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Aliases for TDO2 Gene

Aliases for TDO2 Gene

  • Tryptophan 2,3-Dioxygenase 2 3 5
  • Tryptamin 2,3-Dioxygenase 3 4
  • Tryptophan Oxygenase 3 4
  • Tryptophan Pyrrolase 3 4
  • Tryptophanase 3 4
  • EC 4 56
  • TRPO 3 4
  • TDO 3 4
  • TO 3 4
  • HYPTRP 3
  • TPH2 3

External Ids for TDO2 Gene

Previous GeneCards Identifiers for TDO2 Gene

  • GC04P157712
  • GC04P157252
  • GC04P157402
  • GC04P157182
  • GC04P157044
  • GC04P156824
  • GC04P152563

Summaries for TDO2 Gene

Entrez Gene Summary for TDO2 Gene

  • This gene encodes a heme enzyme that plays a critical role in tryptophan metabolism by catalyzing the first and rate-limiting step of the kynurenine pathway. Increased activity of the encoded protein and subsequent kynurenine production may also play a role in cancer through the suppression of antitumor immune responses, and single nucleotide polymorphisms in this gene may be associated with autism. [provided by RefSeq, Feb 2012]

GeneCards Summary for TDO2 Gene

TDO2 (Tryptophan 2,3-Dioxygenase) is a Protein Coding gene. Diseases associated with TDO2 include Hypertryptophanemia and Photoparoxysmal Response 1. Among its related pathways are superpathway of tryptophan utilization and Viral mRNA Translation. Gene Ontology (GO) annotations related to this gene include heme binding and amino acid binding.

UniProtKB/Swiss-Prot for TDO2 Gene

  • Heme-dependent dioxygenase that catalyzes the oxidative cleavage of the L-tryptophan (L-Trp) pyrrole ring and converts L-tryptophan to N-formyl-L-kynurenine. Catalyzes the oxidative cleavage of the indole moiety.

Tocris Summary for TDO2 Gene

Gene Wiki entry for TDO2 Gene

Additional gene information for TDO2 Gene

No data available for CIViC summary , PharmGKB "VIP" Summary , fRNAdb sequence ontologies and piRNA Summary for TDO2 Gene

Genomics for TDO2 Gene

GeneHancer (GH) Regulatory Elements for TDO2 Gene

Promoters and enhancers for TDO2 Gene
GeneHancer (GH) Identifier GH Type GH
GH Sources Gene Association Score Total Score TSS distance (kb) Number of Genes Away Size (kb) Transcription Factor
Binding Sites
Gene Targets
GH04I155903 Promoter 0.9 EPDnew 550.2 +48.9 48939 0.1 FOXA2 RXRA TAF1 REST RAD21 FOXA1 YY1 JUND ATF3 ZBTB33 TDO2 ASIC5 CTSO
GH04I155854 Enhancer 0.8 Ensembl ENCODE 550.8 +0.1 72 0.8 RXRA TAF1 RAD21 YY1 POLR2A IKZF1 ZNF143 FOS NFE2 LOC105377507 TDO2 ASIC5
GH04I155940 Enhancer 0.6 ENCODE 10.6 +88.2 88159 3.8 FOXA2 JUND ATF3 MAX ZBTB33 HNF4A REST RAD21 FOXA1 TDO2 CTSO ASIC5
GH04I155888 Enhancer 1 Ensembl ENCODE 5.4 +34.8 34800 1.4 SMAD1 TAF1 BACH1 MAX BMI1 BATF RAD21 YY1 HNF4G ATF7 TDO2 ASIC5 CTSO
GH04I156168 Enhancer 0.7 Ensembl ENCODE 6.2 +314.7 314672 1.4 CTCF ZNF654 TRIM22 ZNF143 SMC3 FOS RAD21 TDO2 GLRB LOC102724785 LOC105377508
- Elite GeneHancer and/or Elite GeneHancer-gene association Download GeneHancer data dump

GeneHancers around TDO2 on UCSC Golden Path with GeneCards custom track

Top Transcription factor binding sites by QIAGEN in the TDO2 gene promoter:

Genomic Locations for TDO2 Gene

Genomic Locations for TDO2 Gene
65,669 bases
Plus strand

Genomic View for TDO2 Gene

Genes around TDO2 on UCSC Golden Path with GeneCards custom track

Cytogenetic band:
TDO2 Gene in genomic location: bands according to Ensembl, locations according to GeneLoc (and/or Entrez Gene and/or Ensembl if different)
Genomic Location for TDO2 Gene
GeneLoc Logo Genomic Neighborhood Exon StructureGene Density

RefSeq DNA sequence for TDO2 Gene

Proteins for TDO2 Gene

  • Protein details for TDO2 Gene (UniProtKB/Swiss-Prot)

    Protein Symbol:
    Recommended name:
    Tryptophan 2,3-dioxygenase
    Protein Accession:
    Secondary Accessions:
    • A8K053

    Protein attributes for TDO2 Gene

    406 amino acids
    Molecular mass:
    47872 Da
    Name=heme; Xref=ChEBI:CHEBI:30413;
    Quaternary structure:
    • Homotetramer. Dimer of dimers.

    Three dimensional structures from OCA and Proteopedia for TDO2 Gene

neXtProt entry for TDO2 Gene

Selected DME Specific Peptides for TDO2 Gene


Post-translational modifications for TDO2 Gene

  • Modification sites at PhosphoSitePlus
  • Modification sites at neXtProt

Other Protein References for TDO2 Gene

ENSEMBL proteins:
REFSEQ proteins:

Domains & Families for TDO2 Gene

Gene Families for TDO2 Gene

Human Protein Atlas (HPA):
  • Enzymes
  • Predicted intracellular proteins

Protein Domains for TDO2 Gene

Suggested Antigen Peptide Sequences for TDO2 Gene

GenScript: Design optimal peptide antigens:

Graphical View of Domain Structure for InterPro Entry



  • Belongs to the tryptophan 2,3-dioxygenase family.
  • Belongs to the tryptophan 2,3-dioxygenase family.
genes like me logo Genes that share domains with TDO2: view

Function for TDO2 Gene

Molecular function for TDO2 Gene

GENATLAS Biochemistry:
tryptophan 2-3 dioxygenase
UniProtKB/Swiss-Prot BiophysicochemicalProperties:
Kinetic parameters: KM=0.135 mM for L-tryptophan {ECO:0000269 PubMed:25066423};
UniProtKB/Swiss-Prot CatalyticActivity:
L-tryptophan + O(2) = N-formyl-L-kynurenine.
UniProtKB/Swiss-Prot Function:
Heme-dependent dioxygenase that catalyzes the oxidative cleavage of the L-tryptophan (L-Trp) pyrrole ring and converts L-tryptophan to N-formyl-L-kynurenine. Catalyzes the oxidative cleavage of the indole moiety.

Enzyme Numbers (IUBMB) for TDO2 Gene

Phenotypes From GWAS Catalog for TDO2 Gene

Gene Ontology (GO) - Molecular Function for TDO2 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0004833 tryptophan 2,3-dioxygenase activity TAS --
GO:0005515 protein binding IPI 16189514
GO:0016491 oxidoreductase activity IEA --
GO:0016597 amino acid binding IEA --
GO:0019825 oxygen binding IEA --
genes like me logo Genes that share ontologies with TDO2: view
genes like me logo Genes that share phenotypes with TDO2: view

Animal Models for TDO2 Gene

MGI Knock Outs for TDO2:

Animal Model Products

  • Taconic Biosciences Mouse Models for TDO2

Inhibitory RNA Products

Clone Products

No data available for Human Phenotype Ontology , miRNA , Transcription Factor Targets and HOMER Transcription for TDO2 Gene

Localization for TDO2 Gene

Subcellular locations from

Extracellular space Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi Apparatus Nucleus Mitochondrion 0 1 2 3 4 5 Confidence
COMPARTMENTS Subcellular localization image for TDO2 gene
Compartment Confidence
cytosol 5
plasma membrane 2
peroxisome 2
nucleus 2
extracellular 1
mitochondrion 1

Subcellular locations from the

Human Protein Atlas (HPA)
  • Cytosol (1)
  • Plasma membrane (1)
See all subcellular structures

Gene Ontology (GO) - Cellular Components for TDO2 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0005829 cytosol TAS --
genes like me logo Genes that share ontologies with TDO2: view

No data available for Subcellular locations from UniProtKB/Swiss-Prot for TDO2 Gene

Pathways & Interactions for TDO2 Gene

genes like me logo Genes that share pathways with TDO2: view

UniProtKB/Swiss-Prot P48775-T23O_HUMAN

  • Pathway: Amino-acid degradation; L-tryptophan degradation via kynurenine pathway; L-kynurenine from L-tryptophan: step 1/2.

Gene Ontology (GO) - Biological Process for TDO2 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0006568 tryptophan metabolic process IEA --
GO:0006569 tryptophan catabolic process TAS,IEA --
GO:0019441 tryptophan catabolic process to kynurenine IDA,IEA --
GO:0019442 tryptophan catabolic process to acetyl-CoA IEA,IBA --
GO:0051289 protein homotetramerization IDA 27762317
genes like me logo Genes that share ontologies with TDO2: view

No data available for SIGNOR curated interactions for TDO2 Gene

Drugs & Compounds for TDO2 Gene

(22) Drugs for TDO2 Gene - From: DrugBank, HMDB, Tocris, and Novoseek

Name Status Disease Links Group Role Mechanism of Action Clinical Trials
L-Tryptophan Approved, Withdrawn Nutra Positive, Allosteric regulator, Enzyme, substrate 0
Nalidixic Acid Approved, Investigational Pharma Enzyme, inhibitor 2
Oxygen Approved, Vet_approved Pharma 0
Tolmetin Approved Pharma Enzyme, inhibitor 0
Febuxostat Approved Pharma Xanthine oxidase inhibitor 61

(15) Additional Compounds for TDO2 Gene - From: HMDB, Novoseek, and Tocris

Name Synonyms Role CAS Number PubChem IDs PubMed IDs
LM 10

(5) Tocris Compounds for TDO2 Gene

Compound Action Cas Number
1-Methyl-D-tryptophan Indoleamine 2,3-dioxygenase (IDO) inhibitor 110117-83-4
680C91 Potent and selective tryptophan 2,3-dioxygenase (TDO) inhibitor 163239-22-3
Febuxostat Xanthine oxidase inhibitor 144060-53-7
LM 10 Selective tryptophan 2,3-dioxygenase (TDO) inhibitor 1316695-35-8
MDL 72527 Polyamine oxidase (PAO) inhibitor 93565-01-6
genes like me logo Genes that share compounds with TDO2: view

Transcripts for TDO2 Gene

Unigene Clusters for TDO2 Gene

Tryptophan 2,3-dioxygenase:
Representative Sequences:

Inhibitory RNA Products

Clone Products

Alternative Splicing Database (ASD) splice patterns (SP) for TDO2 Gene

ExUns: 1a · 1b ^ 2 ^ 3a · 3b ^ 4a · 4b · 4c ^ 5a · 5b · 5c ^ 6 ^ 7 ^ 8 ^ 9 ^ 10 ^ 11 ^ 12 ^ 13
SP1: - -
SP2: - -
SP3: -
SP4: - - -
SP5: - - - -

Relevant External Links for TDO2 Gene

GeneLoc Exon Structure for
ECgene alternative splicing isoforms for

Expression for TDO2 Gene

mRNA expression in normal human tissues from GTEx, Illumina, BioGPS, and CGAP SAGE for TDO2 Gene

mRNA expression in embryonic tissues and stem cells from LifeMap Discovery

mRNA differential expression in normal tissues according to GTEx for TDO2 Gene

This gene is overexpressed in Liver (x49.4).

Protein differential expression in normal tissues from HIPED for TDO2 Gene

This gene is overexpressed in Liver (64.2).

Integrated Proteomics: protein expression in normal tissues and cell lines from ProteomicsDB, PaxDb, and MOPED for TDO2 Gene

Protein tissue co-expression partners for TDO2 Gene

NURSA nuclear receptor signaling pathways regulating expression of TDO2 Gene:


SOURCE GeneReport for Unigene cluster for TDO2 Gene:


Evidence on tissue expression from TISSUES for TDO2 Gene

  • Liver(4.9)
  • Nervous system(4.4)
  • Adrenal gland(2)
genes like me logo Genes that share expression patterns with TDO2: view

No data available for mRNA Expression by UniProt/SwissProt and Phenotype-based relationships between genes and organs from Gene ORGANizer for TDO2 Gene

Orthologs for TDO2 Gene

This gene was present in the common ancestor of animals.

Orthologs for TDO2 Gene

Organism Taxonomy Gene Similarity Type Details
(Pan troglodytes)
Mammalia TDO2 33 34
  • 99.59 (n)
(Canis familiaris)
Mammalia TDO2 34 33
  • 91.87 (n)
(Monodelphis domestica)
Mammalia TDO2 34
  • 90 (a)
(Ornithorhynchus anatinus)
Mammalia -- 34
  • 89 (a)
-- 34
  • 85 (a)
(Bos Taurus)
Mammalia TDO2 34 33
  • 86.78 (n)
(Rattus norvegicus)
Mammalia Tdo2 33
  • 83.99 (n)
(Mus musculus)
Mammalia Tdo2 33 16 34
  • 83.58 (n)
(Gallus gallus)
Aves TDO2 33
  • 78.33 (n)
(Anolis carolinensis)
Reptilia TDO2 34
  • 83 (a)
tropical clawed frog
(Silurana tropicalis)
Amphibia tdo2 33
  • 75.78 (n)
African clawed frog
(Xenopus laevis)
Amphibia Xl.30711 33
(Danio rerio)
Actinopterygii tdo2a 34
  • 75 (a)
tdo2b 34 33
  • 67.57 (n)
wufi30d08 33
fruit fly
(Drosophila melanogaster)
Insecta v 35 33 34
  • 60.11 (n)
African malaria mosquito
(Anopheles gambiae)
Insecta T23O_ANOGA 33
  • 55.64 (n)
(Caenorhabditis elegans)
Secernentea C28H8.11 33
  • 56.28 (n)
tdo-2 34
  • 51 (a)
sea squirt
(Ciona savignyi)
Ascidiacea -- 34
  • 47 (a)
-- 34
  • 41 (a)
Species where no ortholog for TDO2 was found in the sources mined by GeneCards:
  • A. gosspyii yeast (Ashbya gossypii)
  • Actinobacteria (Mycobacterium tuberculosis)
  • Alicante grape (Vitis vinifera)
  • alpha proteobacteria (Wolbachia pipientis)
  • amoeba (Dictyostelium discoideum)
  • Archea (Pyrococcus horikoshii)
  • baker's yeast (Saccharomyces cerevisiae)
  • barley (Hordeum vulgare)
  • beta proteobacteria (Neisseria meningitidis)
  • bread mold (Neurospora crassa)
  • Chromalveolata (Phytophthora infestans)
  • common water flea (Daphnia pulex)
  • corn (Zea mays)
  • E. coli (Escherichia coli)
  • filamentous fungi (Aspergillus nidulans)
  • Firmicute bacteria (Streptococcus pneumoniae)
  • fission yeast (Schizosaccharomyces pombe)
  • green algae (Chlamydomonas reinhardtii)
  • honey bee (Apis mellifera)
  • K. lactis yeast (Kluyveromyces lactis)
  • loblloly pine (Pinus taeda)
  • malaria parasite (Plasmodium falciparum)
  • medicago trunc (Medicago Truncatula)
  • moss (Physcomitrella patens)
  • orangutan (Pongo pygmaeus)
  • pig (Sus scrofa)
  • rainbow trout (Oncorhynchus mykiss)
  • rice (Oryza sativa)
  • rice blast fungus (Magnaporthe grisea)
  • schistosome parasite (Schistosoma mansoni)
  • sea anemone (Nematostella vectensis)
  • sea urchin (Strongylocentrotus purpuratus)
  • sorghum (Sorghum bicolor)
  • soybean (Glycine max)
  • stem rust fungus (Puccinia graminis)
  • sugarcane (Saccharum officinarum)
  • thale cress (Arabidopsis thaliana)
  • tomato (Lycopersicon esculentum)
  • toxoplasmosis (Toxoplasma gondii)
  • Trichoplax (Trichoplax adhaerens)
  • wheat (Triticum aestivum)

Evolution for TDO2 Gene

Gene Tree for TDO2 (if available)
Gene Tree for TDO2 (if available)

Paralogs for TDO2 Gene

No data available for Paralogs for TDO2 Gene

Variants for TDO2 Gene

Sequence variations from dbSNP and Humsavar for TDO2 Gene

SNP ID Clin Chr 04 pos Variation AA Info Type
rs767123432 pathogenic, Hypertryptophanemia, familial 155,910,083(+) AA/AAA coding_sequence_variant, frameshift
rs1000404763 -- 155,915,079(+) C/T intron_variant
rs1000432122 -- 155,905,912(+) G/A intron_variant
rs1000457047 -- 155,914,753(+) G/A intron_variant
rs1000591507 -- 155,910,683(+) G/A intron_variant

Structural Variations from Database of Genomic Variants (DGV) for TDO2 Gene

Variant ID Type Subtype PubMed ID
esv3575777 CNV gain 25503493
nsv1029122 CNV gain 25217958
nsv480989 CNV novel sequence insertion 20440878
nsv481477 CNV novel sequence insertion 20440878
nsv830121 CNV gain 17160897

Variation tolerance for TDO2 Gene

Residual Variation Intolerance Score: 14.6% of all genes are more intolerant (likely to be disease-causing)
Gene Damage Index Score: 2.47; 43.38% of all genes are more intolerant (likely to be disease-causing)

Additional Variant Information for TDO2 Gene

Human Gene Mutation Database (HGMD)
SNPedia medical, phenotypic, and genealogical associations of SNPs for

SNP Genotyping and Copy Number Assay Products

No data available for Polymorphic Variants from UniProtKB/Swiss-Prot for TDO2 Gene

Disorders for TDO2 Gene

MalaCards: The human disease database

(8) MalaCards diseases for TDO2 Gene - From: HGMD, OMIM, ClinVar, Orphanet, DISEASES, Novoseek, and GeneCards

Disorder Aliases PubMed IDs
  • hyptrp
photoparoxysmal response 1
  • ppr1
  • digitate dermatosis
tic disorder
  • tics
substance abuse
  • substance-related disorders
- elite association - COSMIC cancer census association via MalaCards
Search TDO2 in MalaCards View complete list of genes associated with diseases

Additional Disease Information for TDO2

Genetic Association Database
Human Genome Epidemiology Navigator
ATLAS of Genetics and Cytogenetics in Oncology and Haematology
genes like me logo Genes that share disorders with TDO2: view

No data available for UniProtKB/Swiss-Prot and Genatlas for TDO2 Gene

Publications for TDO2 Gene

  1. Sequence of human tryptophan 2,3-dioxygenase (TDO2): presence of a glucocorticoid response-like element composed of a GTT repeat and an intronic CCCCT repeat. (PMID: 8666386) Comings DE … Forest GL (Genomics 1995) 3 4 22 58
  2. Molecular basis for catalysis and substrate-mediated cellular stabilization of human tryptophan 2,3-dioxygenase. (PMID: 27762317) Lewis-Ballester A … Tong L (Scientific reports 2016) 3 4 58
  3. Structural and functional analyses of human tryptophan 2,3-dioxygenase. (PMID: 25066423) Meng B … Liu ZJ (Proteins 2014) 3 4 58
  4. First genome-wide association scan on neurophysiological endophenotypes points to trans-regulation effects on SLC2A3 in dyslexic children. (PMID: 19786962) Roeske D … Schulte-Körne G (Molecular psychiatry 2011) 3 44 58
  5. Cooperative binding of L-trp to human tryptophan 2,3-dioxygenase: resonance Raman spectroscopic analysis. (PMID: 19218188) Fukumura E … Shiro Y (Journal of biochemistry 2009) 3 22 58

Products for TDO2 Gene

Sources for TDO2 Gene

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