Stoichiometry of the Retinal Cone Na/Ca-K Exchanger Heterologously Expressed in Insect Cells: Comparison with the Bovine Heart Na/Ca Exchanger
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
The transport stoichiometry is an essential property of antiporter and symporter transport proteins. In this study, we determined the transport stoichiometry of the retinal cone potassium-dependent Na/Ca exchanger (NCKX) expressed in sodium-loaded cultured insect cells. The Na/Ca and Rb/Ca coupling ratios were obtained by direct measurements of the levels of (86)Rb and (45)Ca uptake and sodium release associated with reverse Na/Ca exchange. Rb/Ca coupling ratios of 0.98 [standard deviation (SD) of 0.12, 15 observations] and 0.92 (SD of 0.12, 13 observations) were obtained for the chicken and human retinal cone NCKX, respectively. Na/Ca coupling ratios of 4.11 (SD of 0.24, 10 observations) and 3.98 (SD of 0.34, 15 observations) were obtained for the chicken and human retinal cone NCKX, respectively, whereas a lower average coupling ratio of 3.11 (SD of 0.34, 10 observations) was obtained with cells expressing the bovine Na/Ca exchanger (NCX1). These results are consistent with a 4Na/1Ca + 1K stoichiometry for retinal cone NCKX. High Five cells expressing full-length dolphin rod NCKX, Caenorhabditis elegans NCKX, or bovine rod NCKX from which the two large hydrophilic loops were removed all showed a significant calcium-dependent (86)Rb uptake, whereas no calcium-dependent (86)Rb uptake was observed in cells expressing bovine NCX1. The calcium dependence of (45)Ca uptake yielded values between 1 and 2.5 microM for the external calcium dissociation constant of the different NCKX proteins studied here.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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