Mechanisms of tiRNA-induced translational control

项目摘要 本提案的目的是确定血管生成素（ANG）诱导的转移RNA（tRNA）是如何衍生的。 小的非编码（snc）RNA重新编程蛋白质翻译，以促进暴露于不利环境中的细胞的存活。 条件我们的中心假设是，ANG诱导的tiRNAs的功能是增强原癌基因的表达。 生长和促存活蛋白，以促进肿瘤发生和防止神经元死亡。这是基于 我们自己的初步数据显示ANG选择性地切割tRNA以产生生物活性片段（即， 使用多种机制抑制翻译起始并诱导应激颗粒组装的tiRNAs。这 需要与翻译调节蛋白YB 1和CNBP相互作用。建议的理由 研究表明，一旦我们知道tiRNAs如何重新编程蛋白质翻译以促进细胞存活， 能够调节这些事件来治疗癌症和神经退行性疾病。我们将测试我们的中央 通过完成三个具体目标的假设：目的1。为了阐明tiRNA介导的 翻译抑制我们的工作假设是不同类型的tiRNAs与核酸结合- 结合蛋白质以靶向翻译起始、延伸和/或再循环机制。AIM 2.以确定 含末端寡鸟嘌呤（TOG）tiRNAs如何调节5 '末端寡嘧啶（TOP） 翻译.我们的工作假设是tiRNA：YB 1和tiRNA：CNBP复合物靶向含有5 'TOP的 转录本编码核糖体蛋白和翻译因子，以调节蛋白质合成， 应力AIM 3.确定G4结构如何调节tiRNA/DNA功能。我们的假设是 tiRNA/DNA组装G-四链体（G4）结构，其对于结合YB 1和CNBP是关键的， G4组装的调节可能是调节其生物活性的一种方式。这些目标将是 通过确定不同类型的tiRNAs抑制翻译的机制， tiRNA核糖核蛋白复合物的组成，以及鉴定tiRNA靶转录物。我们还将 确定tiRNAs如何调节YB 1和CNBP抑制和促进mRNA翻译的能力， 特别强调TOP mRNA调节一般蛋白质翻译。最后，我们将确定 CNBP作为G4分子伴侣调节tiRNAs的结构，并检验Li+- G4结构的介导的破坏可以调节tiRNAs的生物学功能。的贡献 拟议的研究将是确定tiRNAs或其DNA类似物如何促进生长和存活， 参与癌症和神经退行性疾病发病机制的细胞。这一贡献意义重大 因为它为开发预防tiRNA的药理学策略提供了分子基础， 介导的肿瘤生长或促进tiRNA介导的运动神经元存活。拟议的研究是 创新，因为它专注于ANG诱导的tRNA切割的下游效应子，并试图 提供了将这些sncRNA开发成治疗药物所需的机制的证据。

Project Summary The objective of this proposal is to determine how angiogenin (ANG)-induced transfer RNA (tRNA)-derived small non-coding (snc) RNAs reprogram protein translation to promote the survival of cells exposed to adverse conditions. Our central hypothesis is that ANG-induced tiRNAs function to enhance the expression of pro- growth and pro-survival proteins to promote tumorigenesis and prevent neuronal death. This is based upon our own preliminary data showing that ANG selectively cleaves tRNAs to produce bioactive fragments (i.e., tiRNAs) that use multiple mechanisms to inhibit translation initiation and induce stress granule assembly. This requires interactions with translational regulatory proteins YB1 and CNBP. The rationale for the proposed research is that, once we know how tiRNAs re-program protein translation to promote cell survival, we will be able to modulate these events to treat cancer and neurodegenerative disease. We will test our central hypothesis by the completion of three specific aims: AIM 1. To elucidate the scope of tiRNA-mediated translational repression. Our working hypothesis is that distinct classes of tiRNAs bind to the nucleic acid- binding proteins to target translation initiation, elongation, and/or recycling machinery. AIM 2. To determine how terminal oligoguanine (TOG)-containing tiRNAs modulate 5'terminal oligopyrimidine (TOP) translation. Our working hypothesis is that tiRNA:YB1 and tiRNA:CNBP complexes target 5'TOP-containing transcripts that encode ribosomal proteins and translation factors to modulate protein synthesis in response to stress. AIM 3. To determine how G4 structures modulate tiRNA/DNA function. Our working hypothesis is that tiRNA/DNAs assembly G-quadruplex (G4) structures that are critical for binding to YB1 and CNBP and that modulation of G4 assembly may be a way to modulate their biological activities. These aims will be accomplished by determining the mechanism by which different classes of tiRNAs inhibit translation, identifying the composition of tiRNA ribonucleoprotein complexes, and identifying tiRNA target transcripts. We will also determine how tiRNAs modulate the ability of YB1 and CNBP to repress and promote mRNA translation with a special emphasis on TOP mRNAs that regulate general protein translation. Finally, we will determine whether CNBP functions as a G4 chaperone to modulate the structure of tiRNAs and test the hypothesis that Li+- mediated disruption of G4 structures can modulate the biological function of tiRNAs. The contribution of the proposed research will be to determine how tiRNAs, or their DNA analgues, promote the growth and survival of cells involved in the pathogenesis of cancer and neurodegenerative disease. This contribution is significant because it provides a molecular basis for the development of pharmacologic strategies to prevent tiRNA- mediated tumor growth or promote tiRNA-mediated motor neuron survival. The proposed research is innovative because it focuses on the downstream effector of ANG-induced tRNA cleavage and attempts to provide a proof of mechanism needed to develop these sncRNAs into therapeutics.