Functional Analysis of PPR-SMR-related Proteins in Zea mays (Maize) and Arabidopsis thaliana

玉米和拟南芥中 PPR-SMR 相关蛋白的功能分析

• 批准号: 30329440
• 负责人: Dr. Jeannette Pfalz
• 金额: --
• 依托单位: Institute of Molecular Biology
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/30329440?language=en
• 关键词: Functional; Analysis; PPR; SMR; related

Plastid gene expression is essential for all metabolic processes in plastids and for plant viability. The regulation of plastid gene expression occurs at various levels of transcription, transcript maturation and protein assembly processes. Numerous nucleus encoded factors are needed for the regulation of plastid gene expression. Pentatricopeptide repeat (PPR) proteins appear to play a particularly important role, and participate in many types of RNA metabolism. In my Ph.D. work, I identified a novel type of PPR protein that is characterized by a second functional motif called SMR (small MutS-releated). Proteins harboring both PPR and SMR domains comprise a small ¿subfamily¿ within the large PPR family. The SMR domain has been shown to have nicking endonuclease activity. This, together with current understanding of PPR motifs, suggests that the PPR-SMR subfamily may participate in DNA or RNA metabolism, DNA repair, transcriptional and/or translational processes by acting as endonucleases. In this project I will explore these possibilities by studying four predicted plastid PPR-SMR proteins in Zea mays (maize) and the orthologous proteins in Arabidopsis; use of the two organisms will be synergistic as they each offer different experimental advantages. Work will include determinations of specific nucleic acid target sequences, endonuclease assays and comparative phenotypic, molecular and biochemical analyses of mutants in maize and Arabidopsis. I will determine whether each protein interacts with specific RNA and/or DNA sequences in vivo, and whether the metabolism of the corresponding nucleic acids is disrupted in the mutant background.

质体基因表达对于质体中的所有代谢过程和植物存活力是必不可少的。质体基因表达的调节发生在转录、转录物成熟和蛋白质组装过程的不同水平。质体基因表达的调控需要大量的核编码因子。五肽重复序列（PPR）蛋白似乎起着特别重要的作用，并参与许多类型的RNA代谢。在我的博士学位上。在这项工作中，我发现了一种新型的PPR蛋白，其特征在于第二个功能基序称为SMR（小MutS-突变）。同时具有PPR和SMR结构域的蛋白质组成了PPR大家族中的一个小亚家族。SMR结构域已显示具有切口核酸内切酶活性。这与目前对PPR基序的理解一起表明PPR-SMR亚家族可能通过充当核酸内切酶参与DNA或RNA代谢、DNA修复、转录和/或翻译过程。在这个项目中，我将探索这些可能性，通过研究四个预测的质体PPR-SMR蛋白质在玉米（玉米）和拟南芥中的orthosteroid蛋白质;使用这两种生物体将是协同作用，因为它们各自提供不同的实验优势。工作将包括确定特定的核酸靶序列，核酸内切酶分析和比较表型，分子和生物化学分析的突变体在玉米和拟南芥。我将确定每种蛋白质是否在体内与特定的RNA和/或DNA序列相互作用，以及在突变背景下相应核酸的代谢是否被破坏。