Dissection of the mechanisms of action of evolutionarily conserved apoptotic pathway components

动物通过一种被称为凋亡的高度控制的过程来消除不需要的细胞。细胞凋亡缺陷可导致癌症或自身免疫性疾病。相反，中风和阿尔茨海默病等疾病与细胞过度死亡有关。为了开发能够促进未发生细胞凋亡或防止细胞不适当死亡的药物，有必要阐明控制细胞凋亡的分子机制。第一个被确认的哺乳动物细胞死亡机制的组成部分是Bcl-2；一种与癌症发展有关的蛋白质。尽管此后进行了大量研究，但Bcl-2及其相关蛋白的作用方式仍然未知。该项目利用以前在一种模式遗传生物（蛔虫）中进行的遗传和生化研究来解决这一重要问题。可以将动物细胞死亡途径成分引入酵母，使所引入途径的激活导致酵母死亡，其抑制促进酵母存活。我们已经用这种方法在酵母中重建了蠕虫细胞死亡途径和一个主要的哺乳动物细胞凋亡途径。携带这些重组途径的酵母菌株将用于测试候选哺乳动物蛋白及其假定的蛔虫对应蛋白的功能等效性。该系统还将被用于识别和表征调节哺乳动物和蠕虫细胞死亡的新蛋白质。了解关键分子调控细胞凋亡的方式将有助于开发诊断和治疗许多细胞死亡调控受到干扰的疾病的试剂。本项目利用细胞凋亡的进化守恒来描述重要的哺乳动物细胞凋亡调节因子的作用机制，并寻求新的哺乳动物细胞凋亡途径成分。以这种方式鉴定的蛋白质可能是重要的凋亡调节因子，因为我们的方法确保了它们的功能在进化上是保守的。

Animals eliminate unwanted cells through a highly controlled process termed apoptosis. Defects in apoptosis can contribute to cancer or autoimmune disease. Conversely, diseases such as stroke and Alzheimer's disease have been linked to excessive cell death. To develop drugs that promote apoptosis when it fails to occur, or prevent inappropriate cell death, it is necessary to elucidate the molecular mechanisms controlling apoptosis. The first recognised component of the mammalian cell death machinery was Bcl-2; a protein associated with development of cancer. Despite much research since then, the way in which Bcl-2 and related proteins function is still unknown. This project capitalises on previous genetic and biochemical studies in a model genetic organism (the roundworm) to address this important issue. Animal cell death pathway components can be introduced into yeast such that activation of the introduced pathways leads to yeast death and its inhibition promotes yeast survival. We have used this approach to reconstitute the worm cell death pathway and a major mammalian apoptosis pathway in yeast. Yeast strains bearing these reconstituted pathways will be used to test functional equivalence of candidate mammalian proteins and their putative roundworm counterparts. The system will also be exploited to identify and characterise novel proteins that regulate cell death in mammals and worms. Understanding the way in which key molecules regulate apoptosis will assist in the development of diagnostic and therapeutic reagents for many diseases in which cell death regulation is perturbed. This project capitalises on the evolutionary conservation of apoptosis to characterise the mechanisms of action of important mammalian apoptotic regulators and to seek novel mammalian apoptotic pathway components. Proteins identified in this way are likely to be important apoptotic regulators, as our approach ensures that their functions are evolutionarily conserved.