Mutations in Fks1p affect the cell wall content of β‐1,3‐ and β‐1,6‐glucan in <i>Saccharomyces cerevisiae</i>
Bibliographic record
Abstract
Fks1p and Fks2p are related proteins thought to be catalytic subunits of the beta-1,3-glucan synthase. Analysis of fks1 delta mutants showed a partial K1 killer toxin-resistant phenotype and a 30% reduction in alkali-soluble beta-1,3-glucan that was accompanied by a modest reduction in beta-1,6-glucan. The gas1 delta mutant lacking a 1,3-beta-glucanosyltransferase displayed a similar reduction in alkali-soluble beta-1,3-glucan but did not share the beta-1,6-glucan defect, indicating that beta-1,6-glucan reduction is not a general phenotype among beta-1,3-glucan biosynthetic mutants. Overexpression of FKS2 suppressed the killer toxin phenotype of fks1 delta mutants, implicating Fks2p in the biosynthesis of the residual beta-1,6-glucan present in fks1 delta cells. In addition, eight out of 12 fks1ts fks2 delta mutants had altered beta-glucan levels at the permissive temperature: the partial killer resistant FKS1F1258Y N1520D allele was severely affected in both polymers and displayed a 55% reduction in beta-1,6-glucan, while the in vitro hyperactive allele FKS1T605I M761T increased both beta-glucan levels. These beta-1,6-glucan phenotypes may be due to altered availability of, and structural changes in, the beta-1,3-glucan polymer, which might serve as a beta-1,6-glucan acceptor at the cell surface. Alternatively, Fks1p and Fks2p could actively participate in the biosynthesis of both polymers as beta-glucan transporters. We analysed Fks1p and Fks2p in beta-1,6-glucan deficient mutants and found that they were mislocalized and that the mutants had reduced in vitro glucan synthase activity, possibly contributing to the observed beta-1,6-glucan defects.
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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) | 0.001 | 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) | 0.002 | 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".