Molecular Motors Involved in Chromaffin Cell Secretion
Bibliographic record
Abstract
Neurosecretory cells, including chromaffin cells, possess a mesh of filamentous actin underneath the plasma membrane. It has been proposed that filamentous actin network separates the secretory vesicles into two compartments: the reserve pool and the release-ready vesicle pool. Disassembly of chromaffin cell cortical filamentous actin in response to stimulation allows the movement of vesicles from the reserve pool into the release-ready vesicle pool. Electron microscopy of cytoskeletons revealed the presence of polygonal areas almost devoid of actin filaments in stimulated cells. The percentage of stimulated cells showing disrupted cytoskeleton correlates well with the increase in secretion in these cells. Fine filaments also remain in these areas of disassembly, and these reacted with actin antibodies, as demonstrated by immunogold staining. In addition, the movement of vesicles between pools requires Ca(2+) and ATP, a condition for activation of a molecular motor. Confocal microscopy images demonstrated colocalization of myosin Va with dopamine-beta-hydroxylase. Cell depolarization induced the dissociation of myosin Va from chromaffin vesicles. 2,3-Butadione-2-monoxime (BDM), an inhibitor of myosin ATPase, inhibited secretion, suggesting a blockage for chromaffin vesicle transport between the reserve pool and the release-ready vesicle pool. On the other hand, myosin II subcellular distribution was not affected by cell depolarization. Confocal microscopy images show myosin II to be localized in the cell cortex and in some perinuclear structures. Chromaffin vesicles were not stained by myosin II antibody.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".