The role of factors regulating transcript elongation by RNA polymerase II in tuning plant gene expression programs

RNA聚合酶II转录延伸调节因子在调节植物基因表达程序中的作用

• 批准号: 261469659
• 负责人: Professor Dr. Klaus Grasser
• 金额: --
• 依托单位: Lehrstuhl für Zellbiologie und Pflanzenbiochemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/261469659?language=en
• 关键词: role; factors; regulating; transcript; elongation

The genomic DNA of eukaryotic organisms is packaged into a nucleoprotein structure termed chromatin, and nucleosome particles represent the basic unit of chromatin. Hence, by restricting the accessibility of DNA nucleosomes repress various DNA-dependent processes such as gene transcription. Accordingly, RNA polymerase II (RNAPII), the enzyme that transcribes protein-coding genes (synthesising mRNAs), requires different assistant factors, which facilitate productive transcript elongation of DNA templates assembled into nucleosomes. Among the proteins that promote the elongation phase of RNAPII transcription are the so-called transcript elongation factors (TEFs). They represent a heterogeneous group of proteins with diverse functions including modulating the catalytic properties of RNAPII or destabilising nucleosomes in the path of the enzyme, allowing efficient mRNA synthesis. In line with their function in gene transcription TEFs contribute to adjusting accurately cellular transcript levels.We have previously characterised various TEFs of the Arabidopsis plant model demonstrating that mutant plants deficient in certain TEFs display distinct defects in growth and development. Not much is known about functional interactions between TEFs that associate with elongating RNAPII forming the transcript elongation complex. We will analyse double-mutant plants lacking different pairs of TEFs to examine their cooperation on the molecular level (recruitment, functional interdependence). Interestingly, only the expression of specific subsets of genes is impaired by the elongation defects brought about by the absence of certain TEFs. Employing genome-wide analyses (transcriptomics, chromatin immunoprecipitation) we intend to identify features of target genes that determine the requirement for TEF action to achieve efficient transcription. Establishing a transcript elongation reporter construct will yield further clues about the mechanism of action of TEFs in planta. In conclusion, the proposed project will provide novel insight into TEF action during RNAPII transcription in vivo and their role in establishing precise gene expression profiles required for proper plant development.

真核生物的基因组DNA被包装成称为染色质的核蛋白结构，核小体颗粒代表染色质的基本单位。因此，通过限制DNA的可及性，核小体抑制各种DNA依赖性过程，如基因转录。因此，RNA聚合酶II（RNAPII），转录蛋白质编码基因（合成mRNA）的酶，需要不同的辅助因子，其促进组装成核小体的DNA模板的生产性转录延长。促进RNAPII转录延伸期的蛋白质包括所谓的转录物延伸因子（TEF）。它们代表了一组具有不同功能的蛋白质，包括调节RNAPII的催化特性或在酶的路径中使核小体不稳定，从而允许有效的mRNA合成。与它们在基因转录中的功能一致，TEFs有助于准确地调节细胞转录水平。我们先前已经表征了拟南芥植物模型的各种TEFs，证明某些TEFs缺陷的突变体植物在生长和发育中显示出明显的缺陷。关于TEF之间与延伸RNAPII形成转录延伸复合物相关的功能相互作用知之甚少。我们将分析缺乏不同TEF对的双突变体植物，以研究它们在分子水平上的合作（招募，功能相互依赖）。有趣的是，只有特定基因子集的表达受到某些TEF缺失所导致的延伸缺陷的损害。采用全基因组分析（转录组学，染色质免疫沉淀），我们打算确定目标基因的功能，确定TEF行动的要求，以实现有效的转录。建立一个转录延长报告构建体将产生进一步的线索TEFs在植物中的作用机制。总之，拟议的项目将提供新的洞察TEF行动在RNAPII体内转录和它们的作用，建立精确的基因表达谱所需的适当的植物发育。