UMLS:C0038187 - FACTA Search

Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Target Concepts:

Query: UMLS:C0038187 (starvation)
24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Five kinds of proteins of Saccharomyces cerevisiae were recently purified to a homogeneous state and identified as yeast cell surface antigens (TLAa, TLAb, TLAc, TLAd, and TLAe), but their physiological functions remained uncertain. In this paper, TLAa was identified as a yeast enolase (EC 4.2.1.11) from the following evidence: (1) molecular weights and amino acid compositions of both proteins were similar, (2) the N-terminal 22 amino acid sequences of both proteins were the same (3), TLAa had enolase activity, and (4) the authentic yeast enolase gave a positive reaction with anti-TLAa serum in the Ouchterlony immunodiffusion test and the immunoblotting test. Two isoproteins of TLAa (enolase) were separated by non-denatured polyacrylamide gel electrophoresis and detected by immunoblotting with anti-TLAa serum. The contents of the two isoproteins varied depending on the following culture conditions: glucose starvation, growth in the presence of non-fermentable carbon sources, and growth in media containing sodium chloride and 2-deoxyglucose. The contents did not vary, however, with heat shock treatment or with growth in media containing sodium azide, tunicamycin, or sorbitol. These results showed that TLAa was a cytoplasmic antigen, and that its synthesis was regulated by some environmental stresses.
...
PMID:Identification and characterization of a thermolabile antigen (TLAa, enolase) in Saccharomyces cerevisiae. 136 97

The impact of maternal starvation during Days 17-20 of gestation was examined in 20-day fetal rat brain tissue cultured for 6 days in MEM and 10% adult rat serum. Acetylcholinesterase (AChE) activities were consistently greater in fetal brain cell cultures from starved mothers. When fetal tissues from starved mothers were continuously exposed to 72-h fasted serum, AChE activities increased from 1.03 +/- 0.14 to 1.59 +/- 0.21 mumol/h/mg protein (P less than 0.001). In fetal tissues from fed mothers, lower AChE activities were increased from 0.78 +/- 0.09 to 1.04 +/- 0.07 mumol/h/mg protein (P less than 0.05) when 72-h fasted serum was used to replace the fed serum during incubation. When fetal brain cell cultures from fed mothers were exposed for 6 days to graded concentrations of fed serum (2.5-15%), the activities of AChE fell reciprocally from 1.34 +/- 0.10 to 0.82 +/- 0.12 mumol/h/mg protein (P less than 0.05). The levels of AChE activity in tissues exposed to fasted serum were consistently greater, but fell similarly from 1.62 +/- 0.10 to 0.97 +/- 14 mumol/h/mg protein (P less than 0.01), when serum concentrations were increased from 2.5 to 15%. AChE activities were 30% higher in tissues incubated with cycloheximide 10(-3) M (P less than 0.02). Unlike AChE, fetal brain enolase activities were unaffected by maternal starvation. In fetal brain cell cultures from fed mothers, enolase fell from 1.85 +/- 0.10 to 1.37 +/- 0.12 mumol/min/mg protein following exposure to fasted instead of fed serum (P less than 0.02). In fetal cultures from starved mothers, enolase activities were depressed similarly from 1.76 +/- 0.08 to 1.41 +/- 0.09 mumol/min/mg protein when fasted replaced fed serum (P less than 0.02). Thus, the fetal brain cell cultures appear to maintain enzymatic realignments imposed by maternal starvation for at least 6 days. In addition, serum from fasted animals has significant growth inhibiting properties manifested by heightened activities of AChE and lower activities of enolase.
...
PMID:Nutrition and fetal brain maturation. II. Impact of maternal starvation on changing levels of acetylcholinesterase and enolase in vitro. 336 58

Growth and starvation of baker's yeast was monitored by on-line microcalorimetry and cells originating from four different physiological states were stored at low temperature (4 degrees C) for up to 26 days. The different physiological states were designated F (respiro-Fermentative phase of growth), R (initial Respiratory phase of growth), -N (non-growing state because of Nitrogen depletion), and -NC (non-growing state because of both Nitrogen and Carbon depletion). The cells were tested before and after cold storage for their fermentative capacity, and characterised by 2D gel analysis (and subsequent quantitative silver staining and image analysis with software PDQUEST) for their levels of six enzymes of the glycolytic pathway (hexokinase 2 (Hxk2p), fructose bisphosphate aldolase (Fba1p), glyceraldehyde-3-phosphate dehydrogenase (Tdh3p), enolase A (Enolp), enolase B (Eno2p), and triose phosphate isomerase (Tpi1p)) and two enzymes of the fermentative branch (pyruvate decarboxylase (Pdc1p) and alcohol dehydrogenase (Adh1p)). The enzymes Hxk2p, Tdh3p, Eno2p, Pdc1p and Adh1p were down-regulated by 25-80% during the transition between the F and R states. During the transition to non-growing states (-N and -NC states), the levels of Hxk2p, Tdh3p and Eno2p were further reduced. However, after cold storage, the glycolytic and fermentative enzymes of the different physiological states were expressed to the same extent. In contrast, the fermentative capacity differed between the states; the R-state cells were superior compared to cells from the other states tested and preserved more than 50% of their initial fermentative capacity (6 mmol ethanol per gram dry weight and hour). Our data therefore clearly demonstrate that persistence of fermentative capacity during total starvation at low temperature after as long as 1 month is strongly dependent on the physiological state from which the cells originate. However, the level of expression of the glycolytic enzymes could not explain the difference in fermentative capacity of the different physiological states after cold storage.
...
PMID:Fermentative capacity after cold storage of baker's yeast is dependent on the initial physiological state but not correlated to the levels of glycolytic enzymes. 1178 28

A comparative expression proteome analysis was carried out by analyzing differential expression patterns of pulse-labelled proteins on two-dimensional gels under standard conditions and during purine nucleotide starvation, followed by mass spectrometric identification of regulated proteins. Based upon the expression patterns, three stimulons could be identified in Lactococcus lactis subsp. cremoris. The Psu proteins (purine starvation up-regulated) had increased synthesis during purine depletion in a purine auxotroph. Among these proteins were enzymes of the purine biosynthesis pathways (PurE, PurS, PurM, PurL), and enzymes involved in the generation of C1 units (GlyA, Fhs). C1 units are primarily required for purine biosynthesis. Upon analysis of the nucleotide sequence preceding the structural genes for these proteins in the L. lactis IL1403 genome sequence showed that all contained PurBox-Pribnov box structures resembling the PurR activated promoters for the purDEK and purCSQLF operons. Most, and possibly all members of the Psu stimulon are thus members of the PurR regulon. Five Psu proteins could not be identified. The second stimulon, the Psd stimulon (purine starvation decreased), whose members are down-regulated during purine depletion, contained proteins related to protein synthesis (PpsB, EF-TS, trigger factor), or to GTPases (FtsZ, EF-TS); or are involved in energy metabolism (GapB, CcpA). No common regulatory elements could be found for members of this stimulon. Two Psd proteins escaped identification. The last, Dcu (decoynine up-regulated), stimulon contained proteins whose synthesis escaped the severe general depression during inhibition of the GMP synthetase by decoynine. This regulon was comprised of mostly glycolytic enzymes (fructose bisphosphate aldolase, enolase, pyruvate kinase) and translation elongation factors (GTPases: EF-TU, EF-G). Two Dcu proteins could not be identified. Out of 28 proteins subjected to mass spectrometry, 19 could be readily identified despite the fact that only the genome sequence of a strain of L. lactis subsp. lactis was available. The two subspecies share about 85% sequence identity, comparable to the genetic distance between Escherichia coli and Salmonella typhimurium. A success rate of 68% indicates that it may be feasible to perform proteomics based upon genomic sequences of relatives outside the genus.
...
PMID:Proteome analysis of the purine stimulon from Lactococcus lactis. 1274 56

Enolase from Tuber borchii mycelium was purified to electrophoretical homogeneity using an anion-exchange and a gel permeation chromatography. Furthermore, the corresponding gene (eno-1) was cloned and characterized. The purified enzyme showed a higher affinity for 2-PGA (0.26 mM) with respect to PEP; the stability and activity of enolase were dependent of the divalent cation Mg2+. T. borchii eno-1 has an ORF of 1323 bp coding for a putative protein of 440 amino acids and Southern blotting analysis revealed that the gene is present as a single copy in T. borchii. The enzymatic activity and the mRNA expression level evaluated in mycelia grown either in different carbon sources, in pyruvate or during starvation were the same in all the conditions tested, while biochemical and Northern blotting analyses performed with mycelia at different days of growth showed T. borchii eno-1 regulation in response to the growth phase. Finally, Western blotting analysis demonstrated that enolase is localized only in the cytosolic fraction confirming its important role in glycolysis.
...
PMID:Enolase from the ectomycorrhizal fungus Tuber borchii Vittad.: biochemical characterization, molecular cloning, and localization. 1473 62

P(II)-type signal transduction proteins play a central role in nitrogen regulation in many bacteria. In response to the intracellular nitrogen status, these proteins are rendered in their function and interaction with other proteins by modification/demodification events, e.g. by phosphorylation or uridylylation. In this study, we show that GlnK, the only P(II)-type protein in Corynebacterium glutamicum, is adenylylated in response to nitrogen starvation and deadenylylated when the nitrogen supply improves again. Both processes depend on the GlnD protein. As shown by mutant analyses, the modifying activity of this enzyme is located in the N-terminal part of the enzyme, while demodification depends on its C-terminal domain. Besides its modification status, the GlnK protein changes its intracellular localization in response to changes of the cellular nitrogen supply. While it is present in the cytoplasm during nitrogen starvation, the GlnK protein is sequestered to the cytoplasmic membrane in response to an ammonium pulse following a nitrogen starvation period. About 2-5% of the GlnK pool is located at the cytoplasmic membrane after ammonium addition. GlnK binding to the cytoplasmic membrane depends on the ammonium transporter AmtB, which is encoded in the same transcriptional unit as GlnK and GlnD, the amtB-glnK-glnD operon. In contrast, the structurally related methylammonium/ammonium permease AmtA does not bind GlnK. The membrane-bound GlnK protein is stable, most likely to inactivate AmtB-dependent ammonium transport in order to prevent a detrimental futile cycle under post-starvation ammonium-rich conditions, while the majority of GlnK is degraded within 2-4 min. Proteolysis in the transition period from nitrogen starvation to nitrogen-rich growth seems to be specific for GlnK; other proteins of the nitrogen metabolism, such as glutamine synthetase, or proteins unrelated to ammonium assimilation, such as enolase and ATP synthase subunit F(1)beta, are stable under these conditions. Our analyses of different mutant strains have shown that at least three different proteases influence the degradation of GlnK, namely FtsH, the ClpCP and the ClpXP protease complex.
...
PMID:Regulation of GlnK activity: modification, membrane sequestration and proteolysis as regulatory principles in the network of nitrogen control in Corynebacterium glutamicum. 1545 11

Copper is an essential micronutrient for plants. Present at a high concentration in soil, copper is also regarded as a major toxicant to plant cells due to its potential inhibitory effects against many physiological and biochemical processes. The interference of germination-related proteins by heavy metals has not been well documented at the proteomic level. In the current study, physiological, biochemical and proteomic changes of germinating rice seeds were investigated under copper stress. Germination rate, shoot elongation, plant biomass, and water content were decreased, whereas accumulation of copper and TBARS content in seeds were increased significantly with increasing copper concentrations from 0.2mM to 1.5mM followed by germination. The SDS-PAGE showed the preliminary changes in the polypeptides patterns under copper stress. Protein profiles analyzed by two-dimensional electrophoresis (2-DE) revealed that 25 protein spots were differentially expressed in copper-treated samples. Among them, 18 protein spots were up-regulated and 7 protein spots were down-regulated. These differentially displayed proteins were identified by MALDI-TOF mass spectrometry. The up-regulation of some antioxidant and stress-related proteins such as glyoxalase I, peroxiredoxin, aldose reductase, and some regulatory proteins such as DnaK-type molecular chaperone, UlpI protease, and receptor-like kinase clearly indicated that excess copper generates oxidative stress that might be disruptive to other important metabolic processes. Moreover, down-regulation of key metabolic enzymes like alpha-amylase or enolase revealed that the inhibition of seed germinations after exposure to excess copper not only affects starvation in water uptake by seeds but also results in failure in the reserve mobilization processes. These results indicate a good correlation between the physiological and biochemical changes in germinating rice seeds exposed to excess copper.
...
PMID:Excess copper induced physiological and proteomic changes in germinating rice seeds. 1718 80

This investigation addresses the following question: what are the important factors for maintenance of a high catabolic capacity under various starvation conditions? Saccharomyces cerevisiae was cultured in aerobic batch cultures, and during the diauxic shift cells were transferred and subjected to 24 h of starvation. The following conditions were used: carbon starvation, nitrogen starvation in the presence of glucose or ethanol, and both carbon starvation and nitrogen starvation. During the starvation period changes in biomass composition (including protein, carbohydrate, lipid, and nucleic acid contents), metabolic activity, sugar transport kinetics, and the levels of selected enzymes were recorded. Subsequent to the starvation period the remaining catabolic capacity was measured by addition of 50 mM glucose. The results showed that the glucose transport capacity is a key factor for maintenance of high metabolic capacity in many, but not all, cases. The results for cells starved of carbon, carbon and nitrogen, or nitrogen in the presence of glucose all indicated that the metabolic capacity was indeed controlled by the glucose transport ability, perhaps with some influence of hexokinase, phosphofructokinase, aldolase, and enolase levels. However, it was also demonstrated that there was no such correlation when nitrogen starvation occurred in the presence of ethanol instead of glucose.
...
PMID:Effect of nutrient starvation on the cellular composition and metabolic capacity of Saccharomyces cerevisiae. 1754 28

Cytosine-5 methyltransferases of the Dnmt2 family function as DNA and tRNA methyltransferases. Insight into the role and biological significance of Dnmt2 is greatly hampered by a lack of knowledge about its protein interactions. In this report, we address the subject of protein interaction by identifying enolase through a yeast two-hybrid screen as a Dnmt2-binding protein. Enolase, which is known to catalyze the conversion of 2-phosphoglycerate (2-PG) to phosphoenolpyruvate (PEP), was shown to have both a cytoplasmatic and a nuclear localization in the parasite Entamoeba histolytica. We discovered that enolase acts as a Dnmt2 inhibitor. This unexpected inhibitory activity was antagonized by 2-PG, which suggests that glucose metabolism controls the non-glycolytic function of enolase. Interestingly, glucose starvation drives enolase to accumulate within the nucleus, which in turn leads to the formation of additional enolase-E.histolytica DNMT2 homolog (Ehmeth) complex, and to a significant reduction of the tRNA(Asp) methylation in the parasite. The crucial role of enolase as a Dnmt2 inhibitor was also demonstrated in E.histolytica expressing a nuclear localization signal (NLS)-fused-enolase. These results establish enolase as the first Dnmt2 interacting protein, and highlight an unexpected role of a glycolytic enzyme in the modulation of Dnmt2 activity.
...
PMID:A new nuclear function of the Entamoeba histolytica glycolytic enzyme enolase: the metabolic regulation of cytosine-5 methyltransferase 2 (Dnmt2) activity. 2017 8

The energy status of plant cells strongly depends on the energy metabolism in chloroplasts and mitochondria, which are capable of generating ATP either by photosynthetic or oxidative phosphorylation, respectively. Another energy-rich metabolite inside plastids is the glycolytic intermediate phosphoenolpyruvate (PEP). However, chloroplasts and most non-green plastids lack the ability to generate PEP via a complete glycolytic pathway. Hence, PEP import mediated by the plastidic PEP/phosphate translocator or PEP provided by the plastidic enolase are vital for plant growth and development. In contrast to chloroplasts, metabolism in non-green plastids (amyloplasts) of starch-storing tissues strongly depends on both the import of ATP mediated by the plastidic nucleotide transporter NTT and of carbon (glucose 6-phosphate, Glc6P) mediated by the plastidic Glc6P/phosphate translocator (GPT). Both transporters have been shown to co-limit starch biosynthesis in potato plants. In addition, non-photosynthetic plastids as well as chloroplasts during the night rely on the import of energy in the form of ATP via the NTT. During energy starvation such as prolonged darkness, chloroplasts strongly depend on the supply of ATP which can be provided by lipid respiration, a process involving chloroplasts, peroxisomes, and mitochondria and the transport of intermediates, i.e. fatty acids, ATP, citrate, and oxaloacetate across their membranes. The role of transporters involved in the provision of energy-rich metabolites and in pathways supplying plastids with metabolic energy is summarized here.
...
PMID:The role of transporters in supplying energy to plant plastids. 2151 15

1 2 Next >>