Histamine is the neurotransmitter of Drosophila photoreceptors and some central neurons. Histidine decarboxylase (Hdc) makes histamine from histidine, and LOVIT, a putative vesicular histamine transporter, maintains histamine in photoreceptor synaptic terminals. After release, histamine is taken up by surrounding epithelial glia, in part by the histamine-specific transporter HisT. In glia, Ebony conjugates histamine with beta-alanine to form carcinine (beta-alanyl-histamine), which returns to photoreceptors through the carcinine transporter CarT. Tan then hydrolyses carcinine, releasing histamine for reuse. This glia-photoreceptor recycling loop sustains visual transmission when de novo synthesis is limiting.
Boundary. The module covers the six FlyBase members. Ebony and Tan also act in cuticle tanning (on dopamine rather than histamine) and appear in that module as well. Histamine receptors (HisCl1, ort) are downstream of the module. FlyBase groups realized by this module: HISMET (FBgg0002224). Participants were generated from the FlyBase gene-group membership and mapped to UniProtKB by projects/FLYBASE_GENE_GROUPS/generate_modules.py from module_specs/dmel_histamine_metabolism.yaml. None of the member genes has a gene review in this repository yet.
All recommended fields populated.
✗ none found
No MODULE:dmel_histamine_metabolism deep-research report alongside the module YAML.
✓ every leaf node grounds to a representative protein.
✓ every declared conforms_to bundle matches its template motif.
✓ every PRECEDES step chains, or its break is acknowledged via chaining_status.
0 gene-function check(s) reflected in core functions · 0 conflict(s) · 5 evidence or coverage gap(s) (5 comparison(s))
Retained noncore functions are reported separately; they do not require promotion to core functions. Support from representative genes does not establish conservation across the whole family. Missing reviews or identifiers leave a claim unverified.
| Annoton | Participant | Function | Assessment |
|---|---|---|---|
| histamine_synthesis_hdc | Hdc UniProtKB:Q05733 Gene |
histidine decarboxylase activity GO:0004398 |
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked. |
| glial_histamine_uptake_hist | HisT UniProtKB:A0A0B4JD50 Gene |
histamine transmembrane transporter activity GO:0160173 |
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked. |
| carcinine_synthesis_e | e UniProtKB:Q9VDC6 Gene |
beta-alanyl amine synthase activity GO:0003833 |
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked. |
| carcinine_transport_cart | CarT UniProtKB:Q9VIK2 Gene |
carcinine transmembrane transporter activity GO:1905131 |
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked. |
| carcinine_hydrolysis_t | t UniProtKB:Q9W369 Gene |
beta-alanyl-histamine hydrolase activity GO:0031964 |
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked. |
0 complete review(s) · 0 with deep research · 6 missing review · 0 reviewed but lacking deep research
| Gene | Review | Complete | Deep research |
|---|---|---|---|
| HisT A0A0B4JD50 | ✗ | — | — |
| lovit A0A0S0WGX2 | ✗ | — | — |
| Hdc Q05733 | ✗ | — | — |
| e Q9VDC6 | ✗ | — | — |
| CarT Q9VIK2 | ✗ | — | — |
| t Q9W369 | ✗ | — | — |
Histamine synthesis by Hdc, vesicular storage by LOVIT and glial recycling through HisT, Ebony, CarT and Tan.
LOVIT is an SLC45 protein on photoreceptor synaptic vesicles; its transport activity has not been shown directly.