Molecular Mechanisms of Sigma Factor Inhibition in a Gene Expression Switch

基因表达开关中 Sigma 因子抑制的分子机制

• 批准号: BB/N006267/1
• 负责人: Rivka Isaacson
• 金额: $ 45.14万
• 依托单位: King's College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FN006267%2F1
• 关键词: Molecular; Mechanisms; Sigma; Factor; Inhibition

We propose to study the way cells can completely transform their identity by activating a 'gene expression switch'. Such transformations are important to naturally maintain health e.g. in embryo development which begins with identical cells which then crucially change into the different types of cells that make up a developed human. Conversely, these transformations can cause harm e.g. when cells become cancerous or pathogens invade hosts. A gene expression switch involves a distinct programme of genetic instruction being deactivated and replaced with an alternative that leads to radical transformation of the cell's nature.In this study my group will examine a particular gene expression switch event in bacterial spore formation which is partially responsible for the persistence of 'hospital superbugs' as spores are a long-lived bacterial form, resistant to cleaning agents and thriving in patients depleted of natural gut microflora.In a gene expression switch there are specific proteins that choreograph genetic instruction in a highly regulated process. We intend to uncover the detailed molecular shapes of some of these proteins using indirect techniques as they are too small to see even using powerful microscopes. We specialise in measuring protein shapes and the way they fit together by producing them artificially in large quantities, with the help of bacteria which act as our 'protein factories'. We then deduce the proteins' molecular structures by processing their behaviour when we bounce X-rays off them or put them in strong magnetic fields. Each of these techniques has its strengths and weaknesses but our combined approach can yield complementary information filling in the gaps left by using just one of the methods. Collaborating with a microbiologist we will feed information into each others' experiments to build up a mechanistic picture of this gene expression switch in bacterial spore formation. For example, if we identify a mutation in one of our proteins that makes it bind more tightly to its partner our collaborator can make the same mutation within bacteria to test whether it has the predicted effect in living systems.By solving this jigsaw puzzle we hope to be in a stronger position to design novel antibiotics to attack the increasing problem of bacterial drug resistance and the project also has longer term implications for understanding gene expression switches in all aspects of health and disease.

我们建议研究细胞如何通过激活“基因表达开关”来完全改变它们的身份。这种转化对于自然地保持健康是很重要的，例如在胚胎发育中，胚胎从相同的细胞开始，然后关键地转变成不同类型的细胞，构成一个发育的人。相反，当细胞癌变或病原体入侵宿主时，这些转化会造成伤害。基因表达转换涉及到一个独特的基因指令程序被停用，并被另一个替代程序所取代，从而导致细胞性质的根本转变。在这项研究中，我的小组将研究细菌孢子形成中的一个特定基因表达开关事件，该事件部分负责“医院超级细菌”的持续存在，因为孢子是一种长寿的细菌形式，对清洁剂具有抗性，并且在天然肠道菌群耗尽的患者中茁壮成长。在基因表达开关中，有特定的蛋白质在高度调控的过程中编排遗传指令。我们打算使用间接技术揭示其中一些蛋白质的详细分子形状，因为它们太小，即使使用强大的显微镜也无法看到。我们专门测量蛋白质的形状，并通过人工大量生产蛋白质，在细菌的帮助下，它们成为我们的“蛋白质工厂”。然后，当我们对蛋白质进行x射线反射或将其置于强磁场中时，我们通过处理它们的行为来推断蛋白质的分子结构。每种技术都有其优点和缺点，但我们的组合方法可以产生互补的信息，填补仅使用其中一种方法留下的空白。我们将与一位微生物学家合作，为彼此的实验提供信息，以建立细菌孢子形成过程中这种基因表达开关的机制图。例如，如果我们在我们的一种蛋白质中发现了一个突变，使其与同伴结合得更紧密，我们的合作者可以在细菌中进行同样的突变，以测试它是否在生命系统中具有预期的效果。通过解决这个拼图，我们希望能够在设计新型抗生素方面处于更有利的地位，以解决日益严重的细菌耐药性问题，该项目还对理解健康和疾病各个方面的基因表达开关具有更长远的意义。

项目成果

Structure and Interactions of the TPR Domain of Sgt2 with Yeast Chaperones and Ybr137wp.

• DOI: 10.3389/fmolb.2017.00068
• 发表时间: 2017
• 期刊: Frontiers in molecular biosciences
• 影响因子: 5
• 作者: Krysztofinska EM;Evans NJ;Thapaliya A;Murray JW;Morgan RML;Martinez-Lumbreras S;Isaacson RL
• 通讯作者: Isaacson RL

A novel RNA polymerase-binding protein that interacts with a sigma-factor docking site.

• DOI: 10.1111/mmi.13724
• 发表时间: 2017-08
• 期刊: Molecular microbiology
• 影响因子: 3.6
• 作者: Wang Erickson AF;Deighan P;Chen S;Barrasso K;Garcia CP;Martínez-Lumbreras S;Alfano C;Krysztofinska EM;Thapaliya A;Camp AH;Isaacson RL;Hochschild A;Losick R
• 通讯作者: Losick R

Meeting Reports

会议报告

• DOI: 10.1042/bio_2023_142
• 发表时间: 2023
• 期刊: The Biochemist
• 作者: Stollar E

Viewing the Invisible: Exploring common methodology across disciplines.

查看看不见的东西：探索跨学科的通用方法。

• DOI: 10.1371/journal.pbio.3000577
• 发表时间: 2019
• 期刊: PLoS biology
• 影响因子: 9.8
• 作者: Witheridge A

Structural and Functional Insights into Bacillus subtilis Sigma Factor Inhibitor, CsfB.

• DOI: 10.1016/j.str.2018.02.007
• 发表时间: 2018-04-03
• 期刊: Structure (London, England : 1993)
• 作者: Martínez-Lumbreras S;Alfano C;Evans NJ;Collins KM;Flanagan KA;Atkinson RA;Krysztofinska EM;Vydyanath A;Jackter J;Fixon-Owoo S;Camp AH;Isaacson RL
• 通讯作者: Isaacson RL