FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Pathway: L-PHENYLALANINE AND L-TYROSINE METABOLISM
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General Information
Name
L-PHENYLALANINE AND L-TYROSINE METABOLISM
Species
D. melanogaster
Symbol
PHETYRME
FlyBase ID
FBgg0002180
Date last reviewed
2025-01-27
Number of members
7
Description
Description
L-tyrosine is synthesized in the cytosol via the hydroxylation of the essential amino-acid L-phenylalanine. Besides its role in protein synthesis, L-tyrosine is a precursor for monoamine neurotransmitters L-dopamine, octopamine and tyramine, and for melanin and other cuticle pigments. L-tyrosine catabolism occurs in the cytosol and produces acetoacetate, a ketone body and fumarate, which can be further catabolized through the tricarboxylic acid (TCA) cycle. (Adapted from FBrf0247596, FBrf0224779 and FBrf0255924.)
Notes

A minor alternative route for L-phenylalanine catabolism via transamination or decarboxylation of the side chain has been described in mammals; however, there is no evidence that this pathway occurs in D. melanogaster. Trhn is a paralog of Hn. Although it has some activity towards L-phenylalanine, L-tryptophan is its main substrate, therefore Trhn is not included in the gene list.

Source Material
The L-PHENYLALANINE AND L-TYROSINE METABOLISM Gene Group has been compiled using the following publication(s): Parkhitko et al., 2020 .
Key Gene Ontology (GO) terms
Biological Process
L-phenylalanine catabolic process
L-tyrosine biosynthetic process
L-tyrosine catabolic process
Cellular Component
cytosol
Related Gene Groups
Parent group(s)
AMINO ACID METABOLISM
GO Causal Activity Model (GO-CAM)
Members (7)
For all members:
GO ribbon stack
 molecular functionbiological processcellular component
External Data
Other resource(s)
Note: The Drosophila pathways shown at these resources are computed using different methods. They may therefore differ from the manually curated and verified pathway shown above.

[FlyCyc: L-tyrosine biosynthesis IV](https://biocyc.org/pathway?orgid=DMEL&id=PWY-6134)

[FlyCyc: L-tyrosine degradation I](https://biocyc.org/pathway?orgid=DMEL&id=TYRFUMCAT-PWY)

[FlyCyc: L-phenylalanine degradation IV (mammalian, via side chain)](https://biocyc.org/pathway?orgid=DMEL&id=PWY-6318)

[Reactome: Phenylalanine metabolism](https://reactome.org/PathwayBrowser/#/R-DME-8964208)

[Reactome: Tyrosine catabolism](https://reactome.org/PathwayBrowser/#/R-DME-8963684)

[KEGG: Phenylalanine metabolism](https://www.kegg.jp/pathway/dme00360)

[KEGG: Tyrosine metabolism](https://www.kegg.jp/pathway/dme00350)

Synonyms and Secondary IDs
Synonym(s)
PHETYRME
L-PHENYLALANINE AND L-TYROSINE METABOLISM
L-phenylalanine catabolism
L-tyrosine biosynthesis
L-tyrosine catabolism
Secondary FlyBase ID(s)
References (2)