Na,K-ATPase from Mice Lacking the γ Subunit (FXYD2) Exhibits Altered Na+ Affinity and Decreased Thermal Stability
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 gamma subunit of the Na,K-ATPase, a 7-kDa single-span membrane protein, is a member of the FXYD gene family. Several FXYD proteins have been shown to bind to Na,K-ATPase and modulate its properties, and each FXYD protein appears to alter enzyme kinetics differently. Different results have sometimes been obtained with different experimental systems, however. To test for effects of gamma in a native tissue environment, mice lacking a functional gamma subunit gene (Fxyd2) were generated. These mice were viable and without observable pathology. Prior work in the mouse embryo showed that gamma is expressed at the blastocyst stage. However, there was no delay in blastocele formation, and the expected Mendelian ratios of offspring were obtained even with Fxyd2-/- dams. In adult Fxyd2-/- mouse kidney, splice variants of gamma that have different nephron segment-specific expression patterns were absent. Purified gamma-deficient renal Na,K-ATPase displayed higher apparent affinity for Na+ without significant change in apparent affinity for K+. Affinity for ATP, which was expected to be decreased, was instead slightly increased. The results suggest that regulation of Na+ sensitivity is a major functional role for this protein, whereas regulation of ATP affinity may be context-specific. Most importantly, this implies that gamma and other FXYD proteins have their effects by local and not global conformation change. Na,K-ATPase lacking the gamma subunit had increased thermal lability. Combined with other evidence that gamma participates in an early step of thermal denaturation, this indicates that FXYD proteins may play an important structural role in the enzyme complex.
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 | 0.000 |
| 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) | 0.000 | 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