The role of lysine acetylation of human threonyl-tRNA synthetase

项目总结 氨基酰基-tRNA合成酶(AARs)是蛋白质合成的重要酶家族，在蛋白质合成中也起着重要作用 在调节转录、翻译和RNA剪接方面发挥重要作用。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疗治疗的有利靶点。 除了突变，蛋白质组学研究还在来自中国的AARS中发现了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，迫切需要确定AARS乙酰化的关联 癌症的形成。这个项目的总体目标是研究一种AARS的赖氨酸乙酰化作用， 人苏氨酰-tRNA合成酶(ThrRS)。鉴于ThrRs在细菌中的同源物已经被证明 通过乙酰化来调节，假设赖氨酸乙酰化影响人类ThrRs功能，而ThrRs功能 促进癌症的形成。为了验证这一假设，本文提出了三个具体目标。目标1是确定 赖氨酸乙酰化对ThrRs功能的生化定位和癌症特异性影响。目标2是为了证明 乙酰化对ThrRs结构的影响。目标3是确定ThrRS乙酰化对全球 人类癌症相关蛋白，即癌基因蛋白和肿瘤抑制因子的翻译和翻译 细胞系。对表达乙酰化ThrRS变异体的正常人细胞的致癌转化试验将是 以发现ThrRS乙酰化是否是癌症形成的启动者或癌症的细胞适应 成长。这一建议的创新之处在于：第一，它将首次研究人类ThrRs的赖氨酸乙酰化， 并有望确定ThrRS相关癌症形成的新机制。第二，解决 经典的谷氨酰胺取代法用于乙酰化研究并不总是有效的问题，遗传 在这项建议中，将采用编码扩展的方法将乙酰赖氨酸与 受控位点，以产生位点特异性乙酰化ThrRs变体，已在 癌细胞。这项拟议的研究具有重要意义，因为它将为 ThrRS乙酰化与肿瘤的形成。最终，拟议的ThrRS乙酰化研究有望 确定癌症诊断和治疗的新靶点。具体到地区计划，研究小组针对 这个项目将主要由本科生组成，包括那些来自代表性不足的群体的学生。 这项提案将采用成熟的方法和新的方法，使项目充满希望， 同时，加强学生的研究体验。

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.