Targets and functions of the chloroplast ribonucleoproteins CP33A and CP33B

叶绿体核糖核蛋白 CP33A 和 CP33B 的靶标和功能

• 批准号: 427447224
• 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: Priority Programmes
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/427447224?language=en
• 关键词: Targets; functions; chloroplast; ribonucleoproteins; CP33A

Chloroplast mRNAs show a tight coordination across various environmental conditions. This is not a function of transcriptional, but rather of post-transcriptional regulation. Strikingly, their half-lives are massively extended relative to their bacterial ancestry, a prerequisite for post-transcriptional control. We have recently characterized the essential chloroplast ribonucleoprotein CP33A that binds most chloroplast mRNAs and is required for their stabilization. The mechanism behind global chloroplast RNA stabilization by Cp33A remains unclear. By using a combination of RIP-Seq, iCLIP and reverse genetics, I propose to decode CP33A’s stunning ability to serve the entire chloroplast mRNA pool.A special case among the chloroplast transcriptome is the psbA mRNA, which codes for the D1 protein. D1 is at the core of photosystem II and has to be constantly produced in the light due to permanent photodamage. How D1 production is regulated is one of the key questions in the field of photosynthetic gene expression. The psbA mRNA is present in vast amounts, arguably the most abundant mRNA on our planet. How are the masses of psbA mRNA stabilized and is stability regulated? We have identified a protein ligand of psbA, CP33B, which captures 90% of the psbA message. In prior experiments, we found an unexpected preference of CP33B for full-length psbA mRNA versus psbA fragments and that loss of CP33B leads to a reduction in psbA message early in plant development, when the need for the production of the photosynthetic machinery is highest. I propose to study the peculiar, possibly cooperative mode of CP33B-psbA interaction and the role of CP33B in psbA stabilization, also in the light of expected redundancy with an evolutionary sister protein. This work will unravel the mechanisms of stabilization of this key RNA of photosynthesis that have not been accessible so far.

叶绿体mRNA在各种环境条件下表现出紧密的协调。这不是转录的功能，而是转录后调节的功能。引人注目的是，它们的半衰期相对于它们的细菌祖先大大延长，这是转录后控制的先决条件。我们最近的特点是必需的叶绿体核糖核蛋白CP 33 A结合大多数叶绿体mRNA，并需要他们的稳定。Cp 33 A稳定叶绿体RNA的机制尚不清楚。通过使用RIP-Seq、iCLIP和反向遗传学的组合，我建议解码CP 33 A的惊人能力，以服务于整个叶绿体mRNA库。叶绿体转录组中的一个特殊情况是psbA mRNA，其编码D1蛋白。D1是光系统II的核心，由于永久性光损伤，必须在光照下不断产生。D1的产生是如何调控的是光合基因表达领域的关键问题之一。psbA mRNA存在于大量，可以说是我们星球上最丰富的mRNA。psbA mRNA的质量是如何稳定的，稳定性是如何调节的？我们已经确定了psbA的蛋白质配体CP 33 B，其捕获90%的psbA信息。在先前的实验中，我们发现了一个意想不到的偏好CP 33 B全长psbA mRNA与psbA片段，并在植物发育的早期，当需要生产的光合机械是最高的，CP 33 B的损失导致减少psbA消息。我建议研究的特殊，可能的合作模式的CP 33 B-psbA的相互作用和CP 33 B在psbA稳定的作用，也在预期的冗余与进化的姐妹蛋白。这项工作将揭示迄今为止尚未获得的光合作用关键RNA的稳定机制。