scholarly journals An internal sensor detects dietary amino acids and promotes food consumption in Drosophila

2017 ◽  
Author(s):  
Zhe Yang ◽  
Rui Huang ◽  
Xin Fu ◽  
Gaohang Wang ◽  
Wei Qi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Consumption ◽  
Protein Intake ◽  
Fruit Fly ◽  
Fruit Flies ◽  
Food Sources ◽  
Dietary Amino Acids ◽  
Necessary And Sufficient ◽  
Amino Acid Sensor

ABSTRACTAdequate protein intake is crucial for animals. Despite the recent progress in understanding protein hunger and satiety in the fruit fly Drosophila melanogaster, how fruit flies assess prospective dietary protein sources and ensure protein consumption remains elusive. We show here that three specific amino acids, L-glutamate (L-Glu), L-alanine (L-Ala), and L-aspartate (L-Asp), rapidly promote food consumption in fruit flies when present in food. The effect of dietary amino acids to promote food consumption is independent of mating experience and internal nutritional status. Genetic analysis identifies six brain neurons expressing diuretic hormone 44 (DH44) as a sensor of dietary amino acids. DH44+ neurons can be directly activated by these three amino acids, and are both necessary and sufficient for dietary amino acids to promote food consumption. By conducting single cell RNAseq analysis, we also identify an amino acid transporter, CG13248, which is highly expressed in DH44+ neurons and is required for dietary amino acids to promote food consumption. Therefore, these data suggest that dietary amino acids may enter DH44+ neurons via CG13248 and modulate their activity and hence food consumption. Taken together, these data identify an internal amino acid sensor in the fly brain that evaluate food sources post-ingestively and facilitates adequate protein intake.

scholarly journals Severe anemia in patients with Propionic acidemia is associated with branched-chain amino acid imbalance

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Sinziana Stanescu ◽  
Amaya Belanger-Quintana ◽  
Borja Manuel Fernandez-Felix ◽  
Francisco Arrieta ◽  
Victor Quintero ◽  
...  
Keyword(s):  
Amino Acids ◽  
Food Consumption ◽  
Protein Intake ◽  
Propionic Acidemia ◽  
Study Data ◽  
Metabolic Decompensation ◽  
Severe Anemia ◽  
Medical Food ◽  
Natural Protein ◽  
Branched Chain

Abstract Background Propionic acidemia (PA), an inborn error of metabolism, is caused by a deficiency in propionyl-CoA carboxylase. Patients have to follow a diet restricted in the propiogenic amino acids isoleucine (Ile), valine (Val), methionine (Met) and threonine (Thr); proper adherence can prevent and treat acute decompensation and increase life expectancy. However, chronic complications occur in several organs even though metabolic control may be largely maintained. Bone marrow aplasia and anemia are among the more common. Materials and methods In this retrospective study, data for patients with PA being monitored at the Hospital Ramón y Cajal (Madrid, Spain) (n = 10) in the past 10 years were examined to statistically detect relationships between persistent severe anemia outside of metabolic decompensation episodes and dietary practices such as natural protein intake and medical food consumption (special mixture of precursor-free amino acids) along with plasma levels of branched-chain amino acids (BCAA). High ferritin levels were deemed to indicate that a patient had received repeated transfusions for persistent anemia since data on hemoglobin levels at the moment of transfusion were not always passed on by the attending centers. Results Three patients had severe, persistent anemia that required repeated blood transfusions. Higher medical food consumption and plasma Leu levels were associated with iron overload. Notably, natural protein intake and plasma Val were negatively correlated with ferritin levels. We also observed an inverse relationship between plasma Val/Leu and Ile/Leu ratios and ferritin. Conclusion The present results suggest that severe anemia in patients with PA might be associated with low natural protein intake and BCAA imbalance.

scholarly journals Activation of the SPS Amino Acid-Sensing Pathway in Saccharomyces cerevisiae Correlates with the Phosphorylation State of a Sensor Component, Ptr3

2007 ◽  
Vol 28 (2) ◽  
pp. 551-563 ◽  
Author(s):  
Zhengchang Liu ◽  
Janet Thornton ◽  
Mário Spírek ◽  
Ronald A. Butow
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Amino Acid ◽  
Nuclear Translocation ◽  
Proteolytic Processing ◽  
Casein Kinase I ◽  
Positive Regulators ◽  
Amino Acid Permeases ◽  
Amino Acid Sensing ◽  
Amino Acid Sensor

ABSTRACT Cells of the budding yeast Saccharomyces cerevisiae sense extracellular amino acids and activate expression of amino acid permeases through the SPS-sensing pathway, which consists of Ssy1, an amino acid sensor on the plasma membrane, and two downstream factors, Ptr3 and Ssy5. Upon activation of SPS signaling, two transcription factors, Stp1 and Stp2, undergo Ssy5-dependent proteolytic processing that enables their nuclear translocation. Here we show that Ptr3 is a phosphoprotein whose hyperphosphorylation is increased by external amino acids and is dependent on Ssy1 but not on Ssy5. A deletion mutation in GRR1, encoding a component of the SCFGrr1 E3 ubiquitin ligase, blocks amino acid-induced hyperphosphorylation of Ptr3. We found that two casein kinase I (CKI) proteins, Yck1 and Yck2, previously identified as positive regulators of SPS signaling, are required for hyperphosphorylation of Ptr3. Loss- and gain-of-function mutations in PTR3 result in decreased and increased Ptr3 hyperphosporylation, respectively. We found that a defect in PP2A phosphatase activity leads to the hyperphosphorylation of Ptr3 and constitutive activation of SPS signaling. Two-hybrid analysis revealed interactions between the N-terminal signal transduction domain of Ssy1 with Ptr3 and Yck1. Our findings reveal that CKI and PP2A phosphatase play antagonistic roles in SPS sensing by regulating Ptr3 phosphorylation.

scholarly journals Analysis of Htra Gene from Zebrafish (Danio Rerio)

2015 ◽  
Vol 10 (2) ◽  
Author(s):  
M. Murwantoko ◽  
Chio Oka ◽  
Masashi Kawaichi
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Danio Rerio ◽  
Serine Proteases ◽  
Catalytic Domain ◽  
Fruit Fly ◽  
Wide Range ◽  
Igf Binding ◽  
Bacterial Homolog

HtrA which is characterized by the combination of a trypsin-like catalytic domain with at least one C-terminalPDZ domain is a highly conserved family of serine proteases found in a wide range of organisms. However theidentified HtrA family numbers varies among spesies, for example the number of mammalian, Eschericia coli,fruit fly-HtrA family are 4, 3 and 1 gene respectively. One gene is predicted exist in zebrafish. Since no completeinformation available on zebrafish HtrA, in this paper zebrafish HtrA (zHtrA) gene was analyzed. The zHtrA isbelonged to HtrA1 member and predicted encodes 478 amino acids with a signal peptide, a IGF binding domain,a Kazal-type inhibitor domain in the up stream of HtrA-bacterial homolog. At the amino acid sequence the zHtrA1showed the 69%, 69%, 68%, 54% and 54% with the rat HtrA1, mouse HtrA1, human HtrA1, human HtrA3 andmouse HtrA4 respectively. The zHtrA1 is firstly expressed at 60 hpf and mainly in the vertebral rudiments in thetail region.

High Protein Intake during Continuous Hemodiafiltration: Impact on Amino Acids and Nitrogen Balance

2002 ◽  
Vol 25 (4) ◽  
pp. 261-268 ◽  
Author(s):  
R. Bellomo ◽  
H. K. Tan ◽  
S. Bhonagiri ◽  
I. Gopal ◽  
J. Seacombe ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nitrogen Balance ◽  
Protein Intake ◽  
Protein Supplementation ◽  
High Protein ◽  
Total Serum ◽  
Amino Acid Supplementation ◽  
Continuous Hemodiafiltration ◽  
High Protein Intake

Aims To study the effect of combined continuous veno-venous hemodiafiltration (CVVHDF) and high (2.5 g/kg/day) parenteral amino acid supplementation on nitrogen balance, amino acid losses and azotemic control in a cohort of patients with severe acute renal failure (ARF). Methods We administered 2.5 grams/kg/day of amino acids intravenously to seven critically ill patients with ARF. We obtained paired blood and ultrafiltrate (UF) samples (n=20) and calculated amino acid clearances and losses, nitrogen balance, protein catabolic rate and total nitrogen losses. Results The median total serum amino acid concentration was high at 5.2 mmol/L with particularly high concentrations of ornithine, lysine, and phenylalanine, but a low level of histidine. The median overall amino acid clearance was 18.6 ml/min (range: 12 to 29 ml/min). UF losses as percentage of administered dose were high for tyrosine (53.6 %) but low for methionine (3.0 %) and arginine (2.3 %). A positive nitrogen balance was achieved in 7 (35%) of the 20 study days with an overall median nitrogen balance of -1.8 g/day. Urea levels were maintained at a median of 26.6 mmol/L. Conclusions High protein intake increases the serum concentrations of most amino acids. Such protein supplementation, when coupled with CVVHDF, achieves a slightly negative overall nitrogen balance in extremely catabolic patients while still allowing adequate azotemic control.

scholarly journals Oxidation of an indicator amino acid by young pigs receiving diets with varying levels of lysine or threonine, and an assessment of amino acid requirements

1983 ◽  
Vol 50 (2) ◽  
pp. 391-399 ◽  
Author(s):  
Kyu-Il Kim ◽  
James I. Elliott ◽  
Henry S. Bayley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino ◽  
Skim Milk ◽  
Linear Increase ◽  
Single Amino Acid ◽  
Dietary Level ◽  
Dietary Amino Acids ◽  
Young Pigs ◽  
Amino Acid Requirements

1. The catabolism of [14C]phenylalanine was used to indicate the effects of varying the dietary level of lysine and threonine on the retention of dietary amino acids by 2-week-old pigs receiving diets containing skim milk and a mixture of free amino acids.2. Reducing the dietary level of lysine from 16 to 12 g/kg had no influence on phenylalanine oxidation, reducing the lysine level from 12 to 11 then to 10 g/kg caused an almost linear increase in phenylalanine oxidation whereas further reduction to 9 or 8 g/kg resulted in a less-marked increase in phenylalanine oxidation. This showed that 12 g lysine/kg was required to maximize amino acid retention and indicated that lysine was conserved more effectively at low dietary concentrations than at dietary concentrations approaching the requirement.3. Reducing the dietary level of threonine from 8 to 6 g/kg had no influence on phenylalanine oxidation, whereas further reduction to 4 g/kg caused a linear increase in phenylalanine catabolism showing that 6 g threonine/kg was required to maximize amino acid retention.4. Reduction of the levels of lysine, threonine and methionine from the generous levels characteristic of a diet containing 240 g protein from skim milk/kg, to the requirement levels determined separately in the presence of the generous levels of all the other amino acids, resulted in a twofold increase in phenylalanine catabolism. This shows that the pig seems able to conserve limiting intakes of a single amino acid, but not if the intakes of two or three amino acids are limiting.

scholarly journals Proline as an essential amino acid for the young pig

1986 ◽  
Vol 55 (3) ◽  
pp. 659-668 ◽  
Author(s):  
Ronald O. Ball ◽  
James L. Atkinson ◽  
Henry S. Bayley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
G Protein ◽  
Crude Protein ◽  
Protein Diet ◽  
Single Amino Acid ◽  
Amino Acid Supplementation ◽  
Protein Nitrogen ◽  
Dietary Amino Acids ◽  
Arginine Concentration

1. The catabolism of L-[ l-14C]phenylalanine was used to indicate the effects of single amino acid supplementation of an inadequate protein diet (200 g crude protein (nitrogen x 6.25)/kg) on the utilization of dietary amino acids in pigs of 2.5 kg body-weight reared on an adequate protein diet (240 g crude protein/kg) containing skim milk and a mixture of free amino acids.2. The oxidation of phenylalanine was decreased by the addition of proline or arginine to the inadequate protein diet but not by the addition of threonine, methionine, lysine or a mixture of essential amino acids, indicating that proline and arginine were limiting the utilization of dietary amino acids in the inadequate protein diet.3. Dietary proline concentrations of 13.9 and 14.2 g/kg minimized phenylalanine oxidation in diets containing 200 or 260 g protein/kg. This indicates a dietary proline requirement of 14 g/kg.4. Increasing the dietary arginine concentration in a diet containing 240 g protein/kg showed that an arginine concentration of 5.1 g/kg minimized phenylalanine oxidation. However, increasing the arginine concentration in a diet containing 200 g protein/kg increased phenylalanine oxidation, suggesting an amino acid imbalance involving arginine at this lower level of protein.

Dietary amino acids fed in free form or as protein do differently affect amino acid absorption in a rat everted sac model

2008 ◽  
Vol 92 (5) ◽  
pp. 529-537 ◽  
Author(s):  
J. A. Nolles ◽  
I. G. S. Peeters ◽  
B. I. Bremer ◽  
R. Moorman ◽  
R. E. Koopmanschap ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Form ◽  
Acid Absorption ◽  
Amino Acid Absorption ◽  
Dietary Amino Acids

scholarly journals Dietary supplementation of propionylated starch to domestic cats provides propionic acid as gluconeogenic substrate potentially sparing the amino acid valine

2014 ◽  
Vol 3 ◽  
Author(s):  
Kristel Rochus ◽  
An Cools ◽  
Geert P. J. Janssens ◽  
Lynn Vanhaecke ◽  
Birgitte Wuyts ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Propionic Acid ◽  
Protein Intake ◽  
Protein Digestibility ◽  
Domestic Cats ◽  
Intake Level ◽  
Health And Disease ◽  
And Control ◽  
Gluconeogenic Substrate

AbstractIn strict carnivorous domestic cats, a metabolic competition arises between the need to use amino acids for gluconeogenesis and for protein synthesis both in health and disease. The present study investigated the amino acid-sparing potential of propionic acid in cats using dietary propionylated starch (HAMSP) supplementation. A total of thirty cats were fed a homemade diet, supplemented with either HAMSP, acetylated starch (HAMSA) or celite (Control) for three adaptation weeks. Propionylated starch was hypothesised to provide propionic acid as an alternative gluconeogenic substrate to amino acids, whereas acetic acid from HAMSA would not provide any gluconeogenic benefit. Post-adaptation, a 5-d total faecal collection was carried out to calculate apparent protein digestibility coefficients. Fresh faecal and blood samples were collected to analyse fermentation endproducts and metabolites. The apparent protein digestibility coefficients did not differ between supplements (P = 0·372) and were not affected by the protein intake level (P = 0·808). Faecal propionic acid concentrations were higher in HAMSP than in HAMSA (P = 0·018) and Control (P = 0·003) groups, whereas concentrations of ammonia (P = 0·007) were higher in HAMSA than in HAMSP cats. Tendencies for or higher propionylcarnitine concentrations were observed in HAMSP compared with HAMSA (P = 0·090) and Control (P = 0·037) groups, and for tiglyl- + 3-methylcrotonylcarnitine concentrations in HAMSP as compared with Control (P = 0·028) cats. Methylmalonylcarnitine concentrations did not differ between groups (P = 0·740), but were negatively correlated with the protein intake level (r –0·459, P = 0·016). These results suggest that HAMSP cats showed more saccharolytic fermentation patterns than those supplemented with HAMSA, as well as signs of sparing of valine in cats with a sufficient protein intake.

scholarly journals LAT1 and SNAT2 Protein Expression and Membrane Localization of LAT1 Are Not Acutely Altered by Dietary Amino Acids or Resistance Exercise Nor Positively Associated with Leucine or Phenylalanine Incorporation in Human Skeletal Muscle

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3906
Author(s):  
Michael Mazzulla ◽  
Nathan Hodson ◽  
Matthew Lees ◽  
Paula J. Scaife ◽  
Kenneth Smith ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Amino Acid ◽  
Protein Expression ◽  
Resistance Exercise ◽  
Membrane Localization ◽  
Amino Acid Incorporation ◽  
Dietary Amino Acids ◽  
Neutral Amino Acid Transporter ◽  
Dietary Amino Acid

The influx of essential amino acids into skeletal muscle is primarily mediated by the large neutral amino acid transporter 1 (LAT1), which is dependent on the glutamine gradient generated by the sodium-dependent neutral amino acid transporter 2 (SNAT2). The protein expression and membrane localization of LAT1 may be influenced by amino acid ingestion and/or resistance exercise, although its acute influence on dietary amino acid incorporation into skeletal muscle protein has not been investigated. In a group design, healthy males consumed a mixed carbohydrate (0.75 g·kg−1) crystalline amino acid (0.25 g·kg−1) beverage enriched to 25% and 30% with LAT1 substrates L-[1-13C]leucine (LEU) and L-[ring-2H5]phenylalanine (PHE), respectively, at rest (FED: n = 7, 23 ± 5 y, 77 ± 4 kg) or after a bout of resistance exercise (EXFED: n = 7, 22 ± 2 y, 78 ± 11 kg). Postprandial muscle biopsies were collected at 0, 120, and 300 min to measure transporter protein expression (immunoblot), LAT1 membrane localization (immunofluorescence), and dietary amino acid incorporation into myofibrillar protein (ΔLEU and ΔPHE). Basal LAT1 and SNAT2 protein contents were correlated with each other (r = 0.55, p = 0.04) but their expression did not change across time in FED or EXFED (all, p > 0.05). Membrane localization of LAT1 did not change across time in FED or EXFED whether measured as outer 1.5 µm intensity or membrane-to-fiber ratio (all, p > 0.05). Basal SNAT2 protein expression was not correlated with ΔLEU or ΔPHE (all, p ≥ 0.05) whereas basal LAT1 expression was negatively correlated with ΔPHE in FED (r = −0.76, p = 0.04) and EXFED (r = −0.81, p = 0.03) but not ΔLEU (p > 0.05). Basal LAT1 membrane localization was not correlated with ΔLEU or ΔPHE (all, p > 0.05). Our results suggest that LAT1/SNAT2 protein expression and LAT1 membrane localization are not influenced by acute anabolic stimuli and do not positively influence the incorporation of dietary amino acids for de novo myofibrillar protein synthesis in healthy young males.

Consumption of Amino Acid Solutions by Anastrepha suspensa Loew (Diptera: Tephritidae)

2007 ◽  
Vol 42 (3) ◽  
pp. 368-374
Author(s):  
Herbert N. Nigg ◽  
Rhonda A. Schumann ◽  
Jing J. Yang ◽  
Suzanne Fraser
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Fruit Fly ◽  
Acid Solutions ◽  
Anastrepha Suspensa ◽  
Caribbean Fruit Fly ◽  
Choice Tests ◽  
Amino Acid Solutions ◽  
Males And Females

The consumption of amino acids by Anastrepha suspensa Loew (Caribbean fruit fly) was quantified by measuring individual fly consumption. For no-choice tests, there were no differences in consumption between 0.2 M sucrose and 0.2 M sucrose plus L-alanine, L-glycine, L-histidine, L-phenylalanine, or L-serine solutions. There was increased consumption of 0.05 M L-lysine by 6-d males and of 0.03 M L-valine solutions by 6-d females compared to sucrose alone. Choice tests showed higher consumption of 0.2 M sucrose plus L-lysine, L-valine, and L-glycine, particularly by 6-d-old flies. There was a 3–8X increase in consumption of 0.05 M L-valine in 0.2 M sucrose for 6-d males and females. Commercial L-lysine, L-methionine, and L-taurine were not different from controls in no-choice tests; L-cysteine was about 95% inhibitory for consumption. Based on these data, better consumed A. suspensa baits might be formulated by eliminating L-cysteine and including 0.05 M L-valine.

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