Transcriptional Regulation of the Copper Transporter Mfc1 in Meiotic Cells
Bibliographic record
Abstract
Mfc1 is a meiosis-specific protein that mediates copper transport during the meiotic program in Schizosaccharomyces pombe. Although the mfc1(+) gene is induced at the transcriptional level in response to copper deprivation, the molecular determinants that are required for its copper starvation-dependent induction are unknown. Promoter deletion and site-directed mutagenesis have allowed identification of a new cis-regulatory element in the promoter region of the mfc1(+) gene. This cis-acting regulatory sequence containing the sequence TCGGCG is responsible for transcriptional activation of mfc1(+) under low-copper conditions. The TCGGCG sequence contains a CGG triplet known to serve as a binding site for members of the Zn(2)Cys(6) binuclear cluster transcriptional regulator family. In agreement with this fact, one member of this group of regulators, denoted Mca1, was found to be required for maximum induction of mfc1(+) gene expression. Analysis of Mca1 cellular distribution during meiosis revealed that it colocalizes with both chromosomes and sister chromatids during early, middle, and late phases of the meiotic program. Cells lacking Mca1 exhibited a meiotic arrest at metaphase I under low-copper conditions. Binding studies revealed that the N-terminal 150-residue segment of Mca1 expressed as a fusion protein in Escherichia coli specifically interacts with the TCGGCG sequence of the mfc1(+) promoter. Taken together, these results identify the cis-regulatory TCGGCG sequence and the transcription factor Mca1 as critical components for activation of the meiotic copper transport mfc1(+) gene in response to copper starvation.
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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 | 0.001 |
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".