Oxidative stress is involved in heat-induced cell death in Saccharomyces cerevisiae
Oxidative stress is involved in heat-induced cell death in Saccharomyces cerevisiae
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DOI：
10.1073/pnas.93.10.5116
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发表时间：
1996-05-14
影响因子：
11.1
通讯作者：
Schiestl, RH
中科院分区：
文献类型：
--
作者：
Davidson, JF;Whyte, B;Schiestl, RH
致死性热休克后的死亡原因尚不清楚。在大多数生物体中，从低温到中温的转变引起热休克蛋白的诱导。然而，除了热休克蛋白104，一个令人信服的参与热休克蛋白在发展中的胁迫抗性尚未建立在酿酒酵母。本文表明，氧化应激和抗氧化酶在热诱导的酵母细胞死亡中起着重要作用。抗氧化基因过氧化氢酶，超氧化物歧化酶和细胞色素c过氧化物酶的突变体删除更敏感的热致死效应比同基因野生型细胞。过氧化氢酶和超氧化物歧化酶基因的过表达引起耐热性的增加。厌氧条件导致耐热性增加500至20，000倍。缺氧条件下细胞的耐热性在氧暴露后立即消失。HSP 104不负责厌氧生长细胞的抗性增加。厌氧生长细胞的耐热性不是由于热休克蛋白的表达。通过使用氧化依赖性荧光分子探针，发现加热后荧光增加2至3倍。因此，我们得出结论，氧化应激参与热诱导的细胞死亡。
The cause for death after lethal heat shock is not well understood. A shift from low to intermediate temperature causes the induction of heat-shock proteins in most organisms. However, except for HSP104, a convincing involvement of heat-shock proteins in the development of stress resistance has not been established in Saccharomyces cerevisiae. This paper shows that oxidative stress and antioxidant enzymes play a major role in heat-induced cell death in yeast. Mutants deleted for the antioxidant genes catalase, superoxide dismutase, and cytochrome c peroxidase were more sensitive to the lethal effect of heat than isogenic wild-type cells. Overexpression of catalase and superoxide dismutase genes caused an increase in thermotolerance. Anaerobic conditions caused a 500- to 20,000-fold increase in thermotolerance. The thermotolerance of cells in anaerobic conditions was immediately abolished upon oxygen exposure. HSP104 is not responsible for the increased resistance of anaerobically grown cells. The thermotolerance of anaerobically grown cells is not due to expression of heat-shock proteins. By using an oxidation-dependent fluorescent molecular probe a 2- to 3-fold increase in fluorescence was found upon heating. Thus, we conclude that oxidative stress is involved in heat-induced cell death.