Hypoxia-inducible factor is a bHLH-PAS heterodimer that activates transcription when oxygen is low. The oxygen-regulated alpha subunit Sima (similar) is hydroxylated by the prolyl hydroxylase Fatiga in normoxia and degraded; in hypoxia it accumulates, enters the nucleus and dimerizes with the constitutive beta subunit Tango (tgo), the Drosophila ARNT homolog, to bind hypoxia response elements. Sima-Tgo drives hypoxia-induced gene expression, including tracheal branching responses, and Sima also has roles in growth control under normoxia.
GO has no specific cellular-component term for the HIF heterodimer, so the general RNA polymerase II transcription regulator complex term is used. Tgo is also the common partner of other bHLH-PAS proteins (for example single-minded, trachealess, spineless); only its HIF role is modelled here. The oxygen sensor Fatiga (Hph) and the VHL ubiquitin ligase are regulators and are not parts. FlyBase groups realized by this module: HIF (FBgg0000902). 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_hif_complex.yaml. Member genes with a gene review in this repository: sima, tgo.
All recommended fields populated.
✗ none found
No MODULE:dmel_hif_complex deep-research report alongside the module YAML.
✓ every leaf node grounds to a representative protein.
✓ every declared conforms_to bundle matches its template motif.
2 gene-function check(s) reflected in core functions · 0 conflict(s) · 0 evidence or coverage gap(s) (2 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 |
|---|---|---|---|
| dmel_hif_complex_sima_sima | sima UniProtKB:Q24167 Gene |
DNA-binding transcription factor activity, RNA polymerase II-specific GO:0000981 |
Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass). |
| dmel_hif_complex_tgo_tgo | tgo UniProtKB:O15945 Gene |
DNA-binding transcription factor activity, RNA polymerase II-specific GO:0000981 |
Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass). |
1 complete review(s) · 2 with deep research · 0 missing review · 0 reviewed but lacking deep research
| Gene | Review | Complete | Deep research |
|---|---|---|---|
| sima Q24167 | ✓ | ✓ | ✓ |
| tgo O15945 | ✓ | 56/57 | ✓ |
Sima-Tgo bHLH-PAS heterodimer that activates gene expression in hypoxia.
oxygen-regulated alpha subunit
constitutive beta subunit (ARNT)