Mitochondrial Thiol Regulation and Programmed Cell Death in Yeast

酵母中线粒体硫醇调节和程序性细胞死亡

• 批准号: BB/J00488X/1
• 负责人: Christopher Grant
• 金额: $ 42.1万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FJ00488X%2F1
• 关键词: Mitochondrial; Thiol; Regulation; Programmed; Cell

Proteins are key molecules that control most biological processes. Each protein is made-up of a linear polymer of amino acids which adopt a unique three-dimensional structure. It is becoming increasingly recognized that the cysteine amino acid can play a key role in regulating the activity of many different proteins. This is because cysteine amino acids contain a sulphur atom in a thiol group which accounts for its high reactivity in oxidation and reduction reactions. This means that the redox state of cysteine residues in many different proteins, such as enzymes and transcription factors, can profoundly influence their activity. Not surprisingly therefore, alterations in the cellular redox balance are implicated in many disease processes. This work programme will investigate how cells maintain the redox state of mitochondrial proteins. Understanding mitochondrial redox regulation is particularly important since there are many established links between mitochondrial dysfunction and disease. The focus of this project will be on the glutathione/glutaredoxin and thioredoxin systems which constitute the main cellular redox systems. Our preliminary data, described in the application, show that the redox state of the mitochondrial thioredoxin is important for growth and its oxidation induces a form of programmed cell death (PCD). PCD is a normal process in the development of healthy organisms where cells die in a controlled, regulated fashion. It is a form of cell suicide which can be induced in response to a variety of stimuli including stress. It is important because cell death processes have been implicated in numerous disease processes and many medical treatments and interventions act through PCD. We will use the yeast model system to systematically examine and define the cellular concentrations and redox state of the mitochondrial redox regulatory systems. Importantly, we will examine these systems under conditions that induce PCD to determine the regulatory role of the mitochondrial thioredoxin in this process. Genetic approaches will be used to understand how the mitochondrial thioredoxin regulates cell death. A key technique will be to mutate the cysteine residues in the mitochondrial thioredoxin to directly examine their role in regulating PCD, measured using various known markers which act in the cell death pathway. Mitochondria are the main source of reactive oxygen species in most organisms and this is thought to represent a key signal that activates PCD. Thiol groups in proteins are known to be particularly sensitive to oxidation and so the final part of the project we will test the hypothesis that the mitochondrial thioredoxin system acts as a sensor of reactive oxygen species to activate PCD.

蛋白质是控制大多数生物过程的关键分子。每种蛋白质都是由氨基酸的线性聚合物组成的，它们具有独特的三维结构。越来越多的人认识到，半胱氨酸氨基酸在调节许多不同蛋白质的活性方面可以发挥关键作用。这是因为半胱氨酸氨基酸在硫醇基团中含有硫原子，这是其在氧化和还原反应中的高反应性的原因。这意味着许多不同蛋白质（如酶和转录因子）中半胱氨酸残基的氧化还原状态可以深刻影响其活性。因此，细胞氧化还原平衡的改变与许多疾病过程有关，这并不奇怪。这项工作计划将研究细胞如何维持线粒体蛋白质的氧化还原状态。了解线粒体氧化还原调节是特别重要的，因为线粒体功能障碍和疾病之间有许多既定的联系。该项目的重点将是谷胱甘肽/谷氧还蛋白和硫氧还蛋白系统，构成了主要的细胞氧化还原系统。我们在申请中描述的初步数据表明，线粒体硫氧还蛋白的氧化还原状态对生长很重要，其氧化诱导一种形式的程序性细胞死亡（PCD）。PCD是健康生物体发育中的正常过程，其中细胞以受控、调节的方式死亡。它是一种细胞自杀的形式，可以在包括压力在内的各种刺激下诱导。它很重要，因为细胞死亡过程涉及许多疾病过程，许多医学治疗和干预措施通过PCD起作用。我们将使用酵母模型系统系统地检查和定义线粒体氧化还原调节系统的细胞浓度和氧化还原状态。重要的是，我们将检查这些系统的条件下，诱导PCD，以确定在这一过程中的线粒体硫氧还蛋白的调节作用。遗传学方法将用于了解线粒体硫氧还蛋白如何调节细胞死亡。一项关键技术将是突变线粒体硫氧还蛋白中的半胱氨酸残基，以直接检查它们在调节PCD中的作用，使用在细胞死亡途径中起作用的各种已知标记物进行测量。线粒体是大多数生物体中活性氧的主要来源，这被认为是激活PCD的关键信号。已知蛋白质中的巯基对氧化特别敏感，因此该项目的最后部分将测试线粒体硫氧还蛋白系统作为活性氧物种的传感器激活PCD的假设。

项目成果

Yeast mitochondrial glutathione is an essential antioxidant with mitochondrial thioredoxin providing a back-up system.

• DOI: 10.1016/j.freeradbiomed.2016.02.015
• 发表时间: 2016-05
• 期刊: Free radical biology & medicine
• 影响因子: 7.4
• 作者: Gostimskaya I;Grant CM
• 通讯作者: Grant CM