Molecular Basis and Redox-Regulation of Plant Glutathione Biosynthesis

环境胁迫导致作物质量和植物生物量生产力的显著损失。 植物暴露于极端温度、干旱、污染和病原体导致活性氧物质的产生，从而改变信号传导途径和生长。 作为对这些压力的反应的一部分，植物产生肽谷胱甘肽。 谷氨酸通过淬灭活性氧作为抗氧化剂，对环境污染物的解毒至关重要。 有两种酶催化谷胱甘肽的合成：谷氨酸-半胱氨酸连接酶（GCL）和谷胱甘肽合成酶（GS）。 本项目探索这些酶如何发挥功能，并通过1）检查植物GS的结构，2）建立GCL作为谷胱甘肽生物合成的调节开关的作用，3）确定作为氧化还原相关调节开关的其他植物蛋白质。 首先，该研究项目为本科生和研究生提供植物生物学，生物化学和结构生物学的多学科培训。 在研究生一级，两名学生参与了该项目。 在本科阶段，PI和Co-PI都活跃在丹佛斯中心的NSF-REU计划和辉瑞-Solutia暑期学生和教师作为研究科学家（STARS）计划中。 其次，PI帮助华盛顿大学开发了一门高水平的本科生/研究生植物生物学课程（Bio 4024），该课程提供了基于研究的实验，结合了联合收割机蛋白质化学、x射线晶体学、质谱/蛋白质组学和显微镜（Jez et al.，2007生物化学分子35，410-415）。 通过混合生物化学和植物生物学，学生获得的理解和解决这些学科的接口问题所需的科学技能的广度。

Environmental stresses result in considerable losses in crop quality and plant biomass productivity. Exposure of plants to temperature extremes, drought, pollution, and pathogens results in the generation of reactive oxygen species that alter signaling pathways and growth. As part of their response to these stresses, plants produce the peptide glutathione. Glutathione acts as an antioxidant by quenching reactive oxygen species and is essential for the detoxification of environmental pollutants. Two enzymes catalyze glutathione synthesis: glutamate-cysteine ligase (GCL), and glutathione synthetase (GS). This project explores how these enzymes function and are regulated by 1) examining the structure of plant GS, 2) establishing the role of GCL as a regulatory switch in glutathione biosynthesis; and 3) identifying additional plant proteins that act as redox-linked regulatory switches.Efforts related to broader impact fall into two categories. First, the research project provides undergraduate and graduate students with multidisciplinary training in plant biology, biochemistry, and structural biology. At the graduate level, two students are involved in the project. At the undergraduate level, both the PI and Co-PI are active in the NSF-REU program at the Danforth Center and in the Pfizer-Solutia Summer Students and Teachers as Research Scientists (STARS) program. Second, the PI helped develop an upper-level undergraduate/graduate plant biology course (Bio4024) at Washington University that offers research-based experiments that combine protein chemistry, x-ray crystallography, mass spectrometry/proteomics, and microscopy (Jez et al., 2007 Biochem. Mol. Biol. Educ. 35, 410-415). By blending biochemistry and plant biology, students acquire the breadth of understanding and the scientific skills required for solving problems at the interface of these disciplines.