Global key players of chloroplast gene expression

叶绿体基因表达的全球关键参与者

• 批准号: 238561773
• 负责人: Privatdozent Dr. Jörg Meurer
• 金额: --
• 依托单位: Lehrstuhl für Molekularbiologie der Pflanzen
• 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 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/238561773?language=en
• 关键词: Global; key; players; chloroplast; gene

The chloroplast Ribonuclease E (RNE) plays an important key role in processing of many transcripts and therefore belongs to the major RNA processing factors in chloroplasts. By means of forward and reverse genetics in Arabidopsis and tagging approaches in combination with mass spectrometry we recently identified a degradosome-like complex (DLC), which contains RNE, RNJ, one helicase, two ribosomal proteins with presumably extraribosomal functions and unknown proteins, like RHON1 and a pentatricopeptide repeat (PPR) protein. A degradosome was previously thought not to exist in chloroplasts. The essential and plant specific RHON1 protein was found to bind specifically to those RNA regions, which are not processed efficiently in rne and rhon1 mutants. Therefore, we hypothesize that RHON1 supports the function of RNE presumably by delivering the target RNAs to the DLC. Interestingly, rne and rhon1 mutants have numerous and tiny chloroplasts strongly supporting an important role in plastid division. Another global player in plastid gene expression is represented by pale cress (PAC). We showed that PAC directly interacts with proteins and RNA. This project aims to analyse the function and importance of interaction partners of RNE, RHON1 and PAC, to identify the precise RNA targets of PAC and to investigate a putative regulatory role in plastid gene expression and the function of PAC in ribosome assembly. We anticipate that future research on the DLC and PAC, their compartmentalization within the chloroplast and association partners will shed new light on chloroplast gene expression, division and development.

叶绿体核糖核酸酶E （chloroplast ribonucase E， RNE）在许多转录本的加工过程中起着重要的关键作用，是叶绿体中主要的RNA加工因子之一。通过对拟南芥的正向和反向遗传学以及标记方法与质谱相结合，我们最近发现了一种降解体样复合体（DLC），它包含RNE， RNJ，一个解旋酶，两个可能具有核糖体外功能的核糖体蛋白和未知蛋白，如RHON1和五肽重复（PPR）蛋白。以前认为叶绿体中不存在降解体。研究发现，必需的和植物特异性的RHON1蛋白特异性地结合在rne和RHON1突变体中不能有效加工的RNA区域。因此，我们假设RHON1可能通过将目标rna传递到DLC来支持RNE的功能。有趣的是，rne和rhon1突变体具有大量微小的叶绿体，有力地支持了质体分裂的重要作用。质体基因表达的另一个全球参与者是pale dress （PAC）。我们发现PAC直接与蛋白质和RNA相互作用。本项目旨在分析RNE、RHON1和PAC相互作用伙伴的功能和重要性，确定PAC的精确RNA靶点，并研究PAC在质体基因表达中的可能调控作用以及PAC在核糖体组装中的功能。我们期待未来对DLC和PAC的研究，以及它们在叶绿体中的区隔和关联伙伴的研究将为叶绿体基因的表达、分裂和发育提供新的思路。