- Tools
- Downloads
- Links
- Community
- About
- Help
FB2026_02
,
released June 18, 2026
DTPH, Tph, Pah, phenylalanine hydroxylase, Trh
Please see the JBrowse view of Dmel\Hn for information on other features
To submit a correction to a gene model please use the Contact FlyBase form
AlphaFold produces a per-residue confidence score (pLDDT) between 0 and 100. Some regions with low pLDDT may be unstructured in isolation.
Gene model reviewed during 5.47
1.75 (northern blot)
1.5 (northern blot)
453 (aa); 50 (kD observed)
50-52 (kD observed); 50-52 (kD)
453 (aa)
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Hn using the Feature Mapper tool.
The testis specificity index was calculated from modENCODE tissue expression data by Vedelek et al., 2018 to indicate the degree of testis enrichment compared to other tissues. Scores range from -2.52 (underrepresented) to 5.2 (very high testis bias).
Comment: reference states 0-6 hr AEL
Hn is expressed ubiquitously in early embryos. It is expressed in cells surrounding invaginating tissues in 2--6-hour embryos. Later it is expressed in fat body and in a subset of neuroblasts. Expression is restricted to dopaminergic neurons.
The Hn protein is present in larval and pupal stages, as well as in the adult head. A 50 kD Hn protein is detected starting in 12-18 hr embryos, and persists through pupal and larval stages, and in adult heads. An additional 45 kD protein is detected in early embryos and in female abdomens. Immunolocalization to central nervous systems dissected from different larval stages stains distinct neurons in the ventral ganglia and brain lobes. Pairs of ventral lateral neurons staining with Hn protein match the position of serotonin-pos tive neurons. The position of dorsolateral neurons in the abdominal neuromeres and medial unpaired neurons staining with Hn match the position of catecholamine-positive neurons. In 0-6 hr embryos, Hn protein is detected in yolk granules.
An antibody against monkey liver phenylalanine hydroxylase cross reacts with a Drosophila protein present in samples from third instar larvae to adult. The strongest signal was seen at pupation with a secondary peak at the end of the pupal stage. Levels quickly decrease in the adult. The protein was also studied in isolated tissues and was detected in 3rd instar larval fat body and in the adult head. Reduced enzyme activity and CRM are observed in Hn(r) and Hn(r3) mutants.
Hn protein is detected from late third instar larval to early adult stages, with highest levels at pupariation and a smaller peak at the end of the pupal stage. In dissected third instar larval tissue, only the fat body showed expression of Hn protein. In young adult flies, expression was detected in the head.
Comment: medium expression
Comment: faint expression
Comment: strong expression
Comment: faint expression
Comment: medium expression
Comment: strong expression
JBrowse - Visual display of RNA-Seq signals
View Dmel\Hn in JBrowse
Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see JBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
polyclonal
S2 cells treated with dsRNA generated against this gene show reduced phagocytosis of Candida albicans compared to untreated cells.
Homologous genetic loci in D.subobscura and D.melanogaster tend to show a similar ultrastructure in the two species.
Hn is involved in the Trp metabolism and pteridine synthesis.
Isolation and characterisation of Hn.
Tryptophan hydrolase catalyses the tetrahydopterin-dependent hydroxylation of L-Phe to yield L-Tyr, the only significant endogenous synthesis of Tyr and the irreversible first step in the phenylalanine degradation pathway. Tryptophan hydrolase activity peaks in pupation and has a minor peak at adult emergence. More likely that H4Bip is the natural cofactor of Hn than H4Ptr.
Chromatographic pattern of pteridine eye pigments neodrosopterin, sepiapterin, pterin, aurodrosopterin, acetyldihidrohomopterin, isoxanthopterin, biopterin and drosopterin measured in Hn alleles.
Analysis of variance of developmental time and viability of pteridine pathway mutants in sf, se, Hn, dke and bw, indicated that viability of induced and natural population alleles is the same whereas developmental time tends to be longer for induced mutations as compared to natural population alleles.
Isolated from a Drosophila adult head cDNA library using a rabbit tryptophan hydroxylase cDNA as a probe under reduced stringency conditions.
A Hn cDNA has been cloned and sequenced.
A monoclonal antibody against monkey liver phenylalanine hydroxylase (PH8) (recognising an epitope of residues 139 to 154 of the monkey protein) cross-reacts with a Drosophila protein whose distribution parallels the pattern of phenylalanine hydroxylase activity distribution, with maxima at pupariation and pharate adult formation. Hn mutants show reduced phenylalanine hydroxylase enzyme activity and decreased amounts of protein as assayed in Western blots.
Isolated from a second larval instar cDNA library using a human pah cDNA as a probe.
A Hn cDNA has been cloned and sequenced, and its expression pattern has been analysed.
A mutant of Hn has been shown to influence the level of in vivo detectable 5,6,7,8-tetrahydroperin and 5,6,7,8-tetrahydrobioperin.
