Seroatlas · Human Serome Atlas

IMPA1

Inositol monophosphatase 1

Also known as: IMPA, IMPA1_HUMAN

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
P29218
Gene
IMPA1
Ensembl
ENSG00000133731
Chromosome
8
Canonical length
277 aa
Protein class
Disease related genes, Enzymes, Human disease related genes, Metabolic proteins, Potential drug targets, Predicted intracellular proteins
Subcellular location
Vesicles,Actin filaments
Quaternary structure
Homodimer

OverviewNCBI Gene

This gene encodes an enzyme 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, Dec 2014]

Canonical amino-acid sequenceUniProt

277 residues, UniProt reviewed canonical sequence.

>P29218|IMPA1
     1  MADPWQECMD YAVTLARQAG EVVCEAIKNE MNVMLKSSPV DLVTATDQKV EKMLISSIKE
    61  KYPSHSFIGE ESVAAGEKSI LTDNPTWIID PIDGTTNFVH RFPFVAVSIG FAVNKKIEFG
   121  VVYSCVEGKM YTARKGKGAF CNGQKLQVSQ QEDITKSLLV TELGSSRTPE TVRMVLSNME
   181  KLFCIPVHGI RSVGTAAVNM CLVATGGADA YYEMGIHCWD VAGAGIIVTE AGGVLMDVTG
   241  GPFDLMSRRV IAANNRILAE RIAKEIQVIP LQRDDED

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against IMPA1 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.23
Highest tissue expression
36 nTPM

Expression across tissuesHPA

Tissue

  • testis: 36 nTPM
  • tongue: 27 nTPM
  • rectum: 27 nTPM
  • bone marrow: 26 nTPM
  • colon: 25 nTPM
  • liver: 25 nTPM

Single-cell type

  • esophageal apical cells: 102 nCPM
  • late primary spermatocytes: 97 nCPM
  • pituicytes/fscs: 82 nCPM
  • colonocytes: 78 nCPM
  • megakaryocytes: 74 nCPM
  • sertoli cells: 73 nCPM

Immune cell

  • basophil: 51 nTPM
  • eosinophil: 30 nTPM
  • NK-cell: 21 nTPM
  • memory B-cell: 20 nTPM
  • T-reg: 20 nTPM
  • MAIT T-cell: 17 nTPM

Brain region

  • cerebral cortex: 36 nTPM
  • choroid plexus: 35 nTPM
  • white matter: 35 nTPM
  • midbrain: 32 nTPM
  • medulla oblongata: 31 nTPM
  • hypothalamus: 31 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about IMPA1.

Disease | AllUniProt

Conditions IMPA1 is implicated in, by any mechanism.

  • Intellectual developmental disorder, autosomal recessive 59 (MRT59) MIM:617323

Disease | GeneticClinVar

2 pathogenic / likely-pathogenic of 67 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Intellectual disability, autosomal recessive 59

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
0.88
gnomAD pLI
0
gnomAD missense Z
0.44
DepMap mean gene effect
0.05
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 11% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of IMPA1 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads IMPA1 as an antibody target. Whether an autoantibody or antibody against IMPA1 could matter depends on whether native IMPA1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

IMPA1 is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label IMPA1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/IMPA1. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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