scholarly journals The sensitivity of the yeast, Saccharomyces cerevisiae, to acetic acid is influenced by DOM34 and RPL36A

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4037 ◽  
Author(s):  
Bahram Samanfar ◽  
Kristina Shostak ◽  
Houman Moteshareie ◽  
Maryam Hajikarimlou ◽  
Sarah Shaikho ◽  
...  

The presence of acetic acid during industrial alcohol fermentation reduces the yield of fermentation by imposing additional stress on the yeast cells. The biology of cellular responses to stress has been a subject of vigorous investigations. Although much has been learned, details of some of these responses remain poorly understood. Members of heat shock chaperone HSP proteins have been linked to acetic acid and heat shock stress responses in yeast. Both acetic acid and heat shock have been identified to trigger different cellular responses including reduction of global protein synthesis and induction of programmed cell death. Yeast HSC82 and HSP82 code for two important heat shock proteins that together account for 1–2% of total cellular proteins. Both proteins have been linked to responses to acetic acid and heat shock. In contrast to the overall rate of protein synthesis which is reduced, the expression of HSC82 and HSP82 is induced in response to acetic acid stress. In the current study we identified two yeast genes DOM34 and RPL36A that are linked to acetic acid and heat shock sensitivity. We investigated the influence of these genes on the expression of HSP proteins. Our observations suggest that Dom34 and RPL36A influence translation in a CAP-independent manner.

1991 ◽  
Vol 11 (2) ◽  
pp. 1062-1068
Author(s):  
H J Yost ◽  
S Lindquist

In the yeast Saccharomyces cerevisiae, the splicing of mRNA precursors is disrupted by a severe heat shock. Mild heat treatments prior to severe heat shock protect splicing from disruption, as was previously reported for Drosophila melanogaster. In contrast to D. melanogaster, protein synthesis during the pretreatment is not required to protect splicing in yeast cells. However, protein synthesis is required for the rapid recovery of splicing once it has been disrupted by a sudden severe heat shock. Mutations in two classes of yeast hsp genes affect the pattern of RNA splicing during the heat shock response. First, certain hsp70 mutants, which overproduce other heat shock proteins at normal temperatures, show constitutive protection of splicing at high temperatures and do not require pretreatment. Second, in hsp104 mutants, the recovery of RNA splicing after a severe heat shock is delayed compared with wild-type cells. These results indicate a greater degree of specialization in the protective functions of hsps than has previously been suspected. Some of the proteins (e.g., members of the hsp70 and hsp82 gene families) help to maintain normal cellular processes at higher temperatures. The particular function of hsp104, at least in splicing, is to facilitate recovery of the process once it has been disrupted.


1991 ◽  
Vol 11 (2) ◽  
pp. 1062-1068 ◽  
Author(s):  
H J Yost ◽  
S Lindquist

In the yeast Saccharomyces cerevisiae, the splicing of mRNA precursors is disrupted by a severe heat shock. Mild heat treatments prior to severe heat shock protect splicing from disruption, as was previously reported for Drosophila melanogaster. In contrast to D. melanogaster, protein synthesis during the pretreatment is not required to protect splicing in yeast cells. However, protein synthesis is required for the rapid recovery of splicing once it has been disrupted by a sudden severe heat shock. Mutations in two classes of yeast hsp genes affect the pattern of RNA splicing during the heat shock response. First, certain hsp70 mutants, which overproduce other heat shock proteins at normal temperatures, show constitutive protection of splicing at high temperatures and do not require pretreatment. Second, in hsp104 mutants, the recovery of RNA splicing after a severe heat shock is delayed compared with wild-type cells. These results indicate a greater degree of specialization in the protective functions of hsps than has previously been suspected. Some of the proteins (e.g., members of the hsp70 and hsp82 gene families) help to maintain normal cellular processes at higher temperatures. The particular function of hsp104, at least in splicing, is to facilitate recovery of the process once it has been disrupted.


1992 ◽  
Vol 12 (9) ◽  
pp. 4215-4229
Author(s):  
S Heidmann ◽  
B Obermaier ◽  
K Vogel ◽  
H Domdey

In contrast to higher eukaryotes, little is known about the nature of the sequences which direct 3'-end formation of pre-mRNAs in the yeast Saccharomyces cerevisiae. The hexanucleotide AAUAAA, which is highly conserved and crucial in mammals, does not seem to have any functional importance for 3'-end formation in yeast cells. Instead, other elements have been proposed to serve as signal sequences. We performed a detailed investigation of the yeast ACT1, ADH1, CYC1, and YPT1 cDNAs, which showed that the polyadenylation sites used in vivo can be scattered over a region spanning up to 200 nucleotides. It therefore seems very unlikely that a single signal sequence is responsible for the selection of all these polyadenylation sites. Our study also showed that in the large majority of mRNAs, polyadenylation starts directly before or after an adenosine residue and that 3'-end formation of ADH1 transcripts occurs preferentially at the sequence PyAAA. Site-directed mutagenesis of these sites in the ADH1 gene suggested that this PyAAA sequence is essential for polyadenylation site selection both in vitro and in vivo. Furthermore, the 3'-terminal regions of the yeast genes investigated here are characterized by their capacity to act as signals for 3'-end formation in vivo in either orientation.


1993 ◽  
Vol 13 (2) ◽  
pp. 877-890 ◽  
Author(s):  
K Kohno ◽  
K Normington ◽  
J Sambrook ◽  
M J Gething ◽  
K Mori

The endoplasmic reticulum (ER) of eukaryotic cells contains an abundant 78,000-Da protein (BiP) that is involved in the translocation, folding, and assembly of secretory and transmembrane proteins. In the yeast Saccharomyces cerevisiae, as in mammalian cells, BiP mRNA is synthesized at a high basal rate and is further induced by the presence of increased amounts of unfolded proteins in the ER. However, unlike mammalian BiP, yeast BiP is also induced severalfold by heat shock, albeit in a transient fashion. To identify the regulatory sequences that respond to these stimuli in the yeast KAR2 gene that encodes BiP, we have cloned a 1.3-kb segment of DNA from the region upstream of the sequences coding for BiP and fused it to a reporter gene, the Escherichia coli beta-galactosidase gene. Analysis of a series of progressive 5' truncations as well as internal deletions of the upstream sequence showed that the information required for accurate transcriptional regulation of the KAR2 gene in S. cerevisiae is contained within a approximately 230-bp XhoI-DraI fragment (nucleotides -245 to -9) and that this fragment contains at least two cis-acting elements, one (heat shock element [HSE]) responding to heat shock and the other (unfolded protein response element [UPR]) responding to the presence of unfolded proteins in the ER. The HSE and UPR elements are functionally independent of each other but work additively for maximum induction of the yeast KAR2 gene. Lying between these two elements is a GC-rich region that is similar in sequence to the consensus element for binding of the mammalian transcription factor Sp1 and that is involved in the basal expression of the KAR2 gene. Finally, we provide evidence suggesting that yeast cells monitor the concentration of free BiP in the ER and adjust the level of transcription of the KAR2 gene accordingly; this effect is mediated via the UPR element in the KAR2 promoter.


1992 ◽  
Vol 12 (8) ◽  
pp. 3460-3469 ◽  
Author(s):  
M S Cyert ◽  
J Thorner

By using an assay specific for detection of calcineurin, a Ca2+/calmodulin-dependent phosphoprotein phosphatase, this enzyme was purified approximately 5,000-fold from extracts of the yeast Saccharomyces cerevisiae. Cna1p and Cna2p, the products of two yeast genes encoding the catalytic (A) subunits of calcineurin, were major constituents of the purified fraction. A third prominent component of apparent molecular mass 16 kDa displayed several properties, including ability to bind 45Ca2+, that are characteristic of the regulatory (B) subunit of mammalian calcineurin and was recognized by an antiserum raised against bovine calcineurin. These antibodies were used to isolate the structural gene (CNB1) encoding this protein from a yeast expression library in the vector lambda gt11. The nucleotide sequence of CNB1 predicted a polypeptide similar in length and highly related in amino acid sequence (56% identity) to the mammalian calcineurin B subunit. Like its counterpart in higher cells, yeast Cnb1p was myristoylated at its N terminus. Mutants lacking Cnb1p, or all three calcineurin subunits (Cna1p, Cna2p, and Cnb1p), were viable. Extracts of cnb1 delta mutants contained no detectable calcineurin activity, even though Cna1p and Cna2p were present at normal levels, suggesting that the B subunit is required for full enzymatic activity in vitro. As was observed previously for MATa cna1 cna2 double mutants, MATa cnb1 mutants were defective in their ability to recover from alpha-factor-induced growth arrest. Thus, the B subunit also is required for the function of calcineurin in promoting adaptation of haploid yeast cells to pheromone in vivo.


Author(s):  
M Lairón-Peris ◽  
S. J. Routledge ◽  
J. A. Linney ◽  
J Alonso-del-Real ◽  
C.M. Spickett ◽  
...  

Saccharomyces cerevisiae is an important unicellular yeast species within the biotechnological and food and beverage industries. A significant application of this species is the production of ethanol, where concentrations are limited by cellular toxicity, often at the level of the cell membrane. Here, we characterize 61 S. cerevisiae strains for ethanol tolerance and further analyse five representatives with varying ethanol tolerances. The most tolerant strain, AJ4, was dominant in co-culture at 0% and 10% ethanol. Unexpectedly, although it does not have the highest NIC or MIC, MY29 was the dominant strain in co-culture at 6% ethanol, which may be linked to differences in its basal lipidome. Whilst relatively few lipidomic differences were observed between strains, a significantly higher PE concentration was observed in the least tolerant strain, MY26, at 0% and 6% ethanol compared to the other strains that became more similar at 10%, indicating potential involvement of this lipid with ethanol sensitivity. Our findings reveal that AJ4 is best able to adapt its membrane to become more fluid in the presence of ethanol and lipid extracts from AJ4 also form the most permeable membranes. Furthermore, MY26 is least able to modulate fluidity in response to ethanol and membranes formed from extracted lipids are least leaky at physiological ethanol concentrations. Overall, these results reveal a potential mechanism of ethanol tolerance and suggests a limited set of membrane compositions that diverse yeast species use to achieve this. Importance Many microbial processes are not implemented at the industrial level because the product yield is poorer and more expensive than can be achieved by chemical synthesis. It is well established that microbes show stress responses during bioprocessing, and one reason for poor product output from cell factories is production conditions that are ultimately toxic to the cells. During fermentative processes, yeast cells encounter culture media with high sugar content, which is later transformed into high ethanol concentrations. Thus, ethanol toxicity is one of the major stresses in traditional and more recent biotechnological processes. We have performed a multilayer phenotypic and lipidomic characterization of a large number of industrial and environmental strains of Saccharomyces to identify key resistant and non-resistant isolates for future applications.


1992 ◽  
Vol 12 (8) ◽  
pp. 3460-3469
Author(s):  
M S Cyert ◽  
J Thorner

By using an assay specific for detection of calcineurin, a Ca2+/calmodulin-dependent phosphoprotein phosphatase, this enzyme was purified approximately 5,000-fold from extracts of the yeast Saccharomyces cerevisiae. Cna1p and Cna2p, the products of two yeast genes encoding the catalytic (A) subunits of calcineurin, were major constituents of the purified fraction. A third prominent component of apparent molecular mass 16 kDa displayed several properties, including ability to bind 45Ca2+, that are characteristic of the regulatory (B) subunit of mammalian calcineurin and was recognized by an antiserum raised against bovine calcineurin. These antibodies were used to isolate the structural gene (CNB1) encoding this protein from a yeast expression library in the vector lambda gt11. The nucleotide sequence of CNB1 predicted a polypeptide similar in length and highly related in amino acid sequence (56% identity) to the mammalian calcineurin B subunit. Like its counterpart in higher cells, yeast Cnb1p was myristoylated at its N terminus. Mutants lacking Cnb1p, or all three calcineurin subunits (Cna1p, Cna2p, and Cnb1p), were viable. Extracts of cnb1 delta mutants contained no detectable calcineurin activity, even though Cna1p and Cna2p were present at normal levels, suggesting that the B subunit is required for full enzymatic activity in vitro. As was observed previously for MATa cna1 cna2 double mutants, MATa cnb1 mutants were defective in their ability to recover from alpha-factor-induced growth arrest. Thus, the B subunit also is required for the function of calcineurin in promoting adaptation of haploid yeast cells to pheromone in vivo.


1988 ◽  
Vol 66 (9) ◽  
pp. 1883-1890 ◽  
Author(s):  
P. C. Bonham-Smith ◽  
M. Kapoor ◽  
J. D. Bewley

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.


Gut ◽  
1997 ◽  
Vol 41 (2) ◽  
pp. 156-163 ◽  
Author(s):  
D Hopwood ◽  
S Moitra ◽  
B Vojtesek ◽  
D A Johnston ◽  
J F Dillon ◽  
...  

Background—The oesophageal epithelium is exposed routinely to noxious agents in the environment, including gastric acid, thermal stress, and chemical toxins. These epithelial cells have presumably evolved effective protective mechanisms to withstand tissue damage and repair injured cells. Heat shock protein or stress protein responses play a central role in protecting distinct cell types from different types of injury.Aim—To determine (i) whether biochemical analysis of stress protein responses in pinch biopsy specimens from human oesophageal epithelium is feasible; (ii) whether undue stresses are imposed on cells by the act of sample collection, thus precluding analysis of stress responses; and (iii) if amenable to experimentation, the type of heat shock protein (Hsp) response that operates in the human oesophageal epithelium.Methods—Tissue from the human oesophagus comprised predominantly of squamous epithelium was acquired within two hours of biopsy and subjected to an in vitro heat shock. Soluble tissue cell lysates derived from untreated or heat shocked samples were examined using denaturing polyacrylamide gel electrophoresis for changes in: (i) the pattern of general protein synthesis by labelling epithelial cells with 35S-methionine and (ii) the levels of soluble Hsp70 protein and related isoforms using immunochemical protein blots.Results—A single pinch biopsy specimen is sufficient to extract and analyse specific sets of polypeptides in the oesophageal epithelium. After ex vivo heat shock, a classic inhibition of general protein synthesis is observed and correlates with the increased synthesis of two major proteins of molecular weight of 60 and 70 kDa. Notably, cells from unheated controls exhibit a “stressed” biochemical state 22 hours after incubation at 37°C, as shown by inhibition of general protein synthesis and increased synthesis of the 70 kDa protein. These data indicate that only freshly acquired specimens are suitable for studying stress responses ex vivo. No evidence was found that the two heat induced polypeptides are previously identified Hsp70 isoforms. In fact, heat shock results in a reduction in the steady state concentrations of Hsp70 protein in the oesophageal epithelium.Conclusion—Systematic and highly controlled studies on protein biochemistry are possible on epithelial biopsy specimens from the human oesophagus. These technical innovations have permitted the discovery of a novel heat shock response operating in the oesophageal epithelium. Notably, two polypeptides were synthesised after heat shock that seem to differ from Hsp70 protein. In addition, the striking reduction in steady state concentrations of Hsp70 protein after heat shock suggests that oesophageal epithelium has evolved an atypical biochemical response to thermal stress.


2004 ◽  
Vol 15 (12) ◽  
pp. 5492-5502 ◽  
Author(s):  
Babette Schade ◽  
Gregor Jansen ◽  
Malcolm Whiteway ◽  
Karl D. Entian ◽  
David Y. Thomas

We have determined the transcriptional response of the budding yeast Saccharomyces cerevisiae to cold. Yeast cells were exposed to 10°C for different lengths of time, and DNA microarrays were used to characterize the changes in transcript abundance. Two distinct groups of transcriptionally modulated genes were identified and defined as the early cold response and the late cold response. A detailed comparison of the cold response with various environmental stress responses revealed a substantial overlap between environmental stress response genes and late cold response genes. In addition, the accumulation of the carbohydrate reserves trehalose and glycogen is induced during late cold response. These observations suggest that the environmental stress response (ESR) occurs during the late cold response. The transcriptional activators Msn2p and Msn4p are involved in the induction of genes common to many stress responses, and we show that they mediate the stress response pattern observed during the late cold response. In contrast, classical markers of the ESR were absent during the early cold response, and the transcriptional response of the early cold response genes was Msn2p/Msn4p independent. This implies that the cold-specific early response is mediated by a different and as yet uncharacterized regulatory mechanism.


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