The COPII coat forms vesicles and tubules that export secretory cargo from endoplasmic reticulum exit sites to the Golgi apparatus. The small GTPase Sar1, activated by its ER-membrane exchange factor, inserts into the membrane and recruits the inner coat, a heterodimer of Sec23 and Sec24. Sec24 binds cargo sorting signals, and Sec23 is the GTPase-activating protein for Sar1. The inner coat then recruits the outer coat of Sec13 and Sec31, which forms a cage around the bud and stimulates Sec23 GAP activity. Drosophila has two Sec24 paralogs, Sec24AB and Sec24CD.
Boundary. The module contains Sar1 and the inner and outer coat proteins. The Sar1 exchange factor (Sec12 homolog), Sec16 and the TANGO1 machinery for large cargo organize exit sites and are context, not parts. The two Sec24 paralogs are modelled as alternative inner-coat variants; their cargo preferences in Drosophila are not fully mapped. FlyBase groups realized by this module: COPII (FBgg0000116). 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_copii_coat.yaml. None of the member genes has a gene review in this repository yet.
All recommended fields populated.
✗ none found
No MODULE:dmel_copii_coat 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.
0 gene-function check(s) reflected in core functions · 0 conflict(s) · 3 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 |
|---|---|---|---|
| sar1_gtpase_sar1 | Sar1 UniProtKB:Q9VD29 Gene |
GTPase activity GO:0003924 |
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked. |
| sec23_sec24ab_complex/sec23 | Sec23 UniProtKB:A0A0B4K5Z8 Complex Unit |
GTPase activator activity GO:0005096 |
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked. |
| sec23_sec24cd_complex/sec23 | Sec23 UniProtKB:A0A0B4K5Z8 Complex Unit |
GTPase activator activity GO:0005096 |
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked. |
✓ every negative regulator described as feedback has an upstream edge closing the loop.
0 complete review(s) · 0 with deep research · 6 missing review · 0 reviewed but lacking deep research
| Gene | Review | Complete | Deep research |
|---|---|---|---|
| Sec23 A0A0B4K5Z8 | ✗ | — | — |
| Sec31 A0A0B4LEZ1 | ✗ | — | — |
| Sec24AB A1Z813 | ✗ | — | — |
| Sec24CD M9PC99 | ✗ | — | — |
| Sec13 Q9V3J4 | ✗ | — | — |
| Sar1 Q9VD29 | ✗ | — | — |
Sar1, Sec23-Sec24 and Sec13-Sec31 coat that packages cargo into vesicles at ER exit sites for transport to the Golgi.