Tryptophan Degradation Via Kynurenine (Saccharomyces cerevisiae)

From WikiPathways

Jump to: navigation, search
1CO2H2OO2O2spontaneousO2H2OH2Oformatenicotinate nucleotide2-amino-3-carboxymuconate semialdehydeH2Oquinolinate3-hydroxy-anthranilateNADPBNA2L-alanineBNA4BNA1BNA3L-formylkynureninePRPPL-tryptophankynurenineBNA5pyrophosphate3-hydroxy-L-kynurenineBNA6NADPH


While Saccharomyces cerevisiae can use most amino acids as their sole nitrogen source, they can only use a few amino acids as a carbon source to support growth (CITS:[Large86][Cooper82]). This is in contrast to most eukaryotes and some fungi, which can metabolize amino acids completely, utilizing them as sole sources of carbon and nitrogen (CITS:[Stryer88][Large 86]). S. cerevisiae degrade the aromatic amino acids (tryptophan, phenylalanine, and tyrosine) and the branched-chain amino acids (valine, leucine, and iso-leucine) via the Ehrlich pathway (CITS:[Sentheshanmuganathan60][10989420]). This pathway is comprised of the following steps: 1) deamination of the amino acid to the corresponding alpha-keto acid; 2) decarboxylation of the resulting alpha-keto acid to the respective aldehyde; and, 3) reduction of the aldehyde to form the corresponding long chain or complex alcohol, known as a fusel alcohol or fusel oil (CITS:[10989420][Large 86]). Fusel alcohols are important flavor and aroma compounds in yeast-fermented food products and beverages (as reported in (CITS:[9546164]). The primary aminotransferase in tryptophan degradation is postulated to be Aro9p (CITS:[6763508]). In vitro studies demonstrated that Aro9p is active with phenylpyruvate, pyruvate, or p-hydroxyphenylpyruvate, but not 2-oxoglutarate as the amino acceptor (CITS:[6763508]). Aro9p is induced by aromatic amino acids and is subject to nitrogen regulation (CITS:[6763508][10207060]). The decarboxylase encoding gene ARO10 appears to be transcriptionally regulated in a similar fashion(CITS:[10207060]). Gap1p, a general amino acid permease, and Wap1p, an inducible amino acid permease with wide substrate specificity, appear to be the main uptake systems for utilizing aromatic amino acids (CITS:[10207060]).

SOURCE: SGD pathways,

Based on

Quality Tags

Ontology Terms



  1. Panozzo C, Nawara M, Suski C, Kucharczyka R, Skoneczny M, Bécam AM, Rytka J, Herbert CJ; ''Aerobic and anaerobic NAD+ metabolism in Saccharomyces cerevisiae.''; FEBS Lett, 2002 PubMed Europe PMC


View all...
92997view18:21, 21 July 2017KhanspersModified description
92996view18:21, 21 July 2017Khanspersremoved GenMAPP notes
92893view19:06, 14 July 2017EgonwReplace a CAS number for a totally different compound with the ChEBI ID for L-alanine.
89659view04:58, 24 September 2016EgonwReplace the CAS number of the salt with that of just the metabolite.
70274view21:52, 15 July 2013MaintBotupdated to 2013 schema
69876view18:11, 11 July 2013EgonwMarked a few DataNodes with CAS registry numbers as metabolites.
67724view11:55, 26 June 2013DdiglesOntology Term : 'kynurenine metabolic pathway' added !
41817view04:49, 2 March 2011MaintBotRemoved redundant pathway information and comments
36665view23:05, 9 April 2010MaintBot
36639view22:36, 9 April 2010MaintBotDescription and bibliography added from SGD
21630view11:32, 14 November 2008MaintBot[[Pathway:Saccharomyces cerevisiae:Tryptophan Degradation Via Kynurenine]] moved to [[Pathway:WP452]]: Moved to stable identifier
12885view08:07, 17 May 2008MaintBotautomated metabolite conversion
8987view14:14, 7 January 2008MaintBotAdded to category $category
8985view14:14, 7 January 2008M.BraymerUploaded new pathway

External references


View all...
NameTypeDatabase referenceComment
3-hydroxy-L-kynurenineMetabolite606-14-4 (CAS)
BNA1GeneProductS000003786 (SGD)
BNA2GeneProductS000003839 (SGD)
BNA3GeneProductS000003596 (SGD)
BNA4GeneProductS000000194 (SGD)
BNA5GeneProductS000004221 (SGD)
BNA6GeneProductS000001943 (SGD)
L-alanineMetaboliteCHEBI:16977 (ChEBI)
L-formylkynurenineMetabolite1022-31-7 (CAS)
L-tryptophanMetabolite73-22-3 (CAS)
NADPHMetabolite53-57-6 (CAS)
PRPPMetabolite97-55-2 (CAS)
kynurenineMetabolite343-65-7 (CAS)
pyrophosphateMetabolite2466-09-3 (CAS)

Annotated Interactions

No annotated interactions

Personal tools