Combination of histidine, lysine, methionine, and leucine promotes β-casein synthesis via the mechanistic target of rapamycin signaling pathway in bovine mammary epithelial cells
Bibliographic record
Abstract
The ratio of different AA in the diets of cows is vital to improve milk protein yield. -Casein is one of the important milk proteins with high nutritive value. However, the suitable ratio of essential amino acids (EAA) for the expression of -casein in the immortalized bovine mammary epithelial cell line is not fully characterized. This study employed response surface methodology to determine the optimal ratio of His, Lys, Met, and Leu on -casein expression level in vitro and clarified the effect of the 4 EAA on -casein via the mechanistic target of rapamycin (mTOR) signaling pathway. A central composite design containing 5 axial points per EAA and 28 combinations of the 4 EAA was used in our study. The results of response surface methodology and the changes of the mTORrelated signaling proteins were determined by western blot. The results showed that -casein level was significantly affected by all 4 EAA (R 2 = 0.71). The optimum conditions for -casein expression are found to be 5.47 mM of His, 7.48 mM of Lys, 1.17 mM of Met, and 8.21 mM of Leu (His:Lys:Met:Leu = 5:6:1:7) in the designed scope of concentration. The interaction of Leu and Met significantly affected -casein expression (P < 0.01). The phosphorylation of mTOR (Ser 2481 ), regulatory associated protein of target of rapamycin (Ser 792 ), ribosomal protein S6 kinase 1 (Thr 389 ), ribosomal protein S6 (Ser 235/236 ), and eukaryotic elongation factor 2 (Thr 56 ) was increased with the supplementation of either single EAA or an optimal combination of EAA. However, the phosphorylation of eukaryotic initiation factor 4E binding protein 1 (Thr 37 ) was decreased with the addition of Lys, Met, or Leu alone. Furthermore, the phosphorylation (P) of eIF2 (Ser 51 ) was decreased when Met was supplemented alone. Under the optimal mixture of 4 EAA, the phosphorylation of mechanistic target of rapamycin complex 1 signaling proteins was significantly greater than the single EAA supplementations and the expression of -casein was 98% as high as the positive control (i.e., medium with all AA). A similar trend was found with P-ribosomal protein S6 kinase 1 and P-ribosomal protein S6. In conclusion, the extracellular concentrations of His, Lys, Met, and Leu at a ratio of 5:6:1:7 maximized -casein expression in the immortalized bovine mammary epithelial cell line may occur via activation of the mechanistic target of rapamycin complex 1 signaling pathway.
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.
How this classification was reachedexpand
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 | 0.002 | 0.001 |
| 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 | 0.001 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, 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".