Octopamine, the insect counterpart of noradrenaline, and its precursor tyramine are monoamine neurotransmitters and neurohormones. Tyrosine is decarboxylated to tyramine by tyrosine decarboxylase: Tdc2 in neurons and Tdc1 in non-neural tissues. Tyramine beta-hydroxylase (Tbh), a copper monooxygenase of the dopamine beta-hydroxylase family that acts inside secretory vesicles, then hydroxylates tyramine to octopamine. Loss of Tbh removes octopamine and causes female sterility from a failure of ovulation, and loss of Tdc2 removes both amines from the nervous system.
Tdc1 and Tdc2 are alternative enzymes for the same step with different tissue distribution, and each is a separate annoton. olf413 is a second dopamine-beta-hydroxylase-like monooxygenase that FlyBase places in this group; it has been proposed to contribute to octopamine synthesis, but its activity has not been measured, so it has no molecular function here. Tyramine is a signalling molecule in its own right, so the decarboxylation step is also the end of tyramine synthesis. Vesicular uptake, release and receptors are outside the module. FlyBase groups realized by this module: TYROCTBI (FBgg0002226). 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_tyramine_octopamine_biosynthesis.yaml. Member genes with a gene review in this repository: olf413, Tbh, Tdc1, Tdc2.
All recommended fields populated.
✗ none found
No MODULE:dmel_tyramine_octopamine_biosynthesis 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.
3 gene-function check(s) reflected in core functions · 0 conflict(s) · 0 evidence or coverage gap(s) (3 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 |
|---|---|---|---|
| tyrosine_decarboxylation_tdc1 | Tdc1 UniProtKB:A1Z6N2 Gene |
tyrosine decarboxylase activity GO:0004837 |
Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass). |
| tyrosine_decarboxylation_tdc2 | Tdc2 UniProtKB:A1Z6N4 Gene |
tyrosine decarboxylase activity GO:0004837 |
Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass). |
| tyramine_hydroxylation_tbh | Tbh UniProtKB:Q86B61 Gene |
tyramine-beta hydroxylase activity GO:0004836 |
Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass). |
3 complete review(s) · 4 with deep research · 0 missing review · 0 reviewed but lacking deep research
| Gene | Review | Complete | Deep research |
|---|---|---|---|
| olf413 Q6NP60 | ✓ | 9/12 | ✓ |
| Tbh Q86B61 | ✓ | ✓ | ✓ |
| Tdc1 A1Z6N2 | ✓ | ✓ | ✓ |
| Tdc2 A1Z6N4 | ✓ | ✓ | ✓ |
Two-step synthesis of tyramine by tyrosine decarboxylase and of octopamine by tyramine beta-hydroxylase.
non-neural tyrosine decarboxylase
neural tyrosine decarboxylase