Gene/Proteome Database (LMPD)

LMPD ID
LMP001572
Gene ID
3612
Species
Homo sapiens (Human)
Gene Name
inositol(myo)-1(or 4)-monophosphatase 1
Gene Symbol
IMPA1
Synonyms
IMP; IMPA
Alternate Names
inositol monophosphatase 1; IMP 1; IMPase 1; inositol-1(or 4)-monophosphatase 1; D-galactose 1-phosphate phosphatase; lithium-sensitive myo-inositol monophosphatase A1
Chromosome
8
Map Location
8q21.13-q21.3
EC Number
3.1.3.25
Summary
This gene encodes an enyzme that dephosphorylates myo-inositol monophosphate to generate free myo-inositol, a precursor of phosphatidylinositol, and is therefore an important modulator of intracellular signal transduction via the production of the second messengers myoinositol 1,4,5-trisphosphate and diacylglycerol. This enzyme can also use myo-inositol-1,3-diphosphate, myo-inositol-1,4-diphosphate, scyllo-inositol-phosphate, glucose-1-phosphate, glucose-6-phosphate, fructose-1-phosphate, beta-glycerophosphate, and 2'-AMP as substrates. This enzyme shows magnesium-dependent phosphatase activity and is inhibited by therapeutic concentrations of lithium. Inhibition of inositol monophosphate hydroylosis and subsequent depletion of inositol for phosphatidylinositol synthesis may explain the anti-manic and anti-depressive effects of lithium administered to treat bipolar disorder. Alternative splicing results in multiple transcript variants encoding distinct isoforms. A pseudogene of this gene is also present on chromosome 8q21.13. [provided by RefSeq, Nov 2009]
Orthologs
View orthologs and multiple alignments for IMPA1

Proteins

inositol monophosphatase 1 isoform 1
Refseq ID NP_005527
Protein GI 5031789
UniProt ID P29218
mRNA ID NM_005536
Length 277
RefSeq Status REVIEWED
MADPWQECMDYAVTLARQAGEVVCEAIKNEMNVMLKSSPVDLVTATDQKVEKMLISSIKEKYPSHSFIGEESVAAGEKSILTDNPTWIIDPIDGTTNFVHRFPFVAVSIGFAVNKKIEFGVVYSCVEGKMYTARKGKGAFCNGQKLQVSQQEDITKSLLVTELGSSRTPETVRMVLSNMEKLFCIPVHGIRSVGTAAVNMCLVATGGADAYYEMGIHCWDVAGAGIIVTEAGGVLMDVTGGPFDLMSRRVIAANNRILAERIAKEIQVIPLQRDDED
inositol monophosphatase 1 isoform 2
Refseq ID NP_001138350
Protein GI 221625487
UniProt ID P29218
mRNA ID NM_001144878
Length 336
RefSeq Status REVIEWED
MGQRPGPVLPAVAVLGQVAKRKVAWLLRWKAVTRTETAGNSSGVYGFGKMKIFVKYFQKMADPWQECMDYAVTLARQAGEVVCEAIKNEMNVMLKSSPVDLVTATDQKVEKMLISSIKEKYPSHSFIGEESVAAGEKSILTDNPTWIIDPIDGTTNFVHRFPFVAVSIGFAVNKKIEFGVVYSCVEGKMYTARKGKGAFCNGQKLQVSQQEDITKSLLVTELGSSRTPETVRMVLSNMEKLFCIPVHGIRSVGTAAVNMCLVATGGADAYYEMGIHCWDVAGAGIIVTEAGGVLMDVTGGPFDLMSRRVIAANNRILAERIAKEIQVIPLQRDDED
inositol monophosphatase 1 isoform 3
Refseq ID NP_001138351
Protein GI 221625507
UniProt ID P29218
mRNA ID NM_001144879
Length 198
RefSeq Status REVIEWED
MADPWQECMDYAVTLARQAGEVVCEAIKNEMNVMLKSSPVDLVTATDQKVEKMLISSIKEKYPSHSFIGEESVAAGEKSILTDNPTWIIDPIDGTTNFVHRFPFVAVSIGFAVNKKIEFGVVYSCVEGKMYTARKGKGAFCNGQKLQVSQQEGSGVLEQQLLICALWQLAEQMHIMKWEFTAGMLQELALLLLKLVAC

Gene Information

Entrez Gene ID
3612
Gene Name
inositol(myo)-1(or 4)-monophosphatase 1
Gene Symbol
IMPA1
Species
Homo sapiens

Gene Ontology (GO Annotations)

GO ID Source Type Description
GO:0005737 IDA:UniProtKB C cytoplasm
GO:0005829 TAS:Reactome C cytosol
GO:0070062 IDA:UniProt C extracellular vesicular exosome
GO:0042802 IPI:IntAct F identical protein binding
GO:0008934 IMP:UniProtKB F inositol monophosphate 1-phosphatase activity
GO:0052832 IEA:UniProtKB-EC F inositol monophosphate 3-phosphatase activity
GO:0052833 IEA:UniProtKB-EC F inositol monophosphate 4-phosphatase activity
GO:0052834 IDA:UniProtKB F inositol monophosphate phosphatase activity
GO:0031403 IDA:UniProtKB F lithium ion binding
GO:0000287 IDA:UniProtKB F magnesium ion binding
GO:0030145 IDA:UniProtKB F manganese ion binding
GO:0042803 IDA:MGI F protein homodimerization activity
GO:0006021 IEA:UniProtKB-UniPathway P inositol biosynthetic process
GO:0046855 IDA:UniProtKB P inositol phosphate dephosphorylation
GO:0043647 TAS:Reactome P inositol phosphate metabolic process
GO:0006796 IMP:UniProtKB P phosphate-containing compound metabolic process
GO:0006661 IMP:UniProtKB P phosphatidylinositol biosynthetic process
GO:0046854 IEA:InterPro P phosphatidylinositol phosphorylation
GO:0007165 IMP:UniProtKB P signal transduction
GO:0044281 TAS:Reactome P small molecule metabolic process

BIOCYC Pathway Links

BIOCYC Pathway ID Description
PWY-6363 D-myo-inositol (1,4,5)-trisphosphate degradation

REACTOME Pathway Links

REACTOME Pathway ID Description
REACT_150352 Synthesis of IP2, IP, and Ins in the cytosol

Domain Information

InterPro Annotations

Accession Description
IPR020552 Inositol monophosphatase, Lithium-sensitive
IPR020550 Inositol monophosphatase, conserved site
IPR020583 Inositol monophosphatase, metal-binding site
IPR000760 Inositol_monophosphatase

UniProt Annotations

Entry Information

Gene Name
inositol(myo)-1(or 4)-monophosphatase 1
Protein Entry
IMPA1_HUMAN
UniProt ID
P29218
Species
Human

Comments

Comment Type Description
Alternative Products Event=Alternative splicing; Named isoforms=3; Name=1; IsoId=P29218-1; Sequence=Displayed; Name=2; IsoId=P29218-2; Sequence=VSP_042521; Note=No experimental confirmation available.; Name=3; IsoId=P29218-3; Sequence=VSP_046308; Note=No experimental confirmation available. Ref.4 (BAH13340) sequence is in conflict in position: 17:Q->R. ;
Biophysicochemical Properties Kinetic parameters: KM=42 uM for D-myo-inositol 1-phosphate ; KM=62 uM for L-myo-inositol 1-phosphate ; pH dependence: Optimum pH is 7.0-7.5. ;
Catalytic Activity Alpha-D-galactose 1-phosphate + H(2)O = D- galactose + phosphate.
Catalytic Activity Myo-inositol phosphate + H(2)O = myo-inositol + phosphate. {ECO
Cofactor Name=Mg(2+); Xref=ChEBI
Enzyme Regulation Activity with myo-inositol monophosphate and D- galactose 1-phosphate is inhibited by Li(+), Ca(2+) and Mn(2+), but also by Mg(2+) at concentrations above 3 mM. {ECO
Function Responsible for the provision of inositol required for synthesis of phosphatidylinositol and polyphosphoinositides and has been implicated as the pharmacological target for lithium action in brain. Has broad substrate specificity and can use myo- inositol monophosphates, myo-inositol 1,3-diphosphate, myo- inositol 1,4-diphosphate, scyllo-inositol-phosphate, D-galactose 1-phosphate, glucose-1-phosphate, glucose-6-phosphate, fructose-1- phosphate, beta-glycerophosphate, and 2'-AMP as substrates. {ECO
Interaction Self; NbExp=3; IntAct=EBI-752410, EBI-752410;
Pathway Polyol metabolism; myo-inositol biosynthesis; myo- inositol from D-glucose 6-phosphate: step 2/2.
Similarity Belongs to the inositol monophosphatase family.
Subcellular Location Cytoplasm .
Subunit Homodimer. {ECO

Identical and Related Proteins

Unique RefSeq proteins for LMP001572 (as displayed in Record Overview)

Protein GI Database Accession Length Protein Name
5031789 RefSeq NP_005527 277 inositol monophosphatase 1 isoform 1
221625487 RefSeq NP_001138350 336 inositol monophosphatase 1 isoform 2
221625507 RefSeq NP_001138351 198 inositol monophosphatase 1 isoform 3

Identical Sequences to LMP001572 proteins

Reference Database Accession Length Protein Name
GI:221625507 DBBJ BAG59595.1 198 unnamed protein product [Homo sapiens]
GI:5031789 GenBank AEN34310.1 277 Sequence 238 from patent US 7998689
GI:5031789 GenBank AHD72909.1 277 Sequence 9977 from patent US 8586006
GI:5031789 GenBank AIC49059.1 277 IMPA1, partial [synthetic construct]
GI:5031789 GenBank AIC63061.1 277 IMPA1, partial [synthetic construct]
GI:5031789 PDB 4AS4 277 Chain A, Structure Of Human Inositol Monophosphatase 1
GI:5031789 PDB 4AS4 277 Chain B, Structure Of Human Inositol Monophosphatase 1
GI:221625507 RefSeq XP_003311834.1 198 PREDICTED: inositol monophosphatase 1 isoform X5 [Pan troglodytes]
GI:221625507 RefSeq XP_008954906.1 198 PREDICTED: inositol monophosphatase 1 isoform X5 [Pan paniscus]

Related Sequences to LMP001572 proteins

Reference Database Accession Length Protein Name
GI:5031789 DBBJ BAH13340.1 336 unnamed protein product [Homo sapiens]
GI:221625487 DBBJ BAH13340.1 336 unnamed protein product [Homo sapiens]
GI:5031789 RefSeq NP_001138350.1 336 inositol monophosphatase 1 isoform 2 [Homo sapiens]
GI:221625487 RefSeq XP_001092596.2 331 PREDICTED: inositol monophosphatase 1 isoform 1 [Macaca mulatta]
GI:221625487 RefSeq XP_003269541.1 336 PREDICTED: inositol monophosphatase 1-like isoform 2 [Nomascus leucogenys]
GI:221625507 RefSeq XP_003269542.1 198 PREDICTED: inositol monophosphatase 1-like isoform 3 [Nomascus leucogenys]
GI:5031789 RefSeq XP_003311832.1 277 PREDICTED: inositol monophosphatase 1 isoform X2 [Pan troglodytes]
GI:221625487 RefSeq XP_003311833.1 336 PREDICTED: inositol monophosphatase 1 isoform X1 [Pan troglodytes]
GI:5031789 RefSeq XP_003311833.1 336 PREDICTED: inositol monophosphatase 1 isoform X1 [Pan troglodytes]
GI:221625487 RefSeq XP_003831311.1 336 PREDICTED: inositol monophosphatase 1 isoform X1 [Pan paniscus]
GI:5031789 RefSeq XP_003831311.1 336 PREDICTED: inositol monophosphatase 1 isoform X1 [Pan paniscus]
GI:221625507 RefSeq XP_006880558.1 198 PREDICTED: inositol monophosphatase 1 isoform X2 [Elephantulus edwardii]
GI:221625507 RefSeq XP_006830876.1 198 PREDICTED: inositol monophosphatase 1 isoform X1 [Chrysochloris asiatica]
GI:221625487 RefSeq XP_007999166.1 331 PREDICTED: LOW QUALITY PROTEIN: inositol monophosphatase 1 [Chlorocebus sabaeus]
GI:221625507 RefSeq XP_008954905.1 257 PREDICTED: inositol monophosphatase 1 isoform X4 [Pan paniscus]
GI:5031789 RefSeq XP_009453832.1 277 PREDICTED: inositol monophosphatase 1 isoform X2 [Pan troglodytes]
GI:221625507 RefSeq XP_009453835.1 257 PREDICTED: inositol monophosphatase 1 isoform X4 [Pan troglodytes]
GI:221625507 RefSeq XP_010349192.1 198 PREDICTED: inositol monophosphatase 1 isoform X2 [Saimiri boliviensis boliviensis]