scholarly journals Heat Shock Drives Genomic Instability and Phenotypic Variations in Yeast

2020 ◽  
Author(s):  
Li Shen ◽  
Yu-Ting Wang ◽  
Xing-Xing Tang ◽  
Ke Zhang ◽  
Pin-Mei Wang ◽  
...  

Abstract High temperature causes ubiquitous environmental stress to microorganisms, but studies have not fully explained whether and to what extent heat shock would affect genome stability. Hence, this study explored heat-shock-induced genomic alterations in the yeast Saccharomyces cerevisiae . Using genetic screening systems and customized single nucleotide polymorphism (SNP) microarrays, we found that heat shock (52°C) for several minutes could heighten mitotic recombination by at least one order of magnitude. More than half of heat-shock-induced mitotic recombinations were likely to be initiated by DNA breaks in the S/G 2 phase of the cell cycle. Chromosomal aberration, mainly trisomy, was elevated hundreds of times in heat-shock-treated cells than in untreated cells. Distinct chromosomal instability patterns were also observed between heat-treated and carbendazim-treated yeast cells. Finally, we demonstrated that heat shock stimulates fast phenotypic evolutions (such as tolerance to ethanol, vanillin, fluconazole, and tunicamycin) in the yeast population. This study not only provided novel insights into the effect of temperature fluctuations on genomic integrity but also developed a simple protocol to generate an aneuploidy mutant of yeast.

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.


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.


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.


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.


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.


2004 ◽  
Vol 377 (3) ◽  
pp. 769-774 ◽  
Author(s):  
Precious MOTSHWENE ◽  
Robert KARREMAN ◽  
Gail KGARI ◽  
Wolf BRANDT ◽  
George LINDSEY

Yeast cells Saccharomyces cerevisiae, late embryogenic abundant-like stress response protein Hsp 12 (heat-shock protein 12) were found by immunocytochemistry to be located both in the cytoplasm and in the cell wall, from where they could be extracted with dilute NaOH solutions. Yeast cells with the Hsp 12 gene disrupted were unable to grow in the presence of either 12 mM caffeine or 0.43 mM Congo Red, molecules known to affect cell-wall integrity. The volume of yeast cells were less affected by rapid changes in the osmolality of the growth medium when compared with the wild-type yeast cells, suggesting a role for Hsp 12 in the flexibility of the cell wall. This was also suggested by subjecting the yeast cells to rapid changes in barometric pressure where it was found that wild-type yeast cells were more resistant to cellular breakage.


1984 ◽  
Vol 4 (11) ◽  
pp. 963-972 ◽  
Author(s):  
Richard C. Nicholson ◽  
Larry A. Moran

A 3.52-kilobase (kb) segment of Drosophila melanogaster DNA carrying the 2.l5-kb transcribed sequence for the 70 000-dalton heat-shock protein hsp70) and l.l4-kb of the 5′ flanking sequence was inserted into an autonomously replicating chimeric plasmid and used to transform the yeast Saccharomyces cerevisiae. The Drosophila gene is efficiently transcribed in the transformed cells, yielding a transcript which is 21 nucleotides shorter than the normal Drosophila mRNA at the 5′ end. Significant increases in the amount of Drosophila-specific RNA occur when the transformed ceils are subjected to heat shock, indicating that the Drosophila gene is inducible in the yeast cells.


Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 342
Author(s):  
Lihi Gershon ◽  
Martin Kupiec

Acetylation on lysine 56 of histone H3 of the yeast Saccharomyces cerevisiae has been implicated in many cellular processes that affect genome stability. Despite being the object of much research, the complete scope of the roles played by K56 acetylation is not fully understood even today. The acetylation is put in place at the S-phase of the cell cycle, in order to flag newly synthesized histones that are incorporated during DNA replication. The signal is removed by two redundant deacetylases, Hst3 and Hst4, at the entry to G2/M phase. Its crucial location, at the entry and exit points of the DNA into and out of the nucleosome, makes this a central modification, and dictates that if acetylation and deacetylation are not well concerted and executed in a timely fashion, severe genomic instability arises. In this review, we explore the wealth of information available on the many roles played by H3K56 acetylation and the deacetylases Hst3 and Hst4 in DNA replication and repair.


Genetics ◽  
1997 ◽  
Vol 145 (3) ◽  
pp. 661-670 ◽  
Author(s):  
Qing-Qing Fan ◽  
Fei Xu ◽  
Michael A White ◽  
Thomas D Petes

In a wild-type strain of Saccharomyces cerevisiae, a hotspot for meiotic recombination is located upstream of the HIS4 gene. An insertion of a 49-bp telomeric sequence into the coding region of HIS4 strongly stimulates meiotic recombination and the local formation of meiosis-specific double-strand DNA breaks (DSBs). When strains are constructed in which both hotspots are heterozygous, hotspot activity is substantially less when the hotspots are on the same chromosome than when they are on opposite chromosomes.


2020 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Somanon Bhattacharya ◽  
Tejas Bouklas ◽  
Bettina C. Fries

Candida albicans, Candida auris, Candida glabrata, and Cryptococcus neoformans are pathogenic yeasts which can cause systemic infections in immune-compromised as well as immune-competent individuals. These yeasts undergo replicative aging analogous to a process first described in the nonpathogenic yeast Saccharomyces cerevisiae. The hallmark of replicative aging is the asymmetric cell division of mother yeast cells that leads to the production of a phenotypically distinct daughter cell. Several techniques to study aging that have been pioneered in S. cerevisiae have been adapted to study aging in other pathogenic yeasts. The studies indicate that aging is relevant for virulence in pathogenic fungi. As the mother yeast cell progressively ages, every ensuing asymmetric cell division leads to striking phenotypic changes, which results in increased antifungal and antiphagocytic resistance. This review summarizes the various techniques that are used to study replicative aging in pathogenic fungi along with their limitations. Additionally, the review summarizes some key phenotypic variations that have been identified and are associated with changes in virulence or resistance and thus promote persistence of older cells.


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