FOR 2092: Biogenesis of Thylakoid Membranes: Spatiotemporal Organisation of Photosynthetic Protein Complex Assembly

光合作用的电子传递是由多亚基色素蛋白复合物介导的，这些复合物位于一个特殊的膜系统中，称为类囊体。尽管对这些复合物的结构和功能有详细的了解，但对它们在类囊体膜生物发生过程中的组装知之甚少。这一过程的新图像描绘了一个高度有序的组装因子支架，该支架以逐步的方式整合了蛋白质和有机以及无机辅因子的掺入。最近的工作还表明，光合复合物的生产线是在生物膜亚区室开始的，从那里它通过离散和保守的组装中间体产生功能性能量转换装置。FOR2092研究单位已着手解开类囊体膜生物发生的时空组织的分子原理，通过应用多学科，系统的方法，结合分子遗传学，生物化学，生物物理学和超微结构分析的独特专业知识。该概念包括对一组合适的模式生物进行比较研究，使人们能够遵循从原始蓝细菌到维管植物叶绿体的类囊体复杂性发展的完整进化路径。通过关注不同的组装因子及其工作模式的时空组织，FOR2092成员的联合力量最近发现了类囊体生物发生的各种新的分子方面。这些发现包括光系统II和光系统I的组装，类囊体蛋白的膜插入，有机和无机辅因子的掺入和生物膜结构的形成的细节。此外，遗传学和生物化学的方法已经确定了几个新的组件的复杂的组装因子网络的类囊体生物合成。总之，这所获得的证据，现在形成了坚实的基础，进行全面的研究的生物合成过程，这将是补充的比较分析的无色素ATP酶复合物，以及国家的最先进的类囊体超微结构原位研究。该财团设想，通过回答问题如何，在哪里和何时不同的组装过程发生，并在类囊体成熟过程中整合，知识为基础的战略，有针对性地修改的生物合成过程中的一组广泛的光合模式生物的发展将成为可行的未来。

Photosynthetic electron transport is mediated by multi-subunit pigment-protein complexes which are situated in a specialized membrane system, named thylakoids. Despite a detailed knowledge on the structure and function of these complexes, little is known on their assembly during thylakoid membrane biogenesis. The emerging picture of this process depicts a highly-ordered scaffold of assembly factors that integrates the incorporation of proteins and organic as well as inorganic co-factors in a step-wise manner. Recent work has also indicated that the production line for photosynthetic complexes is initiated at biogenic membrane sub-compartments from where it proceeds via discrete and conserved assembly intermediates to generate a functional energy converting apparatus. The FOR2092 Research Unit has set out to disentangle the molecular principles of the spatiotemporal organization of thylakoid membrane biogenesis by applying a multidisciplinary, systematic approach combining unique expertise in molecular genetics, biochemistry, biophysics and ultrastructural analyses. The concept includes the comparative investigation of a set of suitable model organisms that enables one to follow the complete evolutionary path for the development of thylakoid complexity from primordial cyanobacteria to chloroplasts of vascular plants. By focusing on distinct assembly factors and the spatiotemporal organization of their working mode, the joined forces of FOR2092 members have recently discovered a variety of new molecular aspects of thylakoid biogenesis. The findings include details of photosystem II and photosystem I assembly, membrane insertion of thylakoid proteins, organic and inorganic co-factor incorporation and formation of biogenic membrane structures. In addition, both genetic and biochemical approaches have identified several new components of the intricate assembly factor network for thylakoid biogenesis. In sum, this obtained body of evidence now forms the solid basis for a proceeding comprehensive study of the biogenesis process which will be complemented by comparative analysis of the pigment-free ATPase complex as well as state-of-the-art studies on thylakoid ultrastructure in situ. The consortium envisions that by answering the questions how, where and when the different assembly processes take place and are integrated during thylakoid maturation, the development of knowledge-based strategies for the targeted modification of the biogenesis process in a broad set of photosynthetic model organisms will become feasible in the future.