scholarly journals Amino acid availability determines plant immune homeostasis in the rhizosphere microbiome

2021 ◽  
Author(s):  
Yang Liu ◽  
Jiatong Han ◽  
Andrew J Wilson ◽  
Lucy O'Sullivan ◽  
Cara H. Haney
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gluconic Acid ◽  
Fungal Pathogens ◽  
Bacterial Overgrowth ◽  
Immune Homeostasis ◽  
Arabidopsis Root ◽  
Rhizosphere Microbiome ◽  
Amino Acid Availability ◽  
Molecular Patterns

Microbes possess conserved microbe-associated molecular patterns (MAMPs) such as flagellin that are recognized by plant receptors to induce immunity. Despite containing the same MAMPs as pathogens, commensals thrive in the plant rhizosphere microbiome indicating they must suppress or evade host immunity. The beneficial bacteria Pseudomonas capeferrum WCS358 can suppress Arabidopsis root immunity via acidification by secreting gluconic acid. While gluconic acid is sufficient to suppress immunity, we found that it is not necessary in a second beneficial strain Pseudomonas simiae WCS417, which produces more gluconic acid than WCS358. To uncover mechanisms that contribute to the suppression of Arabidopsis immunity, we performed a forward genetic screen in EMS-mutagenized P. simiae WCS417 using a flagellin-inducible CYP71A12 pro:GUS reporter as an Arabidopsis immune readout. We identified a mutant that cannot suppress flagellin-elicited CYP71A12 pro:GUS expression or acidify the rhizosphere. Next generation sequencing revealed a mutation in the catabolic site of an ornithine carbamoyltransferase argF, which is required for arginine biosynthesis. The mutant could be complemented by expression of argF from a plasmid, and a ΔargF mutant could not suppress immunity. Fungal pathogens can use alkalization through production of ammonia and glutamate, the arginine biosynthetic precursors, to promote their own growth and virulence. Therefore, we hypothesized that the biosynthesis of specific amino acids may be necessary to reduce levels of ammonia and glutamate to prevent rhizosphere alkalization and bacterial overgrowth. Genetically blocking arginine, glutamine, or proline biosynthesis, or by adding corresponding exogenous amino acids, resulted in rhizosphere alkalization. Interestingly, exogenous amino acids caused bacterial overgrowth in a gluconic acid-deficient mutants. Our findings show that bacterial amino acid biosynthesis contributes to acidification by preventing accumulation of glutamate precursors and the resulting alkalization. Collectively this work shows that by regulating nutrient availability, plants have the potential to regulate their immune homeostasis in the rhizosphere microbiome.

Extent of damage to amino acid availability of whey protein heated with sugar

1991 ◽  
Vol 58 (4) ◽  
pp. 431-441 ◽  
Author(s):  
Thérèse Desrosiers ◽  
Laurent Savoie
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Whey Protein ◽  
Significant Proportion ◽  
Protein Digestibility ◽  
Heating Time ◽  
Heat Treatments ◽  
Molar Ratio ◽  
Amino Acid Availability

SummaryThe effect of heat treatments, at various water activities (αw), on digestibility and on the availabilities of amino acids of whey protein samples in the presence of lactose was estimated by an in vitro digestion method with continuons dialysis. Four αw (0·3, 0·5, 0·7 and 0·97), three temperatures (75, 100 and 121 °C) and three heating periods (50, 500 and 5000 s) were selected. The initial lysine: lactose molar ratio was 1:1. Amino acid profiles showed that excessive heating of whey (121 °C, 5000 s) destroyed a significant proportion of cystine at all αw, lysine at αw 0·3, 0·5 and 0·7, and arginine at αw 0·5 and 0·7. At αw 0·3, 0·5 and 0·7, protein digestibility decreased (P < 0·05) as the temperature increased from 75 to 121 °C for a heating period of 5000 s, and as the heating time was prolonged from 500 to 5000 s at 121 °C. Excessive heating also decreased (P < 0·05) the availabilities of ail amino acids at αw 0·3, 0·5 and 0·7. The availabilities of lysine, proline, aspartic acid, glutamic acid, threonine, alanine, glycine and serine were particularly affected. Severe heating at αw 0·97 did not seem to favour the Maillard reaction, but the availabilities of cystine, tyrosine and arginine were decreased, probably as a result of structural modifications of the protein upon heating. Heating whey protein concentrates in the presence of lactose not only affected lysine, but also impaired enzymic liberation of other amino acids, according to the severity of heat treatments and αw.

scholarly journals Amino acid deprivation induces AKT activation by inducing GCN2/ATF4/REDD1 axis

2021 ◽  
Vol 12 (12) ◽  
Author(s):  
Hyeon-Ok Jin ◽  
Sung-Eun Hong ◽  
Ji-Young Kim ◽  
Se-Kyeong Jang ◽  
In-Chul Park
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cell Survival ◽  
Amino Acid Deprivation ◽  
General Control ◽  
Akt Activation ◽  
Amino Acid Availability ◽  
Survival Signal ◽  
Cancer Cell Survival ◽  
Glutamine Deprivation

AbstractAmino acid availability is sensed by various signaling molecules, including general control nonderepressible 2 (GCN2) and mechanistic target of rapamycin complex 1 (mTORC1). However, it is unclear how these sensors are associated with cancer cell survival under low amino acid availability. In the present study, we investigated AKT activation in non-small cell lung cancer (NSCLC) cells deprived of each one of 20 amino acids. Among the 20 amino acids, deprivation of glutamine, arginine, methionine, and lysine induced AKT activation. AKT activation was induced by GCN2/ATF4/REDD1 axis-mediated mTORC2 activation under amino acid deprivation. In CRISPR-Cas9-mediated REDD1-knockout cells, AKT activation was not induced by amino acid deprivation, indicating that REDD1 plays a major role in AKT activation under amino acid deprivation. Knockout of REDD1 sensitized cells cultured under glutamine deprivation conditions to radiotherapy. Taken together, GCN2/ATF4/REDD1 axis induced by amino acid deprivation promotes cell survival signal, which might be a potential target for cancer therapy.

scholarly journals Amino acid availability: aspects of chemical analysis and bioassay methodology

2003 ◽  
Vol 16 (2) ◽  
pp. 127-141 ◽  
Author(s):  
Paul J. Moughan
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chemical Analysis ◽  
Structural Damage ◽  
Human Subjects ◽  
Scientific Evidence ◽  
Hydrolysis Time ◽  
Amino Acid Availability

AbstractIt is important to be able to characterise foods and feedstuffs according to their available amino acid contents. This involves being able to determine amino acids chemically and the conduct of bioassays to determine amino acid digestibility and availability. The chemical analysis of amino acids is not straightforward and meticulousness is required to achieve consistent results. In particular and for accuracy, the effect of hydrolysis time needs to be accounted for. Some amino acids (for example, lysine) can undergo chemical modification during the processing and storage of foods, which interferes with amino acid analysis. Furthermore, the modified amino acids may also interfere with the determination of digestibility. A new approach to the determination of available lysine using a modifiedin vivodigestibility assay is discussed. Research is required into other amino acids susceptible to structural damage. There is recent compelling scientific evidence that bacterial activity in the small intestine of animals and man leads to the synthesis and uptake of dietary essential amino acids. This has implications for the accuracy of the ileal-based amino acid digestibility assay and further research is required to determine the extent of this synthesis, the source of nitrogenous material used for the synthesis and the degree of synthesis net of amino acid catabolism. Although there may be potential shortcomings in digestibility assays based on the determination of amino acids remaining undigested at the terminal ileum, there is abundant evidence in simple-stomached animals and growing evidence in human subjects that faecal-based amino acid digestibility coefficients are misleading. Hindgut microbial metabolism significantly alters the undigested dietary amino acid profile. The ileal amino acid digestibility bioassay is expected to be more accurate than its faecal-based counterpart, but correction of the ileal amino acid flow for amino acids of endogenous origin is necessary. Approaches to correcting for the endogenous component are discussed.

Amino acids suppress proteolysis independent of insulin throughout the neonatal period

1997 ◽  
Vol 272 (4) ◽  
pp. E592-E599 ◽  
Author(s):  
B. B. Poindexter ◽  
C. A. Karn ◽  
J. A. Ahlrichs ◽  
J. Wang ◽  
C. A. Leitch ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Neonatal Period ◽  
Essential Amino Acids ◽  
Whole Body ◽  
Amino Acid Availability ◽  
Dose Dependent Fashion ◽  
Term Newborns ◽  
Dose Dependent ◽  
Acid Administration

To determine how increased amino acid availability alters rates of whole body proteolysis and the irreversible catabolism of the essential amino acids leucine and phenylalanine throughout the neonatal period, leucine and phenylalanine kinetics were measured under basal conditions and in response to intravenous amino acids in two separate groups of healthy, full-term newborns (at 3 days and 3 wk of age). The endogenous rates of appearance of leucine and phenylalanine (reflecting proteolysis) were suppressed equally in both groups and in a dose-dependent fashion (by approximately 10% with 1.2 g x kg(-1) x day(-1) and by approximately 20% with 2.4 g x kg(-1) x day(-1)) in response to intravenous amino acid delivery. Insulin concentrations remained unchanged from basal values during amino acid administration. The irreversible catabolism of leucine and phenylalanine increased in a stepwise fashion in response to intravenous amino acids; again, no differences were observed between the two groups. This study clearly demonstrates that the capacity to acutely increase rates of leucine oxidation and phenylalanine hydroxylation is fully present early in the neonatal period in normal newborns. Furthermore, these data suggest that amino acid availability is a primary regulator of proteolysis in normal newborns throughout the neonatal period.

scholarly journals Regulation of type I collagen mRNA in lung fibroblasts by cystine availability

1998 ◽  
Vol 331 (2) ◽  
pp. 417-422 ◽  
Author(s):  
David C. RISHIKOF ◽  
Ping-Ping KUANG ◽  
Christine POLIKS ◽  
Ronald H. GOLDSTEIN
Keyword(s):  
Amino Acids ◽  
Steady State ◽  
Amino Acid ◽  
Type I Collagen ◽  
State Level ◽  
Lung Fibroblasts ◽  
Type I ◽  
Mrna Levels ◽  
Collagen Mrna ◽  
Amino Acid Availability

The steady-state level of α1(I) collagen mRNA is regulated by amino acid availability in human lung fibroblasts. Depletion of amino acids decreases α1(I) collagen mRNA levels and repletion of amino acids induces rapid re-expression of α1(I) mRNA. In these studies, we examined the requirements for individual amino acids on the regulation of α1(I) collagen mRNA. We found that re-expression of α1(I) collagen mRNA was critically dependent on cystine but not on other amino acids. However, the addition of cystine alone did not result in re-expression of α1(I) collagen mRNA. Following amino acid depletion, the addition of cystine with selective amino acids increased α1(I) collagen mRNA levels. The combination of glutamine and cystine increased α1(I) collagen mRNA levels 6.3-fold. Methionine or a branch-chain amino acid (leucine, isoleucine or valine) also acted in combination with cystine to increase α1(I) collagen mRNA expression, whereas other amino acids were not effective. The prolonged absence of cystine lowered steady-state levels of α1(I) collagen mRNA through a mechanism involving decreases in both the rate of gene transcription as assessed by nuclear run-on experiments and mRNA stability as assessed by half-life determination in the presence of actinomycin D. The effect of cystine was not mediated via alterations in the level of glutathione, the major redox buffer in cells, as determined by the addition of buthionine sulphoximine, an inhibitor of γ-glutamylcysteine synthetase. These data suggest that cystine directly affects the regulation of α1(I) collagen mRNA.

scholarly journals Minireview: Nutrient Sensing by G Protein-Coupled Receptors

2013 ◽  
Vol 27 (8) ◽  
pp. 1188-1197 ◽  
Author(s):  
Eric M. Wauson ◽  
Andrés Lorente-Rodríguez ◽  
Melanie H. Cobb
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
G Protein ◽  
Taste Receptor ◽  
Sweet Taste ◽  
Nutrient Sensing ◽  
G Protein Coupled Receptors ◽  
Amino Acid Availability ◽  
Class C ◽  
G Protein Coupled

G protein-coupled receptors (GPCRs) are membrane proteins that recognize molecules in the extracellular milieu and transmit signals inside cells to regulate their behaviors. Ligands for many GPCRs are hormones or neurotransmitters that direct coordinated, stereotyped adaptive responses. Ligands for other GPCRs provide information to cells about the extracellular environment. Such information facilitates context-specific decision making that may be cell autonomous. Among ligands that are important for cellular decisions are amino acids, required for continued protein synthesis, as metabolic starting materials and energy sources. Amino acids are detected by a number of class C GPCRs. One cluster of amino acid-sensing class C GPCRs includes umami and sweet taste receptors, GPRC6A, and the calcium-sensing receptor. We have recently found that the umami taste receptor heterodimer T1R1/T1R3 is a sensor of amino acid availability that regulates the activity of the mammalian target of rapamycin. This review focuses on an array of findings on sensing amino acids and sweet molecules outside of neurons by this cluster of class C GPCRs and some of the physiologic processes regulated by them.

EFFECT OF STEAM PELLETING AND REGRINDING ON THE DIGESTIBILITY OF PROTEIN IN CEREAL GRAINS, SOYBEAN MEAL AND WHEAT BRAN BY THE RAT

1968 ◽  
Vol 48 (1) ◽  
pp. 35-39 ◽  
Author(s):  
E. M. Olsen ◽  
S. J. Slinger
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Wheat Bran ◽  
Soybean Meal ◽  
Protein Digestibility ◽  
Essential Amino Acids ◽  
Cereal Grains ◽  
Protein Utilization ◽  
Amino Acid Availability ◽  
Net Protein

The effect if steam pelleting and regrinding on digestibility of protein in corn, wheat, barley, oats, soybean meal and wheat bran was tested with rats. Percentage amino acid absorption and net protein utilization (NPU) were determined for the wheat bran. Pelleting and regrinding improved the digestibility of protein in bran but had no effect on the digestibility of protein in the other ingredients tested. Increased absorption of amino acids caused by the increased digestibility of protein in bran varied considerably for individual amino acids, being greatest for isoleucine, lysine, methionine and threonine of the essential amino acids. The improvement in protein digestibility and amino acid availability was reflected in a higher NPU.

Protein degradation and synthesis measured with multiple amino acid tracers in vivo

1996 ◽  
Vol 271 (4) ◽  
pp. E733-E741 ◽  
Author(s):  
P. Tessari ◽  
R. Barazzoni ◽  
M. Zanetti ◽  
M. Vettore ◽  
S. Normand ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein S ◽  
Essential Amino Acids ◽  
Body Protein ◽  
Amino Acid Availability ◽  
Before And After ◽  
Branched Chain ◽  
Multiple Amino Acid

Whether tracers of different essential amino acids yield the same estimates of body protein turnover is still uncertain. Therefore, we have simultaneously determined leucine (Leu; using [14C]Leu), phenylalanine (Phe; using [13C]Phe), and tyrosine (Tyr; using [2H2]Tyr) rates of appearance (Ra) from proteolysis (PD), as well as Leu and Phe disposal, into protein synthesis (PS) both before and after an anabolic stimulus in healthy volunteers. Protein anabolism was stimulated by insulin plus a branched-chain amino acid-enriched aromatic amino acid-deficient amino acid solution, which increased Leu (from 145 +/- 9 to 266 +/- 10 mumol/l) but decreased Phe (from 57 +/- 2 to 46 +/- 3) and Tyr (from 58.7 +/- 5.5 to 21.0 +/- 2.2) concentrations. Postabsorptive endogenous Leu Ra (2.04 +/- 0.12 mumol.kg-1.min-1), Phe Ra (0.66 +/- 0.03), and Tyr Ra (0.45 +/- 0.06), as well as rates of PS determined with the leucine (1.65 +/- 0.10 mumol.kg-1.min-1) and the phenylalanine tracer (0.57 +/- 0.03), agreed well with the known abundance of these amino acids in body protein(s). After insulin and amino acids, PD was suppressed (P < 0.001) using all tracers. However, although percent suppression of endogenous Leu Ra (-->1.49 +/- 0.10 mumol.kg-1.min-1, 26 +/- 5%) and Phe Ra (-->0.53 +/- 0.02 mumol.kg-1.min-1, -20 +/- 2%) were comparable, endogenous Tyr Ra was suppressed to a larger extent (-->0.23 +/- 0.02 mumol.kg-1.min-1, -46 +/- 3% P = 0.038). PS was stimulated using the Leu (+24 +/- 7%, P < 0.02) but not the Phe (+6 +/- 4%, not significant) data. We conclude that isotopes of different essential amino acid: provide comparable estimates of PD and PS in the postabsorptive state. However, their responses to an anabolic stimulus may differ, possibly depending on exogenous amino acid availability and/or the resulting plasma levels.

Control of Muscle Protein Synthesis as a Result of Contractile Activity and Amino Acid Availability: Implications for Protein Requirements

2001 ◽  
Vol 11 (s1) ◽  
pp. S170-S176 ◽  
Author(s):  
Michael J. Rennie
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Muscle Protein ◽  
Contractile Activity ◽  
Muscle Protein Synthesis ◽  
Protein Requirements ◽  
Amino Acid Availability ◽  
Separate Pathway

The major anabolic influences on muscle are feeding and contractile activity. As a result of feeding, anabolism occurs chiefly by increases in protein synthesis with minor changes in protein breakdown. Insulin has a permissive role in increasing synthesis, but the availability of amino acids is crucial for net anabolism. We have investigated the role of amino acids in stimulating muscle protein synthesis, the synergy between exercise and amino acid availability, and some of the signaling elements involved. The results suggest that muscle is acutely sensitive to amino acids, that exercise probably increases the anabolic effects of amino acids by a separate pathway, and that for this reason it is unlikely that accustomed physical exercise increases protein requirements.

scholarly journals Identification of Genes for Wheat Fungal Resistance Using Bioinformatics Techniques

2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ahmed E. Nassar ◽  
Khaled H. Mousa ◽  
Ahmed A. Madbouly ◽  
Shafik D. Ibrahim ◽  
Alsamman M. Alsamman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Fungal Pathogens ◽  
Gene Annotation ◽  
Average Length ◽  
Amino Acid Sequences ◽  
Protein Domain ◽  
Fungal Resistance ◽  
Domain Identification ◽  
Cereal Grain

For the majority of world populations, wheat (Triticum aestivum L.) would be the first essential and economic cereal grain crop. Pests and pathogens in both rich and developing countries are constantly threatening wheat production and sustainable development. Multiple gene pathways were recorded to share an association with fungal pathogens with wheat biological resistance. Our aim to use such tools in order to detect and classify fungal resistance genes in wheat through sequence alignment, protein domain identification and phylogenetic analysis. In addition the introduction for restriction fragment length polymorphism (RFLP) for such genes in the new primer database. Approximately 138 sequences of DNA were recovered from the wheat genome by aligning 3845 anti-fungal amino acids through tblastn tool. The NCBI blastn online tool used to detect sequences with functional genes, where 92 genes have been detected. The total number of nucleotides was 48385, where the smallest DNA sequence have 302 bp and the longest contains 977 bp with an average length of 525.9 bp per sequence. The wheat chromosomes 3D, and 4B have the highest number of sequences (9) followed by chromosomes 3B (7) and 3A(6), where wheat genomes A, B and D have 30, 35 and 27 genes, respectively. Five different amino acids motifs have been revealed among studied wheat amino acid sequences. The gene annotation tools used to infer studied amino acid gene annotation. Amino acid sequences belongs to lectin, kinase, tyrosine-protein kinase (STK), thaumatin, and cysteine-rich repeats representing 2, 9, 8, 19, 23 genes respectively, in addition to 31 hypothetical genes. The proteins chemical content have been assessed through 16 different amino acid chemical and physical characteristics.

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