Acquired Resistance to Severe Ethanol Stress in Saccharomyces cerevisiae Protein Quality Control

Applied and Environmental Microbiology, Journal Year: 2020, Volume and Issue: 87(6)

Published: Dec. 22, 2020

Acute severe ethanol stress (10% [vol/vol]) damages proteins and causes the intracellular accumulation of insoluble in Saccharomyces cerevisiae On other hand, a pretreatment with mild increases tolerance to subsequent stress, which is called acquired resistance. It currently remains unclear whether under may be mitigated by increasing protein quality control (PQC) activity cells pretreated stress. In present study, we examined induction resistance PQC confirmed that 6% (vol/vol) or thermal at 37°C significantly reduced levels aggregation Lsg1, prone denaturation yeast 10% The this required new synthesis proteins; expression comprising bichaperone system (Hsp104, Ssa3, Fes1), Sis1, Hsp42 was upregulated during maintained Since deficient mutants (fes1Δ hsp104Δ ssa2Δ ssa3Δ ssa4Δ) failed sufficiently reduce Lsg1 aggregation, enhanced appears important for adequate contrast, importance proteasomes aggregases (Btn2 Hsp42) has not been confirmed. These results provide further insights into including brewing process.IMPORTANCE Although budding S. cerevisiae, used production alcoholic beverages bioethanol, highly tolerant ethanol, high concentrations are also stressful cause various adverse effects, denaturation. A improves cells; however, it reduces denatured proteins. found involved proteins, even novel adaptive capacity yeast. They contribute research on physiology process, concentration gradually increases.

Language: Английский

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Large organellar changes occur during mild heat shock in yeast

Journal of Cell Science, Journal Year: 2021, Volume and Issue: 135(5)

Published: July 7, 2021

ABSTRACT When the temperature is increased, heat-shock response activated to protect cellular environment. The transcriptomics and proteomics of this process are intensively studied, while information about how cell responds structurally heat stress mostly lacking. Here, Saccharomyces cerevisiae were subjected a mild continuous shock (38°C) intermittently cryo-immobilised for electron microscopy. Through measuring changes in all distinguishable organelle numbers, sizes morphologies over 2100 micrographs, major restructuring internal architecture during progressive was revealed. grew larger but most organelles within it expanded even more, shrinking volume cytoplasm. Organelles responded at different times, both terms size number, adaptations morphology some (such as vacuole) observed. Multivesicular bodies by almost 70%, indicating previously unknown involvement response. A undescribed electron-translucent structure accumulated close plasma membrane. This all-encompassing approach provides detailed chronological progression adaptation throughout heat-stress article has an associated First Person interview with first author paper.

Language: Английский

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Phosphorylation activates the yeast small heat shock protein Hsp26 by weakening domain contacts in the oligomer ensemble

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Nov. 18, 2021

Abstract Hsp26 is a small heat shock protein (sHsp) from S. cerevisiae . Its chaperone activity activated by oligomer dissociation at temperatures. contains 9 phosphorylation sites in different structural elements. Our analysis of phospho-mimetic mutations shows that activates permissive The cryo-EM structure the 40mer revealed contacts between conserved core domain and so-called thermosensor N-terminal part protein, which are targeted phosphorylation. Furthermore, several C-terminal extension, link subunits within oligomer, sensitive to introduction negative charges. In all cases, intrinsic inhibition relieved becomes accessible for substrate binding. weakening interactions activate response proteotoxic stresses independent stress could be general regulation principle sHsps.

Language: Английский

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CRISPR/Cas9 and genetic screens in malaria parasites: small genomes, big impact

Biochemical Society Transactions, Journal Year: 2022, Volume and Issue: 50(3), P. 1069 - 1079

Published: May 27, 2022

The ∼30 Mb genomes of the Plasmodium parasites that cause malaria each encode ∼5000 genes, but functions majority remain unknown. This is due to a paucity functional annotation from sequence homology, which compounded by low genetic tractability compared with many model organisms. In recent years technical breakthroughs have made forward and reverse genome-scale screens in possible. Furthermore, adaptation Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) CRISPR-Associated protein 9 (CRISPR/Cas9) technology has dramatically improved gene editing efficiency at single level. Here, we review arrival analyse parasite function their impact on understanding biology. CRISPR/Cas9 screens, revolutionised human organism research, not yet been implemented need for more complex targeting vector libraries. We therefore introduce reader CRISPR-based related apicomplexan Toxoplasma gondii discuss how these approaches could be adapted develop based parasites. Moreover, since than half genes are required normal asexual blood-stage reproduction, cannot targeted using knockout methods, used scale up conditional knockdown systematically assign essential genes.

Language: Английский

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Balanced activities of Hsp70 and the ubiquitin proteasome system underlie cellular protein homeostasis

Frontiers in Molecular Biosciences, Journal Year: 2023, Volume and Issue: 9

Published: Jan. 4, 2023

To counteract proteotoxic stress and cellular aging, protein quality control (PQC) systems rely on the refolding, degradation sequestration of misfolded proteins. In Saccharomyces cerevisiae Hsp70 chaperone system plays a central role in while is predominantly executed by ubiquitin proteasome (UPS). The sequestrases Hsp42 Btn2 deposit proteins cytosolic nuclear inclusions, thereby restricting accessibility to preventing exhaustion limited resources. Therefore, yeast, sequestrase mutants show negative genetic interactions with double lacking co-chaperone Fes1 Hsp104 disaggregase ( fes1Δ hsp104Δ , ΔΔ ) suffering from low capacity. Growth ΔΔbtn2Δ highly temperature-sensitive results proteostasis breakdown at non-permissive temperatures. Here, we probed for maintaining homeostasis cells, which are affected two major branches. We that cells induce expression diverse stress-related pathways including defects. Ubiquitin dependent stringent substrate firefly Luciferase mutant mirrors such compensatory activities system. Surprisingly however, enhanced activity does not improve but aggravates growth defects cells. Reducing lowering levels functional 26S proteasomes improved growth, increased refolding yield reporter attenuated global responses. Our findings indicate an imbalance between Hsp70-dependent system-mediated strongly affects capacity contributes their severe phenotypes.

Language: Английский

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