Indoleamine 2,3-dioxygenase 2

Indoleamine 2,3-dioxygenase 2 (IDO2) is a protein that in humans is encoded by the IDO2 gene.^[5]

IDO2
Identifiers
Aliases	IDO2, INDOL1, indoleamine 2,3-dioxygenase 2
External IDs	OMIM: 612129; MGI: 2142489; HomoloGene: 48830; GeneCards: IDO2; OMA:IDO2 - orthologs
Gene location (Human) Chr. Chromosome 8 (human)[1] Band 8p11.21 Start 39,934,614 bp[1] End 40,016,392 bp[1]
Gene location (Mouse) Chr. Chromosome 8 (mouse)[2] Band 8|8 A2 Start 25,021,908 bp[2] End 25,066,349 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in right lobe of liver testicle placenta left lobe of thyroid gland right lobe of thyroid gland appendix gonad endometrium lymph node right testis Top expressed in right kidney proximal tubule zygote secondary oocyte liver embryo embryo left lobe of liver tail of embryo epiblast More reference expression data BioGPS n/a
Gene ontology Molecular function oxidoreductase activity indoleamine 2,3-dioxygenase activity tryptophan 2,3-dioxygenase activity heme binding dioxygenase activity metal ion binding Cellular component cytoplasm cytosol Biological process tryptophan catabolic process immune system process tryptophan catabolic process to kynurenine 'de novo' NAD biosynthetic process from tryptophan Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 169355 209176 Ensembl ENSG00000188676 ENSMUSG00000031549 UniProt Q6ZQW0 Q8R0V5 RefSeq (mRNA) NM_194294 NM_001395206 NM_145949 RefSeq (protein) NP_919270 NP_666061 Location (UCSC) Chr 8: 39.93 – 40.02 Mb Chr 8: 25.02 – 25.07 Mb PubMed search [3] [4]
Wikidata
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Function

IDO2 (indolamine-2,3-dioxygenase) is an enzyme with protein size of 420 amino acids (47 kDa) that is used for catabolism of tryptophan. In organisms, other enzymes participate in L-tryptophan cleavage, namely IDO1 and TDO. Despite IDO1 and IDO2 being closely related enzymes originating by gene duplication and sharing high level (43%) of sequence homology,^[6][7] they differentiate by their kinetics, function and expression pattern. Genes encoding IDO1 and IDO2 have similar genomic structure and are situated closely to each other on chromosome 8.^[8] IDO2 is produced in a very limited type of tissues as kidney, liver or antigen presenting cells.^[9] IDO2 is less active on substrates of IDO1, better catabolizing other Trp derivates as 5-methoxytryptophan. There are several isoforms in population that comes from alternative splicing.^[10] As well as IDO1, IDO2 has been reported in Treg differentiation in vitro,^[11] suggesting a role in tolerance maintenance. Its expression has been found in several cancers, gastric, colon or renal tumors.^[12]