藻胆体核膜连接蛋白的Arm2结构域的功能研究

蓝藻是光合作用研究的良好模型，它们具有由藻胆蛋白与连接蛋白有序组装的光合作用捕光复合物——藻胆体。藻胆体通过两个特殊的亚基ApcD与ApcE将光能高效传递给光合反应中心。由于ApcE对蓝藻光合捕光传能至关重要，故本项目将构建ApcE的Arm2结构域的突变藻，分析各突变藻在光合作用、藻胆体组装、状态转换、非光化学淬灭等方面的差别。通过回复突变精确剖析Arm2的哪部分肽片段和哪几个重要氨基酸对藻胆体组装、状态转换、非光化学淬灭发挥关键作用。分析Arm2缺失所导致的相关基因在转录水平的差别，对蛋白质后修饰如磷酸化的影响，分析Arm2作用于藻胆体组装、状态转换与非光化学淬灭的分子机制。此研究将弄清Arm2在藻胆体组装中的作用、介导状态转换与非光化学淬灭的新规律，对光合作用捕光传能调控研究具有重要意义，对阐明藻类光合生态作用具有重要意义，对由藻胆体设计人造光合捕光传能元件具有重要意义。

Cyanobacteria are good models for photosynthtic researches, they have the unique light-harvesting complexes - phycobilisomes consisting of phycobiliproteins and linkers. Phycobilisomes funnel harvested light highly efficiently to photosynthetic reaction centers via two terminal emitters - ApcD and ApcE. In view of the important functions of ApcE in light harvesting and transfer, we will construct several mutants destructing Arm2 domain of ApcE, and then analyze the phenotypes in photosynthesis, phycobilisome assembly, state transition and non-photochemical quenching. Via recovering the Arm2 domain by the use of reverse mutation, we will discern exactly what motif and key amino acids are responsible to the phenotypes. By analyzing the transcript levels of certain genes involved in phycobilisome and photosynthesis, and analyzing post-translational modifications such as phosphorylation of respective proteins, the new molecular processes of Arm2 of ApcE regulating phycobilisome assembly, state transition and non-photochemical quenching will be realized. These studies will disclose the new mechanisms of Arm2 of ApcE regulating phycobilisome assembly, state transition, non-photochemical quenching, which is important for photosynthetic photoreguations, particularly photoregulations in light-harvesting and transfer, cyanobacterial ecology, and construction of artificial photosynthetic elements such as artificial elements for light-harvesting and transfer.