The ABC transporter Pdr5p mediates the efflux of nonsteroidal ecdysone agonists in <i>Saccharomyces cerevisiae</i>
Bibliographic record
Abstract
We have previously shown that the synthetic nonsteroidal ecdysone agonist tebufenozide (RH-5992) is actively excluded by resistant cells of insects. To identify the transporter that could be involved in the efflux of RH-5992, the role of three ATP binding cassette transporters, Pdr5p, Snq2p and Ycf1p, has been studied using transporter-deletion mutants of yeast Saccharomyces cerevisiae. PDR5 (pleiotropic drug resistance 5) deletion mutants (Deltapdr5 and Deltapdr5Deltasnq2) retained significantly higher levels of 14C-radiolabeled RH-5992 within the cells when compared to wild-type strain or single deletion mutants of SNQ2 (Deltasnq2) and YCF1 (Deltaycf1). Introduction of an expression vector containing the PDR5 gene into the PDR5 single deletion mutant reversed the effect, resulting in the active exclusion of [14C]RH-5992 from these cells as efficiently as the wild-type cells. These results demonstrated that the ABC transporter Pdr5p but not Snq2p or Ycf1p was responsible for the active exclusion of [14C]RH-5992 in yeast. This exclusion was temperature-dependent and was blocked by the ATPase inhibitors oligomycin and vanadate, indicating that the efflux was an active process. The mutants with the PDR5 deletion can also selectively accumulate [14C]RH-0345 and [14C]RH-2485, but not [14C]RH-5849, indicating that these three compounds share the same transporter Pdr5p for efflux.
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How this classification was reachedexpand
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 | 0.002 | 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 | 0.001 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, 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".