Novel role for the <i>Saccharomyces cerevisiae</i> oligopeptide transporter Opt2 in drug detoxificationIn memory of Ghassan Belhadj.
Bibliographic record
Abstract
Saccharomyces cerevisiae Opt2 is a member of the oligopeptide transporter family that was initially identified to transport tetra- and pentapeptides. Mutants deleted for the OPT2 gene exhibit no growth defects under normal culture conditions. We identified OPT2 from a high-throughput screen that when deleted results in mutants that displayed sensitivity to the anticancer agent bleomycin. The opt2Delta mutant was also reisolated in two additional genome-wide screens designed to identify mutants that are sensitive to the immunosuppressant rapamycin and the divalent metal ion zinc. However, the role of Opt2 in protecting cells against these agents was not investigated. Herein, we show that opt2Delta mutants are also sensitive to a wide variety of toxic agents that are typically detoxified by the vacuoles. Mutants lacking two other related oligopeptide transporters, Opt1 and Ygl114w, showed no significant sensitivities to these drugs, indicating a specific role for Opt2 in drug detoxification. The sensitivities of the opt2Delta mutants were not related to an increased drug uptake but rather to the presence of several small vesicles instead of a functional large vacuole. We propose that Opt2 has a novel function involving the fusion of vesicles to form a mature vacuole.
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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 | 0.000 |
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".