The role of lysine acetylation of human threonyl-tRNA synthetase

项目摘要 氨酰-tRNA合成酶（aminoacyl-tRNA synthetases，AARS）是蛋白质合成所必需的酶家族， 在调节转录、翻译和RNA剪接中起重要作用。AARS的体细胞突变已经被 在许多人类疾病中发现，使其成为药物开发和医学治疗的有利目标。 除了突变，蛋白质组学研究还鉴定了AARS中的一系列乙酰化赖氨酸残基， 癌细胞，但没有进一步的研究。因此，迫切需要鉴定阿尔斯乙酰化的相关性 癌症的形成。本项目的总体目标是研究一个阿尔斯的赖氨酸乙酰化的作用， 人的苏氨酰-tRNA合成酶（ThrRS）。鉴于细菌中ThrRS的同源物已被证明 由乙酰化调节，假设赖氨酸乙酰化影响人ThrRS功能， 促进癌症形成。为了检验这一假设，提出了三个具体目标。目标1是确定 赖氨酸乙酰化对ThrRS生物化学功能的位点和癌症特异性影响。目的二是证明 乙酰化对ThrRS结构的影响。目的3是确定ThrRS乙酰化对全局的影响， 癌症相关蛋白，即致癌蛋白和肿瘤抑制蛋白在人类中的翻译和翻译 细胞系将对表达乙酰化ThrRS变体的正常人细胞进行致癌转化试验。 进行，以发现ThrRS乙酰化是否是癌症形成的引发剂或癌症的细胞适应 增长这一方案之所以具有创新性，是因为：首先，它将是第一个研究人ThrRS的赖氨酸乙酰化， 并有望鉴定ThrRS相关癌症形成的新机制。其次，为了解决 问题是，用于乙酰化研究的经典谷氨酰胺取代方法并不总是有效的， 在本提案中将采用代码扩展方法， 控制的位点，以产生位点特异性乙酰化的ThrRS变体，这些变体已经在 癌细胞这项拟议中的研究意义重大，因为它将为以下方面的关联提供坚实的证据： ThrRS乙酰化与癌症形成。最后，对ThrRS乙酰化的拟议研究预计将 确定癌症诊断和治疗的新靶点。具体到AREA计划，研究团队为 该项目将主要由本科生组成，包括来自代表性不足群体的本科生。 本提案将采用既有既定方法又有新方法，使项目有希望， 同时加强学生的研究经验。

PROJECT SUMMARY Aminoacyl-tRNA synthetases (AARSs) are a family of essential enzymes for protein synthesis, which also play important roles in regulating transcription, translation, and RNA splicing. Somatic mutations of AARSs have been found in many human diseases, making them favorable targets for drug development and medical therapies. Besides mutation, proteomic studies have also identified a series of acetylated lysine residues in AARSs from cancer cells but without further studies. So there is a critical need to identify the association of AARS acetylation with cancer formation. The overall goal of this project is to study the role of lysine acetylation of one AARS, threonyl-tRNA synthetase (ThrRS) in human. Given that the homologue of ThrRS in bacteria has been shown to be regulated by acetylation, the hypothesis is that lysine acetylation affects human ThrRS functions which facilitates cancer formation. To test this hypothesis, three specific aims are proposed. Aim 1 is to identify the site- and cancer-specific effects of lysine acetylation on ThrRS functions biochemically. Aim 2 is to demonstrate the impacts of acetylation on ThrRS structurally. Aim 3 is to identify the impacts of ThrRS acetylation on global translation and translation of cancer-associated proteins, i.e. oncogenic proteins and tumor suppressor in human cell lines. Oncogenic transformation tests on normal human cells expressing acetylated ThrRS variants will be performed to find whether ThrRS acetylation is an initiator for cancer formation or a cellular adaption for cancer growth. This proposal is innovative because: First, it will be the first to study lysine acetylation of human ThrRS, and is expected to identify novel mechanisms for ThrRS-associated cancer formation. Second, to address the problem that the classic glutamine-substitution method for acetylation studies is not always effective, the genetic code expansion approach will be applied in this proposal to co-translationally incorporate acetyllysine at controlled sites in order to produce site-specifically acetylated ThrRS variants which have been identified in cancer cells. The proposed research is significant because it will provide solid evidence for the association of ThrRS acetylation with cancer formation. Ultimately, the proposed studies on ThrRS acetylation are expected to identify novel targets for cancer diagnosis and treatment. Specific for the AREA program, the research team for this project will be composed primarily of undergraduate students including those from underrepresented groups. Both well-established methods and new approaches will be applied in this proposal to make the project promising, and in the meantime, to strengthen students’ research experiences.