Reciprocal regulation of chloroplast protein synthesis and carbon metabolism for thylakoid membrane biogenesis

类囊体膜生物发生中叶绿体蛋白质合成和碳代谢的相互调节

• 批准号: 241420340
• 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: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/241420340?language=en
• 关键词: Reciprocal; regulation; chloroplast; protein; synthesis

Thylakoid membranes represent highly developed sites for photosynthetic energy transduction. Their biogenesis requires the synthesis of both lipids as well as proteins. However, little is known regarding if and how these two biosynthetic pathways are interconnected at the molecular level. The chloroplast pyruvate dehydrogenase complex is well-known to produce activated di-carbon precursor molecules (acetyl-CoA) for fatty acid - and as a consequence - lipid synthesis. Our prework shows that the DLA2 subunit of this enzyme is additionally a component of a ribonculeoprotein complex and as this has a function in the spatial organization of chloroplast mRNA translation in the green algal model system Chlamydomonas reinhardtii. Conversely, RNA binding affects pyruvate dehydrogenase activity. These findings provide a first clue regarding how intraplastidic metabolic signaling and chloroplast gene expression could be reciprocally connected for thylakoid membrane biogenesis. In addition, our data provide first hints that these dual roles of the protein might exist in evolutionary distant organisms ranging from cyanobacteria to humans.In this project, we aim at elucidating the precise molecular working mode of this regulatory principle involving metabolic control of gene expression. By following molecular, genetical, and biochemical approaches in C. reinhardtii, we will use in vivo and in vitro techniques to characterize both the RNA binding and the enzymatic forms of DLA2 which appears to shuttle between different protein sub-complexes. A special focus will be on the dynamics and composition of these complexes and the role of acetate/acetyl-CoA for balancing both functions of DLA2. This work will be complemented by related analyses in cyanobacteria and higher plants, to test for an evolutionary conservation of such a regulatory switch.

类囊体膜代表用于光合作用转导的高度发达的位点。它们的生物发生需要同仅脂质和蛋白质的合成。但是，关于这两种生物合成途径在分子水平上是否相互联系的知之甚少。丙烯酸丙酮酸脱氢酶复合物众所周知，旨在产生活化的双碳前体分子（乙酰-COA）用于脂肪酸 - 因此 - 脂质合成。我们的预要表明该酶的DLA2亚基是核糖蛋白蛋白复合物的组成部分，因为这在绿色藻类模型系统Chlamydomonas Reinhardtii中的叶绿体mRNA平移空间组织中具有功能。相反，RNA结合影响丙酮酸脱氢酶活性。这些发现提供了有关如何相互连接的类囊体膜膜生物发生的第一条线索。此外，我们的数据提供了第一暗示，即蛋白质的这些双重作用可能存在于从蓝细菌到人类的进化远处生物中。在这个项目中，我们旨在阐明该调节性原理的精确分子工作模式，涉及基因表达的代谢控制。通过在C. reinhardtii中遵循分子，遗传和生化方法，我们将在体内和体外技术中使用RNA结合和DLA2的酶促形式来表征不同蛋白质亚复合物之间的DLA2的酶促形式。特别的重点将放在这些复合物的动力学和组成上，以及乙酸/乙酰辅酶A在平衡DLA2功能方面的作用。这项工作将通过蓝细菌和较高植物的相关分析来补充，以测试对这种调节转换的进化保护。