Regulation and structural organisation of a key regulatory translation factor eIF2B

关键调控翻译因子 eIF2B 的调控和结构组织

• 批准号: BB/G008396/1
• 负责人: Christopher Proud
• 金额: $ 84.15万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FG008396%2F1
• 关键词: Regulation; structural; organisation; key; regulatory

The production of proteins (protein synthesis) is an essential process for living cells. It is needed for them to grow, divide and survive. Protein synthesis is stimulated by hormones, like insulin, and decreased when nutrients are scarce. The availability of amino acids, the building blocks for proteins, is especially important in controlling this process. The applicant's laboratory studies how protein synthesis is normally controlled and why errors in these control systems lead to human disease. One of the key cellular components that control protein synthesis is a protein termed 'eukaryotic initiation factor 2B' (eIF2B). The applicant has studied eIF2B and its control for a more than 15 years. The activity of eIF2B is stimulated by amino acids and by hormones. It is inhibited under stressful conditions where protein synthesis slows down. Several years ago, the applicant's laboratory identified a key link between insulin and the control of eIF2B, which helped to pave the way to a better understanding of the actions of insulin. This laboratory has now identified a new way in which amino acids can control eIF2B. eIF2B is made up of five components, called subunits, one of which carries out the cellular function of eIF2B. This is the one that is known to be important for the control of eIF2B, which operates through the addition or removal of phosphate groups (called 'phosphorylation-dephosphorylation', a very common way of regulating proteins). The other four subunits have ancillary functions in the control of eIF2B or in the assembly of the eIF2B 'complex'. Recent work has shown that changes (mutations) in the genes for the subunits of eIF2B are responsible for an inherited severe brain disease called 'vanishing white matter' (VWM for short) which mainly affects children. This underlines the fact that the proper actions and control of eIF2B are crucial. It is important to understand how these mutations affect eIF2B and why this leads to a brain disease. The principal aims of this project are: 1. to find out how amino acids control the activity of eIF2B: in particular we wish to identify the links (so-called 'signalling components') that relay information about the availability of amino acids to control eIF2B's activity. This goal is important for understanding how protein synthesis is controlled. It will also provide valuable new information about the ways that nutrients are detected by animal cells and affect their functions. 2. to discover other ways in which the function of eIF2B can be controlled. By applying start-of-the-art 'proteomic' techniques, we will learn more about the control of eIF2B by phosphorylation-dephosphorylation. We will apply this technology to learn more about the ways in which eIF2B is controlled under different conditions that affect protein synthesis. This aim is important for achieving a more complete understanding of the control of eIF2B, a key regulatory molecule in animal cells. 3. to investigate how the five different subunits of eIF2B work together to create a properly functioning eIF2B protein, although our initial data have already provided insights into this. We will build on this information to establish how this protein works. We will use both biochemical methods and new biophysical techniques. This aspect is also very relevant for understanding how mutations that cause the disease VWM affect the function of eIF2B. 4. to apply our established methods to explore how VWM mutations affect the function, assembly and control of eIF2B. This work will be valuable in understanding both the disease processes that lead to VWM and the properties of eIF2B itself. 5. eIF2B is known to control the production of specific proteins. We will use information gained in this project to extend our understanding of how it does this, and of the implications for the expression of the genetic information of mammalian cells.

蛋白质的产生（蛋白质合成）是活细胞的一个重要过程。它们需要成长、分裂和生存。蛋白质合成受激素刺激，如胰岛素，当营养缺乏时会减少。氨基酸是蛋白质的基本组成部分，它的可用性在控制这一过程中尤为重要。申请人的实验室研究蛋白质合成通常是如何控制的，以及为什么这些控制系统中的错误会导致人类疾病。控制蛋白质合成的关键细胞组分之一是称为“真核起始因子2B”（eIF 2B）的蛋白质。申请人研究eIF 2B及其对照超过15年。eIF 2B的活性受到氨基酸和激素的刺激。它在蛋白质合成减慢的压力条件下被抑制。几年前，申请人的实验室确定了胰岛素与eIF 2B控制之间的关键联系，这有助于为更好地理解胰岛素的作用铺平道路。该实验室现在已经确定了一种氨基酸可以控制eIF 2B的新方法。eIF 2B由五种称为亚基的组分组成，其中一种亚基执行eIF 2B的细胞功能。这是已知的对eIF 2B的控制很重要的一个，eIF 2B通过添加或去除磷酸基团（称为“磷酸化-去磷酸化”，一种非常常见的调节蛋白质的方式）来起作用。其他四个亚基在eIF 2B的控制或eIF 2B“复合物”的组装中具有辅助功能。最近的研究表明，eIF 2B亚基基因的变化（突变）是导致一种名为“消失的白色物质”（简称VWM）的遗传性严重脑部疾病的原因，这种疾病主要影响儿童。这强调了eIF 2B的适当行动和控制至关重要。重要的是要了解这些突变如何影响eIF 2B以及为什么这会导致脑部疾病。该项目的主要目标是：1。为了找出氨基酸如何控制eIF 2B的活性：特别是我们希望确定传递关于氨基酸可用性的信息以控制eIF 2B活性的链接（所谓的“信号传导组件”）。这个目标对于理解蛋白质合成是如何控制的很重要。它还将提供有关营养物质被动物细胞检测并影响其功能的方式的有价值的新信息。2.发现控制eIF 2B功能的其他方法。通过应用最先进的“蛋白质组学”技术，我们将更多地了解通过磷酸化-去磷酸化控制eIF 2B的信息。我们将应用这项技术来了解更多关于eIF 2B在不同条件下控制蛋白质合成的方式。这一目标对于更全面地了解动物细胞中的关键调控分子eIF 2B的控制非常重要。3.研究eIF 2B的五个不同亚基如何协同工作以产生功能正常的eIF 2B蛋白，尽管我们的初步数据已经提供了对此的见解。我们将建立在这些信息的基础上，以确定这种蛋白质如何工作。我们将使用生物化学方法和新的生物物理技术。这方面对于理解导致疾病VWM的突变如何影响eIF 2B的功能也非常相关。4.应用我们建立的方法来探索VWM突变如何影响eIF 2B的功能，组装和控制。这项工作对于理解导致VWM的疾病过程和eIF 2B本身的特性都是有价值的。5.已知eIF 2B控制特定蛋白质的产生。我们将利用在这个项目中获得的信息来扩展我们对它如何做到这一点的理解，以及对哺乳动物细胞遗传信息表达的影响。

项目成果

eIF2B: recent structural and functional insights into a key regulator of translation.

eIF2B：最近对翻译关键调节因子的结构和功能见解。

• DOI: 10.1042/bst20150164
• 发表时间: 2015
• 期刊: Biochemical Society transactions
• 影响因子: 3.9
• 作者: Wortham NC