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IDO1

Function

Catalyzes the first and rate limiting step of the catabolism of the essential amino acid tryptophan along the kynurenine pathway. Involved in the peripheral immune tolerance, contributing to maintain homeostasis by preventing autoimmunity or immunopathology that would result from uncontrolled and overreacting immune responses. Tryptophan shortage inhibits T lymphocytes division and accumulation of tryptophan catabolites induces T-cell apoptosis and differentiation of regulatory T-cells. Acts as a suppressor of anti-tumor immunity (PubMed:25691885). Limits the growth of intracellular pathogens by depriving tryptophan. Protects the fetus from maternal immune rejection (Ref. 3).

Sequence similarities

Belongs to the indoleamine 2,3-dioxygenase family.

Tissue specificity

Highly expressed in epididymis, duodemum, jejunum, ileum, colon and spleen (PubMed:19741271). Highly expressed in epididymis, prostate, duodemum, jejunum, ileum, colon and spleen, not detected in the liver (at protein level) (PubMed:19741271). Expressed in tumors only upon exposure to IFN gamma (PubMed:25691885). Constitutively expressed in placenta in trophoblast cells (PubMed:15063630). Expression is restricted to perinuclear regions of primary trophoblast giant cells (TGCs) of fetal origin at mid-gestation (E10.5). After placentation (E14), no IDO expression was detected at the maternal-fetal interface (PubMed:15063630).

Cellular localization

  • Cytoplasm
  • Cytosol

Alternative names

  • IDO-1
  • Indo
  • Ido
  • Ido1

Target type

Proteins

Primary research area

Immuno-oncology

Other research areas

  • Immunology & Infectious Disease
  • Oncology

Molecular weight

45641Da