BMP signaling pathway in Drosophila melanogaster

Bone morphogenetic protein (BMP) signaling in Drosophila is triggered by the ligands Decapentaplegic (Dpp), Glass bottom boat (Gbb) and Screw (Scw), which act as homo- or heterodimers. Ligands bind heteromeric complexes of type I receptor kinases (Thickveins, Saxophone) and type II receptor kinases (Punt, Wishful thinking). The activated type I receptor phosphorylates the receptor-regulated SMAD Mad, which forms a complex with the co-SMAD Medea and accumulates in the nucleus. With the zinc-finger protein Schnurri, the Mad-Medea complex represses brinker and activates other targets. The pathway patterns the dorsal-ventral axis of the embryo and the wing imaginal disc, maintains germline stem cells, and regulates synaptic growth at the neuromuscular junction, where Gbb and Wishful thinking act.

MODULE:dmel_bmp_signalingDRAFTCONCRETESignaling Pathwaymodules/dmel_bmp_signaling.yaml

BMP signaling pathwayGO:0030509

FB:FBgg0001086

FlyBase gene group BMP-MAD: Bmp signaling pathway

FlyBase release FB2026_03 groups 69 D. melanogaster genes as bmp signaling pathway (BMP-MAD); this module models that group.

GO:0030509

BMP signaling pathway

GO term grounding the module as BMP signaling pathway.

Boundary. Core components only (FlyBase BMP-C). Medea and the type II receptors Punt and Wishful thinking are shared with the activin pathway. Extracellular modulators (Sog, Tsg, Tolloid, Crossveinless-2) and the repressor Brinker are FlyBase regulators and are not parts. Maverick is kept in the ligand part because FlyBase lists it as core, but no receptor activity or ligand activity is asserted for it. FlyBase groups realized by this module: BMP-MAD (FBgg0001086). Subgroups folded into it: BMP-C. FlyBase also curates regulator sets for this pathway, which are context and not modelled as parts: BMP-N (negative regulators of bmp signaling pathway, 41 genes); BMP-P (positive regulators of bmp signaling pathway, 22 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_bmp_signaling.yaml. None of the member genes has a gene review in this repository yet.

6Nodes

5Parts

0Variant Sets

0Variants

10Annotons

4Connections

Derived QC

Recommended-field compliance

100.0% recommended fields populated

All recommended fields populated.

Module deep research

✗ none found

No MODULE:dmel_bmp_signaling deep-research report alongside the module YAML.

Leaf nodes lacking representative members

✓ every leaf node grounds to a representative protein.

Template conformance

✓ every declared conforms_to bundle matches its template motif.

Function consistency and core coverage

0 gene-function check(s) reflected in core functions · 0 conflict(s) · 7 evidence or coverage gap(s) (8 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
bmp_ligands_dpp	dpp UniProtKB:P07713 Gene	cytokine activity GO:0005125	Review Missing No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
bmp_ligands_gbb	gbb UniProtKB:P27091 Gene	cytokine activity GO:0005125	Review Missing No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
bmp_ligands_scw	scw UniProtKB:P54631 Gene	cytokine activity GO:0005125	Review Missing No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
bmp_type_i_receptors_tkv	tkv UniProtKB:Q9VMT1 Gene	BMP receptor activity GO:0098821	Review Missing No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
bmp_type_i_receptors_sax	sax UniProtKB:A0A0B4K7J3 Gene	BMP receptor activity GO:0098821	Review Missing No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
bmp_type_ii_receptors_put	put UniProtKB:Q24468 Gene	transforming growth factor beta receptor activity, type II GO:0005026	Function Unreviewed No retained annotation or core molecular function supports this GO assertion. Missing or broader evidence is a coverage gap, not proof the activity is absent.
bmp_type_ii_receptors_wit	wit UniProtKB:M9PE88 Gene	transforming growth factor beta receptor activity, type II GO:0005026	Review Missing No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
mad_medea_complex_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.

Gene-review completeness (3/11 grounded genes reviewed)

0 complete review(s) · 3 with deep research · 8 missing review · 0 reviewed but lacking deep research

Gene	Review	Complete	Deep research
sax A0A0B4K7J3	✗	—	—
shn A1Z8F4	✗	—	—
wit M9PE88	✗	—	—
Mad P42003	✓	134/136	✓
Med O62609	✓	82/87	✓
dpp P07713	✗	—	—
gbb P27091	✗	—	—
scw P54631	✗	—	—
put Q24468	✓	79/83	✓
mav Q9V4E6	✗	—	—
tkv Q9VMT1	✗	—	—

Tree

BMP signalingSignaling Pathwaydmel_bmp_signaling

Parts
1. 1. secreted ligands
2. BMP ligandsSignaling Pathwaybmp_ligands
  
  Annotons
  - dpp BMP ligands Gene Product: dpp
  - gbb BMP ligands Gene Product: gbb
  - scw BMP ligands Gene Product: scw
  - mav BMP ligands Gene Product: mav
3. 2. type I receptor serine/threonine kinases
4. BMP type I receptorsSignaling Pathwaybmp_type_i_receptors
  
  Annotons
  - tkv BMP type I receptors Gene Product: tkv
  - sax BMP type I receptors Gene Product: sax
5. 3. type II receptor serine/threonine kinases
6. BMP type II receptorsSignaling Pathwaybmp_type_ii_receptors
  
  Annotons
  - put BMP type II receptors Gene Product: put
  - wit BMP type II receptors Gene Product: wit
7. 4. signal transducers and transcriptional regulators
8. Mad-Medea SMAD complexSignaling Pathwaymad_medea_complex
  
  Annotons
  - Mad-Medea SMAD complex Protein Complex: Mad-Medea SMAD complex
9. 5. nuclear SMAD cofactor
10. SchnurriSignaling Pathwayschnurri
  
  Annotons
  - shn Schnurri Gene Product: shn

Details

Context

Drosophila melanogasterNCBITaxon:7227

BMP signalingSignaling Pathwaydmel_bmp_signaling

Dpp, Gbb and Scw signal through Tkv/Sax and Punt/Wit receptors to phosphorylate Mad, which acts with Medea and Schnurri to regulate transcription.

BMP signaling pathwayGO:0030509

Context

Drosophila melanogasterNCBITaxon:7227

Connections

bmp_ligands -> bmp_type_i_receptors Positively Regulates

Ligand binding assembles type I/type II receptor complexes.

bmp_type_ii_receptors -> bmp_type_i_receptors Positively Regulates

Type II receptor kinases phosphorylate and activate the type I receptors.

bmp_type_i_receptors -> mad_medea_complex Positively Regulates

Thickveins and Saxophone phosphorylate Mad, which then associates with Medea.

mad_medea_complex -> schnurri Provides Input For

Mad-Medea and Schnurri form a repressor complex on brinker silencer elements.

Part 1: secreted ligands

BMP ligandsSignaling Pathwaybmp_ligands

Dpp, Gbb and Scw are BMP ligands. Maverick is a divergent TGF-beta superfamily ligand that FlyBase includes among the core components.

Annotons

dpp BMP ligands

bmp_ligands_dpp

Participant: Gene Product: dpp

Gene Product:

dppUniProtKB:P07713

Function

cytokine activityGO:0005125

gbb BMP ligands

bmp_ligands_gbb

Participant: Gene Product: gbb

Gene Product:

gbbUniProtKB:P27091

Function

cytokine activityGO:0005125

scw BMP ligands

bmp_ligands_scw

Participant: Gene Product: scw

Gene Product:

scwUniProtKB:P54631

Function

cytokine activityGO:0005125

mav BMP ligands

bmp_ligands_mav

Participant: Gene Product: mav

Gene Product:

mavUniProtKB:Q9V4E6

Part 2: type I receptor serine/threonine kinases

BMP type I receptorsSignaling Pathwaybmp_type_i_receptors

Annotons

tkv BMP type I receptors

bmp_type_i_receptors_tkv

Participant: Gene Product: tkv

Gene Product:

tkvUniProtKB:Q9VMT1

Function

BMP receptor activityGO:0098821

sax BMP type I receptors

bmp_type_i_receptors_sax

Participant: Gene Product: sax

Gene Product:

saxUniProtKB:A0A0B4K7J3

Function

BMP receptor activityGO:0098821

Part 3: type II receptor serine/threonine kinases

BMP type II receptorsSignaling Pathwaybmp_type_ii_receptors

Punt is the main type II receptor in embryonic and imaginal BMP signaling; Wishful thinking acts in motor neurons at the neuromuscular junction.

Annotons

put BMP type II receptors

bmp_type_ii_receptors_put

Participant: Gene Product: put

Gene Product:

putUniProtKB:Q24468

Function

transforming growth factor beta receptor activity, type IIGO:0005026

wit BMP type II receptors

bmp_type_ii_receptors_wit

Participant: Gene Product: wit

Gene Product:

witUniProtKB:M9PE88

Function

transforming growth factor beta receptor activity, type IIGO:0005026

Part 4: signal transducers and transcriptional regulators

Mad-Medea SMAD complexSignaling Pathwaymad_medea_complex

Phosphorylated Mad associates with the co-SMAD Medea and enters the nucleus.

Annotons

Mad-Medea SMAD complex

mad_medea_complex_complex

Participant: Protein Complex: Mad-Medea SMAD complex

Protein Complex:

Mad-Medea SMAD complexGO:0071144

Active units:

Mad

Participant: Gene Product: Mad

Gene Product:

MadUniProtKB:P42003

Med

Participant: Gene Product: Med

Gene Product:

MedUniProtKB:O62609

Function

DNA-binding transcription factor activity, RNA polymerase II-specificGO:0000981

Part 5: nuclear SMAD cofactor

SchnurriSignaling Pathwayschnurri

Zinc-finger protein that joins Mad and Medea on silencer elements to repress brinker and other targets.

Annotons

shn Schnurri

schnurri_shn

Participant: Gene Product: shn

Gene Product:

shnUniProtKB:A1Z8F4