Peroxiredoxinylation; a new post-translational modification promoting redox signal transduction?

过氧化氧还蛋白酰化；

• 批准号: BB/T002484/1
• 负责人: Elizabeth Ann Veal
• 金额: $ 47.94万
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FT002484%2F1
• 关键词: Peroxiredoxinylation; new; post; translational; modification

All oxygen-using organisms inevitably encounter reactive oxygen species (ROS), produced by a multitude of exogenous and endogenous sources. ROS can be extremely damaging, hence highly conserved mechanisms have evolved to prevent this damage. In yeast, plants and animal cells, these include activating conserved signalling pathways, such as p38/JNK MAPK pathways, that initiate a variety of responses, including increasing the levels of protective proteins. However, ROS have many other signalling functions in these organisms too; promoting wound healing, root tip growth, movement of cancer cells etc through effects on cell growth, division, differentiation and migration. Moreover, although oxidative damage is a general hallmark of many diseases and ageing, small increases in ROS are actually essential for the pro-longevity effects of dietary restriction/changes in mitochondrial activity. This discovery has challenged the theory that ROS cause ageing and led to the current view that localised ROS signals are able to protect against ageing and age-associated diseases. Nevertheless, despite the ever-increasing number of important biological processes in which ROS signals are implicated, there remain big gaps in our understanding of how these ROS signals are actually sensed and transmitted. For instance, in most cases, the identity of the ROS-regulated signalling proteins, and the mechanisms by which ROS regulate their activity are both unknown. This work will address these questions, exploiting the well-established advantages of yeast (Schizosaccharomyces pombe) and microscopic nematode worms (Caenorhabditis elegans) as powerful model systems for studying the mechanisms involved in regulating cell division, ROS responses and ageing.The applicant's previous work has established important roles for ubiquitous, peroxide-reactive proteins, 2-Cys peroxiredoxins (Prx), in promoting ROS-signalling and longevity in yeast and worms. Importantly, ROS-signalling and anti-ageing functions have been found to be shared by Prx in mammals and plants, illustrating the value of studies in these models for identifying conserved ROS-signalling and pro-longevity mechanisms. However, the mechanisms underlying many of the ROS-signalling and pro-longevity functions of Prx have yet to be uncovered. Pilot data: Our approach to identify ROS-regulated target proteins has identified a number of proteins that form ROS-induced disulphide-bonded complexes with Prx. These Prx-complexed proteins include multiple components of a p38-related MAPK signalling pathway, that plays a key role in coordinating responses to environmental/metabolic stimuli. Here we will test the hypothesis that the formation of these reversible chemical bonds with a Prx, or 'peroxiredoxinylation', represents a new protein modification, regulating these proteins and thus mediating many of the physiological effects of ROS. By establishing how Prx regulates these signalling proteins, we hope to establish a new paradigm for how ROS signals are transduced into cell responses. We will use yeast and worms containing mutant versions targeting specific activities to determine which of Prx's functions require its ability to form disulphide complexes with (or 'peroxiredoxinylate') other proteins, or to come together to form stackable, doughnut-like ring structures. For instance, we will determine whether 'peroxiredoxinylation' or the ability of Prx to form these ring structures is important for Prx's anti-ageing function. This will be important for understanding how the new mechanisms we have identified contribute to some of the beneficial effects of ROS e.g.on ageing. Indeed, we expect this work to fill a significant gap in our current understanding of how ROS effect many biological responses.

所有耗氧生物都​​不可避免地会遇到由多种外源和内源产生的活性氧 (ROS)。 ROS 可能具有极大的破坏性，因此高度保守的机制已经进化来防止这种破坏。在酵母、植物和动物细胞中，这些包括激活保守的信号通路，例如 p38/JNK MAPK 通路，从而启动各种反应，包括增加保护蛋白的水平。然而，ROS 在这些生物体中还具有许多其他信号传导功能；通过对细胞生长、分裂、分化和迁移的影响，促进伤口愈合、根尖生长、癌细胞运动等。此外，尽管氧化损伤是许多疾病和衰老的普遍标志，但活性氧的小幅增加实际上对于饮食限制/线粒体活性变化的长寿作用至关重要。这一发现挑战了 ROS 导致衰老的理论，并引发了当前的观点，即局部 ROS 信号能够预防衰老和与年龄相关的疾病。然而，尽管涉及 ROS 信号的重要生物过程越来越多，但我们对这些 ROS 信号如何实际感知和传输的理解仍然存在很大差距。例如，在大多数情况下，ROS 调节信号蛋白的身份以及 ROS 调节其活性的机制都是未知的。这项工作将解决这些问题，利用酵母（粟酒裂殖酵母）和微小线虫（秀丽隐杆线虫）作为强大的模型系统来研究调节细胞分裂、ROS 反应和衰老的机制的既定优势。申请人之前的工作已经确定了普遍存在的过氧化物反应蛋白 2-Cys 过氧化还原蛋白的重要作用。 (Prx)，促进酵母和蠕虫中的 ROS 信号传导和寿命。重要的是，已发现哺乳动物和植物中的 Prx 具有 ROS 信号传导和抗衰老功能，这说明了在这些模型中进行研究对于识别保守的 ROS 信号传导和延长寿命机制的价值。然而，Prx 的许多 ROS 信号传导和延长寿命功能的潜在机制尚未被揭示。试点数据：我们鉴定 ROS 调节靶蛋白的方法已鉴定出许多与 Prx 形成 ROS 诱导的二硫键复合物的蛋白质。这些 Prx 复合蛋白包括 p38 相关 MAPK 信号通路的多个成分，该通路在协调对环境/代谢刺激的反应中发挥着关键作用。在这里，我们将测试以下假设：这些与 Prx 或“过氧化还原酶化”形成的可逆化学键代表了一种新的蛋白质修饰，可调节这些蛋白质，从而介导 ROS 的许多生理效应。通过确定 Prx 如何调节这些信号蛋白，我们希望为 ROS 信号如何转导为细胞反应建立一个新的范例。我们将使用含有针对特定活性的突变版本的酵母和蠕虫来确定 Prx 的哪些功能需要其能够与其他蛋白质（或“过氧化还原酶”）形成二硫化物复合物，或者聚集在一起形成可堆叠的甜甜圈状环状结构。例如，我们将确定“过氧化还原酶化”或 Prx 形成这些环状结构的能力对于 Prx 的抗衰老功能是否重要。这对于理解我们发现的新机制如何促进 ROS 的一些有益作用（例如衰老）非常重要。事实上，我们希望这项工作能够填补我们目前对 ROS 如何影响许多生物反应的理解的重大空白。