Dissecting the roles of ubiquitin in translation control

项目摘要 席尔瓦实验室的长期目标是确定蛋白质泛素化的分子机制 控制蛋白质合成和细胞存活，以应对氧化应激。不断地产生氧化剂 通过各种内源和外源，翻译是一个基本的细胞过程，必须 当细胞受到氧化剂的挑战时，进行精细的重新编程。未能对蛋白质表达进行重新编程， 受损蛋白质的堆积和氧化剂管理不善是导致 各种神经退行性疾病、肿瘤进展和衰老过程。了解和 调节压力防御途径，如翻译，将提供新的工具来促进更健康的生活和 与疾病作斗争。在真核生物中，多种防御途径受泛素调控。蛋白质泛素化是一种 普遍的翻译后修饰最初被认为是蛋白质降解的分子标记。 我们最近发现了一种多泛素变异体(K63连接)在蛋白质调节中的新作用 氧化应激时的合成。利用分子和蛋白质组学方法，我们的实验室表明，核糖体 是K63泛素的主要靶点，K63泛素是细胞存活所必需的，而特定的酶是 参与核糖体泛素化和去泛素化反应。然而，人们对此的理解仍然有限。 K63泛素如何影响核糖体活性和蛋白质表达程序。这个Mira奖将支持 席尔瓦实验室的研究计划，它将使用大规模、分子和计算的组合 了解K63泛素调控翻译所必需的每一个步骤的方法。这些 步骤包括泛素酶对核糖体的识别，个别泛素位点的修饰，改变 核糖体3D结构，翻译景观的重组，以及泛素化的命运的决定 核糖体。确定调控蛋白质这一基本生物过程的分子机制 合成是增强细胞对压力的抵抗力和重塑我们对基因表达的理解的关键 控制力。这项工作将导致一个既定的独立研究计划，未来的NIH研究奖， 扩大协作网络，并在NIGMS任务范围内进行跨学科研究。

Project Summary The long-term goal of the Silva Lab is to determine the molecular mechanism by which protein ubiquitination controls protein synthesis and cellular survival in response to oxidative stress. Oxidizers are constantly produced by a variety of endogenous and exogenous sources and translation is an essential cellular process that must be finely reprogrammed when cells are challenged with oxidizers. Failure to reprogram protein expression, accumulation of damaged proteins, and inadequate management of oxidizers are the underlying causes of a variety of neurodegenerative diseases, tumor progression, and the process of aging. Understanding and modulating stress defense pathways, such as translation, would provide new tools to promote healthier lives and fight diseases. In eukaryotes, a variety of defense pathways is regulated by ubiquitin. Protein ubiquitination is a prevalent post-translational modification initially characterized as the molecular marker for protein degradation. We have recently identified a new role for a poly-ubiquitin variant (K63-linked) in the regulation of protein synthesis during oxidative stress. Using molecular and proteomics approaches, our lab showed that ribosomes are the main target of K63 ubiquitin, K63 ubiquitin is essential for cellular viability, and that specific enzymes are involved in ribosomal ubiquitination and deubiquitination reactions. However, there is still a limited understanding of how K63 ubiquitin impacts ribosome activity and the protein expression program. This MIRA award will support the Silva Lab program of research, which will use a combination of large-scale, molecular, and computational approaches to understand each one of the steps necessary for regulation of translation by K63 ubiquitin. These steps include recognition of ribosome by ubiquitin enzymes, modification of individual ubiquitin sites, alteration of ribosome 3D structure, reconfiguration of translation landscape, and determination of the fate of ubiquitinated ribosomes. Defining the molecular mechanisms regulating such a fundamental biological process as protein synthesis is key to enhancing cellular resistance to stress and reshaping our understanding of gene expression control. This work will lead to an established and independent research program, future NIH research awards, expanded collaboration network, and interdisciplinary research within the NIGMS mission.