Mechanisms of Light Regulated Translation in Chloroplasts

叶绿体中光调控翻译的机制

• 批准号: 2034758
• 负责人: Alice Barkan
• 金额: $ 95万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2034758&HistoricalAwards=false
• 关键词: Mechanisms; Light; Regulated; Translation; Chloroplasts

This project addresses a fundamental question in biology: How do organisms regulate gene expression to adapt to environmental fluctuations? It focuses on effects of light on the synthesis of proteins required for photosynthesis, a process that consumes atmospheric CO2 and produces the carbohydrates that fuel life. Light drives photosynthesis, but it also damages the photosynthetic apparatus. Repair of the damage requires the replacement of damaged parts with newly synthesized proteins. This project examines how the same light that damages the photosynthetic apparatus also activates the synthesis of new proteins required for repair. An understanding of this repair mechanism has implications for crop productivity and resilience in the face of changing environmental conditions. High school students, high school teachers, and undergraduate students will gain hands-on experience with research through involvement in this project. The primary target of photodamage is a protein called D1, which resides in Photosystem II (PSII) and is encoded by the psbA gene. The rate of D1 synthesis increases with light intensity to provide D1 for PSII repair. In chloroplasts, this regulation occurs at the level of translation. Prior work revealed an intimate connection between light-induced D1 damage, the recruitment of ribosomes specifically to psbA mRNA, and a conserved protein complex in the thylakoid membrane that mediates PSII assembly and repair. This work culminated in a model that invokes the assembly/repair complex as the hub of a translational autoregulatory mechanism that couples psbA translation to the need for D1 following its light-induced damage. Experiments will test and elaborate on this proposed mechanism, with a focus on communication between the membrane-bound assembly complex and a translational activator in the stroma that binds psbA mRNA. Experiments will employ multifaceted genetic, molecular, genomic, and biochemical approaches in maize and Arabidopsis.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目解决了生物学中的一个基本问题：生物体如何调节基因表达以适应环境波动？它专注于光对光合作用所需蛋白质合成的影响，光合作用是一个消耗大气二氧化碳并产生碳水化合物的过程。光驱动光合作用，但它也破坏光合机构。损伤的修复需要用新合成的蛋白质替换受损的部分。该项目研究了破坏光合装置的相同光如何也激活修复所需的新蛋白质的合成。了解这种修复机制对作物在不断变化的环境条件下的生产力和恢复力具有重要意义。高中生，高中教师和本科生将通过参与这个项目获得实践经验的研究。光损伤的主要目标是一种称为D1的蛋白质，它存在于光系统II（PSII）中，由psbA基因编码。D1的合成速率随着光强度的增加而增加，为PSII修复提供D1。在叶绿体中，这种调节发生在翻译水平。先前的工作揭示了光诱导的D1损伤，核糖体特异性psbA mRNA的招募，和介导PSII组装和修复的类囊体膜中的保守蛋白复合物之间的密切联系。这项工作最终在一个模型，调用组装/修复复合体作为枢纽的翻译自动调节机制，耦合psbA翻译需要D1后，其光诱导的损伤。实验将测试和阐述这一机制，重点是膜结合组装复合物和基质中结合psbA mRNA的翻译激活剂之间的通信。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Correlated retrograde and developmental regulons implicate multiple retrograde signals as coordinators of chloroplast development in maize

相关的逆行和发育调节子暗示多个逆行信号作为玉米叶绿体发育的协调者

• DOI: 10.1093/plcell/koac276
• 发表时间: 2022
• 期刊: The Plant Cell
• 作者: Kendrick, Rennie;Chotewutmontri, Prakitchai;Belcher, Susan;Barkan, Alice
• 通讯作者: Barkan, Alice