scholarly journals The concentration of amino acids by yeast cells depleted of adenosine triphosphate

1970 ◽  
Vol 120 (4) ◽  
pp. 853-858 ◽  
Author(s):  
A. A. Eddy ◽  
K. Backen ◽  
G. Watson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Energy Metabolism ◽  
Adenosine Triphosphate ◽  
Physical Process ◽  
Ionic Species ◽  
Yeast Cells ◽  
Atp Content ◽  
Chemically Modified ◽  
Endogenous Amino Acids

1. The ATP content of preparations of a strain of Saccharomyces carlsbergensis was lowered below 0.3nmol/mg of yeast by starving the yeast cells in the presence of both antimycin and 5mm-deoxyglucose. 2. When the depleted cells were put at pH4.5 with glycine up to about 20nmol of the amino acid/mg of yeast was absorbed without being chemically modified. The mechanism did not depend on an exchange with endogenous amino acids. 3. The concentration of the absorbed glycine could apparently reach 100–200 times that outside the cells. 4. Replacement of the cellular K+ by Na+ almost stopped amino acid absorption in the presence of antimycin and deoxyglucose, but not in their absence. 5. It is suggested that, when energy metabolism itself had stopped, a purely physical process, namely the movements of H+ and K+ into and out of the yeast respectively, served to concentrate the amino acids in the cells. Both ionic species appear to be co-substrates of the system transporting amino acids.

The immunosuppressant FK506 inhibits amino acid import in Saccharomyces cerevisiae

1993 ◽  
Vol 13 (8) ◽  
pp. 5010-5019 ◽  
Author(s):  
J Heitman ◽  
A Koller ◽  
J Kunz ◽  
R Henriquez ◽  
A Schmidt ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Amino Acid ◽  
Cyclosporin A ◽  
Secretory Pathway ◽  
Yeast Cells ◽  
Amino Acid Transporters ◽  
Yeast Saccharomyces Cerevisiae ◽  
Eukaryotic Microorganisms

The immunosuppressants cyclosporin A, FK506, and rapamycin inhibit growth of unicellular eukaryotic microorganisms and also block activation of T lymphocytes from multicellular eukaryotes. In vitro, these compounds bind and inhibit two different types of peptidyl-prolyl cis-trans isomerases. Cyclosporin A binds cyclophilins, whereas FK506 and rapamycin bind FK506-binding proteins (FKBPs). Cyclophilins and FKBPs are ubiquitous, abundant, and targeted to multiple cellular compartments, and they may fold proteins in vivo. Previously, a 12-kDa cytoplasmic FKBP was shown to be only one of at least two FK506-sensitive targets in the yeast Saccharomyces cerevisiae. We find that a second FK506-sensitive target is required for amino acid import. Amino acid-auxotrophic yeast strains (trp1 his4 leu2) are FK506 sensitive, whereas prototrophic strains (TRP1 his4 leu2, trp1 HIS4 leu2, and trp1 his4 LEU2) are FK506 resistant. Amino acids added exogenously to the growth medium mitigate FK506 toxicity. FK506 induces GCN4 expression, which is normally induced by amino acid starvation. FK506 inhibits transport of tryptophan, histidine, and leucine into yeast cells. Lastly, several genes encoding proteins involved in amino acid import or biosynthesis confer FK506 resistance. These findings demonstrate that FK506 inhibits amino acid import in yeast cells, most likely by inhibiting amino acid transporters. Amino acid transporters are integral membrane proteins which import extracellular amino acids and constitute a protein family sharing 30 to 35% identity, including eight invariant prolines. Thus, the second FK506-sensitive target in yeast cells may be a proline isomerase that plays a role in folding amino acid transporters during transit through the secretory pathway.

scholarly journals Amino acids whose intracellular levels change most during aging alter chronological lifespan of fission yeast

2020 ◽  
Author(s):  
Charalampos Rallis ◽  
Michael Mülleder ◽  
Graeme Smith ◽  
Yan Zi Au ◽  
Markus Ralser ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Fission Yeast ◽  
Yeast Cells ◽  
Total Amino Acid ◽  
Wild Type ◽  
Chronological Lifespan ◽  
Biomarkers Of Aging ◽  
Concentration Changes ◽  
Amino Acid Levels

AbstractAmino acid deprivation or supplementation can affect cellular and organismal lifespan, but we know little about the role of concentration changes in free, intracellular amino acids during aging. Here, we determine free amino-acid levels during chronological aging of non-dividing fission yeast cells. We compare wild-type with long-lived mutant cells that lack the Pka1 protein of the protein kinase A signalling pathway. In wild-type cells, total amino-acid levels decrease during aging, but much less so in pka1 mutants. Two amino acids strongly change as a function of age: glutamine decreases, especially in wild-type cells, while aspartate increases, especially in pka1 mutants. Supplementation of glutamine is sufficient to extend the chronological lifespan of wild-type but not of pka1Δ cells. Supplementation of aspartate, on the other hand, shortens the lifespan of pka1Δ but not of wild-type cells. Our results raise the possibility that certain amino acids are biomarkers of aging, and their concentrations during aging can promote or limit cellular lifespan.

Protein and energy metabolism in the pre-implantation cattle embryo

2001 ◽  
Vol 26 (2) ◽  
pp. 443-446 ◽  
Author(s):  
D.G. Morris ◽  
P. Humpherson ◽  
H.J. Leese ◽  
J.M. Sreenan
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Energy Metabolism ◽  
Metabolic Rate ◽  
Protein Content ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Glucose Utilisation ◽  
Embryonic Loss

AbstractThere is no information on the metabolism of the cattle embryo during the period from day 8 to 16 a period of greatest embryonic loss. In this study the rate of protein synthesis and phosphorylation was measured in 13 to 15 day old cattle embryos. The rate of glucose utilisation and amino acid uptake/efflux by day 14 to 16 embryos was also measured. Protein synthesis and phosphorylation activity when expressed per unit of protein decreased with increasing embryo size and age. Similarly the rate of glucose utilisation was greatest for the earlier day 14 embryos. Embryos differed in their requirement for different amino acids. The pattern of uptake/efflux was similar to that of the earlier day 7 embryo. This study suggests that the metabolic rate of cattle embryos expressed per unit of protein content tends to decrease with increasing age and size from the initial burst of activity at day 13 around the time that expansion of the embryo begins.

scholarly journals The putative electrogenic nitrate-proton symport of the yeast Candida utilis. Comparison with the systems absorbing glucose or lactate

1985 ◽  
Vol 231 (2) ◽  
pp. 291-297 ◽  
Author(s):  
A A Eddy ◽  
P G Hopkins
Keyword(s):  
Amino Acids ◽  
Energy Metabolism ◽  
Candida Utilis ◽  
Membrane Depolarization ◽  
Yeast Cells ◽  
Charge Balance ◽  
Proton Symport ◽  
Limiting Nutrient ◽  
Proton Uptake ◽  
Aerobic Energy Metabolism

Strain N.C.Y.C. 193 of Candida utilis was grown aerobically at 30 degrees C with nitrate as limiting nutrient in a chemostat. The washed yeast cells depleted of ATP absorbed up to 5 nmol of nitrate/mg dry wt. of yeast. At pH 4-6, extra protons and nitrate entered the yeast cells together, in a ratio of about 2:1. Charge balance was maintained by an outflow of about 1 equiv. of K+. Nitrate stimulated the uptake of about 1 proton equivalent during glycolysis or aerobic energy metabolism. Studies with 3,3′-dipropylthiadicarbocyanine indicated that the proton-linked absorption of nitrate, amino acids or glucose depolarized the yeast cells. Proton uptake along with lactate led neither to net expulsion of K+ nor to membrane depolarization.

Amino acid transport: microinfusion and micropuncture of Henle's loops and vasa recta

1990 ◽  
Vol 258 (3) ◽  
pp. F504-F513 ◽  
Author(s):  
W. H. Dantzler ◽  
S. Silbernagl
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Transport ◽  
Systemic Circulation ◽  
Passive Movement ◽  
Neutral Amino Acid ◽  
Acid Transport ◽  
Similar Extent ◽  
Endogenous Amino Acids ◽  
Vasa Recta

Amino acids appear to be reabsorbed distal to the tips of loops of Henle and may be recycled between loops and vasa recta in rat papilla. These possibilities were examined further by microinfusion and micropuncture of loops of Henle and vasa recta. To obtain information on the specificity of amino acid transport distal to the tips of the loops, ascending limbs were continuously microinfused with radioactively labeled L- and D-alanine, L-glutamate, taurine, and mannitol. About 30% of the L- and D-alanine and L-glutamate but none of the taurine or mannitol appeared to be reabsorbed. These results suggest that an acidic and a neutral amino acid are reabsorbed to a similar extent, that reabsorption is not stereospecific, but that it does not occur indiscriminately for all amino acids or for all molecules of similar size. Continuous microinfusion of ascending vasa recta with radioactively labeled L- and D-alanine suggests that amino acids may be able to move from vasa recta into tubules (apparently loops of Henle) without first entering the systemic circulation. However, micropuncture measurements of concentrations of endogenous amino acids in thin ascending limbs and adjacent descending vasa recta do not demonstrate a gradient for passive movement out of loops.

scholarly journals The immunosuppressant FK506 inhibits amino acid import in Saccharomyces cerevisiae.

1993 ◽  
Vol 13 (8) ◽  
pp. 5010-5019 ◽  
Author(s):  
J Heitman ◽  
A Koller ◽  
J Kunz ◽  
R Henriquez ◽  
A Schmidt ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Amino Acid ◽  
Cyclosporin A ◽  
Secretory Pathway ◽  
Yeast Cells ◽  
Amino Acid Transporters ◽  
Yeast Saccharomyces Cerevisiae ◽  
Eukaryotic Microorganisms

The immunosuppressants cyclosporin A, FK506, and rapamycin inhibit growth of unicellular eukaryotic microorganisms and also block activation of T lymphocytes from multicellular eukaryotes. In vitro, these compounds bind and inhibit two different types of peptidyl-prolyl cis-trans isomerases. Cyclosporin A binds cyclophilins, whereas FK506 and rapamycin bind FK506-binding proteins (FKBPs). Cyclophilins and FKBPs are ubiquitous, abundant, and targeted to multiple cellular compartments, and they may fold proteins in vivo. Previously, a 12-kDa cytoplasmic FKBP was shown to be only one of at least two FK506-sensitive targets in the yeast Saccharomyces cerevisiae. We find that a second FK506-sensitive target is required for amino acid import. Amino acid-auxotrophic yeast strains (trp1 his4 leu2) are FK506 sensitive, whereas prototrophic strains (TRP1 his4 leu2, trp1 HIS4 leu2, and trp1 his4 LEU2) are FK506 resistant. Amino acids added exogenously to the growth medium mitigate FK506 toxicity. FK506 induces GCN4 expression, which is normally induced by amino acid starvation. FK506 inhibits transport of tryptophan, histidine, and leucine into yeast cells. Lastly, several genes encoding proteins involved in amino acid import or biosynthesis confer FK506 resistance. These findings demonstrate that FK506 inhibits amino acid import in yeast cells, most likely by inhibiting amino acid transporters. Amino acid transporters are integral membrane proteins which import extracellular amino acids and constitute a protein family sharing 30 to 35% identity, including eight invariant prolines. Thus, the second FK506-sensitive target in yeast cells may be a proline isomerase that plays a role in folding amino acid transporters during transit through the secretory pathway.

scholarly journals Ammonium-Dependent Shortening of CLS in Yeast Cells Starved for Essential Amino Acids Is Determined by the Specific Amino Acid Deprived, through Different Signaling Pathways

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Júlia Santos ◽  
Cecília Leão ◽  
Maria João Sousa
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Essential Amino Acid ◽  
Essential Amino Acids ◽  
Amino Acid Starvation ◽  
Yeast Cells ◽  
Environmental Interventions ◽  
Specific Amino Acid ◽  
Chronological Life Span ◽  
In Cells

Ammonium (NH4+) leads to chronological life span (CLS) shortening inSaccharomyces cerevisiaeBY4742 cells, particularly evident in cells starved for auxotrophy-complementing amino acids (leucine, lysine, and histidine) simultaneously. Here, we report that the effect ofNH4+on aging yeast depends on the specific amino acid they are deprived of. Compared with no amino acid starvation, starvation for leucine alone or in combination with histidine resulted in the most pronouncedNH4+-induced CLS shortening, whereas starvation for lysine, alone or in combination with histidine resulted in the least sensitivity toNH4+. We also show thatNH4+-induced CLS shortening is mainly mediated by Tor1p in cells starved for leucine or histidine but by Ras2p in cells starved for lysine, and in nonstarved cells. Sch9p protected cells from the effect ofNH4+under all conditions tested (starved or nonstarved cells), which was associated with Sch9p-dependent Hog1p phosphorylation. Our data show thatNH4+toxicity can be modulated through manipulation of the specific essential amino acid supplied to cells and of the conserved Ras2p, Tor1p, and Sch9p regulators, thus providing new clues to the development of environmental interventions for CLS extension and to the identification of new therapeutic targets for diseases associated with hyperammonemia.

Amino acid, sugar, and organic acid content during germination of Gateway barley and its chlorophyll mutant

1968 ◽  
Vol 46 (12) ◽  
pp. 1479-1486 ◽  
Author(s):  
P. V. Sane ◽  
Saul Zalik
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino ◽  
Soluble Sugars ◽  
Seedling Development ◽  
Total Soluble Sugars ◽  
Endogenous Amino Acids ◽  
Etiolated Seedlings ◽  
Organic Acid Content ◽  
Mutant Seed

Amino acids and total soluble sugars in the embryo and endosperm of etiolated seedlings of Gateway barley and its mutant were compared over a 10-day period. The endosperm of the mutant had a lower reserve of protein but the levels of protein and free glycine, which is the nitrogenous precursor of chlorophyll, were similar in the embryos of both lines. Thus the low reserve of nitrogen in the mutant seed was not responsible for its virescent character. Based upon the changes in the amounts of endogenous amino acids it appeared that the free amino acids were direct precursors of protein. The content of total soluble sugars was similar in both lines. Shoots of light-grown seedlings of the mutant accumulated considerably more malate than those of the normal line. Although there was special interest in determining the amount of succinate at different stages of seedling development, none was detectable until the 10th day.

Binding and Uptake of Amino Acids by Brain Tissue

1973 ◽  
Vol 51 (2) ◽  
pp. 121-128 ◽  
Author(s):  
P. C. Shiu ◽  
K. A. C. Elliott
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sodium Chloride ◽  
Incubation Medium ◽  
Sucrose Solution ◽  
The Other ◽  
Percentage Increase ◽  
Endogenous Amino Acids ◽  
Sodium Dependent ◽  
Net Uptake

(1) Of the endogenous glutamate, aspartate, alanine, glycine, and γ-aminobutyrate (GABA), 26–37% remains bound in particles when rat brain is homogenized in isosmotic salt-free sucrose solution; a smaller proportion, 16%, of the glutamine is bound. The amounts bound are increased if sodium chloride is present; the percentage increase is greatest in the case of GABA, followed by glutamate, and least with glutamine. When tracer amounts of radioactive amino acids are present in the solution in the absence of salt very little radioactivity appears in bound GABA or glutamine, but appreciable amounts are found in the other amino acids. In the presence of sodium chloride, the total amount of bound amino acid increases as does, to a lesser extent, the radioactivity bound. Ouabain and protoveratrine seem to cause some release of sodium-dependent binding of the amino acids; this is most marked with GABA.(2) Slices incubated in the presence of oxygen and glucose take up each of the amino acids when these are added to the incubation medium. The highest intracellular concentration and the greatest net uptake occur with GABA. The endogenous concentration of glutamate is higher than that of the other amino acids but the net uptake is the least. The highest ratios of uptake to endogenous content occur with alanine and glycine. Determinations of radioactivity indicate that, in the cases of GABA and glycine, the increase in radioactivity in the slices is almost completely accounted for by uptake from the medium with almost no exchange. Some exchange occurs with other amino acids. Protoveratrine inhibits uptake of all the amino acids and actually causes loss of glutamate and aspartate from slices. Ouabain inhibits in all cases; the uptakes of glutamate and aspartate are least affected. Tetrodotoxin, alone or with either of the other two drugs, tends to increase uptake of all the amino acids. When the net uptake is inhibited by drugs considerable exchange of endogenous amino acids with radioactive amino acids in the medium is observed.

scholarly journals Comparison of the Nutritional Properties and Transcriptome Profiling Between the Two Different Harvesting Periods of Auricularia polytricha

2021 ◽  
Vol 8 ◽  
Author(s):  
Wenliang Wang ◽  
Yansheng Wang ◽  
Zhiqing Gong ◽  
Shifa Yang ◽  
Fengjuan Jia
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Energy Metabolism ◽  
Transcriptome Profiling ◽  
Nutritional Properties ◽  
Genetic Characteristics ◽  
Auricularia Polytricha ◽  
The Third ◽  
The Difference ◽  
Amino Acid Contents

Auricularia polytricha (A. polytricha), regarded as an edible and medical mushroom, has attracted toward the research interests because of the high nutrition and bioactivity. The nutritional and medical properties of A. polytricha have been well-studied; however, research about the difference of the nutritional properties and transcriptome profiling between the two different harvesting periods of A. polytricha was limited. In this study, the nutritional properties and transcriptome profiling were compared between the two different harvesting periods of A. polytricha: AP_S1 (the stage for the first harvesting period) and AP_S2 (the stage for the third harvesting period). This study showed that AP_S1 had the more growth advantages than AP_S2 including biomass, auricle area and thickness, protein and calcium contents, and most species of the amino acid contents, which contributed to the higher sensory evaluation and acceptability of AP_S1. Transcriptome profiling showed that a total of 30,298 unigenes were successfully annotated in the two different harvesting periods of A. polytricha. At a threshold of two-fold change, 1,415 and 3,213 unigenes were up- and downregulated, respectively. All the differentially expressed genes (DEGs) analysis showed that the some synthesis and metabolic processes were strengthened in AP_S1, especially the synthesis and metabolism of the amino acids and protein. The enhanced energy metabolism pathways could provide more energy for AP_S1 to synthesize the nutritional substance. Moreover, the expressions of 10 selected DEGs involved in the amino acid and protein synthesis pathways and energy metabolism pathways were higher in AP_S1 compared to AP_S2, consistent with Illumina analysis. To the best of our knowledge, this is the first study that compares the nutritional properties and transcriptome profiling between the two different harvesting periods of A. polytricha and the results can present insights into the growth and genetic characteristics of A. polytricha.

Sign in / Sign up

Export Citation Format

Share Document