Seroatlas · Human Serome Atlas

IDO1

Indoleamine 2,3-dioxygenase 1

Also known as: I23O1_HUMAN, IDO, INDO

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

Protein identityUniProt · HPA

UniProt accession
P14902
Gene
IDO1
Ensembl
ENSG00000131203
Chromosome
8
Canonical length
403 aa
Protein class
Cancer-related genes, Enzymes, Metabolic proteins, Predicted intracellular proteins
Subcellular location
Microtubules,Primary cilium

OverviewNCBI Gene

This gene encodes indoleamine 2,3-dioxygenase (IDO) - a heme enzyme that catalyzes the first and rate-limiting step in tryptophan catabolism to N-formyl-kynurenine. This enzyme acts on multiple tryptophan substrates including D-tryptophan, L-tryptophan, 5-hydroxy-tryptophan, tryptamine, and serotonin. This enzyme is thought to play a role in a variety of pathophysiological processes such as antimicrobial and antitumor defense, neuropathology, immunoregulation, and antioxidant activity. Through its expression in dendritic cells, monocytes, and macrophages this enzyme modulates T-cell behavior by its peri-cellular catabolization of the essential amino acid tryptophan.[provided by RefSeq, Feb 2011]

Canonical amino-acid sequenceUniProt

403 residues, UniProt reviewed canonical sequence.

>P14902|IDO1
     1  MAHAMENSWT ISKEYHIDEE VGFALPNPQE NLPDFYNDWM FIAKHLPDLI ESGQLRERVE
    61  KLNMLSIDHL TDHKSQRLAR LVLGCITMAY VWGKGHGDVR KVLPRNIAVP YCQLSKKLEL
   121  PPILVYADCV LANWKKKDPN KPLTYENMDV LFSFRDGDCS KGFFLVSLLV EIAAASAIKV
   181  IPTVFKAMQM QERDTLLKAL LEIASCLEKA LQVFHQIHDH VNPKAFFSVL RIYLSGWKGN
   241  PQLSDGLVYE GFWEDPKEFA GGSAGQSSVF QCFDVLLGIQ QTAGGGHAAQ FLQDMRRYMP
   301  PAHRNFLCSL ESNPSVREFV LSKGDAGLRE AYDACVKALV SLRSYHLQIV TKYILIPASQ
   361  QPKENKTSED PSKLEAKGTG GTDLMNFLKT VRSTTEKSLL KEG

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against IDO1 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
104 nTPM

Expression across tissuesHPA

Tissue

  • placenta: 104 nTPM
  • lymph node: 55 nTPM
  • appendix: 38 nTPM
  • tonsil: 30 nTPM
  • thymus: 29 nTPM
  • lung: 25 nTPM

Single-cell type

  • endometrial glandular cells: 365 nCPM
  • endometrial luminal cells: 315 nCPM
  • cdc: 110 nCPM
  • epididymal basal cells: 76 nCPM
  • endometrial secretory cells: 67 nCPM
  • endometrial ciliated cells: 47 nCPM

Immune cell

  • eosinophil: 466 nTPM
  • basophil: 32 nTPM
  • myeloid DC: 27 nTPM
  • neutrophil: 5.2 nTPM
  • intermediate monocyte: 1.5 nTPM
  • classical monocyte: 1.4 nTPM

Brain region

  • choroid plexus: 4.5 nTPM
  • hypothalamus: 4.2 nTPM
  • cerebral cortex: 4.1 nTPM
  • medulla oblongata: 3.9 nTPM
  • white matter: 3.7 nTPM
  • basal ganglia: 3.6 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about IDO1.

Disease | ImmuneIEDB

Conditions an epitope on IDO1 was assayed in.

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)
1.08
gnomAD pLI
0
gnomAD missense Z
-0.4
DepMap mean gene effect
0.03
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads IDO1 as an antibody target. Whether an autoantibody or antibody against IDO1 could matter depends on whether native IDO1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

IDO1 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 IDO1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/IDO1. 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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