating)
A pyridoxal-phosphate protein.
CAS REGISTRY NUMBER
COMMENTARY hide
62213-50-7
-
ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
LCB2; ssp. chinensis
UniProt
Manually annotated by BRENDA team
infects the globally important marine calcifying microalga Emiliania huxleyi, gene ehv050
-
-
Manually annotated by BRENDA team
cv. early profilic straightneck
-
-
Manually annotated by BRENDA team
strain GTC97
UniProt
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
evolution
-
the enzyme belongs to the PLP-superfamily and a member of the alpha-oxoamine synthase family (AOS, fold type I)
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
acyl-CoA + L-serine
CoA + ?
show the reaction diagram
-
-
-
-
?
arachidoyl-CoA + L-serine
CoA + 2-amino-1-hydroxydocosan-3-one + CO2
show the reaction diagram
-
37% activity compared to that with palmitoyl-CoA
-
-
?
elaidoyl-CoA + L-serine
CoA + 2-amino-1-hydroxy-trans-11-eicosen-3-one + CO2
show the reaction diagram
-
39% activity compared to that with palmitoyl-CoA
-
-
?
L-alanine + palmitoyl-CoA
CoA + (2S)-2-aminooctadecan-3-one + CO2
show the reaction diagram
-
-
-
-
?
L-alanine + stearoyl-CoA
CoA + (2S)-2-aminoicosan-3-one + CO2
show the reaction diagram
-
-
-
-
?
L-serine + palmitoyl-CoA
CoA + 3-dehydro-D-sphinganine + CO2
show the reaction diagram
L-serine + stearoyl-CoA
CoA + (2S)-2-amino-1-hydroxyicosan-3-one + CO2
show the reaction diagram
-
-
-
-
?
lauroyl-CoA + L-serine
CoA + 2-amino-1-hydroxytetradecan-3-one + CO2
show the reaction diagram
-
18% activity compared to that with palmitoyl-CoA
-
-
?
myristoleoyl-CoA + L-serine
CoA + 2-amino-1-hydroxy-cis-11-hexadecen-3-one + CO2
show the reaction diagram
-
46% activity compared to that with palmitoyl-CoA
-
-
?
myristoyl-CoA + L-serine
CoA + 2-amino-1-hydroxy-cis-11-hexadecen-3-one + CO2
show the reaction diagram
myristoyl-CoA + L-serine
CoA + 2-amino-1-hydroxyhexadecan-3-one + CO2
show the reaction diagram
myristoyl-CoA + L-serine
CoA + ? + CO2
show the reaction diagram
n-heptadecanoyl-CoA + L-serine
CoA + 2-amino-1-hydroxynonadecan-3-one + CO2
show the reaction diagram
oleoyl-CoA + L-serine
CoA + 2-amino-1-hydroxy-11-cis-eicosen-3-one + CO2
show the reaction diagram
-
57% activity compared to that with palmitoyl-CoA
-
-
?
palmitoleoyl-CoA + L-serine
CoA + 2-amino-1-hydroxy-cis-11-octadecen-3-one + CO2
show the reaction diagram
palmitoyl-CoA + L-alanine
CoA + (2S)-2-aminooctadecan-3-one + CO2
show the reaction diagram
palmitoyl-CoA + L-serine
3-dehydrosphinganine + CoA + CO2
show the reaction diagram
-
-
-
-
?
palmitoyl-CoA + L-serine
CoA + 3-dehydro-D-sphinganine + CO2
show the reaction diagram
S-(2-oxoheptadecyl)-CoA + L-serine
CoA + ?
show the reaction diagram
stearoyl-CoA + L-serine
(2S)-2-amino-1-hydroxyicosan-3-one + CoA + CO2
show the reaction diagram
-
-
-
-
?
stearoyl-CoA + L-serine
CoA + (2S)-2-amino-1-hydroxyicosan-3-one + CO2
show the reaction diagram
-
-
-
-
?
stearoyl-CoA + L-serine
CoA + 2-amino-1-hydroxyeicosan-3-one + CO2
show the reaction diagram
-
51% activity compared to that with palmitoyl-CoA
-
-
?
additional information
?
-
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
myristoyl-CoA + L-serine
CoA + 2-amino-1-hydroxy-cis-11-hexadecen-3-one + CO2
show the reaction diagram
-
SPT is the first and rate-limiting enzyme of sphingolipid biosynthesis
-
-
?
myristoyl-CoA + L-serine
CoA + ? + CO2
show the reaction diagram
-
recombinant SPTLC3 subunit in HEK-293 cells
-
-
?
palmitoyl-CoA + L-alanine
CoA + (2S)-2-aminooctadecan-3-one + CO2
show the reaction diagram
O15270
wild-type enzyme can metabolize L-alanine under certain conditions
-
-
?
palmitoyl-CoA + L-serine
CoA + 3-dehydro-D-sphinganine + CO2
show the reaction diagram
additional information
?
-
COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
pyridoxal 5'-phosphate
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
Mg2+
-
-
additional information
-
NaCl, LiCl, MgCl2, MnCl2 have no effect on activity
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
(2S,3R)-2-amino-12-hydroxy-2-hydroxymethyl-3-sulfooxy-octadecanoic acid
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IC50: 5.4 nM
(2S,3R)-2-amino-12-[(Z)-hydroxyimino]-2-hydroxymethyl-3-sulfooxy-octadecanoic acid
-
IC50: 30 nM
(2S,3R)-2-amino-3,12-dihydroxy-2-hydroxymethyl-octadecanoic acid
-
IC50: 3.2 nM
(2S,3R)-2-amino-3-hydroxy-2-hydroxymethyl-12-oxo-octadecanoic acid
-
IC50: 3.5 nM
(2S,3R)-2-amino-3-hydroxy-2-hydroxymethyl-12-oxo-octadecanoic acid methyl ester
-
IC50: 17 nM
3-hydroxypropionate
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competitive to L-serine
4-amino-3-isoxazolidone
-
D-cycloserine and L-cycloserine are inhibitors, L-cycloserine is 14-fold more effective than D-cycloserine
alpha-methyl-DL-serine
-
competitive to L-serine
beta-chloro-L-alanine
beta-Haloalanines
-
-
-
ceramide 1-phosphate
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from bovine brain, inhibits the enzyme and blocks apoptosis in alveolar macrophages, overview
cis-4-methylsphingosine
-
time- and concentration-dependent, causes drastic morphological changes of the cells in vivo
cis-5-methylsphingosine
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weak inhibition
cis-sphingosine
-
weak inhibition
cysteine
-
competitive to L-serine
L-alanine
-
inhibition of serine utilization
L-Cycloserine
lipoxamycin
mycotoxin fumonisin B1
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enzyme sensitivity to the inhibitor is increased by small subunit ssSPTa overexpression
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myriocin
myrocin
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-
O-phosphoserine
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competitive to L-serine
palmitoyl CoA
enzyme shows remarkable substrate inhibition at palmitoyl-CoA concentrations higher than 0.1 nM
palmitoyl-CoA
serine methylester
-
competitive to L-serine
sphingofungin B
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-
sulfamisterin
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antibiotic derived from Pycnidiella sp., IC50: 3 nM
thermozymocidin
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i.e. ISP-1; strong inhibition, reversible by sphingosine
threonine
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competitive to L-serine
trans-4-methylsphingosine
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-
trans-5-methylsphingosine
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weak inhibition
additional information
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
dithiothreitol
EDTA
-
required for enzyme activity
etoposide
fenretinide
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up-regulates enzyme activity in neuroblastoma cells
pioglitazone
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increases the enzyme activity in vitro and in vivo independent of standard or high-fat diet
retinoic acid
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up-regulates enzyme activity in embryonic carcinoma cell ine PCC7-Mz1
S-(2-oxoheptadecyl)-CoA
binds to the smSPT-external aldimine complex and enhances the exchange rate of the alpha-proton of L-serine by smSPT
small activating subunit of serine palmitoyltransferase
-
ssSPT, the small subunits of human serine palmitoyltransferase (hssSPTs) are glycoproteins and activate the catalytic hLCB1/hLCB2 heterodimer. Two isoforms exist, ssSPTa and ssSPTb, a single amino acid, residue 25, difference between ssSPTa and ssSPTb is responsible for the acyl-CoA preference of heterotrimers containing each isoform. the role of the small activating subunits of serine palmitoyltransferase, ssSPTs, is to increase SPT activity without compromising substrate specificity. Activity and acyl-CoA selectivity of the ssSPTs reside in the conserved core. Deletion of the N-terminal 10 amino acids of small activating subunit of serine palmitoyltransferase isoforms ssSPTa or ssSPTb has no effect on the ability of the proteins to activate hLCB1/hLCB2a heterodimers sufficiently to complement growth of yeast lacking endogenous serine palmitoyltransferase. The region responsible for the acyl-CoA selectivity of ssSPTa lays between residues Ser11 and Glu27, the acyl-CoA selectivity does not lie in the C-terminal region of ssSPTb, overview
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small subunits of serine palmitoyltransferase
-
additional information
-
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
9.6
L-alanine
-
C133W mutant protein, pH not specified in the publication, temperature not specified in the publication
0.1 - 10.6
L-serine
0.03
myristoyl-CoA
-
pH 8.0, 37C, recombinant SPTLC3
0.019 - 1.2
palmitoyl-CoA
0.0129
stearoyl-CoA
-
pH not specified in the publication, temperature not specified in the publication
additional information
L-alanine
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.005 - 1.54
L-serine
0.009 - 1.15
palmitoyl-CoA
0.083
stearoyl-CoA
Sphingomonas wittichii
-
pH not specified in the publication, temperature not specified in the publication
kcat/KM VALUE [1/mMs-1]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.002 - 3.437
L-serine
95
0.136 - 32.02
palmitoyl-CoA
128
6.416
stearoyl-CoA
Sphingomonas wittichii
-
pH not specified in the publication, temperature not specified in the publication
526
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
2 - 5
L-alanine
IC50 VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.0000054
(2S,3R)-2-amino-12-hydroxy-2-hydroxymethyl-3-sulfooxy-octadecanoic acid
Cricetulus griseus
-
IC50: 5.4 nM
0.00003
(2S,3R)-2-amino-12-[(Z)-hydroxyimino]-2-hydroxymethyl-3-sulfooxy-octadecanoic acid
Cricetulus griseus
-
IC50: 30 nM
0.0000032
(2S,3R)-2-amino-3,12-dihydroxy-2-hydroxymethyl-octadecanoic acid
Cricetulus griseus
-
IC50: 3.2 nM
0.0000035
(2S,3R)-2-amino-3-hydroxy-2-hydroxymethyl-12-oxo-octadecanoic acid
Cricetulus griseus
-
IC50: 3.5 nM
0.000017
(2S,3R)-2-amino-3-hydroxy-2-hydroxymethyl-12-oxo-octadecanoic acid methyl ester
Cricetulus griseus
-
IC50: 17 nM
0.000003
sulfamisterin
Cricetulus griseus
-
antibiotic derived from Pycnidiella sp., IC50: 3 nM
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
0.000018
-
HEK cell extract
0.000044
0.0000465
-
activity in microsomes
0.000063
-
-
0.00011
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substrate alanine, C133W mutant protein, pH not specified in the publication, temperature not specified in the publication
0.00027
-
-
0.000275
-
substrate serine, C133W mutant protein, pH not specified in the publication, temperature not specified in the publication
0.00135
-
substrate serine, wild type protein, pH not specified in the publication, temperature not specified in the publication
0.057 - 0.084
-
-
0.7
-
purified enzyme
additional information
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
7.5
O15269 and O15270
assay at
7.5 - 8
8.1
-
assay at
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6.7 - 8.6
-
about 50% of activity maximum at pH 6.7 and pH 8.6
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
30
-
assay at
36 - 40
-
-
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
-
embryonic cell line PCC7-Mz1
Manually annotated by BRENDA team
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the cell shows very low enzyme activity due to deficiency of subunit LCB1
Manually annotated by BRENDA team
-
strong overexpression of both SPT subunits
Manually annotated by BRENDA team
vascular; vascular
Manually annotated by BRENDA team
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protein expression of SPT in both psoriatic epidermis and non-lesional epidermis is investigated. Expression of SPT in psoriatic epidermis is significantly less than that of the non-lesional epidermis, which is inversely correlated with PASI score
Manually annotated by BRENDA team
except for ovarian epithelium; except for ovarian epithelium
Manually annotated by BRENDA team
-
proliferating, neonatal, dermal
Manually annotated by BRENDA team
-
age-dependent amount of enzyme activity
Manually annotated by BRENDA team
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isozyme SPT2
Manually annotated by BRENDA team
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increased expression of SPT in reactive astrocytes of the hippocampus after kainate injections is shown; increased SPT enzyme activity in reactive astrocytes of the hippocampus at 2 weeks post-kainate injection
Manually annotated by BRENDA team
-
strong overexpression of both SPT subunits
Manually annotated by BRENDA team
-
-
Manually annotated by BRENDA team
-
from patients with hereditary sensory neuropathy type I
Manually annotated by BRENDA team
-
strong overexpression of both SPT subunits
Manually annotated by BRENDA team
-
beta-cells
Manually annotated by BRENDA team
-
strong overexpression of both SPT subunits
Manually annotated by BRENDA team
-
small subunit ssSPTa transcripts are more enriched in all organs and over 400fold more abundant in pollen than small subunit ssSPTb transcripts
Manually annotated by BRENDA team
-
strong overexpression of both SPT subunits
Manually annotated by BRENDA team
-
strong overexpression of both SPT subunits
Manually annotated by BRENDA team
-
high SPTLC3 content
Manually annotated by BRENDA team
additional information
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
additional information
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
480000
-
holoenzyme, gel filtration; molecular mass of SPT complex determined by gel filtration
additional information
-
amino acid sequence determination
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
heterodimer
heterotrimer
-
SPT is a heterodimer of 2 highly-related subunits, LCB1 and LCB2, existing in two isozyme forms LCB2a and LCB2b, associated with a third small activating subunit, either protein ssSPTa and protein ssSPTb, the proteins have a conserved hydrophobic central domain, reside in the membrane and interact with both hLCB1 and hLCB2 subunits, overview,protein ssSPTa and protein ssSPTb are required for maximal enzyme activity. SPT subunit interaction analysis, overview
homodimer
monomer
-
single-chain enzyme, domain structure, overview
octamer
-
results show that functional SPT is not a dimer, but a higher organized complex, composed of three distinct subunits (SPTLC1, SPTLC2 and SPTLC3) with a molecular mass of 480 kDa (gel filtration). The stoichiometry of SPTLC2 and SPTLC3 in this complex is not to be fixed and is changed dynamically in dependence of the tissue specific SPTLC2 and SPTLC3 expression levels. A model of an octameric SPT structure is proposed. By Blue-native-PAGE experiments it is shown that all three SPT subunits (SPTLC1-3) are co-localized within a single SPT complex
oligomer
additional information
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
glycoprotein
-
the small activating subunits of serine palmitoyltransferase, ssSPTs, are glycoproteins and are part of the enzyme complex
no glycoprotein
-
-
phosphoprotein
additional information
-
carrier lipid during extraction required for activity
Crystallization/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
purified recombinant enzyme complexed with L-serine, sitting drop vapor diffusion method, 0.002 ml of protein solution containing 20 mg/ml SPT, 20 mM potasium phosphate, pH 7.7, and 10 mM pyridoxal 5'-phosphate, is mixed with 0.004 ml of reservoir solution containing 100 mM Tris-HCl; pH 8.5, 200 mM sodium acetate, 21.6% w/v PEG 4000, equilibration against 0.5 ml reservoir solution at 20C, 2 weeks, Schiff base formation between L-serine and pyridoxal 5'-phosphate in the crystal, X-ray diffraction structure determination and analysis at 2.3 A resolution, structural modelling
after incubation with L-cycloserine
-
crystal structure of the holo-form of SPT is determined to 1.3 A resolution. Enzyme is a symmetrical homodimer with two active sites and a monomeric tertiary structure consisting of three domains. PLP cofactor is bound covalently to Lys265 as an internal aldimine/Schiff base and the active site is composed of residues from both subunits, located at the bottom of a deep cleft
-
determination of the crystal structure of enzyme mutant K265A that diffract to 1.6 A resolution and contain a canonical dimer in the asymmetric unit. Crystallization of the wild-type SPT:PLP-myriocin aldimine complex is not possible, most likely due to aldimine degradation
-
purified His-tagged recombinant wild-type and mutant enzymes in complex with cofactor and substrates, wild-type enzyme from 10 mM Tris, pH 7.5, 150 mM NaCl, and 0.025 mM or 0.250 mM pyridoxal 5'-phosphate, different conditions for the mutants, overview. Mass spectroscopic structure analysis, overview
pH 7.5, 30% PEG monomethylether 2000
-
pH STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6.8 - 8.5
additional information
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
37
-
30 min, stable
50
-
above, precipitation of enzyme
STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
4C, Tris-HCl 20 mM, in sterile capped vials, 2 months without loss of activity
-
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
immobilized metal ion affinity chromatography
-
immobilized metal ion affinity chromatography (Ni2+), gel filtration
-
native and recombinant from E. coli, LCB1 and LCB2 co-immunoprecipitate
-
of affinity-peptide tagged SPT complex
-
purified as a water-soluble active homodimer
purified as water-soluble active homodimers
recombinant His-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromatography
O15269 and O15270
recombinant His-tagged wild-type and enzyme and mutants V246M and G385F from Escherichia coli strain BL21(DE3) by nickel affinity chromatography
-
recombinant His-tagged wild-type and mutant enzymes from Escherichia coli strain BL21(DE3) by nickel affinity chromatography and gel filtration
-
recombinant SPT from Escherichia coli strain BL21(DE3)
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
; hLCB1 and hLCB2
-
expressed as a His-tagged fusion protein in Escherichia coli; individual overexpression of subunits SPTLC1, SPTLC2, and SPTLC3, fused to a C-terminal V5-his tag, in HEK-293 cells
-
expressed in Escherichia coli
expressed in HEK293T cells
expressed in yeast and mammalian cells, a triple fusion protein of the three subunits expressed in yeast and mammalian cells
-
expression in Escherichia coli
-
expression in HEK 293 cells; expression in HEK 293 cells
expression of FLAG-tagged LCB1 in the deficient mutant LY-B, overproduction of LCB2 requires co-overproduction of LCB1
-
expression of HA-tagged C133W mutant SPTLC1 in CHO-K1 cells and in transgenic mice, the expression dominantly inhibits SPT activity
-
expression of mLCB1 and LCB2 as glutathione-S-transferase fusion protein in Escherichia coli DH5alpha; in vitro transcription and translation of mLCB2; overexpression of mLCB1 and mLCB2 in human embryonic kidney cells, independently and in coexpression with mLCB1
-
expression of wild-type and mutant enzymes in HEK-293 cells. The overexpression of wild-type subunit SPTLC1 does not increase SPT enzyme activity compared with controls (empty vector), whereas overexpressing subunit SPTLC2 results in a 2fold increase in enzyme activity
O15269 and O15270
expression of wild-type and mutant smalll subunits isoforms of serine palmitoyltransferase in yeast microsomes
-
gene ehv050, DNA and amino acid sequence determination and analysis, functional expression of HA-tagged enzyme in Saccharmoyces cerevisiae endoplasmic reticulum, when the two subunits of the yeast SPT are thus expressed, the single-chain chimera is functional and displays a different substrate preference, independently expressed domains of the viral SPT reassemble into an active protein, overview
-
genes LCB1 and LCB2, overexpression
-
His-tagged protein expressed in Escherichia coli BL21(DE3)
LCB2 cloning by ESTs, DNA and amino acid sequence determination and analysis, LCB2 expression analysis and phylogenetic analysis, overexpression of subunit LCB2 in Saccharomyces cerevisiae strain W303, transient overexpression in Nicotiana tabacum leaves via Agrobacterium tumefaciens strain GV2260-mediated transfection. BcLCB2 encodes a bona fide LCB2 subunit and the SPT activity in yeast results from co-expression of the BcLCB1 and BcLCB2 subunits
overexpression in Escherichia coli BL21 (DE3) pLysS, DNA sequence determination
-
overexpression of SPTLC3 in HEK-293 cells leads to the formation of two new sphingoid base metabolites, namely C16-sphinganine and C16-sphingosine. SPTLC3-expressing cells have higher in vitro SPT activities with lauryl- and myristoyl-CoA than SPTLC2-expressing cells, and SPTLC3 mRNA expression levels correlate closely with the C16-sphinganine synthesis rates in various human and murine cell lines. Quantitative reverse transcription--PCR analysis
-
overexpression of subunit SPTLC3 in HEK-293 cells, leading to an 2-3fold increased SPT activity, expression of subunit SPTLC3 in Hep-G2 cells and human trophoblast cells, quantitative expression analysis of SPTLC3
-
recombinant expression of FLAG-tagged enzyme subunit LCB1 and of Myc-tagged enzyme subunit LCB2 in Saccharomyces cerevisiae microsomes. Expressing the Arabidopsis thaliana LCB1/LCB2 heterodimers has very low SPT activity, whereas coexpression of Arabidopsis thaliana ssSPTs, ssSPTa and ssSPTb, derived 56-amino acid polypeptides in a Saccharomyces cerevisiae enzyme SPT null mutant and stimulate SPT enzyme activity of the Arabidopsis LCB1/LCB2 heterodimer by over 100fold through physical interaction with LCB1/LCB2. Transient Agrobacterium tumefaciens-mediated transformation of Nicotiana benthaminana with YFP-labeled small subunits of serine palmitoyltransferase, ssSPTa and ssSPTb
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recombinant expression of His-tagged wild-type and mutant enzymes in Escherichia coli strain BL21(DE3)
-
recombinant expression of ssSPTa, tagged with EGFP at its N-terminus, in HEK-293 cells
recombinant expression of subunit LCB2a mutants in HEK293 cells, recombinant His-tagged enzyme expression in Escherichia coli strain BL21(DE3). Recombinant expression of wild-type hLCB1/hLCB2a subunits in Saccharomyces cerevisiae microsomes in the absence of either small subunit, the enzyme shows very low activity. Coexpression of each of the three subunit hLCB2a mutants, V359M, G382V, and I504F, along with subunit hLCB1 results in low activity, with G382V barely detectable above background
O15269 and O15270
recombinant stable expression of mutant and wild-type SPTLC2 subunit in HEK293 cells
RT-PCR from mRNA of Molt-4 cells; RT-PCR from mRNA of Molt-4 cells
SPT expression in Escherichia coli strain BL21(DE3)
SPT1 and SPT2 real-time PCR expression analysis
-
ssSPTa and ssSPTb, DNA and amino acid sequence determination and analysis. Transient functional overexpression of ssSPTb-containing isozymes in CHO LyB cells increasing C20-long-chain bases. Expression of the human enzyme subunits in the lcb1DELTAlcb2DELTA double mutant Saccharomyces cerevisiae cells in various combinations constituting enzyme activity, overview. Expression in CHO LyB cells lacking endogenous SPT activity
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stable expression of LCB1 and R246G mutant SPT in enzyme-deficient hamster LY-B ovary cells restores SPT activity, DNA and amino acid sequence determination and analysis of the recombinantly expressed R246G mutant enzyme
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subunit 2 expressed in HEK293 cells
O15270 and Q9NUV7
subunit LCB1, DNA and amino acid sequence determination and analysis; subunit LCB2
subunits LCB1 and LCB2 expression analysis; subunits LCB1 and LCB2 expression analysis
subunits LCB1 and LCB2, phylogenetic tree, expression of Arabidopsis thaliana subunit LCB1 rescues the sphingolipid long-chain base auxotrophy of Saccharomyces cerevisiae SPT mutants when coexpressed with Arabidopsis thaliana LCB2
EXPRESSION
ORGANISM
UNIPROT
LITERATURE
imatinib does not affect SPTLC1 expression
LCB2 is upregulated during hypersensitive cell death nduced by the Phytophthora boehmeriae elicitor PB90
lithospermic acid and two derivative esters, 9''-methyl lithospermate and 9'-methyl lithospermate,isolated from roots of Lithospermum erythrorhizon, significantly increase SPT expression in the relative quantity of SPT1 mRNA as well as SPT2 mRNA, by 21-59%, overview
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Pseudomonas cichorii infection induces expression of subunit LCB2; Pseudomonas cichorii infection induces expression of subunit LCB2
short-term Mg deficiency results in an upregulation of major subunit 1 and 2 in cardiovascular tissues
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ENGINEERING
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
K311E
construction of mutant BcLCB2DELTAK311E that shows reduced activity compared to the wild-type enzyme
C133W
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site-directed mutagenesis, mutation of subunit SPTLC1, construction of transgenic mouse lines that ubiquitously overexpress either wild-type SPTLC1WT or mutant SPTLC1C133W in brain and liver microsomes, SPTLC1C133W mice develop age-dependent weight loss and mild sensory and motor impairments, fed SPTLC1C133W mice lose large myelinated axons in the ventral root of the spinal cord and demonstrate myelin thinning, there is also a loss of large myelinated axons in the dorsal roots, although the unmyelinated fibers are preserved, in the dorsal root ganglia, IB4 staining is diminished, whereas expression of the injury-induced transcription factor ATF3 is increased, phenotype, detailed overview
R246G
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naturally occuring mutation, comparison of de novo sphingolipid biosynthesis in wild-type LY-B cells and in LY-B cells expressing long-chain base subunit 1, LCB1, LC-ESI-MS/MS mass spectrometric analysis, overview
A182P
O15269 and O15270
naturally occuring mutation in subunit LCB1 involved in hereditary sensory and autonomic neuropathy type I disease, and associated with increased synthesis of neurotoxic 1-deoxy-sphingolipids
A352V
subunit 1, naturally occuring mutation, reduced activity in cells expressing mutant protein
C133V
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reduced activity
G246R
O15269 and O15270
expression of mutant G246R in in LYB cells, which is the same mutation that is present in LYB endogenously, neither restores canonical activity nor results in the formation of 1-deoxy-sphingolipids
I505Y
O15269 and O15270
naturally occuring mutation in subunit LCB2 involved in hereditary sensory and autonomic neuropathy type I disease, and associated with increased synthesis of neurotoxic 1-deoxy-sphingolipids. The mutant shows an increased canonical activity and increased formation of C20 sphingoid base, associated with an exceptionally severe HSAN1 phenotype, where C20 sphingosine levels are also confirmed in plasma of patients
S331Y
O15269 and O15270
naturally occuring mutation in subunit LCB1 involved in hereditary sensory and autonomic neuropathy type I disease, and associated with increased synthesis of neurotoxic 1-deoxy-sphingolipids.The mutant shows an increased canonical activity and increased formation of C20 sphingoid base, associated with an exceptionally severe HSAN1 phenotype, where C20 sphingosine levels are also confirmed in plasma of patients
S384A
a subunit SPTLC2 phosphorylation site mutant, the mutation has no effect n enzyme activity
S384D
a subunit SPTLC2 phosphorylation site mutant, the mutation is associated with increased 1-deoxysphingolipids formation
S384E
a subunit SPTLC2 phosphorylation site mutant, the mutation is not associated with increased 1-deoxysphingolipids formation
V144D
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reduced activity
Y164F
site-directed mutagenesis, the mutant shows increased serine palmitoyltransferase activity compared to the wild-type enzyme. The Y164F mutation also promotes the remodeling of cellular sphingolipid content, thereby sensitizing K562 cells to apoptosis. the Y164F mutation affects SPTLC1 subcellular localization, induction of apoptosis, and sell sensitivity to imatinib
Y387F
a subunit SPTLC2 phosphorylation site mutant, the mutation has no effect n enzyme activity
Y387F/S384A
a subunit SPTLC2 phosphorylation sites mutant, the mutation has no effect n enzyme activity
DELTA2-9SPT
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mutant bearing deleted residues from Ala2 to Pro9: Km values are not significantly changed compared to wild-type
G268V
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site-directed mutagenesis, the mutation perturbs the pyridoxal 5'-phosphate cofactor binding and reduces the affinity for both substrates, inactive mutant, the protein is expressed in a completely insoluble form, structure homology modeling of the mutant enzyme using the Sp SPT PLP-L-serine external aldimine structure, PDB ID 2W8J
G385F
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site-directed mutagenesis, the mutation perturbs the pyridoxal 5'-phosphate cofactor binding, reduces the affinity for both substrates, decreases the enzyme activity, soluble protein
H159A
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site-directed mutagenesis, the mutant shows reduced activity and still forms the pyridoxal 5'-phosphate-L-serine-aldimine reaction intermediate
H159W
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site-directed mutagenesis, inactive mutant
H159Y
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site-directed mutagenesis, inactive mutant
K265A
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site-directed mutagenesis, the mutant is unable to bind pyridoxal 5'-phosphate, structure of a SPT K265A:PLP-myriocin external aldimine complex, molecular replacement study
N100C
site-directed mutagenesis, the mutation mimics the wild-type human enzyme and is fully active, crystal structure analysis
N100W
site-directed mutagenesis, the mutation mimics the mutation in the human enzyme causing hereditary sensory autonomic neuropathy type 1, the mutant shows reduced activity compared to the wild-type enzyme. The mutation affects the chemistry of the pyridoxal 5'-phosphate, crystal structure analysis
N100Y
site-directed mutagenesis, N100Y is less able to stabilize a quinonoid intermediate, the mutation mimics the mutation in the human enzyme causing hereditary sensory autonomic neuropathy type 1, the mutant shows reduced activity compared to the wild-type enzyme. The mutation affects the chemistry of the pyridoxal 5'-phosphate. The L-Ser external aldimine structure N100Y reveals significant differences that hinder the movement of a catalytically important Arg378 residue into the active site, crystal structure analysis
R378A
site-directed mutagenesis, crystal structure analysis, the mutant is less able to stabilize a quinonoid intermediate
V246M
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site-directed mutagenesis, the mutation perturbs the pyridoxal 5'-phosphate cofactor binding, reduces the affinity for both substrates, decreases the enzyme activity, soluble protein
N100C
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site-directed mutagenesis, the mutation mimics the wild-type human enzyme and is fully active, crystal structure analysis
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N100W
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site-directed mutagenesis, the mutation mimics the mutation in the human enzyme causing hereditary sensory autonomic neuropathy type 1, the mutant shows reduced activity compared to the wild-type enzyme. The mutation affects the chemistry of the pyridoxal 5'-phosphate, crystal structure analysis
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N100Y
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site-directed mutagenesis, N100Y is less able to stabilize a quinonoid intermediate, the mutation mimics the mutation in the human enzyme causing hereditary sensory autonomic neuropathy type 1, the mutant shows reduced activity compared to the wild-type enzyme. The mutation affects the chemistry of the pyridoxal 5'-phosphate. The L-Ser external aldimine structure N100Y reveals significant differences that hinder the movement of a catalytically important Arg378 residue into the active site, crystal structure analysis
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R378A
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site-directed mutagenesis, crystal structure analysis, the mutant is less able to stabilize a quinonoid intermediate
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R378N
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site-directed mutagenesis, crystal structure analysis
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R370A
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strictly conserved in all prokaryotic enzymes and the Icb2 subunit of eukaryotic enzymes, no catalytic activity
R370K
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strictly conserved in all prokaryotic enzymes and the Icb2 subunit of eukaryotic enzymes, 3% catalytic activity of wild type enzyme
additional information