Selection and Delivery of Substrates to the Essential Clp Protease Complex in Plastids of Arabidopsis Thaliana

智力价值：质体是存在于每一个植物细胞中的重要细胞器。质体包括叶绿体，植物和藻类光合作用能量产生的场所，淀粉体，在根和块茎中储存淀粉，以及有色体，在水果中积累类胡萝卜素。据预测，植物基因组中约14%的基因将编码叶绿体蛋白，这突显了叶绿体对植物生物学的重要性。本项目涉及模式植物拟南芥中必需的叶绿体定位的CLP蛋白水解酶的功能和底物。ClpPR蛋白酶是一个双环复合体，含有10种不同的ClpPR蛋白，其中大部分对胚胎发育或幼苗发育是必需的。桶上附着着小的ClpS1，2蛋白质，功能未知，是光合作用有机体独有的。胞内蛋白水解酶具有多种功能，在识别其底物时必须具有高度的选择性。叶绿体定位的CLP蛋白显然对叶绿体的生物发生和分化具有重要作用，但其在叶绿体中的作用机制，包括CLP底物和底物识别机制，尚不清楚。该项目的目标是确定CLP蛋白酶底物及其降解信号，确定CLP在底物输送到CLP蛋白酶系统中的作用，确定ClpT1、T2作为CLP系统的特定质体成分的功能，并在体内测试目标1、2和3(或新文献)中确定的潜在底物和降解信号(降解信号)。更广泛的影响：该项目将有助于确定CLP蛋白酶系统的分子功能和组织，以及其底物和底物识别机制。了解CLP蛋白分解机制和底物识别信号的作用对于控制蛋白质稳定性也是至关重要的，目的是改善叶绿体作为过量生产具有营养或其他附加值的外源蛋白质的位置。拟议的研究将在本科生、研究生和博士后水平上提供植物分子遗传学和生物化学的多学科培训。PI将参加高中教师的课程开发研讨会，为课堂开发基于基因组学的模块。

Intellectual Merit:Plastids are essential organelles that are present in every plant cell. Plastids include chloroplasts, the sites of photosynthetic energy generation in plants and algae, amyloplasts, which store starch in roots and tubers, and chromoplasts, which accumulate carotenoids in fruits. Around 14% percent of genes in the plant genome are predicted to encode plastid proteins, underlining the importance of the plastid for plant biology. This project concerns the function and substrates of the essential plastid localized Clp protease machinery in the model plant Arabidopsis. The ClpPR protease is a double ring shaped complex containing 10 different ClpPR proteins, most of which are essential for embryogenesis or seedling development. Attached to the barrel are small ClpS1,2 proteins with unknown function and unique to photosynthetic organisms. Intracellular proteases have many functions and must be highly selective in recognizing their substrates. The plastid-localized Clp proteins are clearly important for plastid biogenesis and differentiation, but their mechanism of action in plastids, including Clp substrates and substrate recognition mechanisms, are unknown. The objectives of the project are to identify Clp protease substrates and their degradation signals, to determine the role of ClpS in substrate delivery to the Clp protease system, to determine the function of ClpT1,T2 as a specific plastid component of the Clp system, and to test potential substrates and degradation signals (degrons) identified in objectives 1, 2 and 3 (or in new literature) in vivo. Broader impacts: This project will help to determine the molecular function and organization of the Clp protease system, as well as its substrates and substrate recognition mechanisms. Understanding the role of the Clp proteolytic machinery and substrate recognition signals is also critical to control protein stability with the objective to improve the plastid as the site for overproduction of foreign proteins with nutritional or other added value. The proposed research will provide multi-disciplinary training in plant molecular genetics and biochemistry at the undergraduate, graduate and post-doctoral levels. The PI will participate in curriculum development workshops for high school teachers to develop genomics-based modules for the classroom.