Functional Analysis of Metacaspases in Plant Development and Cell Death.

程序性细胞死亡（PCD）被认为是酵母、植物和动物等所有真核生物的基本过程。在动物凋亡（PCD的一种特殊形式）中，核心死亡引擎是高度保守的，被称为半胱天冬酶的特殊半胱氨酸蛋白酶家族是决定性的刽子手。然而，在植物和酵母中，典型的半胱天冬酶在测序基因组中缺失，取而代之的是，通过基于结构的迭代数据库搜索确定了一个称为metacaspases的远亲半胱氨酸蛋白酶家族。本项目将通过详细的遗传、分子、细胞生物学和生化分析，对模式植物拟南芥（鼠耳衣）中选定的metacaspase基因的功能进行研究。具体来说，研究者旨在揭示metacaspase的一些上游调控因子和下游靶点。因此，这项工作将为全面了解涉及metacaspase和高等植物细胞死亡调控的调控途径提供基础。与动物半胱天冬酶的相关研究相比较，将为理解高等真核生物PCD的进化提供一个更好的框架。在更广泛的背景下，这项研究应该有助于我们理解植物对生物和非生物胁迫的反应，因为PCD通常与这些条件有关，从而为未来的作物改良提供重要的知识。该项目还将在为博士后研究人员提供多元化、跨学科的培训方面产生更广泛的影响。此外，研究人员还将通过罗格斯大学的道格拉斯女性科学项目和乔治·h·库克学者项目，以及RISE高中暑期研究项目，为本科生、研究生和高中生提供研究经验。

Programmed cell death (PCD) is recognized to be a fundamental process found in all eukaryotes ranging from yeasts, plants and animals. In animal apoptosis, a specialized form of PCD, the core death engine is highly conserved with a family of specialized cysteine proteases called caspases as the determinate executioner. In plants and yeasts, however, canonical caspases are absent from sequenced genomes and instead, a family of distantly related cysteine proteases called metacaspases were identified through structure-based iterative database searches. In this proposed project, the function of selected metacaspase genes in the model plant Arabidopsis (mouse-ear cress) will be studied through detailed genetic, molecular, cell biological and biochemical analyses. Specifically, the investigator aims to uncover some of the upstream regulators and downstream targets of metacaspases. This proposed work will thus provide the foundation for a comprehensive understanding of the regulatory pathways involving metacaspases and cell death regulation in higher plants. Comparison to related studies with animal caspases will provide a better framework for understanding the evolution of PCD in higher eukaryotes. In a broader context, this study should contribute to our understanding of plant responses to biotic and abiotic stresses since PCD is often associated with these conditions, and thus provide important knowledge for future crop improvement. This project will also have broader impact in providing a diversified, interdisciplinary training to postdoctoral researchers. In addition, the investigators will also provide research experience for undergraduate, graduate and high school students through the Douglass Women in Science and George H. Cook Scholar programs of Rutgers University, and the RISE summer research program for high schools.