Biogenesis of thylakoid membranes in cyanobacteria

蓝藻类囊体膜的生物发生

• 批准号: 223817724
• 负责人: Professor Dr. Jörg Nickelsen, Ph.D.
• 金额: --
• 依托单位: Arbeitsgruppe Molekulare Pflanzenwissenschaften
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/223817724?language=en
• 关键词: Biogenesis; thylakoid; membranes; cyanobacteria

The thylakoid membrane (TM) represents the site of the energy-producing photosynthetic electron transport via the protein/pigment complexes photosystem II (PSII), Cytb6f and photosystem I (PSI). While the structure and working mode of this molecular machine is well understood, less is known about its development during ontogenesis. This research project is dedicated to the elucidation of the spatial/temporal organization of TM biogenesis in the cyanobacterial model system Synechocystis sp. PCC 6803. As a case study, we will focus on the assembly of PSII, especially its oxygen-evolving manganese cluster, which we have recently been postulated to take place in specialized biogenesis centers close to the plasma membrane. In this regard, the periplasmic PratA factor as well as the gene product of reading frame slr0483 seem to play essential roles. While the tetratricopeptide repeat (TPR) protein PratA transports manganese and, thus, is directly involved in the maturation of the water splitting apparatus of PSII, the membrane protein Slr0483p appears to be generally required for the formation of biogenesis centers based on latest ultrastructural investigations.The goal of the planned work is to gain detailed insights into the molecular working mode as well as the spatial organization of these factors by applying molecular genetical, biochemical/biophysical and electron microscopical methods. In addition other factors like the recently identified PratA interaction partners, i.e., Slr1277p and the Deg-protease HhoA will be analyzed in regard to their function and subcellular localization. Parallel X-ray structure analysis of the PratA/D1 complex will reveal details of the manganese uptake process by the D1 protein of PSII. This work will be complemented by biochemical analyses of PratA-related factors from green algae and vascular plants to test for an evolutionary conserved manganese delivery to PSII.

类囊体膜（TM）代表了通过蛋白质/色素复合物光系统II （PSII）、Cytb6f和光系统I （PSI）产生能量的光合电子传递的部位。虽然这种分子机器的结构和工作模式已经被很好地理解，但对其在个体发生过程中的发展却知之甚少。本研究项目旨在阐明蓝藻模型系统Synechocystis sp. PCC 6803中TM生物发生的时空组织。作为一个案例研究，我们将重点关注PSII的组装，特别是其进化氧的锰簇，我们最近假设它发生在靠近质膜的特殊生物发生中心。在这方面，外质PratA因子以及阅读框slr0483的基因产物似乎起着至关重要的作用。虽然四肽重复（TPR）蛋白PratA运输锰，因此直接参与PSII水裂解装置的成熟，但根据最新的超微结构研究，膜蛋白Slr0483p似乎通常是形成生物发生中心所必需的。计划工作的目标是通过应用分子遗传学，生物化学/生物物理和电子显微镜方法来详细了解这些因素的分子工作模式以及空间组织。此外，其他因素，如最近发现的PratA相互作用伙伴，即Slr1277p和脱蛋白酶HhoA，将分析其功能和亚细胞定位。PratA/D1复合物的平行x射线结构分析将揭示PSII D1蛋白摄取锰过程的细节。这项工作将通过对绿藻和维管植物中prata相关因子的生化分析来补充，以测试进化保守的锰递送到PSII。