The impact and regulation of eIF4A-multimerisation in establishing translational programmes

eIF4A多聚化对建立转化项目的影响和监管

• 批准号: BB/Y004248/1
• 负责人: Martin Bushell
• 金额: $ 66.14万
• 依托单位: University of Glasgow
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FY004248%2F1
• 关键词: impact; regulation; eIF4A; multimerisation; establishing

Genes are the blueprints for building an organism and define its biological properties. They are made of DNA that is kept in the nucleus of the cell. In the process of gene expression, to create what is encoded by a gene, DNA is copied and made in a new form as RNA. The information within RNAs is read by molecular machines, called ribosomes, that translate and convert this information into amino acid sequences named proteins. The collection of proteins within a cell is termed the proteome. RNA and the proteome are the main particles to carry out functions within cells. Altering the RNAs within a cell enables dynamic changes to the proteome and, hence, changes cell function and fate. Groups of genes are co-ordinately regulated and are combined to form a programme of cell activity that dictate which RNAs produce which proteins at specific times. Unfortunately, these mechanisms can be faulty due to mutations in genes that regulate the expression of these genes. Such dysregulation can lead to activation of cellular programmes at the wrong time producing RNA and proteins that cause fatal illnesses. A devastating example is cancer, when RNAs lead to uncontrolled production of proteins related to cell division.Most cellular processes that dictate which RNAs are selected for translation into protein operate by adjusting the function of the translation initiation complex eIF4F. At its hearts operates a protein called eIF4A1. This protein is essential for loading RNAs onto ribosomes and starting protein translation. eIF4A1 activity is changed by interacting with many other proteins, called cofactors. In addition, RNAs themselves can contain elements that may change which function of eIF4A1 is needed. Researchers have gathered information on how eIF4A1 activity is changed by its cofactors and are starting to understand that dysregulation of eIF4A1 has fatal outcomes. However, we still do not know why and how this dysregulation is established. To shed light on this, we first need to know how eIF4A1 function is controlled by its cofactors and RNA targets which together dictate which of these RNAs are selected for translation by the ribosome. This research proposal aims to identify these patterns and mechanisms of eIF4A1 regulation.It has been believed that eIF4A1 is active as a single molecule but our recent work revealed that eIF4A1 forms protein complexes that are assembled from one or three copies of it. We also gathered evidence that these complexes have different activities and that RNA affects the distribution between these different states. This creates the hypothesis of how RNA might dictate eIF4A1 activity. Thus, this research will focus particularly on the power of RNA itself to direct activity of eIF4A1.To achieve this goal, we need to understand which RNAs recruit which eIF4A1 complex and exactly define the eIF4A1 activity required by the RNA targets. To do this, we will isolate the RNAs that are specifically bound by different eIF4A1 complexes. We will then use computational tools to find out what discriminates these RNAs from others. To understand how the multi-eIF4A1 complexes perform their function on RNA we will determine the 3D structure of the complexes using state-of-the-art microscopes. This will identify how the complexes form and enable us to generate modified eIF4A1 that cannot form these complexes. We will use the modified complexes to dissect their activities and reconstitute key steps of how RNAs are translated into protein in a cell-free environment to understand their function. Together these findings will identify a relationship between eIF4A1, RNAs and cofactors that ultimately dictate protein translation. With this, we will contribute fundamental knowledge to increase our understanding of the regulation and dysregulation of eIF4A1 and how this affects cell function. In the further it may allow specific drugs to be designed that will affect specific eIF4A1 activities.

基因是建立生物体并定义其生物学特性的蓝图。它们由保存在细胞核中的DNA制成。在基因表达的过程中，为了创建由基因编码的内容，将DNA复制并以新形式作为RNA制成。 RNA中的信息通过称为核糖体的分子机读取，该机器将这些信息转化为氨基酸序列，称为蛋白质。细胞内蛋白质的收集称为蛋白质组。 RNA和蛋白质组是在细胞内执行功能的主要颗粒。改变单元内的RNA可以使蛋白质组的动态变化，从而改变细胞功能和命运。基因组进行协同调节，并结合起来形成一个细胞活性程序，该程序决定了哪些RNA在特定时间产生哪些蛋白质。不幸的是，由于调节这些基因表达的基因突变，这些机制可能是错误的。这种失调会导致在错误的时间激活细胞程序，从而产生引起致命疾病的RNA和蛋白质。一个毁灭性的例子是癌症，当RNA导致与细胞分裂相关的蛋白质的不受控制的产生时，大多数细胞过程决定选择哪种RNA通过调整翻译起始复合物EIF4F的功能来转化为蛋白质。在其心中运行一种称为EIF4A1的蛋白质。该蛋白对于将RNA载入核糖体和启动蛋白质翻译至关重要。 EIF4A1活性通过与许多其他蛋白质（称为辅助因子）相互作用而改变。此外，RNA本身可以包含可能需要更改EIF4A1功能的元素。研究人员收集了有关其辅助因子如何改变EIF4A1活动的信息，并开始了解EIF4A1的失调具有致命的结果。但是，我们仍然不知道为什么以及如何建立这种失调。为了阐明这一点，我们首先需要知道eIF4A1函数如何由其辅助因子和RNA靶标控制，而RNA靶标共同决定了这些RNA中的哪个是由核糖体选择用于翻译的。该研究建议旨在识别EIF4A1调节的这些模式和机制。据信EIF4A1活跃为单个分子，但是我们最近的工作表明，EIF4A1形成了从其一两个副本中组装的蛋白质复合物。我们还收集了这些复合物具有不同活性的证据，RNA会影响这些不同状态之间的分布。这创建了RNA如何决定EIF4A1活性的假设。因此，这项研究将特别关注RNA本身在指导EIF4A1的活性的力量上。要实现此目标，我们需要了解RNA募集了哪些EIF4A1复合物并准确地定义了RNA目标所需的EIF4A1活性。为此，我们将隔离由不同的EIF4A1复合物约束的RNA。然后，我们将使用计算工具来找出这些RNA与其他RNA的区别。为了了解多EIF4A1复合物如何在RNA上执行其功能，我们将使用最新的显微镜确定复合物的3D结构。这将确定复合物如何形成并使我们能够生成无法形成这些复合物的修改后的EIF4A1。我们将使用修改后的复合物来剖析其活动，并重构如何将RNA在无细胞环境中转化为蛋白质以了解其功能的关键步骤。这些发现共同确定EIF4A1，RNA和辅因子之间最终决定蛋白质翻译的关系。这样，我们将贡献基本知识，以增加对EIF4A1的调节和失调以及这如何影响细胞功能的理解。在另外，它可以设计出来的特定药物，以影响特定的EIF4A1活动。