MITOCHONDRIAL FUNCTION IN APOPTOSIS

细胞凋亡中的线粒体功能

• 批准号: 6228448
• 负责人: DONALD DAVID NEWMEYER
• 金额: $ 28.2万
• 依托单位: LA JOLLA INSTITUTE FOR IMMUNOLOGY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-03-01 至 2005-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6228448
• 关键词: BCL2 gene /protein; Bax gene /protein; Xenopus oocyte; apoptosis; cysteine endopeptidases; cytochrome c; enzyme activity; enzyme induction /repression; laboratory rat; membrane permeability; mitochondria; mitochondrial membrane

DESCRIPTION (appended verbatim from investigator's abstract): Apoptosis is an active form of cellular suicide that ensures that superfluous or undesirable cells are eliminated. Besides its importance in embryogenesis and physiology, this phenomenon has considerable significance in the etiology and treatment of disorders such as cancer, AIDS and Alzheimer's Disease. The intracellular pathways of apoptosis are not fully understood. However, the basic machinery is largely conserved among species and cell types. We have been studying the mechanisms of apoptosis using a cell-free system based on extracts from eggs of the frog, Xenopus laevis. This system displays authentic biochemical and morphological features of apoptosis, and has been used to uncover novel aspects of the apoptotic process, particularly the function of Bcl-2 in blocking the release of cytochrome c from mitochondria, thereby preventing caspase activation and apoptosis. Recent studies have shown that certain pro-apoptotic relatives of Bcl-2, including Bax and Bid, can interact directly with mitochondria to cause the release of cytochrome c. The research proposed here aims to determine the mechanisms through which Bid and Bax cause the outer mitochondrial membrane to be permeable to proteins like cytochrome c. First, we will determine whether Bax- and Bid-induced cytochrome c release can occur without compromising other aspects of mitochondrial function, particularly protein import via the classical pathway. Second, we will elucidate the molecular mechanisms through which Bax and Bid induce membrane permeabilization, using systems that range in complexity from isolated whole mitochondria down to synthetic liposomes reconstituted with purified or recombinant proteins. Finally, we will use biochemical and genetic methods to identify novel proteins that mediate or modulate the mitochondrial events in Bax- or Bid-dependent pathways. Such studies will help address the question of whether mitochondrial events in the apoptotic program represent a point of no return, or instead can be reversed under certain conditions, resulting in cell survival.

描述（研究者摘要的逐字化）：凋亡是一种 细胞自杀的主动形式可确保多余或不良 消除细胞。除了其在胚胎发生和生理学方面的重要性外， 这种现象在病因学和治疗中具有相当大的意义 癌症，艾滋病和阿尔茨海默氏病等疾病。细胞内 凋亡的途径尚不完全了解。但是，基本机械是 在物种和细胞类型中大部分保守。我们一直在研究 使用无细胞系统的凋亡机制，基于卵的提取物 青蛙，Xenopus laevis。该系统显示真实的生化和 细胞凋亡的形态特征，已用于发现新方面 凋亡过程，特别是Bcl-2在阻止该过程中的功能 从线粒体释放细胞色素C，从而防止caspase 激活和凋亡。最近的研究表明，某些促凋亡 Bcl-2的亲属，包括Bax和Bid，可以直接与 线粒体导致细胞色素c的释放。这里提出的研究 旨在确定出价和BAX引起外部的机制 线粒体膜可渗透到细胞色素c等蛋白质。首先，我们 将确定是否可能发生BAX-和BID诱导的细胞色素C释放 不损害线粒体功能的其他方面，特别是 蛋白质通过经典途径导入。第二，我们将阐明 BAX和BID诱导膜的分子机制 透化，使用从孤立整体中复杂性范围的系统 用纯化或 重组蛋白。最后，我们将使用生化和遗传学方法 识别介导或调节线粒体事件的新型蛋白质 Bax或BID依赖性途径。这样的研究将有助于解决 凋亡程序中的线粒体事件是否表示否 返回，或者可以在某些条件下逆转，导致细胞 生存。