Saccharomyces cerevisiae shows similar responses to heat shock and ethanol stress. Cells treated with severe ethanol stress activate the transcription of HSP genes and cause the aggregation of Hsp104-GFP, implying that severe ethanol stress as well as heat shock causes the accumulation of denatured proteins in yeast cells. However, there is currently no concrete evidence to show that severe ethanol stress causes protein denaturation in living yeast cells. In the present study, we investigated whether severe ethanol stress causes protein denaturation, and confirmed that a treatment with 10% (v/v) ethanol stress resulted in the accumulation of insoluble proteins and ubiquitinated proteins in yeast cells. We also found that increased denatured protein levels were efficiently reduced by the ubiquitin-proteasome system after the elimination of ethanol. Since our previous findings demonstrated that the expression of Btn2 was induced by severe ethanol stress, we herein examined the importance of Btn2 in protein quality control in cells treated with severe ethanol stress. btn2∆ cells showed a significant delay in the clearance of denatured proteins during the recovery process. These results provide further insights into the effects of severe ethanol stress on yeast proteostasis and the contribution of Btn2 to the efficient clearance of denatured proteins.

中文翻译：

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Btn2参与了酿酒酵母中由严重乙醇胁迫引起的变性蛋白的清除。

酿酒酵母对热​​休克和乙醇胁迫表现出相似的反应。受到严重乙醇胁迫的细胞会激活HSP基因的转录并引起Hsp104-GFP聚集，这意味着严重乙醇胁迫以及热休克会导致变性蛋白在酵母细胞中积累。但是，目前尚无具体证据表明严重的乙醇胁迫会导致活酵母细胞中蛋白质变性。在本研究中，我们调查了严重的乙醇胁迫是否会引起蛋白质变性，并确认以10％（v / v）乙醇胁迫处理会导致酵母细胞中不溶性蛋白质和泛素化蛋白质的积累。我们还发现，去除乙醇后，泛素-蛋白酶体系统有效地降低了变性蛋白水平的提高。由于我们先前的发现表明Btn2的表达是由严重的乙醇胁迫诱导的，因此我们在本文中研究了Btn2在用严重的乙醇胁迫处理的细胞中蛋白质质量控​​制中的重要性。btn2∆细胞在恢复过程中清除变性蛋白质的过程显着延迟。这些结果提供了进一步的见解，以了解严重的乙醇胁迫对酵母菌蛋白变性的影响以及Btn2对变性蛋白质有效清除的贡献。