The Hsp110 molecular chaperone stabilizes apolipoprotein B from endoplasmic reticulum associated degradation
Bibliographic record
Abstract
Apolipoprotein B (apoB) is the most abundant protein in low‐density lipoproteins and plays key roles in cholesterol homeostasis. The co‐translational degradation of apoB is controlled by fatty acid levels in the ER and is mediated by the proteasome. To define the mechanism of apoB degradation, we employed a cell‐free system in which proteasome‐dependent degradation is recapitulated with yeast cytosol and we developed an apoB yeast expression system. We discovered that a yeast Hsp110, Sse1p, associates with and stabilizes apoB, which contrasts with data indicating that Hsp70 and Hsp90 facilitate apoB degradation. However, the Ssb chaperones, another class of Hsp70s, have no effect on apoB turnover. To determine whether our results are relevant in mammalian cells, Hsp110 was over‐expressed in hepatocytes and enhanced apoB secretion was observed. This study indicates that chaperones within distinct complexes can play unique roles during ER associated degradation (ERAD), establishes a role for Sse1/Hsp110 in ERAD, and identifies Hsp110 as a target to lower cholesterol.
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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 | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".