Post-translational regulation of ATP synthase assembly in chloroplasts

叶绿体和蓝细菌中的ATP酶是利用光驱动的质子梯度穿过类囊体膜以在光合作用中产生ATP的纳米马达。类囊体ATP酶的结构和分子功能已被广泛研究。目前研究的一个目的是优化或专门调整其活动。然而，复杂数量的结构修饰或调整需要了解模块化组装过程和相关的辅助因子，这些辅助因子也可以在特定组装步骤的调节中发挥作用。因此，该项目将重点关注拟南芥中负责基质组装模块CF 1招募关键步骤的辅助因子（AtCGL 160）。突变体分析，生化研究和遗传生物传感器将调查AtCGL 160依赖的CF 1招聘叶绿体能量学的影响。此外，CF 1和AtCGL 160的N-末端结构域之间的复合物将通过高分辨率冷冻电子显微镜来确定结构，以阐明AtCGL 160依赖性CF 1募集的分子机制。此外，抑制因子PAF 1在ATP合成酶组装中的作用及其作为AtCGL 160的可能拮抗剂的功能将在拟南芥中进行研究。由于PAF 1样蛋白也发现在蓝藻，我们将扩展我们的分析集胞藻和比较研究将揭示蓝藻和叶绿体之间的ATP合酶组装的进化方面。作为一个长期目标，该研究项目将阐明类囊体ATP合酶组装的调控原理，并为操纵光合自养生物中的ATP预算和质子回路提供优雅的策略。

ATP synthases in chloroplasts and cyanobacteria are nanomotors that harness the light-driven proton gradient across thylakoid membranes for ATP generation in photosynthesis. The structure and molecular function of thylakoid ATP synthases are well studied. One aim of current research is to optimize or specifically adapt their activity. However, structural modifications or adjustments of complex amounts require knowledge about the modular assembly process and the involved auxiliary factors, which can also play a role in the regulation of specific assembly steps.The project will therefore focus on an auxiliary factor (AtCGL160) from Arabidopsis that is responsible for the critical step in the recruitment of the stromal assembly module CF1. Mutant analysis, biochemical studies and genetic biosensors will be employed to investigate the influence of AtCGL160-dependent CF1 recruitment on chloroplast energetics. Furthermore, the complex between CF1 and the N-terminal domain of AtCGL160 will be structurally determined by high-resolution cryo-electron microscopy to elucidate the molecular mechanism of AtCGL160-dependent CF1 recruitment. In addition, the role of the suppressor PAF1 in ATP synthase assembly and its function as a possible antagonist to AtCGL160 will be investigated in Arabidopsis. Since PAF1-like proteins are also found in cyanobacteria, we will extend our analyses to Synechocystis and comparative studies will reveal evolutionary aspects of ATP synthase assembly between cyanobacteria and chloroplasts. As a long-term goal, the research project will elucidate regulatory principles of thylakoid ATP synthase assembly and provide elegant strategies for manipulating the ATP budget and proton circuits in photoautotrophic organisms.