Functions of CURT1 proteins in thylakoid grana formation

CURT1蛋白在类囊体基粒形成中的功能

• 批准号: 254831856
• 负责人: Professor Dr. Dario Leister
• 金额: --
• 依托单位: Lehrstuhl für Molekularbiologie der Pflanzen
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/254831856?language=en
• 关键词: Functions; CURT1; proteins; thylakoid; grana

Chloroplasts of land plants characteristically contain grana, cylindrical stacks of thylakoid membranes. The mechanisms leading to the formation of grana, and in particular the factors that generate the extreme curvature in grana margins are largely unknown. In previous work we have identified a small family of proteins, designated CURT1, which is required for grana formation. Because overexpresion of CURT1 proteins increases the number of membrane layers in grana, the CURT1 proteins are highly enriched in grana margins, and CURT1 proteins can induce tubulation of liposomes in vitro, we conclude that these proteins are directly involved in inducing/maintained the membrane curvature in margins. The five central questions which will be addressed in this project are: 1. By which mechanism do CURT1 proteins bend membranes? 2. What is the role of phosphorylation of thylakoid proteins (including CURT1) in grana stacking? 3. How has the grana stacking function of CURT1 protein evolutionary developed? 4. Is CURT1 sufficient in vivo to mediate grana stacking? Which other factors are involved? 5. What is the physiological relevance, in particular under natural conditions, of grana stacking? To address these questions we will apply methods from molecular genetics, molecular biology, biochemistry and electron microscopy (EM) and study several model species, in particular Arabidopsis thaliana, Synechocystis 6803 and Chlamydomonas reinhardtii.

陆地植物的叶绿体通常含有基粒、类囊体膜的圆柱形堆叠体。导致基粒形成的机制，特别是在基粒边缘产生极端曲率的因素在很大程度上是未知的。在之前的工作中，我们已经鉴定了一个蛋白质小家族，命名为 CURT1，它是基粒形成所必需的。由于CURT1蛋白的过度表达增加了基粒中膜层的数量，CURT1蛋白在基粒边缘高度富集，并且CURT1蛋白可以在体外诱导脂质体管状化，因此我们得出结论，这些蛋白直接参与诱导/维持膜曲率在页边距中。该项目将解决的五个核心问题是： 1. CURT1 蛋白通过哪种机制使膜弯曲？ 2. 类囊体蛋白（包括CURT1）的磷酸化在基粒堆积中起什么作用？ 3. CURT1蛋白的基粒堆积功能是如何进化的？ 4. CURT1在体内是否足以介导基粒堆积？还涉及哪些其他因素？ 5. 基粒堆积的生理相关性是什么，特别是在自然条件下？为了解决这些问题，我们将应用分子遗传学、分子生物学、生物化学和电子显微镜 (EM) 的方法，研究几种模式物种，特别是拟南芥、集胞藻 6803 和莱茵衣藻。