scholarly journals Glucose Depletion Rapidly Inhibits Translation Initiation in Yeast

2000 ◽  
Vol 11 (3) ◽  
pp. 833-848 ◽  
Author(s):  
Mark P. Ashe ◽  
Susan K. De Long ◽  
Alan B. Sachs
Keyword(s):  
Protein Synthesis ◽  
Posttranscriptional Regulation ◽  
Glucose Repression ◽  
Nutrient Status ◽  
Transcriptional Level ◽  
Inhibitory Effects ◽  
Glucose Depletion ◽  
Tor Kinase ◽  
Dependent Protein ◽  
Effect Of Glucose

Glucose performs key functions as a signaling molecule in the yeastSaccharomyces cerevisiae. Glucose depletion is known to regulate gene expression via pathways that lead to derepression of genes at the transcriptional level. In this study, we have investigated the effect of glucose depletion on protein synthesis. We discovered that glucose withdrawal from the growth medium led to a rapid inhibition of protein synthesis and that this effect was readily reversed upon readdition of glucose. Neither the inhibition nor the reactivation of translation required new transcription. This inhibition also did not require activation of the amino acid starvation pathway or inactivation of the TOR kinase pathway. However, mutants in the glucose repression (reg1, glc7,hxk2, and ssn6), hexose transporter induction (snf3 rgt2), and cAMP-dependent protein kinase (tpk1wandtpk2w) pathways were resistant to the inhibitory effects of glucose withdrawal on translation. These findings highlight the intimate connection between the nutrient status of the cell and its translational capacity. They also help to define a new area of posttranscriptional regulation in yeast.

scholarly journals Glucose repression of the yeast ADH2 gene occurs through multiple mechanisms, including control of the protein synthesis of its transcriptional activator, ADR1.

1992 ◽  
Vol 12 (4) ◽  
pp. 1663-1673 ◽  
Author(s):  
R C Vallari ◽  
W J Cook ◽  
D C Audino ◽  
M J Morgan ◽  
D E Jensen ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Glucose Repression ◽  
Regulatory Protein ◽  
Transcriptional Activator ◽  
Protein Translation ◽  
Growth Conditions ◽  
Mrna Levels ◽  
Coding Region ◽  
Glucose Depletion

The rate of ADH2 transcription increases dramatically when Saccharomyces cerevisiae cells are shifted from glucose to ethanol growth conditions. Since ADH2 expression under glucose growth conditions is strictly dependent on the dosage of the transcriptional activator ADR1, we investigated the possibility that regulation of the rate of ADR1 protein synthesis plays a role in controlling ADR1 activation of ADH2 transcription. We found that the rate of ADR1 protein synthesis increased 10- to 16-fold within 40 to 60 min after glucose depletion, coterminous with initiation of ADH2 transcription. Changes in ADR1 mRNA levels contributed only a twofold effect on ADR1 protein synthetic differences. The 510-nt untranslated ADR1 mRNA leader sequence was found to have no involvement in regulating the rate of ADR1 protein synthesis. In contrast, sequences internal to ADR1 coding region were determined to be necessary for controlling ADR1 translation. The ADR1c mutations which enhance ADR1 activity under glucose growth conditions did not affect ADR1 protein translation. ADR1 was also shown to be multiply phosphorylated in vivo under both ethanol and glucose growth conditions. Our results indicate that derepression of ADH2 occurs through multiple mechanisms involving the ADR1 regulatory protein.

Glucose repression of the yeast ADH2 gene occurs through multiple mechanisms, including control of the protein synthesis of its transcriptional activator, ADR1

1992 ◽  
Vol 12 (4) ◽  
pp. 1663-1673
Author(s):  
R C Vallari ◽  
W J Cook ◽  
D C Audino ◽  
M J Morgan ◽  
D E Jensen ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Glucose Repression ◽  
Regulatory Protein ◽  
Transcriptional Activator ◽  
Protein Translation ◽  
Growth Conditions ◽  
Mrna Levels ◽  
Coding Region ◽  
Glucose Depletion

The rate of ADH2 transcription increases dramatically when Saccharomyces cerevisiae cells are shifted from glucose to ethanol growth conditions. Since ADH2 expression under glucose growth conditions is strictly dependent on the dosage of the transcriptional activator ADR1, we investigated the possibility that regulation of the rate of ADR1 protein synthesis plays a role in controlling ADR1 activation of ADH2 transcription. We found that the rate of ADR1 protein synthesis increased 10- to 16-fold within 40 to 60 min after glucose depletion, coterminous with initiation of ADH2 transcription. Changes in ADR1 mRNA levels contributed only a twofold effect on ADR1 protein synthetic differences. The 510-nt untranslated ADR1 mRNA leader sequence was found to have no involvement in regulating the rate of ADR1 protein synthesis. In contrast, sequences internal to ADR1 coding region were determined to be necessary for controlling ADR1 translation. The ADR1c mutations which enhance ADR1 activity under glucose growth conditions did not affect ADR1 protein translation. ADR1 was also shown to be multiply phosphorylated in vivo under both ethanol and glucose growth conditions. Our results indicate that derepression of ADH2 occurs through multiple mechanisms involving the ADR1 regulatory protein.

scholarly journals P2-202: INHIBITION OF ACTIVITY-DEPENDENT PROTEIN SYNTHESIS BY IL-1β IN HIPPOCAMPAL DENDRITES

2019 ◽  
Vol 15 ◽  
pp. P654-P654
Author(s):  
G. Aleph Prieto ◽  
Erica D. Smith ◽  
Liqi Tong ◽  
Michelle Nguyen ◽  
Carl W. Cotman
Keyword(s):  
Protein Synthesis ◽  
Dependent Protein ◽  
Activity Dependent

Troglitazone acutely inhibits protein synthesis in endothelial cells via a novel mechanism involving protein phosphatase 2A-dependent p70 S6 kinase inhibition

2006 ◽  
Vol 291 (2) ◽  
pp. C317-C326 ◽  
Author(s):  
Du-Hyong Cho ◽  
Yoon Jung Choi ◽  
Sangmee Ahn Jo ◽  
Jungsang Ryou ◽  
Jin Yi Kim ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Protein Synthesis ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Peroxisome Proliferator ◽  
Inhibitory Effects ◽  
S6 Kinase ◽  
P70 S6 Kinase ◽  
Inhibition Of Protein Synthesis ◽  
Phosphatase 2A

Thiazolidinediones (TZDs), synthetic peroxisome proliferator-activated receptor γ (PPARγ) ligands, have been implicated in the inhibition of protein synthesis in a variety of cells, but the underlying mechanisms remain obscure. We report that troglitazone, the first TZD drug, acutely inhibited protein synthesis by decreasing p70 S6 kinase (p70S6K) activity in bovine aortic endothelial cells (BAEC). This inhibition was not accompanied by decreased phosphorylation status or in vitro kinase activity of mammalian target of rapamycin (mTOR). Furthermore, cotreatment with rapamycin, a specific mTOR inhibitor, and troglitazone additively inhibited both p70S6K activity and protein synthesis, suggesting that the inhibitory effects of troglitazone are not mediated by mTOR. Overexpression of the wild-type p70S6K gene significantly reversed the troglitazone-induced inhibition of protein synthesis, indicating an important role of p70S6K. Okadaic acid, a protein phosphatase 2A (PP2A) inhibitor, partially reversed the troglitazone-induced inhibition of p70S6K activity and protein synthesis. Although troglitazone did not alter total cellular PP2A activity, it increased the physical association between p70S6K and PP2A, suggesting an underlying molecular mechanism. GW9662, a PPARγ antagonist, did not alter any of the observed inhibitory effects. Finally, we also found that the mTOR-independent inhibitory mechanism of troglitazone holds for the TZDs ciglitazone, pioglitazone, and rosiglitazone, in BAEC and other types of endothelial cells tested. In conclusion, our data demonstrate for the first time that troglitazone (and perhaps other TZDs) acutely decreases p70S6K activity through a PP2A-dependent mechanism that is independent of mTOR and PPARγ, leading to the inhibition of protein synthesis in endothelial cells.

BCL2 protein expression parallels its mRNA level in normal and malignant B cells

Blood ◽  
2004 ◽  
Vol 104 (9) ◽  
pp. 2936-2939 ◽  
Author(s):  
Yulei Shen ◽  
Javeed Iqbal ◽  
James Z. Huang ◽  
Guimei Zhou ◽  
Wing C. Chan
Keyword(s):  
B Cells ◽  
Protein Expression ◽  
B Cell ◽  
Posttranscriptional Regulation ◽  
Cell Lymphoma ◽  
Dominant Role ◽  
Mrna Level ◽  
B Cell Lymphoma ◽  
Transcriptional Level ◽  
Bcl2 Protein

Abstract The regulation of B-cell lymphoma 2 (BCL2) protein expression in germinal center (GC) B cells has been controversial. Previous reports have indicated posttranscriptional regulation plays a dominant role. However, a number of recent studies contradicted these reports. Using real-time polymerase chain reaction (PCR) and Standardized Reverse Transcriptase-PCR (StaRT-PCR), we measured the level of mRNA expression in GC, mantle zone (MNZ), and marginal zone (MGZ) cells from laser capture microdissection. Both quantitative RT-PCR measurements of microdissected GC cells from tonsils showed that GC cells had low expression of BCL2 transcripts commensurate with the low protein expression level. These results are in agreement with microarray studies on fluorescence-activated cell sorter (FACS)-sorted cells and microdissected GC cells. We also examined BCL2 mRNA and protein expression on a series of 30 cases of diffuse large B-cell lymphoma (DLBCL) and found, in general, a good correlation. The results suggested that BCL2 protein expression is regulated at the transcriptional level in normal B cells and in the neoplastic cells in most B-cell lymphoproliferative disorders.

Constitutive RNA synthesis for the yeast activator ADR1 and identification of the ADR1-5c mutation: implications in posttranslational control of ADR1

1986 ◽  
Vol 6 (11) ◽  
pp. 4026-4030
Author(s):  
C L Denis ◽  
C Gallo
Keyword(s):  
Rna Synthesis ◽  
Potential Role ◽  
Glucose Repression ◽  
Posttranslational Regulation ◽  
Mrna Levels ◽  
Recognition Sequence ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Kinase Phosphorylation

The regulation of mRNA production for the yeast positive activator ADR1, a gene required for the expression of the glucose-repressible alcohol dehydrogenase (ADH II), was studied. ADR1 mRNA levels did not vary when yeasts were switched from glucose- to ethanol-containing medium, while ADH II expression increased 100-fold. The mRNA for the ADR1-5c allele, which augments ADH II expression 60-fold during glucose repression, was not present in greater abundance than ADR1 mRNA. Additionally, the ccr1-1 allele, which blocks ADH2 mRNA formation and partially suppresses the ADR1-5c phenotype, did not alter the levels of ADR1 mRNA. These results indicate that ADR1 is not transcriptionally controlled. To determine the character of the ADR1-5c mutation, the region containing the mutation was identified and sequenced. At base pair +683 a G-to-A transition was detected in the ADR1 coding sequence which would result in the substitution of a lysine residue for an arginine at amino acid 228. The location of the ADR1-5c mutation in the interior of the ADR1 coding sequences suggests that it enhances the activity of an extant but inactive ADR1 protein rather than increases the abundance of ADR1 by altered translation of its mRNA. The ADR1-5c mutation occurs in a region of the polypeptide corresponding to a cyclic AMP-dependent protein kinase phosphorylation recognition sequence. The potential role of reversible phosphorylation in the posttranslational regulation of ADR1 is discussed.

Six git genes encode a glucose-induced adenylate cyclase activation pathway in the fission yeast Schizosaccharomyces pombe

1993 ◽  
Vol 105 (4) ◽  
pp. 1095-1100 ◽  
Author(s):  
S.M. Byrne ◽  
C.S. Hoffman
Keyword(s):  
Adenylate Cyclase ◽  
Schizosaccharomyces Pombe ◽  
Glucose Repression ◽  
Signal Transduction Pathway ◽  
Activation Pathway ◽  
Cyclase Activation ◽  
Adenylate Cyclase Activation ◽  
Before And After ◽  
Dependent Protein ◽  
Camp Levels

An important eukaryotic signal transduction pathway involves the regulation of the effector enzyme adenylate cyclase, which produces the second messenger, cAMP. Previous genetic analyses demonstrated that glucose repression of transcription of the Schizosaccharomyces pombe fbp1 gene requires the function of adenylate cyclase, encoded by the git2 gene. As mutations in git2 and in six additional git genes are suppressed by exogenous cAMP, these ‘upstream’ git genes were proposed to act to produce a glucose-induced cAMP signal. We report here that assays of cAMP levels in wild-type and various mutant S. pombe cells, before and after exposure to glucose, show that this is the case. The data suggest that the cAMP signal results from the activation of adenylate cyclase. Therefore these ‘upstream’ git genes appear to encode a glucose-induced adenylate cyclase activation pathway. Assays of cAMP on a strain carrying a mutation in the git6 gene, which acts downstream of adenylate cyclase, indicate that git6 may function to feedback regulate adenylate cyclase activity. Thus git6 may encode a cAMP-dependent protein kinase.

ADH2 expression is repressed by REG1 independently of mutations that alter the phosphorylation of the yeast transcription factor ADR1

1993 ◽  
Vol 13 (7) ◽  
pp. 4391-4399
Author(s):  
K M Dombek ◽  
S Camier ◽  
E T Young
Keyword(s):  
Transcription Factor ◽  
Glucose Repression ◽  
Phosphorylation Site ◽  
Constitutive Expression ◽  
Partial Activation ◽  
Dependent Protein ◽  
Multiple Levels ◽  
Kinase Phosphorylation ◽  
Protein Kinase Phosphorylation Site ◽  
Dependent Pathway

In Saccharomyces cerevisiae, expression of the ADH2 gene is undetectable during growth on glucose. The transcription factor ADR1 is required to fully activate expression when glucose becomes depleted. Partial activation during growth on glucose occurred in cells carrying a constitutive allele of ADR1 in which the phosphorylatable serine of a cyclic AMP (cAMP)-dependent protein kinase phosphorylation site had been changed to alanine. When glucose was removed from the growth medium, a substantial increase in the level of this constitutive expression was observed for both the ADH2 gene and a reporter construct containing the ADR1 binding site. This suggests that glucose can block ADR1-mediated activation independently of cAMP-dependent phosphorylation at serine 230. REG1/HEX2/SRN1 was identified as a potential serine 230-independent repressor of ADH2 expression. Yeast strains carrying a deletion of the REG1 gene, reg1-1966, showed a large increase in ADR1-dependent expression of ADH2 during growth on glucose. A smaller increase in ADR1-independent expression was also observed. Additionally, an increase in the level of ADR1 expression and posttranslational modification of the ADR1 protein were observed. When the reg1-1966 allele was combined with various ADR1 constitutive alleles, the level of ADH2 expression was synergistically elevated. This indicates that REG1 can act independently of phosphorylation at serine 230. Our results suggest that glucose repression in the presence of ADR1 constitutive alleles occurs primarily through a REG1-dependent pathway which appears to affect ADH2 transcription at multiple levels.

Effects of glucose, pyruvate, lactate, and amino acids on muscle protein synthesis

1982 ◽  
Vol 242 (3) ◽  
pp. E184-E192 ◽  
Author(s):  
M. P. Hedden ◽  
M. G. Buse
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Creatine Phosphate ◽  
Serum Amino Acids ◽  
14Co2 Production ◽  
Beta Hydroxybutyrate ◽  
Free Media ◽  
Effect Of Glucose

Protein synthesis was measured in rat diaphragms incubated with serum amino acids + 0.35 mM L-[2,6-3H]tyrosine and different energy-yielding substrates. Muscles incubated with 5.5 mM glucose (with or without actinomycin D) synthesized more protein than those incubated with 11 mM pyruvate or 11 mM lactate. Tissue ATP decreased during incubation with lactate, but pyruvate maintained ATP, ADP, and creatine phosphate as well as glucose. Glucose 6-phosphate decreased in muscles incubated in glucose-free media. 14CO2 production from substrates was [1-14C]pyruvate greater than [1-14C]lactate greater than [3,4-14C]glucose. Intracellular lactate/pyruvate was measured to assess cytoplasmic free NADH/NAD+; the effect of different media on these ratios was lactate greater than glucose = lactate + pyruvate greater than pyruvate + glucose greater than pyruvate. Lactate + pyruvate (8.8 + 2.2 mM) supported protein synthesis better than pyruvate and as well as glucose. Adding glucose to pyruvate accelerated protein synthesis and increased NADH/NAD+. Iodoacetate (0.1 mM) inhibited glycolytic NAD reduction and abolished the stimulatory effect of glucose on protein synthesis in the presence of pyruvate. Supplementation of pyruvate media with 1 mM leucine or isoleucine stimulated protein synthesis, but beta-hydroxybutyrate, malate, alpha-ketoisocaproate, and all other amino acids were ineffective. The cytoplasmic redox potential may act as a translational modulator of protein synthesis in skeletal muscle.

Initiation in einem Polyribosomen-abhängigen Protein-synthetisierenden zellfreien System aus Saccharomyces / Initiation in a Polyribosome-Dependent Protein-Synthesizing Cell-Free System from Saccharomyces

1976 ◽  
Vol 31 (3-4) ◽  
pp. 169-173 ◽  
Author(s):  
Bernd Schulz-Harder ◽  
Ernst-Randolf Lochmann
Keyword(s):  
Protein Synthesis ◽  
Free System ◽  
Cell Free System ◽  
Aurintricarboxylic Acid ◽  
Dependent Protein ◽  
A Cell

Abstract A method to prepare polyribosomes from yeasts by using the french-press is described. The highest yield of polyribosomes was derived from late log-phase cells. These polyribosomes, incubated in a cell-free system, were able to reinitiate protein synthesis, which was shown by inhibiting aminoacid incorporation by aurintricarboxylic acid, edeine and sodiumfluoride. We developed the translational system in order to look for the optimal ion-conditions of a DNA-dependent protein-synthesizing system. We found out that at the optimal MgCL2-concentration (6 mᴍ) protein synthesis was strongly inhibited by Mangan ions which are required for transcription in yeast. If protein-synthesis was carried out with 2 mᴍ and 3 mᴍ MgCl2 maximal aminoacid incorporation was observed at 2 mᴍ and 1.5 mᴍ MnCl2.

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