Kempf Claudia, Lengeler Klaus, Wendland Jürgen
Carlsberg Laboratory, Yeast & Fermentation, DK-1799 Copenhagen V, Denmark.
Carlsberg Laboratory, Yeast & Fermentation, DK-1799 Copenhagen V, Denmark; Vrije Universiteit Brussel, Functional Yeast Genomics, BE-1050 Brussels, Belgium.
Microbiol Res. 2017 Jul;200:53-63. doi: 10.1016/j.micres.2017.03.009. Epub 2017 Apr 5.
Proteotoxic stress may occur upon exposure of yeast cells to different stress conditions. The induction of stress response mechanisms is important for cells to adapt to changes in the environment and ensure survival. For example, during exposure to elevated temperatures the expression of heat shock proteins such as Hsp104 is induced in yeast. Hsp104 extracts misfolded proteins from aggregates to promote their refolding. We used an Hsp104-GFP reporter to analyze the stress profiles of Saccharomyces species hybrids. To this end a haploid S. cerevisiae strain, harboring a chromosomal HSP104-GFP under control of its endogenous promoter, was mated with stable haploids of S. bayanus, S. cariocanus, S. kudriavzevii, S. mikatae, S. paradoxus and S. uvarum. Stress response behaviors in these hybrids were followed over time by monitoring the appearance and dissolution of Hsp104-GFP foci upon heat shock. General stress tolerance of these hybrids was related to the growth rate detected during exposure to e.g. ethanol and oxidizing agents. We observed that hybrids were generally more resistant to high temperature and ethanol stress compared to their parental strains. Amongst the hybrids differential responses regarding the appearance of Hsp104-foci and the time required for dissolving these aggregates were observed. The S. cerevisiae/S. paradoxus hybrid, combining the two most closely related strains, performed best under these conditions.
当酵母细胞暴露于不同的应激条件下时，可能会发生蛋白质毒性应激。诱导应激反应机制对于细胞适应环境变化并确保生存至关重要。例如，在暴露于高温期间，酵母中会诱导热休克蛋白如Hsp104的表达。Hsp104从聚集体中提取错误折叠的蛋白质以促进其重新折叠。我们使用Hsp104-GFP报告基因来分析酿酒酵母属杂种的应激谱。为此，将一个在其内源启动子控制下含有染色体HSP104-GFP的单倍体酿酒酵母菌株与巴氏酵母、卡里奥卡酵母、库德里亚夫齐酵母、米卡塔酵母、奇异酵母和葡萄汁酵母的稳定单倍体进行交配。通过监测热休克后Hsp104-GFP焦点的出现和溶解情况，随时间跟踪这些杂种中的应激反应行为。这些杂种的一般应激耐受性与在暴露于例如乙醇和氧化剂期间检测到的生长速率有关。我们观察到，与它们的亲本菌株相比，杂种通常对高温和乙醇应激更具抗性。在杂种中，观察到关于Hsp104焦点的出现以及溶解这些聚集体所需时间的差异反应。结合了两个关系最密切的菌株的酿酒酵母/奇异酵母杂种在这些条件下表现最佳。
