Chloroplastidäre Ribonukleoproteine (cpRNPs): globale Stabilisatoren chloroplastidärer RNA-Reservoirs während der Stressantwort

叶绿体核糖核蛋白 (cpRNP)：应激反应期间叶绿体 RNA 库的全局稳定剂

• 批准号: 194100979
• 负责人: Professor Dr. Christian Schmitz-Linneweber
• 金额: --
• 依托单位: Arbeitsgruppe Molekulare Genetik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/194100979?language=en
• 关键词: Chloroplastid; re; Ribonukleoproteine; cpRNPs; globale

Chloroplast RNA processing is mediated by a multitude of nuclear-encoded RNA binding proteins. Despite growing knowledge on the factors involved and mechanistic questions of individual gene expression steps being addressed, we still know little about the truly regulatory steps of chloroplast gene expression. Nor do we understand how chloroplast genes are co-regulated and how chloroplast gene expression is acclimated to changing external conditions. We have recently demonstrated that chloroplast ribonucleoproteins (cpRNPs) impact chloroplast mRNA accumulation and processing under low temperature conditions on a global scale. Unpublished experiments furthermore demonstrate that cpRNPs globally bind RNAs freed from chloroplast ribosomes under conditions of translational stress. cpRNPs are expressed and phosphorylated in a light and temperature-dependent manner. Taken together, cpRNPs have the unique potential to act as global modulators of external signals towards chloroplast RNA pools. We propose to address the following questions:I. How do RNA-pools bound by cpRNPs and by ribosomes, respectively, correspond to each other during stress acclimation?II. How does phosphorylation impact the role of cpRNPs and what are the kinases linking cpRNPs to external signals?III. How do cpRNPs mediate cold-resistance in Arabidopsis?IV. What is the molecular mechanism of cpRNP action, in particular, what are the exact binding sites on chloroplast mRNAs?We will use genome-wide quantitative profiling of RNA ligands of cpRNPs (RIP-Chip and iCLIP) to determine the role of cpRNPs and their known phosphorylation sites during acclimation processes. Furthermore, we will identify kinases acting upon cpRNPs using a combination of genetic and biochemical approaches. Finally, pharmacological, genetic and physiological perturbations of chloroplast gene expression will be harnessed to determine, at what time during development and stress acclimation cpRNPs are important to provide stability to chloroplast mRNAs. In sum, our analysis is designed to unravel, how chloroplast RNA metabolism is controlled and executed by cpRNPs on a global scale in response to stressors relevant for chloroplast function and plant survival.

叶绿体RNA加工是由多种核编码RNA结合蛋白介导的。尽管对所涉及的因素和单个基因表达步骤的机制问题的了解越来越多，但我们对叶绿体基因表达的真正调控步骤仍然知之甚少。我们也不了解叶绿体基因是如何协同调节的，以及叶绿体基因的表达是如何适应不断变化的外部条件的。我们最近证明了叶绿体核糖核蛋白（cpRNPs）在全球范围内影响低温条件下叶绿体mRNA的积累和加工。未发表的实验进一步证明，在翻译胁迫条件下，cpRNPs可以全局结合从叶绿体核糖体中释放的rna。cpRNPs以光和温度依赖的方式表达和磷酸化。综上所述，cpRNPs具有作为叶绿体RNA池外部信号的全局调节剂的独特潜力。我们建议解决以下问题：在胁迫适应过程中，分别由cpRNPs和核糖体结合的rna池是如何相互对应的？2。磷酸化如何影响cpRNPs的作用，以及哪些激酶将cpRNPs连接到外部信号？3。cpRNPs如何介导拟南芥的抗寒性？四、cpRNP作用的分子机制是什么，特别是叶绿体mrna的确切结合位点是什么？我们将使用cpRNPs的RNA配体的全基因组定量分析（RIP-Chip和iCLIP）来确定cpRNPs及其已知磷酸化位点在驯化过程中的作用。此外，我们将使用遗传和生化方法的组合来确定作用于cpRNPs的激酶。最后，叶绿体基因表达的药理学、遗传和生理扰动将被利用来确定，在发育和胁迫适应过程中，cpRNPs在提供叶绿体mrna稳定性方面是重要的。总之，我们的分析旨在揭示叶绿体RNA代谢如何在全球范围内由cpRNPs控制和执行，以响应与叶绿体功能和植物存活相关的应激源。