Target of Rapamycin drives unequal responses to essential amino acid depletion in egg laying

2021 ◽  
Author(s):  
André Nogueira Alves ◽  
Carla M Sgrò ◽  
Matthew D Piper ◽  
Christen K Mirth

Nutrition shapes a broad range of life history traits, ultimately impacting animal fitness. A key fitness-related trait, female fecundity is well known to change as a function of diet. In particular, the availability of dietary protein is one of the main drivers of egg production, and in the absence of essential amino acids egg laying declines. However, it is unclear whether all essential amino acids have the same impact on phenotypes like fecundity. Using a holidic diet, we fed adult female D. melanogaster diets that contain all necessary nutrients except one of the 10 essential amino acids and assessed the effects on egg production. For most essential amino acids, depleting a single amino acid induced as rapid a decline in egg production as when there were no amino acids in the diet. However, when either methionine or histidine were excluded from the diet, egg production declined more slowly. Next, we tested whether GCN2 and TOR were involved in this difference in response across amino acids. While mutations in GCN2 did not eliminate the differences in the rates of decline in egg laying among amino acid drop-out diets, we found that inhibiting TOR signalling caused egg laying to decline rapidly for all drop-out diets. TOR signalling does this by regulating the yolk-forming stages of egg chamber development. Our results suggest that amino acids differ in their ability to induce signalling via the TOR pathway. This is important because if phenotypes differ in sensitivity to individual amino acids, this generates the potential for mismatches between the output of a pathway and the animal's true nutritional status.

1957 ◽  
Vol 35 (1) ◽  
pp. 1005-1016 ◽  
Author(s):  
J. B. Derrick ◽  
Audrey P. Hanley

Observations have been made on the specific free amino acids (chromatographic analysis) and other nitrogenous constituents in the serum and urine of normal and arthritic men under controlled dietary conditions, before and after a glycine load and adrenocorticotropin administered separately and together.Differences in the metabolism of amino acids between normal individuals and arthritics, particularly of alanine, proline, glutamic acid, taurine, and possibly tyrosine (and/or tryptophan) and cystine, were apparent. The differences were largely confined to the non-essential amino acids. Concomitant increases seen in the serum levels and in the excretion of several amino acids, in response to a load of a single amino acid, indicate that the increases in excretion are more than a matter of competition for reabsorption in the kidney. A prerenal phenomenon appears to be involved, possibly interconversion of amino acids. This concept is supported by the evidence that the increases in the serum levels were restricted to the non-essential amino acids.


1957 ◽  
Vol 35 (11) ◽  
pp. 1005-1016 ◽  
Author(s):  
J. B. Derrick ◽  
Audrey P. Hanley

Observations have been made on the specific free amino acids (chromatographic analysis) and other nitrogenous constituents in the serum and urine of normal and arthritic men under controlled dietary conditions, before and after a glycine load and adrenocorticotropin administered separately and together.Differences in the metabolism of amino acids between normal individuals and arthritics, particularly of alanine, proline, glutamic acid, taurine, and possibly tyrosine (and/or tryptophan) and cystine, were apparent. The differences were largely confined to the non-essential amino acids. Concomitant increases seen in the serum levels and in the excretion of several amino acids, in response to a load of a single amino acid, indicate that the increases in excretion are more than a matter of competition for reabsorption in the kidney. A prerenal phenomenon appears to be involved, possibly interconversion of amino acids. This concept is supported by the evidence that the increases in the serum levels were restricted to the non-essential amino acids.


1989 ◽  
Vol 62 (1) ◽  
pp. 77-89 ◽  
Author(s):  
T. C. Wang ◽  
M. F. Fuller

A series of four nitrogen-balance experiments was carried out with growing pigs to determine the optimum balance amongst the amino acids in the diet. The reduction in N retention when 20 % of a single amino acid was removed from the diet was used to calculate a dietary amino acid pattern in which each amino acid would he equally limiting. A mixture of amino acids simulating the amino acid pattern of casein was used with the same efficiency as casein. From two successive deletion experiments an optimum balance amongst the essential amino acids was derived. Expressed relative to lysine = 100 this had threonine 72, valine 75, methionine + cystine 63, isoleucine 60, leucine 110, phenylalanine + tryosine 120, tryptophan 18. No estimate was made for histidine. Essential amino acids in this pattern were mixed with non-essential amino acids in ratios of 36:64 up to 57:43. The highest efficiency of N retention was achieved with diets having a ratio of at least 45:55. This included (g/16 g N) lysine 6 5, threonine 4.7, valine 4 9, methionine + cystine 4.1, isoleucine 3 9, leucine 7.2, phenylalanine + tyrosine 7.8, tryptophan 12. The N of diets with this amino acid pattern was utilized significantly better than when the pattern proposed by the Agricultural Research Council (1981) was used. The flow of amino acids past the terminal ileum of pigs given the semi-synthetic diet with this amino acid pattern was no greater than that observed with protein-free diets. The proposed pattern thus describes the intrinsic requirements of the growing pig for absorbed amino acids.


2013 ◽  
Vol 57 (11) ◽  
pp. 5733-5736 ◽  
Author(s):  
George A. Jacoby ◽  
Marian A. Corcoran ◽  
Debra M. Mills ◽  
Caitlin M. Griffin ◽  
David C. Hooper

ABSTRACTAlanine substitutions and selected deletions have been used to localize amino acids in QnrB essential for its protective activity. Essential amino acids are found at positions i and i−2in the pentapeptide repeat module and in the larger of two loops, where deletion of only a single amino acid compromises activity. Deletion of 10 amino acids at the N terminus is tolerated, but removal of 3 amino acids in the C-terminal dimerization unit destroys activity.


1970 ◽  
Vol 24 (4) ◽  
pp. 1071-1081 ◽  
Author(s):  
T. G. Taylor ◽  
J. J. Waring ◽  
R. K. Scougall

1. The changes occurring in the free amino acids of the plasma of laying hens in relation to egg formation have been investigated in fed and starved hens in three experiments, each with eight birds.2. The mean concentrations of most amino acids and of the totals were higher at night than in the morning.3. In general, egg formation was associated with increases in the concentrations of non- essential and decreases in the concentrations of essential amino acids. Cystine and glutamic acid tended to behave like the essential amino acids.4. After 40 h starvation seven amino acids, particularly serine, histidine and lysine, in- creased in concentration and only three, proline, ornithine and arginine, decreased significantly.5. When eight cocks were injected with oestrogen most of the amino acids increased in con-centration. The essential amino acids (with the exception of phenylalanine), serine, proline, cystine and ornithine showed the greatest increases.6. The results are discussed in relation to the possibility that the voluntary food intake of hens may be influenced by changes in the plasma levels of one or more essential amino acids associated with the synthesis of egg albumen. Arginine appeared to be the only amino acid that might possibly fulfil this role.7. It was concluded that investigations of changes in the free amino acids of hen plasma are unlikely to provide a useful approach to a study of the amino acid requirements or the nutritive value of particular proteins for egg production.


2017 ◽  
Vol 474 (12) ◽  
pp. 1935-1963 ◽  
Author(s):  
Stefan Bröer ◽  
Angelika Bröer

Cells have a constant turnover of proteins that recycle most amino acids over time. Net loss is mainly due to amino acid oxidation. Homeostasis is achieved through exchange of essential amino acids with non-essential amino acids and the transfer of amino groups from oxidised amino acids to amino acid biosynthesis. This homeostatic condition is maintained through an active mTORC1 complex. Under amino acid depletion, mTORC1 is inactivated. This increases the breakdown of cellular proteins through autophagy and reduces protein biosynthesis. The general control non-derepressable 2/ATF4 pathway may be activated in addition, resulting in transcription of genes involved in amino acid transport and biosynthesis of non-essential amino acids. Metabolism is autoregulated to minimise oxidation of amino acids. Systemic amino acid levels are also tightly regulated. Food intake briefly increases plasma amino acid levels, which stimulates insulin release and mTOR-dependent protein synthesis in muscle. Excess amino acids are oxidised, resulting in increased urea production. Short-term fasting does not result in depletion of plasma amino acids due to reduced protein synthesis and the onset of autophagy. Owing to the fact that half of all amino acids are essential, reduction in protein synthesis and amino acid oxidation are the only two measures to reduce amino acid demand. Long-term malnutrition causes depletion of plasma amino acids. The CNS appears to generate a protein-specific response upon amino acid depletion, resulting in avoidance of an inadequate diet. High protein levels, in contrast, contribute together with other nutrients to a reduction in food intake.


2016 ◽  
Vol 37 (3) ◽  
pp. 1539 ◽  
Author(s):  
Danilo Vargas Gonçalves Vieira ◽  
Thiago De Sousa Melo ◽  
José Humberto Vilar da Silva ◽  
Fernando Guilherme Perazzo Costa ◽  
Danilo Teixeira Cavalcante ◽  
...  

Three hundred and twenty-four DeKalb White laying hens aged 42 weeks were distributed in a completely randomised design with nine treatments and six replicates of six birds in each treatment. The experiment lasted 112 days. Diets were: T1 = 16.02% crude protein - CP [Met + Lys + Thr + Trp + Val]; T2 = 14.02% CP [Met + Lys + Thr + Trp + Ile + Val]; T3 = 14.02% CP [no amino acid supplementation]; T4 = 14.02% CP [Met + Lys + Thr + Trp]; T5 = 14.02% CP [Met + Lys + Thr]; T6 = 14.02% CP [Met]; T7 = 14.02% CP [Lys]; T8 = 14.02% CP [Thr]; T9 = 14.02% CP [Trp]. Regarding the quality of the eggs, the percentage of yolk and albumen, shell thickness and Haugh unit were not affected by the different diets. The percentage of shell, specific gravity and albumen height showed significant differences. We found that supplementation of only one amino acid in the diet (T7, T8 or T9), with the exception of methionine (T6), worsened performance relative to the control. Supplementation of three amino acids (methionine, lysine and threonine; T5) or four amino acids (methionine, lysine, threonine and tryptophan; T4) worsened egg production and conversion per mass and per dozen eggs; however, feed intake and egg weight and mass were similar to the control treatment. When all amino acids (methionine, lysine, threonine, tryptophan, isoleucine and valine; T2) were supplemented performance was similar to the control treatment in all variables. Supplementation of methionine, lysine and threonine is essential for birds in the laying phase; however the addition of six essential amino acids (lysine, methionine, threonine, tryptophan, valine and isoleucine) to the diet of laying hens is important for a good productive performance comparable with the control treatment T1. However, the inclusion of the latter two (isoleucine and valine) is justified only if the production cost is lower.


1956 ◽  
Vol 88 (2) ◽  
pp. 57-62 ◽  
Author(s):  
J. B. Dimond ◽  
A. O. Lea ◽  
W. F. Hahnert ◽  
D. M. DeLong

Since the monumental work of Rose (1938) on the essential amino acids for growth in the rat, similar studies have been made on other vertebrates. It has been shown that most of these animals have the same pattern of amino acid requirements for growth of the immature form and for maintenance of nitrogen equilibrium in the adult. The amino acids usually required are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophane, and valine. These studies have been adequately reviewed in recent texts (Bourne and Kidder 1953, Albanese 1950).


2018 ◽  
Author(s):  
Nidhi Gour ◽  
Bharti Koshti ◽  
Chandra Kanth P. ◽  
Dhruvi Shah ◽  
Vivek Shinh Kshatriya ◽  
...  

We report for the very first time self-assembly of Cysteine and Methionine to discrenible strucutres under neutral condition. To get insights into the structure formation, thioflavin T and Congo red binding assays were done which revealed that aggregates may not have amyloid like characteristics. The nature of interactions which lead to such self-assemblies was purported by coincubating assemblies in urea and mercaptoethanol. Further interaction of aggregates with short amyloidogenic dipeptide diphenylalanine (FF) was assessed. While cysteine aggregates completely disrupted FF fibres, methionine albeit triggered fibrillation. The cytotoxicity assays of cysteine and methionine structures were performed on Human Neuroblastoma IMR-32 cells which suggested that aggregates are not cytotoxic in nature and thus, may not have amyloid like etiology. The results presented in the manuscript are striking, since to the best of our knowledge,this is the first report which demonstrates that even non-aromatic amino acids (cysteine and methionine) can undergo spontaneous self-assembly to form ordered aggregates.


Sign in / Sign up

Export Citation Format

Share Document