The Drosophila activin branch of TGF-beta signaling is triggered by the activin-like ligands Activin-beta, Dawdle and Myoglianin. These ligands bind a receptor complex of the type I serine/threonine kinase Baboon and a type II receptor kinase (Punt, or Wishful thinking). The activated type I receptor phosphorylates the receptor-regulated SMAD Smox (dSmad2), which partners with the co-SMAD Medea and enters the nucleus to regulate target genes. The pathway acts in neuronal remodeling, cell and tissue growth, and metabolic homeostasis.
Boundary. Core components only (FlyBase ACT-C). Medea is shared with the BMP pathway and Punt and Wishful thinking also act as BMP type II receptors. The role of Wishful thinking in activin signaling is less well defined than that of Punt, so no receptor activity is asserted for it here. Extracellular modulators (Follistatin, the tolloid proteases) are regulators, not parts. FlyBase groups realized by this module: ACT-SMAD2 (FBgg0001093). Subgroups folded into it: ACT-C. FlyBase also curates regulator sets for this pathway, which are context and not modelled as parts: ACT-N (negative regulators of activin signaling pathway, 2 genes); ACT-P (positive regulators of activin signaling pathway, 4 genes). 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_activin_signaling.yaml. None of the member genes has a gene review in this repository yet.
All recommended fields populated.
✗ none found
No MODULE:dmel_activin_signaling deep-research report alongside the module YAML.
✓ every leaf node grounds to a representative protein.
✓ every declared conforms_to bundle matches its template motif.
3 gene-function check(s) reflected in core functions · 0 conflict(s) · 2 evidence or coverage gap(s) (6 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 |
|---|---|---|---|
| activin_ligands_actbeta | Actbeta UniProtKB:O61643 Gene |
cytokine activity GO:0005125 |
Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass). |
| activin_ligands_daw | daw UniProtKB:Q9VQG9 Gene |
cytokine activity GO:0005125 |
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked. |
| activin_ligands_myo | myo UniProtKB:Q9V4F4 Gene |
cytokine activity GO:0005125 |
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked. |
| activin_receptors_babo | babo UniProtKB:A1Z7L8 Gene |
activin receptor activity, type I GO:0016361 |
Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass). |
| activin_receptors_put | put UniProtKB:Q24468 Gene |
activin receptor activity, type II GO:0016362 |
Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass). |
| activin_smads_complex | PROTEIN_COMPLEX Gene |
DNA-binding transcription factor activity, RNA polymerase II-specific GO:0000981 |
Participant Unchecked
No direct UniProt participant to compare. Abstract selectors and complex-wide activities cannot be inferred from donor or subunit gene reviews. |
2 complete review(s) · 5 with deep research · 3 missing review · 0 reviewed but lacking deep research
| Gene | Review | Complete | Deep research |
|---|---|---|---|
| Actbeta O61643 | ✓ | ✓ | ✓ |
| babo A1Z7L8 | ✓ | ✓ | ✓ |
| wit M9PE88 | ✗ | — | — |
| Med O62609 | ✓ | 82/87 | ✓ |
| put Q24468 | ✓ | 79/83 | ✓ |
| myo Q9V4F4 | ✗ | — | — |
| daw Q9VQG9 | ✗ | — | — |
| Smox O96660 | ✓ | 70/71 | ✓ |
Activin-like ligands signal through Baboon and type II receptors to phosphorylate Smox, which acts with Medea to regulate transcription.
TGF-beta superfamily ligands of the activin branch.
Baboon is the type I receptor of the activin branch; Punt and Wishful thinking are type II receptor kinases that FlyBase places in the core pathway.
Phosphorylated Smox (receptor-regulated SMAD) forms a complex with the co-SMAD Medea that regulates target gene transcription.