The catalytic domain CysPc of the <scp>DEK</scp>1 calpain is functionally conserved in land plants
Bibliographic record
Abstract
DEK1, the single calpain of land plants, is a member of the ancient membrane bound TML-CysPc-C2L calpain family that dates back 1.5 billion years. Here we show that the CysPc-C2L domains of land plant calpains form a separate sub-clade in the DEK1 clade of the phylogenetic tree of plants. The charophycean alga Mesostigma viride DEK1-like gene is clearly divergent from those in land plants, suggesting that a major evolutionary shift in DEK1 occurred during the transition to land plants. Based on genetic complementation of the Arabidopsis thaliana dek1-3 mutant using CysPc-C2L domains of various origins, we show that these two domains have been functionally conserved within land plants for at least 450 million years. This conclusion is based on the observation that the CysPc-C2L domains of DEK1 from the moss Physcomitrella patens complements the A. thaliana dek1-3 mutant phenotype. In contrast, neither the CysPc-C2L domains from M. viride nor chimeric animal-plant calpains complement this mutant. Co-evolution analysis identified differences in the interactions between the CysPc-C2L residues of DEK1 and classical calpains, supporting the view that the two enzymes are regulated by fundamentally different mechanisms. Using the A. thaliana dek1-3 complementation assay, we show that four conserved amino acid residues of two Ca²⁺-binding sites in the CysPc domain of classical calpains are conserved in land plants and functionally essential in A. thaliana DEK1.
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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 | 0.000 |
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".