Activin receptor signaling pathway module

Activin ligands signal through ACVR type I and type II serine/threonine kinase receptors to activate SMAD2/3-SMAD4 transcriptional programs controlling growth and differentiation.

MODULE:activin_receptor_signalingDRAFTSignaling Pathwaymodules/activin_receptor_signaling.yaml
activin receptor signaling pathwayGO:0032924
file:modules/activin_receptor_signaling-deep-research-falcon.md
Activin receptor signaling pathway Falcon module review
Falcon/Edison module review generated 2026-06-28 is linked as supporting evidence for module boundaries, core mechanism, variation, constraints, and failure modes; open questions in that report require manual review before promotion to curated knowledge gaps.
GO:0032924
activin receptor signaling pathway
The module is grounded in the GO biological process term for activin receptor signaling pathway.
PANTHER:PTN000218063
PAINT node PTN000218063 for INHBA
Local PAINT IBD node in PTHR11848 with propagated terms C:GO:0005576, P:GO:0007178; PAINT date 20260528.

Curated compact signaling-pathway module generated from verified UniProt exemplar accessions and local PAINT IBD rows. PTN anchors are included only when the exemplar accession appears in an IBD seed row in interpro/panther; roles without local PAINT seeds remain grounded by verified UniProt exemplar accessions. Falcon integration (2026-06-28): Falcon findings are linked as evidence and family-level support. Automatically extracted open-question headings were intentionally not retained as knowledge_gap entries because they were not manually curated. Machine-generated Falcon citations remain curation support and are not manually adjudicated here.

4Nodes
3Parts
0Variant Sets
0Variants
7Annotons
2Connections

Derived QC

Recommended-field compliance

100.0% recommended fields populated

All recommended fields populated.

Module deep research

✓ present

  • activin_receptor_signaling-deep-research-falcon.md (falcon)

Leaf nodes lacking representative members

✓ every leaf node grounds to a representative protein.

Template conformance

✓ every declared conforms_to bundle matches its template motif.

Gene-review completeness (1/6 grounded genes reviewed)

1 complete review(s) · 1 with deep research · 5 missing review · 0 reviewed but lacking deep research

Gene Review Complete Deep research
INHBA P08476 ✗ — —
ACVR2A P27037 ✗ — —
ACVR1B P36896 ✗ — —
SMAD4 Q13485 ✗ — —
SMAD2 Q15796 ✗ — —
SMAD3 P84022 ✓ ✓ ✓

Details

Context
metazoaNCBITaxon:33208
plasma membraneGO:0005886 cytosolGO:0005829 nucleusGO:0005634
Activin receptor signaling pathwaySignaling Pathwayactivin_receptor_signaling
activin receptor signaling pathwayGO:0032924
Context
metazoaNCBITaxon:33208
plasma membraneGO:0005886 cytosolGO:0005829 nucleusGO:0005634

Connections

The initiating event promotes smad2/3 activation.
SMAD2/3 activation leads to activin transcriptional output.
Part 1: activin receptor engagement
Activin receptor engagementRegulatory Stepactivin_receptor_engagement

INHBA-containing activin ligands engage ACVR1B and ACVR2 receptor complexes.

Annotons

Activin beta A ligand
inhba_activin_beta_a_ligand
Participant: Family: Activin beta A ligand family/ortholog group
Family:
Activin beta A ligand family/ortholog groupPANTHER:PTHR11848
Representative Members: INHBAUniProtKB:P08476

Curated exemplar for the activin beta a ligand role in activin receptor signaling pathway.

ACVR1B type I receptor
acvr1b_acvr1b_type_i_receptor
Participant: Gene Product: ACVR1B
Gene Product:
ACVR1BUniProtKB:P36896

Curated exemplar for the acvr1b type i receptor role in activin receptor signaling pathway.

ACVR2A type II receptor
acvr2a_acvr2a_type_ii_receptor
Participant: Gene Product: ACVR2A
Gene Product:
ACVR2AUniProtKB:P27037

Curated exemplar for the acvr2a type ii receptor role in activin receptor signaling pathway.

Part 2: smad2/3 activation
SMAD2/3 activationRegulatory Stepsmad2_3_activation

Activin receptor kinases phosphorylate SMAD2 and SMAD3.

Annotons

SMAD2 receptor-regulated SMAD
smad2_smad2_receptor_regulated_smad
Participant: Gene Product: SMAD2
Gene Product:
SMAD2UniProtKB:Q15796

Curated exemplar for the smad2 receptor-regulated smad role in activin receptor signaling pathway.

SMAD3 receptor-regulated SMAD
smad3_smad3_receptor_regulated_smad
Participant: Gene Product: SMAD3
Gene Product:
SMAD3UniProtKB:P84022

Curated exemplar for the smad3 receptor-regulated smad role in activin receptor signaling pathway.

Part 3: activin transcriptional output
Activin transcriptional outputRegulatory Stepactivin_transcriptional_output

SMAD2/3-SMAD4 complexes drive activin-responsive transcription.

Annotons

SMAD4 common mediator
smad4_smad4_common_mediator
Participant: Gene Product: SMAD4
Gene Product:
SMAD4UniProtKB:Q13485

Curated exemplar for the smad4 common mediator role in activin receptor signaling pathway.

SMAD3 transcriptional effector
smad3_smad3_transcriptional_effector
Participant: Gene Product: SMAD3
Gene Product:
SMAD3UniProtKB:P84022

Curated exemplar for the smad3 transcriptional effector role in activin receptor signaling pathway.