Spatiotemporal organization of thylakoid membrane biogenesis in cyanobacteria

蓝藻类囊体膜生物发生的时空组织

• 批准号: 515047629
• 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
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/515047629?language=en
• 关键词: Spatiotemporal; organization; thylakoid; membrane; biogenesis

Most photoautotrophic bacteria contain a sophisticated intracellular membrane system named thylakoids. These internal structures represent energy transducing membranes that mediate photosynthetic electron flow and subsequent ATP generation. Accumulating evidence suggests that the biogenesis and structural dynamics of this bioenergetic machinery are highly ordered by both spatial and temporal means. Our recent findings indicate that photosystem II (PSII) biogenesis in the model cyanobacterium Synechocystis 6803 is initiated at regions where thylakoids fuse to form convergence tubules. These occasionally contact the plasma membrane at sites named “thylapses” due to their synapse-like appearance. The establishment of these biogenic membrane sub-domains requires the membrane-shaping factors CurT and AncM. CurT accumulates to high levels at heavily bended interconnected tubules which from a biogenic membrane network spanning the periphery of the entire cell. In contrast, AncM localizes only to distinct spots of the tubular system and marks thylapse regions. Thus, both serve as bona fide landmarks for the subcellular organization of thylakoid membrane biogenesis in Synechocystis 6803. By applying a blend of genetic, biochemical, and various microscopic methods this project aims at elucidating the working mode of these internal membrane sub-domains during the spatiotemporal organization of PSII biogenesis. Based on the identification of CurT and AncM as well as several PSII-related biogenesis factors, the central questions to be addressed are: (i) What determines the structural dynamics of biogenic regions? (ii) What is their precise functional organization?

大多数光合自养细菌含有一种复杂的细胞内膜系统，称为类囊体。这些内部结构代表能量转导膜，介导光合作用电子流和随后的 ATP 生成。越来越多的证据表明，这种生物能量机器的生物发生和结构动力学在空间和时间上都是高度有序的。我们最近的研究结果表明，蓝藻集胞藻 6803 模型中的光系统 II (PSII) 生物发生是在类囊体融合形成会聚小管的区域启动的。由于它们的突触状外观，它们偶尔会在称为“thylapses”的位置接触质膜。这些生物膜子结构域的建立需要膜成形因子 CurT 和 AncM。 CurT 在严重弯曲的相互连接的小管中积累到高水平，这些小管来自跨越整个细胞外围的生物膜网络。相比之下，AncM 仅定位于管状系统的不同点并标记 thylapse 区域。因此，两者都是集胞藻 6803 中类囊体膜生物发生的亚细胞组织的真正里程碑。通过应用遗传、生物化学和各种微观方法，该项目旨在阐明这些内膜子域在 PSII 生物发生的时空组织过程中的工作模式。基于 CurT 和 AncM 以及几个 PSII 相关生物发生因子的识别，需要解决的核心问题是：（i）什么决定了生物发生区域的结构动态？ (ii) 他们的具体职能组织是什么？