Structure-function studies of Drosophila NaS+-Ca2S+ exchanger proteins
Bibliographic record
Abstract
The cardiac Na$\\sp{+}$-Ca$\\sp{2+}$ exchanger, NCX1.1, is the most extensively studied member of this multi-gene family of ion counter-transporters. It is unknown whether the structure-function relationships of NCX1.1 apply to any other exchanger. To examine this possibility, structure-function studies targeting these regulatory domains were performed with a Drosophila Na$\\sp{+}$-Ca$\\sp{2+}$ exchanger, CALX1.1. Although NCX1.1. and CALX1.1. are both regulated by Na$\\sp{+}\\sb{i}$ and Ca$\\sp{2+}\\sb{i}$, an opposite response to regulatory Ca$\\sp{2+}\\sb{i}$ is observed between these two exchangers. That is, whereas Ca$\\sp{2+}\\sb{i}$ activates NCX1.1 exchange activity, CALX1.1 is inhibited. Wild-type and mutant exchangers were expressed in Xenopus laevis oocytes and characterized electrophysiologically using the giant excised patch clamp technique. The second major aspects of this thesis involves the study of two alternatively spliced isoforms of the Na$\\sp{+}$-Ca$\\sp{2+}$ exchanger identified in Drosophila melanogaster. These isoforms, called CALX1.1 and CALX1.2, differ by five amino acids in a region near the C-terminus of the large cytoplasmic loop. To determine whether the sequence difference observed for Drosophila isoforms influenced intrinsic regulatory properties, we examined Na$\\sp{+}\\sb{i}$- and Ca$\\sp{2+}\\sb{i}$-dependent regulation for both exchangers using the giant excised membrane patch clamp technique. (Abstract shortened by UMI.)
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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".