GBF1, a cis-Golgi and VTCs-localized ARF-GEF, is implicated in ER-to-Golgi protein traffic
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
The formation and maturation of membrane carriers that transport cargo from the ER to the Golgi complex involves the sequential action of the coat protein complexes COPII and COPI. Recruitment of COPI to nascent carriers requires activation of ADP-ribosylation factors by a BrefeldinA-sensitive guanine nucleotide exchange factor. Using new antisera and a GFP-tagged protein, we demonstrate that the exchange factor GBF1 localized to both Golgi membranes and peripheral puncta, near but separate from ER exit sites. Live cell imaging revealed that GFP-GBF1 associates dynamically with both membranes through rapid exchange with a large cytosolic pool. Treatment with BrefeldinA dramatically altered this rapid exchange, causing accumulation of GBF1 on both Golgi and peripheral puncta before eventual redistribution to the ER in a microtubule-dependent manner. Measurement of diffusion coefficients and subcellular fractionation confirmed this shift in GBF1 from cytosolic to membrane bound. BrefeldinA-induced accumulation of GBF1 coincided with loss of COPI from peripheral puncta. Furthermore, recruitment of GBF1 to cargo-containing peripheral puncta coincided with recruitment of COPI, but not COPII. Strikingly, microinjection of anti-GBF1 antibodies specifically caused dissociation of COPI from membranes. These observations strongly suggest that GBF1 regulates COPI membrane recruitment in the early secretory pathway.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it