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Saccharomyces cerevisiae genes involved in survival of heat shock.

Jarolim S, Ayer A, Pillay B, Gee AC, Phrakaysone A, Perrone GG, Breitenbach M, Dawes IW - G3 (Bethesda) (2013)

Bottom Line: Mutants affected in l-tryptophan metabolism were heat-shock resistant in both growth phases; those affected in cytoplasmic ribosome biogenesis and DNA double-strand break repair were resistant in stationary phase, and in mRNA catabolic processes in exponential phase.Mutations affecting mitochondrial genome maintenance were highly represented in sensitive mutants.The cell division transcription factor Swi6p and Hac1p involved in the unfolded protein response also play roles in maintenance of heat-shock resistance.

View Article: PubMed Central - PubMed

Affiliation: Division of Genetics, Department of Cell Biology, University of Salzburg, Salzburg, A-5020 Austria.

ABSTRACT
The heat-shock response in cells, involving increased transcription of a specific set of genes in response to a sudden increase in temperature, is a highly conserved biological response occurring in all organisms. Despite considerable attention to the processes activated during heat shock, less is known about the role of genes in survival of a sudden temperature increase. Saccharomyces cerevisiae genes involved in the maintenance of heat-shock resistance in exponential and stationary phase were identified by screening the homozygous diploid deletants in nonessential genes and the heterozygous diploid mutants in essential genes for survival after a sudden shift in temperature from 30 to 50°. More than a thousand genes were identified that led to altered sensitivity to heat shock, with little overlap between them and those previously identified to affect thermotolerance. There was also little overlap with genes that are activated or repressed during heat-shock, with only 5% of them regulated by the heat-shock transcription factor. The target of rapamycin and protein kinase A pathways, lipid metabolism, vacuolar H(+)-ATPase, vacuolar protein sorting, and mitochondrial genome maintenance/translation were critical to maintenance of resistance. Mutants affected in l-tryptophan metabolism were heat-shock resistant in both growth phases; those affected in cytoplasmic ribosome biogenesis and DNA double-strand break repair were resistant in stationary phase, and in mRNA catabolic processes in exponential phase. Mutations affecting mitochondrial genome maintenance were highly represented in sensitive mutants. The cell division transcription factor Swi6p and Hac1p involved in the unfolded protein response also play roles in maintenance of heat-shock resistance.

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Mutations affecting aromatic amino acid biosynthesis lead to heat-shock resistance in both exponential and stationary phase. Pathway modified from the Saccharomyces Genome Database. Genes that when deleted led to heat-shock resistance are indicated in red.
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fig4: Mutations affecting aromatic amino acid biosynthesis lead to heat-shock resistance in both exponential and stationary phase. Pathway modified from the Saccharomyces Genome Database. Genes that when deleted led to heat-shock resistance are indicated in red.

Mentions: To identify cell functions important in maintaining resistance and sensitivity, genes were grouped into overrepresented molecular functions, biological processes, and cellular component categories (Figure 3, A and B) according to FunSpec and Yeastmine programs. A striking feature of mutants resistant to heat shock in both exponential and stationary phase was the involvement of aromatic amino acid biosynthesis (Figure 4), one of the most significantly enriched functional categories of any gene set examined and trpΔ mutants were among the more resistant mutants identified. Mutations affecting synthesis of the tryptophan precursors erythrose-4-phosphate (tkl1Δ) and 5-phosphoribosyl-1-pyrophosphate (prs3Δ) were also resistant. This effect appeared to be specific to l-tryptophan and not L-phenylalanine or L-tyrosine since only the tryptophan branch of the pathway was represented in the resistant mutants.


Saccharomyces cerevisiae genes involved in survival of heat shock.

Jarolim S, Ayer A, Pillay B, Gee AC, Phrakaysone A, Perrone GG, Breitenbach M, Dawes IW - G3 (Bethesda) (2013)

Mutations affecting aromatic amino acid biosynthesis lead to heat-shock resistance in both exponential and stationary phase. Pathway modified from the Saccharomyces Genome Database. Genes that when deleted led to heat-shock resistance are indicated in red.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3852394&req=5

fig4: Mutations affecting aromatic amino acid biosynthesis lead to heat-shock resistance in both exponential and stationary phase. Pathway modified from the Saccharomyces Genome Database. Genes that when deleted led to heat-shock resistance are indicated in red.
Mentions: To identify cell functions important in maintaining resistance and sensitivity, genes were grouped into overrepresented molecular functions, biological processes, and cellular component categories (Figure 3, A and B) according to FunSpec and Yeastmine programs. A striking feature of mutants resistant to heat shock in both exponential and stationary phase was the involvement of aromatic amino acid biosynthesis (Figure 4), one of the most significantly enriched functional categories of any gene set examined and trpΔ mutants were among the more resistant mutants identified. Mutations affecting synthesis of the tryptophan precursors erythrose-4-phosphate (tkl1Δ) and 5-phosphoribosyl-1-pyrophosphate (prs3Δ) were also resistant. This effect appeared to be specific to l-tryptophan and not L-phenylalanine or L-tyrosine since only the tryptophan branch of the pathway was represented in the resistant mutants.

Bottom Line: Mutants affected in l-tryptophan metabolism were heat-shock resistant in both growth phases; those affected in cytoplasmic ribosome biogenesis and DNA double-strand break repair were resistant in stationary phase, and in mRNA catabolic processes in exponential phase.Mutations affecting mitochondrial genome maintenance were highly represented in sensitive mutants.The cell division transcription factor Swi6p and Hac1p involved in the unfolded protein response also play roles in maintenance of heat-shock resistance.

View Article: PubMed Central - PubMed

Affiliation: Division of Genetics, Department of Cell Biology, University of Salzburg, Salzburg, A-5020 Austria.

ABSTRACT
The heat-shock response in cells, involving increased transcription of a specific set of genes in response to a sudden increase in temperature, is a highly conserved biological response occurring in all organisms. Despite considerable attention to the processes activated during heat shock, less is known about the role of genes in survival of a sudden temperature increase. Saccharomyces cerevisiae genes involved in the maintenance of heat-shock resistance in exponential and stationary phase were identified by screening the homozygous diploid deletants in nonessential genes and the heterozygous diploid mutants in essential genes for survival after a sudden shift in temperature from 30 to 50°. More than a thousand genes were identified that led to altered sensitivity to heat shock, with little overlap between them and those previously identified to affect thermotolerance. There was also little overlap with genes that are activated or repressed during heat-shock, with only 5% of them regulated by the heat-shock transcription factor. The target of rapamycin and protein kinase A pathways, lipid metabolism, vacuolar H(+)-ATPase, vacuolar protein sorting, and mitochondrial genome maintenance/translation were critical to maintenance of resistance. Mutants affected in l-tryptophan metabolism were heat-shock resistant in both growth phases; those affected in cytoplasmic ribosome biogenesis and DNA double-strand break repair were resistant in stationary phase, and in mRNA catabolic processes in exponential phase. Mutations affecting mitochondrial genome maintenance were highly represented in sensitive mutants. The cell division transcription factor Swi6p and Hac1p involved in the unfolded protein response also play roles in maintenance of heat-shock resistance.

Show MeSH
Related in: MedlinePlus