Adaptations of chloroplast protein transport mechanisms during land plant evolution

类囊体膜的生物发生需要细胞核和质体编码的膜蛋白的协调运输。叶绿体信号识别颗粒（SRP）系统在这些蛋白质子集的翻译后和翻译共转运中起重要作用。先前的研究表明，随着链藻和陆生植物的进化，这些运输机制经历了惊人的分子适应。在本项目中，我们旨在进一步了解陆地植物进化过程中SRP系统的分子变化，揭示潜在的进化驱动力。我们将特别分析(i) cpSRP蛋白（cpSRP43, cpSRP54）和SRP RNA的功能，（ii） SRP依赖性转运的调控，以及（iii）苔藓壶菌和多态地茅中核糖体与Alb3插入酶的对接机制。为此，我们将结合遗传学、细胞生物学、生物化学和结构方法。

Thylakoid membrane biogenesis requires the coordinated transport of nucleus- and plastid-encoded membrane proteins. The chloroplast signal recognition particle (SRP) system plays an important role in the post- and cotranslational transport of a subset of these proteins. Previous research has shown that these transport mechanisms underwent striking molecular adaptations with the evolution of streptophyte algae and land plants. In the proposed project we aim to get further insight into the molecular changes of the SRP system during land plant evolution and to reveal the underlying evolutionary driving forces. We will particularly analyze (i) the function of the cpSRP proteins (cpSRP43, cpSRP54) and the SRP RNA, (ii) the regulation of SRP-dependent transport and (iii) the docking mechanism of ribosomes to the Alb3 insertase in the moss Physcomitrium patens and the liverwort Marchantia polymorpha. To this end, we will combine genetic, cell biological, biochemical, and structural approaches.