Functional Characterization of an Arabidopsis Aspartic Protease That Regulates Cell Survival and Cell Death

标题：调节细胞存活和细胞死亡的拟南芥天冬氨酸蛋白酶的功能特性在生物体的发育和对环境的反应中，细胞的死亡和存活受到精确的控制。许多人类疾病是由于未能调节正常的细胞死亡过程而引起的。细胞程序性死亡(PCD)也与植物的各种发育过程有关。然而，植物编码的调节和执行PCD的分子机制在很大程度上仍然未知。这项拟议的研究结合了分子、遗传和细胞生物学的方法，以模式植物拟南芥为例，剖析了天冬氨酸蛋白酶PCS1(一种蛋白质加工酶)介导的PCD过程。已发现PCS1是一种抗细胞死亡成分。PCS1功能的丧失会导致发育中的配子体和胚胎组织过度的细胞死亡，而它的过度表达会导致一些正常的细胞死亡过程的阻断。细胞生物学工具将被用来描述PCS1介导的细胞死亡过程。基因和分子方法将被用来确定PCD途径中涉及的其他成分。这项研究将促进我们对调控植物发育过程中细胞死亡和存活的分子机制的理解。该项目还将为利用农业上重要的作物性状提供有用的工具，并为学生和博士后研究员提供一个极好的跨学科培训机会。

AbstractPI: Yiji XiaProposal number: 0450168Title: Functional Characterization of an Arabidopsis Aspartic Protease That Regulates Cell Survival and Cell DeathThe death and survival of a cell are precisely controlled during an organism's development and in its response to environments. Many human diseases are caused by a failure in regulating normal cell death processes. Programmed cell death (PCD) is also associated with a variety of developmental processes in plants. However, the plant-encoded molecular machinery that regulates and executes PCD remains largely unknown. The proposed study employs a combination of molecular, genetic, and cell biology approaches to dissect the PCD process mediated by the aspartic protease PCS1, a protein-processing enzyme, using the model plant Arabidopsis. PCS1 has been found to function as an anti-cell death component. Loss of PCS1 function causes excessive cell death of developing gametophytes and embryonic tissues, whereas its over-expression leads to blockage of some normal cell death processes. Cell biology tools will be used to characterize the PCS1-mediated cell death process. Genetic and molecular approaches will be used to identify other components involved in the PCD pathway. The study will advance our understanding of molecular mechanisms that regulate cell death and survival in developmental processes in plants. This project will also make available a useful tool for engineering agriculturally important traits of crops and provide an excellent cross-disciplinary training opportunity for students and post-doctoral fellows.