Mechanisms of light regulated translation in chloroplasts

叶绿体中光调节翻译的机制

• 批准号: 1616016
• 负责人: Alice Barkan
• 金额: $ 77.54万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-15 至 2021-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1616016&HistoricalAwards=false
• 关键词: Mechanisms; light; regulated; translation; chloroplasts

Energy from sunlight fuels life on earth through the process of photosynthesis. Light is both an essential resource and a source of stress, in that it damages the photosynthetic apparatus and other cellular structures through a process called photo-oxidative processes. As such, plants have evolved mechanisms that optimize the use of light, minimize light-induced damage, and promote repair of the photosynthetic apparatus should it occur. In this study the light-regulated synthesis of a gene product essential to this process, D1, will be examined. The rate of D1 synthesis changes rapidly in response to shifting light intensity and therefore the goal of this project is to elucidate the signaling pathways and mechanisms that mediate D1?s response. This problem will be addressed through genetic, molecular, and biochemical approaches in maize and Arabidopsis. These activities will provide research training for two undergraduate students, one PhD student, and a high school teacher. In addition, novel methods will be explored that have the potential to propel research on other topics. The hypotheses to be tested arise from recent ribosome profiling data that provide the first genome-wide views of the impact of light on translation in chloroplasts. Genetic, molecular, and biochemical approaches in maize and Arabidopsis will be employed, including a state-of-the-art method for identifying proteins bound to specific RNAs-of-interest in vivo, and a novel strategy involving designer RNA binding proteins. One set of experiments will test the hypothesis that the rapid light-induced change in ribosome occupancy on psbA mRNA (which encodes D1) is mediated by post-translational modification of proteins that bind the psbA 5' untranslated region. A second set of experiments will test the hypothesis that the global change in translation elongation rate is mediated by light-dependent post-translational modifications of proteins that stall ribosomes or catalyze translation elongation. A third set of experiments will address whether light induces these responses via the same signal transduction pathways that trigger other adaptations in response to photosynthetic activity. Finally, experiments will test the hypothesis that gene-specific translational regulators in chloroplasts, including those that regulate translation in response to light, generally act by modulating RNA structure proximal to ribosome binding sites.This project is co-funded by the Genetic Mechanisms Program in the Division of Molecular and Cellular Biosciences and by the Plant Genome Research Program in the Division of Integrative Organismal Systems.

来自阳光的能量通过光合作用为地球上的生命提供燃料。光既是一种重要资源，也是一种压力来源，因为它通过一种称为光氧化过程的过程破坏光合装置和其他细胞结构。因此，植物已经进化出优化光的利用、最小化光诱导的损伤并促进光合机构的修复的机制。在这项研究中，光调控合成的基因产物必不可少的这个过程中，D1，将进行检查。D1的合成率的变化迅速响应于光强度的变化，因此，本项目的目标是阐明介导D1的信号通路和机制？的回应。 这一问题将通过玉米和拟南芥的遗传、分子和生物化学方法来解决。 这些活动将为两名本科生、一名博士生和一名高中教师提供研究培训。此外，还将探索有可能推动其他主题研究的新方法。 要测试的假设来自最近的核糖体分析数据，提供了第一个全基因组的光在叶绿体翻译的影响的意见。将采用玉米和拟南芥中的遗传、分子和生物化学方法，包括用于鉴定体内与特定RNA结合的蛋白质的最新方法，以及涉及设计RNA结合蛋白的新策略。一组实验将检验这样的假设，即光诱导的psbA mRNA（其编码D1）上核糖体占据的快速变化是由结合psbA 5'非翻译区的蛋白质的翻译后修饰介导的。第二组实验将检验以下假设：翻译延伸率的总体变化是由蛋白质的光依赖性翻译后修饰介导的，所述蛋白质使核糖体停滞或催化翻译延伸。第三组实验将解决光是否通过相同的信号转导途径诱导这些反应，这些信号转导途径触发其他适应光合活性。最后，实验将测试的假设，即基因特异性的叶绿体翻译调节，包括那些调节翻译响应光，一般通过调节RNA结构的核糖体bindingsites.This项目是共同资助的遗传机制计划在分子和细胞生物科学司和植物基因组研究计划在综合有机体系统司。