scholarly journals Membrane and lipid metabolism plays an important role in desiccation resistance in the yeast Saccharomyces cerevisiae

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Qun Ren ◽  
Rebecca Brenner ◽  
Thomas C. Boothby ◽  
Zhaojie Zhang

Abstract Background Anhydrobiotes, such as the yeast Saccharomyces cerevisiae, are capable of surviving almost total loss of water. Desiccation tolerance requires an interplay of multiple events, including preserving the protein function and membrane integrity, preventing and mitigating oxidative stress, maintaining certain level of energy required for cellular activities in the desiccated state. Many of these crucial processes can be controlled and modulated at the level of organelle morphology and dynamics. However, little is understood about what organelle perturbations manifest in desiccation-sensitive cells as a consequence of drying or how this differs from organelle biology in desiccation-tolerant organisms undergoing anhydrobiosis. Results In this study, electron and optical microscopy was used to examine the dynamic changes of yeast cells during the desiccation process. Dramatic structural changes were observed during the desiccation process, including the diminishing of vacuoles, decrease of lipid droplets, decrease in mitochondrial cristae and increase of ER membrane, which is likely caused by ER stress and unfolded protein response. The survival rate was significantly decreased in mutants that are defective in lipid droplet biosynthesis, or cells treated with cerulenin, an inhibitor of fatty acid synthesis. Conclusion Our study suggests that the metabolism of lipid droplets and membrane may play an important role in yeast desiccation tolerance by providing cells with energy and possibly metabolic water. Additionally, the decrease in mitochondrial cristae coupled with a decrease in lipid droplets is indicative of a cellular response to reduce the production of reactive oxygen species.

2020 ◽  
Author(s):  
Qun Ren ◽  
Rebecca Brenner ◽  
Thomas C. Boothby ◽  
Zhaojie Zhang

Abstract BackgroundAnhydrobiotes, such as the yeast Saccharomyces cerevisiae, are capable of surviving almost total loss of water. Desiccation tolerance requires an interplay of multiple events, including preserving the protein function and membrane integrity, preventing and mitigating oxidative stress, maintaining certain level of energy required for cellular activities in the desiccated state. Many of these crucial processes can be controlled and modulated at the level of organelle morphology and dynamics. However, little is understood about what organelle perturbations manifest in desiccation-sensitive cells as a consequence of drying or how this differs from organelle biology in desiccation-tolerant organisms undergoing anhydrobiosis.ResultsIn this study, electron and optical microscopy was used to examine the dynamic changes of yeast cells during the desiccation process. Dramatic structural changes were observed during the desiccation process, including the diminishing of vacuoles, decrease of lipid droplets, decrease in mitochondrial cristae and increase of ER membrane, which is likely caused by ER stress and unfolded protein response. The survival rate was significantly decreased in mutants that are defective in lipid droplet biosynthesis, or cells treated with cerulenin, an inhibitor of fatty acid synthesis.ConclusionOur study suggests that the metabolism of lipid droplets and membrane may play an important role in yeast desiccation tolerance by providing cells with energy and possibly metabolic water. Additionally, the decrease in mitochondrial cristae coupled with a decrease in lipid droplets is indicative of a cellular response to reduce the production of reactive oxygen species.


2020 ◽  
Author(s):  
Qun Ren ◽  
Rebecca Brenner ◽  
Thomas C. Boothby ◽  
Zhaojie Zhang

Abstract Background Anhydrobiotes, such as the yeast Saccharomyces cerevisiae, are capable of surviving almost total loss of water. Desiccation tolerance requires an interplay of multiple events, including preserving the protein function and membrane integrity, preventing and mitigating oxidative stress, maintaining certain level of energy required for cellular activities in the desiccated state. Many of these crucial processes can be controlled and modulated at the level of organelle morphology and dynamics. However, little is understood about what organelle perturbations manifest in desiccation-sensitive cells as a consequence of drying or how this differs from organelle biology in desiccation-tolerant organisms undergoing anhydrobiosis.Results In this study, electron and optical microscopy was used to examine the dynamic changes of yeast cells during the desiccation process. Dramatic structural changes were observed during the desiccation process, including the diminishing of vacuoles, decrease of lipid droplets, decrease in mitochondrial cristae and increase of ER membrane, which is likely caused by ER stress and unfolded protein response. The survival rate was significantly decreased in mutants that are defective in lipid droplet biosynthesis, or cells treated with cerulenin, an inhibitor of fatty acid synthesis.Conclusion Our study suggests that the metabolism of lipid droplets and membrane may play an important role in yeast desiccation tolerance by providing cells with energy and possibly metabolic water. Additionally, the decrease in mitochondrial cristae coupled with a decrease in lipid droplets is indicative of a cellular response to reduce the production of reactive oxygen species.


2020 ◽  
Author(s):  
Qun Ren ◽  
Rebecca Brenner ◽  
Thomas C. Boothby ◽  
Zhaojie Zhang

Abstract Background: Anhydrobiotes, such as the yeast Saccharomyces cerevisiae , are capable of surviving almost total loss of water. Desiccation tolerance requires an interplay of multiple events, including preserving the protein function and membrane integrity, preventing and mitigating oxidative stress, maintaining certain level of energy required for cellular activities in the desiccated state. Many of these crucial processes can be controlled and modulated at the level of organelle morphology and dynamics. However, little is understood about what organelle perturbations manifest in desiccation-sensitive cells as a consequence of drying or how this differs from organelle biology in desiccation-tolerant organisms undergoing anhydrobiosis. Results: In this study, electron and optical microscopy was used to examine the dynamic changes of yeast cells during the desiccation process. Dramatic structural changes were observed during the desiccation process, including the diminishing of vacuoles, and increase and then decrease of lipid droplets as well as a decrease in mitochondria and mitochondrial cristae and an increase of ER membrane, which is likely caused by ER stress and unfolded protein response. The survival rate was significantly decreased in mutants that are defective in lipid droplet biosynthesis, or cells treated with cerulenin, an inhibitor of fatty acid synthesis. Conclusion: Our study suggests that the metabolism of lipid droplets and membrane may play an important role in yeast desiccation tolerance by providing cells with energy and possibly metabolic water. Additionally, the decrease in mitochondria and cristae coupled with an initial increase and then drop in lipid droplets number is indicative of a cellular response to reduce the production of reactive oxygen species.


1994 ◽  
Vol 14 (8) ◽  
pp. 5412-5424
Author(s):  
C J Yoo ◽  
S L Wolin

The human autoantigen La is a 50-kDa protein which binds to the 3' termini of virtually all nascent polymerase III transcripts. Experiments with mammalian transcription extracts have led to the proposal that the La protein is required for multiple rounds of transcription by RNA polymerase III (E. Gottlieb and J. A. Steitz, EMBO J. 8:851-861, 1989; R. J. Maraia, D. J. Kenan, and J. D. Keene, Mol. Cell. Biol. 14:2147-2158, 1994). Although La protein homologs have been identified in a variety of vertebrate species, the protein has not been identified in invertebrates. In order to begin a genetic analysis of La protein function, we have characterized homologs of the La protein in the fruit fly Drosophila melanogaster and the yeast Saccharomyces cerevisiae. We show that both the Drosophila and yeast La proteins are bound to precursors of polymerase III RNAs in vivo. The Drosophila and yeast proteins resemble the human La protein in their biochemical properties, as both proteins can be partially purified from cells by a procedure previously devised to purify the human protein. Similarly to vertebrate La proteins, the Drosophila and yeast homologs preferentially bind RNAs that terminate with a 3' hydroxyl. Despite the fact that the La protein is conserved between humans and Saccharomyces cerevisiae, yeast cells containing a null allele of the gene encoding the La protein are viable, suggesting that another protein(s) plays a functionally redundant role.


1994 ◽  
Vol 14 (8) ◽  
pp. 5412-5424 ◽  
Author(s):  
C J Yoo ◽  
S L Wolin

The human autoantigen La is a 50-kDa protein which binds to the 3' termini of virtually all nascent polymerase III transcripts. Experiments with mammalian transcription extracts have led to the proposal that the La protein is required for multiple rounds of transcription by RNA polymerase III (E. Gottlieb and J. A. Steitz, EMBO J. 8:851-861, 1989; R. J. Maraia, D. J. Kenan, and J. D. Keene, Mol. Cell. Biol. 14:2147-2158, 1994). Although La protein homologs have been identified in a variety of vertebrate species, the protein has not been identified in invertebrates. In order to begin a genetic analysis of La protein function, we have characterized homologs of the La protein in the fruit fly Drosophila melanogaster and the yeast Saccharomyces cerevisiae. We show that both the Drosophila and yeast La proteins are bound to precursors of polymerase III RNAs in vivo. The Drosophila and yeast proteins resemble the human La protein in their biochemical properties, as both proteins can be partially purified from cells by a procedure previously devised to purify the human protein. Similarly to vertebrate La proteins, the Drosophila and yeast homologs preferentially bind RNAs that terminate with a 3' hydroxyl. Despite the fact that the La protein is conserved between humans and Saccharomyces cerevisiae, yeast cells containing a null allele of the gene encoding the La protein are viable, suggesting that another protein(s) plays a functionally redundant role.


2013 ◽  
Vol 8 (8) ◽  
pp. 724-729 ◽  
Author(s):  
Aurelijus Zimkus ◽  
Audrius Misiūnas ◽  
Larisa Chaustova

AbstractThe effect of Li+ ions as a transformation inducing agent on the yeast cell wall has been studied. Two Saccharomyces cerevisiae strains, p63-DC5 with a native cell wall, and strain XCY42-30D(mnn1) which contains structural changes in the mannan-protein complex, were used. Fourier transform infrared (FT-IR) spectroscopy has been used for the characterization of the yeast strains and for determination of the effect of lithium cations on the cell wall. A comparison of the carbohydrate absorption band positions in the 970–1185 cm−1 range, of Na+ and Li+ treated yeast cells has been estimated. Absorption band positions of the cell wall carbohydrates of p63-DC5 were not influenced by the studied ions. On the contrary, the treatment of XCY42-30D(mnn1) cells with Li+ ions shifted glucan band positions, implying that the cell wall structure of strain XCY42-30D(mnn1) is more sensitive to Li+ ion treatment.


Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 850
Author(s):  
Karolina Nowosad ◽  
Monika Sujka ◽  
Urszula Pankiewicz ◽  
Damijan Miklavčič ◽  
Marta Arczewska

The aim of the study was to investigate the influence of a pulsed electric field (PEF) on the level of iron ion accumulation in Saccharomyces cerevisiae cells and to select PEF conditions optimal for the highest uptake of this element. Iron ions were accumulated most efficiently when their source was iron (III) nitrate. When the following conditions of PEF treatment were used: voltage 1500 V, pulse width 10 μs, treatment time 20 min, and a number of pulses 1200, accumulation of iron ions in the cells from a 20 h-culture reached a maximum value of 48.01 mg/g dry mass. Application of the optimal PEF conditions thus increased iron accumulation in cells by 157% as compared to the sample enriched with iron without PEF. The second derivative of the FTIR spectra of iron-loaded and -unloaded yeast cells allowed us to determine the functional groups which may be involved in metal ion binding. The exposure of cells to PEF treatment only slightly influenced the biomass and cell viability. However, iron-enriched yeast (both with or without PEF) showed lower fermentative activity than a control sample. Thus obtained yeast biomass containing a high amount of incorporated iron may serve as an alternative to pharmacological supplementation in the state of iron deficiency.


Genetics ◽  
1987 ◽  
Vol 116 (4) ◽  
pp. 531-540
Author(s):  
Aileen K W Taguchi ◽  
Elton T Young

ABSTRACT The alcohol dehydrogenase II (ADH2) gene of the yeast, Saccharomyces cerevisiae, is not transcribed during growth on fermentable carbon sources such as glucose. Growth of yeast cells in a medium containing only nonfermentable carbon sources leads to a marked increase or derepression of ADH2 expression. The recessive mutation, adr6-1, leads to an inability to fully derepress ADH2 expression and to an inability to sporulate. The ADR6 gene product appears to act directly or indirectly on ADH2 sequences 3' to or including the presumptive TATAA box. The upstream activating sequence (UAS) located 5' to the TATAA box is not required for the Adr6- phenotype. Here, we describe the isolation of a recombinant plasmid containing the wild-type ADR6 gene. ADR6 codes for a 4.4-kb RNA which is present during growth both on glucose and on nonfermentable carbon sources. Disruption of the ADR6 transcription unit led to viable cells with decreased ADHII activity and an inability to sporulate. This indicates that both phenotypes result from mutations within a single gene and that the adr6-1 allele was representative of mutations at this locus. The ADR6 gene mapped to the left arm of chromosome XVI at a site 18 centimorgans from the centromere.


1989 ◽  
Vol 9 (2) ◽  
pp. 442-451
Author(s):  
M Nishizawa ◽  
R Araki ◽  
Y Teranishi

To clarify carbon source-dependent control of the glycolytic pathway in the yeast Saccharomyces cerevisiae, we have initiated a study of transcriptional regulation of the pyruvate kinase gene (PYK). By deletion analysis of the 5'-noncoding region of the PYK gene, we have identified an upstream activating sequence (UASPYK1) located between 634 and 653 nucleotides upstream of the initiating ATG codon. The promoter activity of the PYK 5'-noncoding region was abolished when the sequence containing the UASPYK1 was deleted from the region. Synthetic UASPYK1 (26mer), in either orientation, was able to restore the transcriptional activity of UAS-depleted mutants when placed upstream of the TATA sequence located at -199 (ATG as +1). While the UASPYK1 was required for basal to intermediate levels of transcriptional activation, a sequence between -714 and -811 was found to be necessary for full activation. On the other hand, a sequence between -344 and -468 was found to be responsible for transcriptional repression of the PYK gene when yeast cells were grown on nonfermentable carbon sources. This upstream repressible sequence also repressed transcription, although to a lesser extent, when glucose was present in the medium. The possible mechanism for carbon source-dependent regulation of PYK expression through these cis-acting regulatory elements is discussed.


Genetics ◽  
1977 ◽  
Vol 85 (3) ◽  
pp. 373A-393
Author(s):  
James B Hicks ◽  
Ira Herskowitz

ABSTRACT The two mating types of the yeast Saccharomyces cerevisiae can be interconverted in both homothallic and heterothallic strains. Previous work indicates that all yeast cells contain the information to be both a and α and that the HO gene (in homothallic strains) promotes a change in mating type by causing a change at the mating type locus itself. In both heterothallic and homothallic strains, a defective α mating type locus can be converted to a functional a locus and subsequently to a functional α locus. In contrast, action of the HO gene does not restore mating ability to a strain defective in another gene for mating which is not at the mating type locus. These observations indicate that a yeast cell contains an additional copy (or copies) of α information, and lead to the "cassette" model for mating type interconversion. In this model, HM  a and hmα loci are blocs of unexpressed α regulatory information, and HMα and hm  a loci are blocs of unexpressed a regulatory information. These blocs are silent because they lack an essential site for expression, and become active upon insertion of this information (or a copy of the information) into the mating type locus by action of the HO gene.


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