Proprotein convertase subtilisin/kexin type 4 in mammalian fertility: a review
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
BACKGROUND: Proprotein convertase subtilisin/kexin type 4 (PCSK4), also known as proprotein convertase 4, belongs to a family of endoproteinases involved in the proteolytic conversion of secretory precursor proteins to their active forms. Its amino acid sequence is highly conserved in mammals, an indication of its biological importance. METHODS: We have searched PubMed and molecular biology databases for information relating to the structure, expression and biological functions of PCSK4. RESULTS: PCSK4 is predominantly expressed in male germ cells and located on the plasma membrane overlying the acrosome of sperm. It is also present in ovary and placenta. Inactivation of its gene in mouse does not alter spermatogenesis, but renders sperm incapable of fertilizing oocytes. This incapacity results in part from sperm susceptibility to a premature acrosome reaction and their reduced ability to bind to the zona pellucida. In female mice, a lack of PCSK4 causes subfertility associated with impaired folliculogenesis. In addition, this enzyme has been shown to stimulate the invasiveness of human placental trophoblasts in culture, suggesting that it may facilitate placentation in vivo. CONCLUSIONS: PCSK4 appears to be a crucial enzyme for reproduction. Alterations of PCSK4 expression or activity could be the underlying cause of some unexplained cases of human infertility. Conversely, inactivation of this protease represents a potential strategy for non-hormonal contraception.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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) | 0.000 | 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 it