A lysine residue from an extracellular turret switches the ion preference in a Cav3 T-Type channel
Bibliographic record
Abstract
Abstract A dominant sodium influx is mediated by a lysine residue in a novel extracellular loop of T-type Cav3 channels. Here we expressed calcium- and sodium-permeable splice variants which have exons 12b and 12a, respectively, as well as mutated channels containing exons Lys-12a-Ala and Ala-12b-Lys. We demonstrate that the mutant channels render high sodium permeability and calcium selectivity, respectively. Modelling illustrate that the pore lysine is salt-bridged to an aspartate residue immediately C-terminal to the second-domain glutamate of the selectivity-filter. We propose that a calcium ion chelated between the aspartate and the selectivity-filter glutamate is knocked-out by the incoming calcium ion in the process of calcium permeation, but sodium ions are repelled. The aspartate is neutralized by the lysine residue in the sodium-permeant variant, allowing for sodium permeation through the selectivity filter ring of four acidic residues akin to the prokaryotic sodium channels with four glutamates in the selectivity filter.
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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".