Adaptation to stress in yeast: to translate or not?

2012 ◽  
Vol 40 (4) ◽  
pp. 794-799 ◽  
Author(s):  
Clare E. Simpson ◽  
Mark P. Ashe
Keyword(s):  
Protein Synthesis ◽  
Translation Initiation ◽  
Stress Responses ◽  
Translational Regulation ◽  
Protein Production ◽  
Yeast Cells ◽  
Specific Proteins ◽  
Response To Stress ◽  
Eukaryotic Organisms ◽  
The Impact

For most eukaryotic organisms, including Saccharomyces cerevisiae, the rapid inhibition of protein synthesis forms part of a response to stress. In order to balance the changing conditions, precise stress-specific alterations to the cell's proteome are required. Therefore, in the background of a global down-regulation in protein synthesis, specific proteins are induced. Given the level of plasticity required to enable stress-specific alterations of this kind, it is surprising that the mechanisms of translational regulation are not more diverse. In the present review, we summarize the impact of stress on translation initiation, highlighting both the similarities and distinctions between various stress responses. Finally, we speculate as to how yeast cells generate stress-responsive programmes of protein production when regulation is focused on the same steps in the translation pathway.

Rare Human Codons and HCMV Translational Regulation

2017 ◽  
Vol 27 (4) ◽  
pp. 213-216 ◽  
Author(s):  
Darja Kanduc
Keyword(s):  
Protein Synthesis ◽  
Codon Usage ◽  
Human Cytomegalovirus ◽  
Translational Regulation ◽  
Protein Production ◽  
Nucleotide Sequences ◽  
Positive Correlation ◽  
Human Host ◽  
Rare Codons

Restriction of protein synthesis characterizes human cytomegalovirus (HCMV) latency in the human host. In analyzing the molecular factors that hinder HCMV expression, the present study shows that HCMV genes frequently use 6 rare codons, i.e., GCG (Ala), CCG (Pro), CGT (Arg), CGC (Arg), TCG (Ser), and ACG (Thr). In some instances, the rare host codons are clustered along viral nucleotide sequences and represent the majority in sequences encoding short alanine and proline repeats. Given the positive correlation between codon usage, tRNA content, and protein production, the results support the hypothesis that HCMV usage of rare human codons might hinder HCMV protein synthesis, in this way leading to HCMV latency.

scholarly journals CReP mediates selective translation initiation at the endoplasmic reticulum

2020 ◽  
Vol 6 (23) ◽  
pp. eaba0745 ◽  
Author(s):  
Jonathan P. Kastan ◽  
Elena Y. Dobrikova ◽  
Jeffrey D. Bryant ◽  
Matthias Gromeier
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Translation Initiation ◽  
Stress Responses ◽  
Spatial Organization ◽  
Acute Stress ◽  
Cell Fractionation ◽  
Local Protein Synthesis ◽  
Eif2α Phosphorylation ◽  
Selective Translation

Eukaryotic protein synthesis control at multiple levels allows for dynamic, selective responses to diverse conditions, but spatial organization of translation initiation machinery as a regulatory principle has remained largely unexplored. Here we report on a role of constitutive repressor of eIF2α phosphorylation (CReP) in translation of poliovirus and the endoplasmic reticulum (ER)–resident chaperone binding immunoglobulin protein (BiP) at the ER. Functional, proximity-dependent labeling and cell fractionation studies revealed that CReP, through binding eIF2α, anchors translation initiation machinery at the ER and enables local protein synthesis in this compartment. This ER site was protected from the suppression of cytoplasmic protein synthesis by acute stress responses, e.g., phosphorylation of eIF2α(S51) or mTOR blockade. We propose that partitioning of translation initiation machinery at the ER enables cells to maintain active translation during stress conditions associated with global protein synthesis suppression.

scholarly journals Characterization of Temporal Protein Production in Pseudomonas aeruginosa Biofilms

2005 ◽  
Vol 187 (23) ◽  
pp. 8114-8126 ◽  
Author(s):  
Christopher J. Southey-Pillig ◽  
David G. Davies ◽  
Karin Sauer
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Protein Production ◽  
Developmental Stages ◽  
Developmental Process ◽  
Developmental Cycle ◽  
Specific Proteins ◽  
Biofilm Development ◽  
The Impact

ABSTRACT Phenotypic and genetic evidence supporting the notion of biofilm formation as a developmental process is growing. In the present work, we provide additional support for this hypothesis by identifying the onset of accumulation of biofilm-stage specific proteins during Pseudomonas aeruginosa biofilm maturation and by tracking the abundance of these proteins in planktonic and three biofilm developmental stages. The onset of protein production was found to correlate with the progression of biofilms in developmental stages. Protein identification revealed that proteins with similar function grouped within similar protein abundance patterns. Metabolic and housekeeping proteins were found to group within a pattern separate from virulence, antibiotic resistance, and quorum-sensing-related proteins. The latter were produced in a progressive manner, indicating that attendant features that are characteristic of biofilms such as antibiotic resistance and virulence may be part of the biofilm developmental process. Mutations in genes for selected proteins from several protein production patterns were made, and the impact of these mutations on biofilm development was evaluated. The proteins cytochrome c oxidase, a probable chemotaxis transducer, a two-component response regulator, and MexH were produced only in mature and late-stage biofilms. Mutations in the genes encoding these proteins did not confer defects in growth, initial attachment, early biofilm formation, or twitching motility but were observed to arrest biofilm development at the stage of cell cluster formation we call the maturation-1 stage. The results indicated that expression of theses genes was required for the progression of biofilms into three-dimensional structures on abiotic surfaces and the completion of the biofilm developmental cycle. Reverse transcription-PCR analysis confirmed the detectable change in expression of the respective genes ccoO, PA4101, and PA4208. We propose a possible mechanism for the role of these biofilm-specific proteins in biofilm formation.

scholarly journals Label-Free Comparative Proteomic Analysis Combined with Laser-Capture Microdissection Suggests Important Roles of Stress Responses in the Black Layer of Maize Kernels

2020 ◽  
Vol 21 (4) ◽  
pp. 1369
Author(s):  
Quanquan Chen ◽  
Ran Huang ◽  
Zhenxiang Xu ◽  
Yaxin Zhang ◽  
Li Li ◽  
...  
Keyword(s):  
Laser Capture Microdissection ◽  
Stress Responses ◽  
Label Free ◽  
Kernel Development ◽  
Flight Mass Spectrometry ◽  
Specific Proteins ◽  
Response To Stress ◽  
Black Layer ◽  
Maize Kernels ◽  
Laser Capture

The black layer (BL) is traditionally used as an indicator for kernel harvesting in maize, as it turns visibly dark when the kernel reaches physiological maturity. However, the molecular roles of BL in kernel development have not been fully elucidated. In this work, microscopy images showed that BL began to appear at a growth stage earlier than 10 days after pollination (DAP), and its color gradually deepened to become dark as the development period progressed. Scanning electron microscopy observations revealed that BL is a tissue structure composed of several layers of cells that are gradually squeezed and compressed during kernel development. Laser-capture microdissection (LCM) was used to sample BL and its neighboring inner tissue, basal endosperm transfer layer (BETL), and outer tissue, inner epidermis (IEP), from 20 DAP of kernels. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry profiling (MALDI-TOF MS profiling) detected 41, 104, and 120 proteins from LCM-sampled BL, BETL, and IEP, respectively. Gene ontology (GO) analysis indicated that the 41 BL proteins were primarily involved in the response to stress and stimuli. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis found that the BL proteins were enriched in several defense pathways, such as the ascorbate and aldarate metabolic pathways. Among the 41 BL proteins, six were BL-specific proteins that were only detected from BL. Annotations of five BL-specific proteins were related to stress responses. During kernel development, transcriptional expression of most BL proteins showed an increase, followed by a decrease, and reached a maximum zero to 20 DAP. These results suggest a role for BL in stress responses for protecting filial tissue against threats from maternal sides, which helps to elucidate the biological functions of BL.

scholarly journals The yeast eIF2 kinase Gcn2 facilitates H2O2-mediated feedback inhibition of both protein synthesis and ER oxidative folding during recombinant protein production

2021 ◽  
Author(s):  
Veronica Gast ◽  
Kate Campbell ◽  
Cecilia Picazo Campos ◽  
Martin Engqvist ◽  
Verena Siewers ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Recombinant Protein ◽  
Translation Initiation ◽  
Recombinant Protein Production ◽  
Protein Production ◽  
Feedback Inhibition ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Oxidative Folding ◽  
Amylase Production

AbstractRecombinant protein production is a known source of oxidative stress. Knowledge of which ROS are involved or the specific growth phase in which stress occurs however remains lacking. Using modern, hypersensitive genetic H2O2-specific probes, micro-cultivation and continuous measurements in batch culture, we observed H2O2 accumulation during and following the diauxic shift in engineered Saccharomyces cerevisiae, correlating with peak α-amylase production. In agreement with previous studies supporting a role of the translation initiation factor kinase Gcn2 in the response to H2O2, we find Gcn2-dependent phosphorylation of eIF2α to increase alongside translational attenuation in strains engineered to produce large amounts of α-amylase. Gcn2 removal significantly improved α-amylase production in two previously optimized high-producing strains, but not in the wild-type. Gcn2-deficiency furthermore reduced intracellular H2O2 levels and the unfolded protein response whilst expression of antioxidants and the ER disulfide isomerase PDI1 increased. These results suggest protein synthesis and ER oxidative folding to be coupled and subject to feedback inhibition by H2O2.ImportanceReactive oxygen species (ROS) accumulate during recombinant protein production both in yeast and Chinese hamster ovary cells, two of the most popular organisms used in the multi-million dollar protein production industry. Here we document increased H2O2 in the cytosol of yeast cells producing α-amylase. Since H2O2 predominantly targets the protein synthesis machinery and activates the translation initiation factor kinase Gcn2, we removed Gcn2, resulting in increased recombinant α-amylase production in two different previously engineered high-producing protein production strains. Removal of this negative feed-back loop thus represents a complementary strategy for improving recombinant protein production efforts currently used in yeast. Gcn2-deficiency also increased the expression of antioxidant genes and the ER-foldase PDI1, suggesting that protein synthesis and ER oxidative folding are linked and feed-back regulated via H2O2. Identification of additional components in this complex regulation may further improve protein production and contribute to the development of novel protein-based therapeutic strategies.

scholarly journals Continuous Feeding Does Not Blunt Skeletal Muscle Protein Synthesis and Lean Growth Compared to Intermittent Bolus Feeding in the Preterm Piglet (OR26-06-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Marko Rudar ◽  
Jane Naberhuis ◽  
Hanh Nguyen ◽  
Agus Suryawan ◽  
Candace Style ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Protein Synthesis ◽  
Translation Initiation ◽  
Muscle Protein ◽  
Feeding Strategies ◽  
Intermittent Bolus ◽  
Lean Growth ◽  
Continuous Feeding ◽  
The Impact

Abstract Objectives Refining early feeding strategies for premature infants is essential for mitigating adverse outcomes of prematurity. In neonatal term piglets, continuous feeding blunts growth compared to intermittent bolus feeding. Our objective was to determine the impact of feeding modality on lean growth in preterm pigs. We hypothesized that intermittent bolus feeding can mitigate low lean growth rates in preterm neonates compared to continuous feeding. Methods Pigs obtained by C-section (105 d gestation; 952 ± 205 g body weight) were fitted with an umbilical artery catheter (later replaced with jugular vein catheter) and an orogastric tube for parenteral and enteral nutrition, respectively. Pigs were assigned to continuous (CONT; 7.5 mL/[kg·h]) or intermittent bolus (INT; 30 mL/kg every 4 h over 15 min) feeding for 21 d. Pigs initially received parenteral nutrition and were advanced to full oral feeds over 6 d (220 kcal/kg and 16 g/kg protein per day). Body composition (by DXA), plasma insulin, and skeletal muscle anabolic signaling and fractional protein synthesis rates (PS; L-[ring-2H5]phenylalanine) were determined in INT pigs in the postabsorptive (before a meal, INT-PA; n = 13) and postprandial (after a meal, INT-PP; n = 16) states and in CONT pigs (n = 14). Results Body weight gain, lean mass, and fat mass did not differ between INT and CONT pigs. Insulin was lower before feeding for INT pigs than CONT pigs (P < 0.05). Insulin increased with feeding for INT pigs and exceeded that of CONT pigs at 30 and 60 min (P < 0.01) before returning to baseline levels at 240 min. In the longissimus dorsi (LD), gastrocnemius, and soleus muscles, the abundance of the eIF4E·eIF4G complex, which is required for translation initiation, was greater in INT-PP and CONT pigs than INT-PA pigs (P < 0.01), but did not differ between INT-PP and CONT pigs. PS in the LD muscle was greater in INT-PP pigs than INT-PA pigs (P < 0.01), but did not differ between INT-PP and CONT pigs. Conclusions Continuous feeding does not blunt translation initiation and protein synthesis in skeletal muscle compared to intermittent bolus feeding in preterm piglets. The resulting absence of enhanced lean growth with intermittent bolus compared to continuous feeding contrasts with term piglets and may be a consequence of prematurity. Funding Sources USDA CRIS 6250-51000-055, NIH HD072891, and USDA NIFA 2013-67015-20438.

scholarly journals Effect of salt hyperosmotic stress on yeast cell viability

2007 ◽  
pp. 271-284 ◽  
Author(s):  
Stelios Logothetis ◽  
Graeme Walker ◽  
Elias Nerantzis
Keyword(s):  
Cell Viability ◽  
Yeast Cell ◽  
Stress Responses ◽  
Transcriptional Activation ◽  
Yeast Strain ◽  
Research Work ◽  
Wine Yeast ◽  
Yeast Cells ◽  
Wine Yeast Strain ◽  
The Impact

During fermentation for ethanol production, yeasts are subjected to different kinds of physico-chemical stresses such as: initially high sugar concentration and low temperature; and later, increased ethanol concentrations. Such conditions trigger a series of biological responses in an effort to maintain cell cycle progress and yeast cell viability. Regarding osmostress, many studies have been focused on transcriptional activation and gene expression in laboratory strains of Saccharomyces cerevisiae. The overall aim of this present work was to further our understanding of wine yeast performance during fermentations under osmotic stress conditions. Specifically, the research work focused on the evaluation of NaCl-induced stress responses of an industrial wine yeast strain S. cerevisiae (VIN 13), particularly with regard to yeast cell growth and viability. The hypothesis was that osmostress conditions energized specific genes to enable yeast cells to survive under stressful conditions. Experiments were designed by pretreating cells with different sodium chloride concentrations (NaCl: 4%, 6% and 10% w/v) growing in defined media containing D-glucose and evaluating the impact of this on yeast growth and viability. Subsequent fermentation cycles took place with increasing concentrations of D-glucose (20%, 30%, 40% w/v) using salt-adapted cells as inocula. We present evidence that osmostress induced by mild salt pre-treatments resulted in beneficial influences on both cell viability and fermentation performance of an industrial wine yeast strain.

A comparison of the stress responses of Zea mays seedlings as shown by qualitative changes in protein synthesis

1988 ◽  
Vol 66 (9) ◽  
pp. 1883-1890 ◽  
Author(s):  
P. C. Bonham-Smith ◽  
M. Kapoor ◽  
J. D. Bewley
Keyword(s):  
Protein Synthesis ◽  
Abscisic Acid ◽  
Water Stress ◽  
Heat Shock ◽  
Stress Responses ◽  
Protein Profile ◽  
Tissue Response ◽  
Specific Proteins ◽  
Induced Proteins ◽  
Qualitative Changes

Maize seedlings respond to heat shock, water stress, abscisic acid treatment, and wounding with the synthesis of stress-specific proteins. Unlike the almost instantaneous (10 min) heat-shock response, a much longer stress exposure is required before the synthesis of water stress induced, abscisic acid induced, or wound-induced proteins. As with heat shock, the protein profile of 24 h water stress induced proteins is consistent between tissue types, whereas seedling tissue response to wounding or heavy metals varies. Wounding of the mesocotyl for 12 h or more results in a complex change (induction and inhibition) in protein synthesis in the growing region, while protein synthesis in the nongrowing region is affected to a much lesser extent.

scholarly journals Translational Control of Canonical and Non-Canonical Translation Initiation Factors at the Sea Urchin Egg to Embryo Transition

2019 ◽  
Vol 20 (3) ◽  
pp. 626
Author(s):  
Héloïse Chassé ◽  
Sandrine Boulben ◽  
Patrick Cormier ◽  
Julia Morales
Keyword(s):  
Early Development ◽  
Sea Urchin ◽  
Translation Initiation ◽  
Translational Control ◽  
Translational Regulation ◽  
Sea Urchins ◽  
Embryonic Cell ◽  
Scaffolding Protein ◽  
Initiation Factors ◽  
The Impact

Sea urchin early development is a powerful model to study translational regulation under physiological conditions. Fertilization triggers an activation of the translation machinery responsible for the increase of protein synthesis necessary for the completion of the first embryonic cell cycles. The cap-binding protein eIF4E, the helicase eIF4A and the large scaffolding protein eIF4G are assembled upon fertilization to form an initiation complex on mRNAs involved in cap-dependent translation initiation. The presence of these proteins in unfertilized and fertilized eggs has already been demonstrated, however data concerning the translational status of translation factors are still scarce. Using polysome fractionation, we analyzed the impact of fertilization on the recruitment of mRNAs encoding initiation factors. Strikingly, whereas the mRNAs coding eIF4E, eIF4A, and eIF4G were not recruited into polysomes at 1 h post-fertilization, mRNAs for eIF4B and for non-canonical initiation factors such as DAP5, eIF4E2, eIF4E3, or hnRNP Q, are recruited and are differentially sensitive to the activation state of the mechanistic target of rapamycin (mTOR) pathway. We discuss our results suggesting alternative translation initiation in the context of the early development of sea urchins.

scholarly journals Evidence for a high proportion of inactive ribosomes in slow-growing yeast cells

1977 ◽  
Vol 168 (3) ◽  
pp. 409-415 ◽  
Author(s):  
C Waldron ◽  
R Jund ◽  
F Lacroute
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Protein Turnover ◽  
Protein Production ◽  
Yeast Cells ◽  
Fast Growing ◽  
Molecular Weights ◽  
The Times ◽  
Slow Growing

From the protein and RNA content of Saccharomyces cerevisiae growing in different media we calculate that ribosome efficiency is changed: incorporation of amino acids into protein decreases from 8.8 amino acids/s per ribosome in fast-growing cells (0.54 doubling/h) to 5.2 amino acids/s per ribosome in slow-growing cells (0.30 doubling/h). We could not detect significant protein turnover in either fast-or slow-growing cultures, so the lower ribosome efficiency does not seem to be an artifact caused by changes in unstable protein production at different growth rates. Nor is the lower ribosome efficiency due to slower migration of ribosomes along mRNA: the times required to complete polypeptides of known molecular weights are the same in slow-growing cells as those previously determined for fast-growing cells [Waldron, Jund & Lacroute (1974) FEBS Lett. 46, 11-16]. We therefore deduce that ribosome efficiency changes in yeast because the fraction of ribosomes engaged in protein synthesis falls (from 84% in fast-growing cells to 50% in slow-growing cells.

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