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) 代表通过蛋白质/色素复合物光系统 II (PSII)、Cytb6f 和光系统 I (PSI) 进行产生能量的光合电子传输的位点。虽然这种分子机器的结构和工作模式已广为人知，但对其在个体发生过程中的发育却知之甚少。该研究项目致力于阐明蓝藻模型系统集胞藻 (Synechocystis sp) 中 TM 生物发生的空间/时间组织。 PCC 6803。作为一个案例研究，我们将重点关注 PSII 的组装，特别是其析氧锰簇，我们最近假设它发生在靠近质膜的专门生物发生中心。在这方面，周质 PratA 因子以及阅读框 slr0483 的基因产物似乎发挥着重要作用。虽然四肽重复 (TPR) 蛋白 PratA 转运锰，因此直接参与 PSII 水分解装置的成熟，但根据最新的超微结构研究，膜蛋白 Slr0483p 似乎是生物发生中心形成所必需的。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，详细了解分子工作模式以及这些因素的空间组织。此外，还将分析其他因素，例如最近确定的 PratA 相互作用伙伴，即 Slr1277p 和 Deg 蛋白酶 HhoA，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 的 D1 蛋白吸收锰过程的细节。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向 PSII 的传递。