scholarly journals Oxidative Damage of Mussels Living in Seawater Enriched with Trace Metals, from the Viewpoint of Proteins Expression and Modification

Toxics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 89
Author(s):  
Georgia G. Kournoutou ◽  
Panagiota C. Giannopoulou ◽  
Eleni Sazakli ◽  
Michalis Leotsinidis ◽  
Dimitrios L. Kalpaxis ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Trace Metals ◽  
Oxidative Damage ◽  
Ribosomal Proteins ◽  
Prolonged Exposure ◽  
Protein Biosynthesis ◽  
Mechanisms Of Toxicity ◽  
Translation Factors ◽  
Oxidative Biomarkers ◽  
The Impact

The impact of metals bioaccumulation in marine organisms is a subject of intense investigation. This study was designed to determine the association between oxidative stress induced by seawater enriched with trace metals and protein synthesis using as a model the mussels Mytilus galloprovincialis. Mussels were exposed to 40 μg/L Cu, 30 μg/L Hg, or 100 μg/L Cd for 5 and 15 days, and the pollution effect was evaluated by measuring established oxidative biomarkers. The results showed damage on the protein synthesis machine integrity and specifically on translation factors and ribosomal proteins expression and modifications. The exposure of mussels to all metals caused oxidative damage that was milder in the cases of Cu and Hg and more pronounced for Cd. However, after prolonged exposure of mussels to Cd (15 days), the effects receded. These changes that perturb protein biosynthesis can serve as a great tool for elucidating the mechanisms of toxicity and could be integrated in biomonitoring programs.

scholarly journals Oxidative Damage of Mussels Living in Seawater Enriched with Trace Metals, from the Viewpoint of Proteins Expression and Modification

2020 ◽  
Author(s):  
Georgia G. Kournoutou ◽  
Panagiota C. Giannopoulou ◽  
Eleni Sazakli ◽  
Michalis Leotsinidis ◽  
Dimitrios L. Kalpaxis ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Trace Metals ◽  
Oxidative Damage ◽  
Ribosomal Proteins ◽  
Prolonged Exposure ◽  
Protein Biosynthesis ◽  
Mechanisms Of Toxicity ◽  
Translation Factors ◽  
Oxidative Biomarkers ◽  
The Impact

The impact of metals bioaccumulation on marine organisms is under investigation. This study was designed to determine the association of oxidative stress in mussels Mytilus galloprovincialis induced by seawater enriched with trace metals with protein synthesis. Mussels were exposed to 40 μg/L Cu, 30 μg/L Hg, or 100 μg/L Cd for 5 and 15 days, and the pollution effect was evaluated by measuring established oxidative biomarkers. The results showed damage on the protein synthesis machine integrity and specifically, on translation factors and ribosomal proteins expression and modifications. Exposure of mussels to all metals caused oxidative damage that was milder in the cases of Cu and Hg, and more pronounced for Cd. However, after prolonged exposure of mussels to Cd (15 days), the effects receded. These changes that perturb protein biosynthesis can serve as a great tool for elucidating the mechanisms of toxicity and could be integrated in biomonitoring programs.

Suppressors suaC 109 and suaA 101 of Aspergillus nidulans alter the ribosomal phenotype in vitro

1987 ◽  
Vol 7 (12) ◽  
pp. 941-948 ◽  
Author(s):  
A. Zamir ◽  
S. S. Martinelli
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Aspergillus Nidulans ◽  
Ribosomal Proteins ◽  
Amino Acid Incorporation ◽  
Free System ◽  
Cell Free System ◽  
Translation Factors ◽  
Acid Incorporation

A new homologous, cell-free system for protein synthesis has been devised for use with ribosomes and elongation factors from Aspergillus nidulans. Ribosome preparations from strains with either the suaAlO1 or suaCl09 mutations have a higher misreading ratio (non-cognate:cognate amino acid incorporation) in the presence of hygromycin than controls. They can be classed as fidelity mutants. These results also prove that the mutations must be in genes coding for ribosomal proteins or enzymes which modify ribosomal proteins post-translationally. Alternatively, the genes could code for translation factors.

scholarly journals Effect of Chronic Exposure to Prometryne on Oxidative Stress and Antioxidant Response in Red Swamp Crayfish (Procambarus clarkii)

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Alžběta Stará ◽  
Antonín Kouba ◽  
Josef Velíšek
Keyword(s):  
Oxidative Stress ◽  
Oxidative Damage ◽  
Chronic Exposure ◽  
Prolonged Exposure ◽  
Procambarus Clarkii ◽  
Thiobarbituric Acid ◽  
Antioxidant Systems ◽  
Control Group ◽  
Red Swamp Crayfish ◽  
The Impact

The aim of the study was to investigate effects of the triazine herbicide prometryne on red swamp crayfish on the basis of oxidative stress, antioxidant indices in hepatopancreas and muscle, and histopathology of hepatopancreas. Crayfish were exposed to prometryne concentrations of 0.51 μg L−1, 0.144 mg L−1, and 1.144 mg L−1for 11 and 25 days. Indices of oxidative stress (thiobarbituric acid reactive substances (TBARS)), and antioxidant parameters (superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR)) in crayfish muscle and hepatopancreas were measured. Chronic exposure to prometryne did not showed the impact of oxidative damage to cells. Changes activity of the antioxidant enzymes SOD, CAT, and GR were observed in all tested concentrations to prometryne for 11 and 25 days (P<0.01) as compared with the control group. We did not see any differences in histopatological examination to hepatopancreas. Prolonged exposure of prometryne did not result in oxidative damage to cell lipids and proteins, but it led to changes in antioxidant activity in crayfish tissues. Changes in antioxidant systems were also observed in the environmental prometryne concentration of 0.51 μg L−1. The results suggest that antioxidant responses may have potential as biomarkers for monitoring residual triazine herbicides in aquatic environments.

scholarly journals Continued Protein Synthesis at Low [ATP] and [GTP] Enables Cell Adaptation during Energy Limitation

2008 ◽  
Vol 191 (3) ◽  
pp. 1083-1091 ◽  
Author(s):  
Michael C. Jewett ◽  
Mark L. Miller ◽  
Yvonne Chen ◽  
James R. Swartz
Keyword(s):  
Protein Synthesis ◽  
Protein Biosynthesis ◽  
Protein Composition ◽  
System Level ◽  
Translation Factors ◽  
Metabolic Systems ◽  
Energy Limitation ◽  
The Individual ◽  
Intracellular Energy

ABSTRACT One of biology's critical ironies is the need to adapt to periods of energy limitation by using the energy-intensive process of protein synthesis. Although previous work has identified the individual energy-requiring steps in protein synthesis, we still lack an understanding of the dependence of protein biosynthesis rates on [ATP] and [GTP]. Here, we used an integrated Escherichia coli cell-free platform that mimics the intracellular, energy-limited environment to show that protein synthesis rates are governed by simple Michaelis-Menten dependence on [ATP] and [GTP] (Km ATP, 27 ± 4 μM; Km GTP, 14 ± 2 μM). Although the system-level GTP affinity agrees well with the individual affinities of the GTP-dependent translation factors, the system-level Km ATP is unexpectedly low. Especially under starvation conditions, when energy sources are limited, cells need to replace catalysts that become inactive and to produce new catalysts in order to effectively adapt. Our results show how this crucial survival priority for synthesizing new proteins can be enforced after rapidly growing cells encounter energy limitation. A diminished energy supply can be rationed based on the relative ATP and GTP affinities, and, since these affinities for protein synthesis are high, the cells can adapt with substantial changes in protein composition. Furthermore, our work suggests that characterization of individual enzymes may not always predict the performance of multicomponent systems with complex interdependencies. We anticipate that cell-free studies in which complex metabolic systems are activated will be valuable tools for elucidating the behavior of such systems.

scholarly journals O-GlcNAc Cycling Enzymes Associate with the Translational Machinery and Modify Core Ribosomal Proteins

2010 ◽  
Vol 21 (12) ◽  
pp. 1922-1936 ◽  
Author(s):  
Quira Zeidan ◽  
Zihao Wang ◽  
Antonio De Maio ◽  
Gerald W. Hart
Keyword(s):  
Protein Synthesis ◽  
Posttranslational Modifications ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Mammalian Target Of Rapamycin ◽  
Nuclear Staining ◽  
Mtor Signaling Pathway ◽  
Translational Machinery ◽  
Translation Factors ◽  
Nucleolar Stress

Protein synthesis is globally regulated through posttranslational modifications of initiation and elongation factors. Recent high-throughput studies have identified translation factors and ribosomal proteins (RPs) as substrates for the O-GlcNAc modification. Here we determine the extent and abundance of O-GlcNAcylated proteins in translational preparations. O-GlcNAc is present on many proteins that form active polysomes. We identify twenty O-GlcNAcylated core RPs, of which eight are newly reported. We map sites of O-GlcNAc modification on four RPs (L6, L29, L32, and L36). RPS6, a component of the mammalian target of rapamycin (mTOR) signaling pathway, follows different dynamics of O-GlcNAcylation than nutrient-induced phosphorylation. We also show that both O-GlcNAc cycling enzymes OGT and OGAse strongly associate with cytosolic ribosomes. Immunofluorescence experiments demonstrate that OGAse is present uniformly throughout the nucleus, whereas OGT is excluded from the nucleolus. Moreover, nucleolar stress only alters OGAse nuclear staining, but not OGT staining. Lastly, adenovirus-mediated overexpression of OGT, but not of OGAse or GFP control, causes an accumulation of 60S subunits and 80S monosomes. Our results not only establish that O-GlcNAcylation extensively modifies RPs, but also suggest that O-GlcNAc play important roles in regulating translation and ribosome biogenesis.

Roles of the mammalian target of rapamycin, mTOR, in controlling ribosome biogenesis and protein synthesis

2012 ◽  
Vol 40 (1) ◽  
pp. 168-172 ◽  
Author(s):  
Valentina Iadevaia ◽  
Yilin Huo ◽  
Ze Zhang ◽  
Leonard J. Foster ◽  
Christopher G. Proud
Keyword(s):  
Protein Synthesis ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Kinase Inhibitors ◽  
Mammalian Target Of Rapamycin ◽  
Target Of Rapamycin ◽  
Energy Status ◽  
Stable Isotope Labelling ◽  
Mtor Kinase ◽  
The Impact

mTORC1 (mammalian target of rapamycin complex 1) is controlled by diverse signals (e.g. hormones, growth factors, nutrients and cellular energy status) and regulates a range of processes including anabolic metabolism, cell growth and cell division. We have studied the impact of inhibiting mTOR on protein synthesis in human cells. Partial inhibition of mTORC1 by rapamycin has only a limited impact on protein synthesis, but inhibiting mTOR kinase activity causes much greater inhibition of protein synthesis. Using a pulsed stable-isotope-labelling technique, we show that the rapamycin and mTOR (mammalian target of rapamycin) kinase inhibitors have differential effects on the synthesis of specific proteins. In particular, the synthesis of proteins encoded by mRNAs that have a 5′-terminal pyrimidine tract is strongly inhibited by mTOR kinase inhibitors. Many of these mRNAs encode ribosomal proteins. mTORC1 also promotes the synthesis of rRNA, although the mechanisms involved remain to be clarified. We found that mTORC1 also regulates the processing of the precursors of rRNA. mTORC1 thus co-ordinates several steps in ribosome biogenesis.

4EBP1 Is Dephosphorylated by Respiratory Syncytial Virus Infection

Intervirology ◽  
2015 ◽  
Vol 58 (4) ◽  
pp. 205-208
Author(s):  
Gustavo Pérez-Gil ◽  
Adriana Landa-Cardeña ◽  
Rocío Coutiño ◽  
Rebeca García-Román ◽  
Clara L. Sampieri ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Respiratory Syncytial Virus ◽  
Virus Infection ◽  
Protein Biosynthesis ◽  
Host Cells ◽  
Translation Factors ◽  
Global Rate ◽  
Cellular Translation ◽  
Syncytial Virus ◽  
Replicative Cycle

Respiratory syncytial virus (RSV) requires protein biosynthesis machinery to generate progeny. There is evidence that RSV might alter some translation components since stress granules are formed in their host cells. Consistent with these observations, we found that RSV induces dephosphorylation of 4EBP1 (eIF4E-binding protein), an important cellular translation factor. Our results show no correlation between the 4EBP1 dephosphorylation time and the decrease in the global rate of protein synthesis. Interestingly, treatment with rapamycin stimulates virus generation. The results suggest that RSV is a virus that still contains unknown mechanisms involved in the translation of their mRNAs through the alteration or modification of some translation factors, such as 4EBP1, possibly to favor its replicative cycle.

scholarly journals CDK1 couples proliferation with protein synthesis

2020 ◽  
Vol 219 (3) ◽  
Author(s):  
Katharina Haneke ◽  
Johanna Schott ◽  
Doris Lindner ◽  
Anne Kruse Hollensen ◽  
Christian Kroun Damgaard ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Protein Synthesis ◽  
Ribosomal Proteins ◽  
High Demand ◽  
Cell Synchronization ◽  
Translation Factors ◽  
Mrna Binding Protein ◽  
Mrna Binding ◽  
Global Translation

Cell proliferation exerts a high demand on protein synthesis, yet the mechanisms coupling the two processes are not fully understood. A kinase and phosphatase screen for activators of translation, based on the formation of stress granules in human cells, revealed cell cycle–associated kinases as major candidates. CDK1 was identified as a positive regulator of global translation, and cell synchronization experiments showed that this is an extramitotic function of CDK1. Different pathways including eIF2α, 4EBP, and S6K1 signaling contribute to controlling global translation downstream of CDK1. Moreover, Ribo-Seq analysis uncovered that CDK1 exerts a particularly strong effect on the translation of 5′TOP mRNAs, which includes mRNAs encoding ribosomal proteins and several translation factors. This effect requires the 5′TOP mRNA-binding protein LARP1, concurrent to our finding that LARP1 phosphorylation is strongly dependent on CDK1. Thus, CDK1 provides a direct means to couple cell proliferation with biosynthesis of the translation machinery and the rate of protein synthesis.

scholarly journals CDK1 couples proliferation with protein synthesis

2019 ◽  
Author(s):  
Katharina Haneke ◽  
Johanna Schott ◽  
Doris Lindner ◽  
Anne K. Hollensen ◽  
Christian K. Damgaard ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Protein Synthesis ◽  
Ribosomal Proteins ◽  
High Demand ◽  
Cell Synchronization ◽  
Translation Factors ◽  
Mrna Binding Protein ◽  
Mrna Binding ◽  
Global Translation

ABSTRACTCell proliferation exerts a high demand on protein synthesis, yet the mechanisms coupling the two processes are not fully understood. A kinase and phosphatase screen for activators of translation, based on the formation of stress granules in human cells, revealed cell cycle-associated kinases as major candidates. CDK1 was identified as a positive regulator of global translation, and cell synchronization experiments showed that this is an extra-mitotic function of CDK1. Dephosphorylation of eIF2α and S6K1 signaling were found to act downstream of CDK1. Moreover, Ribo-Seq analysis uncovered that CDK1 exerts a particularly strong effect on the translation of 5’TOP mRNAs, which includes mRNAs encoding for ribosomal proteins and several translation factors. This effect requires the 5’TOP mRNA-binding protein LARP1, concurrent to our finding that LARP1 phosphorylation is strongly dependent on CDK1. Taken together, our results show that CDK1 provides a direct means to couple cell proliferation with biosynthesis of the translation machinery and the rate of protein synthesis.

scholarly journals The Impact of Oxidative Stress on Ribosomes: From Injury to Regulation

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1379 ◽  
Author(s):  
Natalia Shcherbik ◽  
Dimitri G. Pestov
Keyword(s):  
Reactive Oxygen Species ◽  
Oxidative Damage ◽  
Ribosomal Proteins ◽  
Reactive Oxygen ◽  
Special Role ◽  
Oxygen Species ◽  
Active Transition ◽  
Dynamics And Function ◽  
And Function ◽  
The Impact

The ribosome is a complex ribonucleoprotein-based molecular machine that orchestrates protein synthesis in the cell. Both ribosomal RNA and ribosomal proteins can be chemically modified by reactive oxygen species, which may alter the ribosome′s functions or cause a complete loss of functionality. The oxidative damage that ribosomes accumulate during their lifespan in a cell may lead to reduced or faulty translation and contribute to various pathologies. However, remarkably little is known about the biological consequences of oxidative damage to the ribosome. Here, we provide a concise summary of the known types of changes induced by reactive oxygen species in rRNA and ribosomal proteins and discuss the existing experimental evidence of how these modifications may affect ribosome dynamics and function. We emphasize the special role that redox-active transition metals, such as iron, play in ribosome homeostasis and stability. We also discuss the hypothesis that redox-mediated ribosome modifications may contribute to adaptive cellular responses to stress.

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