How does the cell distinguish between coding and non-coding RNAs in the cytoplasm?

神经退行性变是神经元功能的进行性丧失，通常是基因表达错误调节的结果。为了细胞的正常功能，需要准确地表达遗传密码。这依赖于复制一种名为核糖核酸(RNA)的遗传物质，它会移动到细胞中需要它的地方。每个RNA都受到许多调节其活性的蛋白质因子的约束。RNA-蛋白质(RNP)相互作用的中断对细胞的健康非常有害。扰乱RNPs的突变会导致许多人类疾病，包括脊髓性肌萎缩症。为了更好地了解这些疾病，必须扩大我们对RNA和蛋白质如何相互作用的了解。基因的RNA拷贝可以被核糖体和蛋白质破译，或者RNA本身具有活性而不被破译。我们称这些未解码的RNA为非编码的。被解码(翻译)成蛋白质的RNA就是编码RNA。对于细胞来说，识别哪些RNA应该解码，哪些不应该解码是至关重要的。我们目前的理解是，这两种类型的RNA看起来非常相似。许多非编码RNA存在于神经元中，其水平的变化可导致神经细胞失去功能，最终导致神经疾病，如阿尔茨海默病。因此，重要的是要了解这些非编码RNA在做什么。这个项目将展示哪些RNA在人类神经元中编码和非编码。我假设，有特定的蛋白质因子结合到编码RNA上，以标记它们进行翻译，而其他蛋白质则标记非编码RNA进行其他活动。我将验证这一假设，找出哪些蛋白质起到区分编码和非编码RNA的作用，并发现破坏这些RNA-蛋白质复合体的生物学效应。在这项研究中，我将使用我参与开发的新的测序技术来确定哪些RNA是非编码的，哪些是在人类神经元中编码的。一旦我们知道了哪些是哪些，我将从细胞中分离出编码和非编码RNA的例子，并寻找它们结合的蛋白质的差异。我建议在果蝇S2组织培养细胞和培养的人类神经元中进行非编码和编码RNPs的纯化。为了证明这些RNPs的生物学重要性，我将使用遗传工具并创造苍蝇品系；对RNPs的干扰将在发育中的果蝇中进行评估。我将在模式生物果蝇(果蝇)和培养的人类神经元上进行实验。结合这两个模型，我将观察细胞用来区分编码和非编码RNA的机制是否在苍蝇和人类之间保守。果蝇是评估破坏非编码RNA的生物影响的理想选择，因为有广泛的遗传工具可用。识别人类神经元中哪些是编码的RNAs，哪些是非编码的RNAs是至关重要的，因为我们识别的RNPs可能对神经元功能很重要。鉴定神经元中的细胞质非编码RNA将有助于我们进一步理解神经元中基因表达的错误调控如何导致神经系统疾病，例如神经规格降低。这项工作将揭开细胞如何区分编码和非编码RNA的重要机制理解，这将促进我们对神经疾病的分子基础的理解。

Neurodegeneration is the progressive loss of function in neurons and is frequently the result of mis-regulation of gene expression. For proper cell function the genetic code needs to be expressed accurately. This relies upon making a copy of the genetic material termed ribonucleic acid (RNA) that moves to the place in the cell where it is needed. Each RNA is bound by a number of protein factors that regulate its activity. Disruptions to RNA-protein (RNP) interactions are highly detrimental to the cell's health. Mutations that upset RNPs can lead to many human diseases including spinal muscular atrophy. To understand such diseases better it is essential to expand our knowledge of how RNAs and proteins interact. The RNA copy of the gene can either be decoded by the ribosome and a protein made, or the RNA has activity itself without being decoded. We term these RNA that are not decoded, non-coding. The RNAs that are decoded (translated) into protein are coding RNAs. It is essential for the cell to recognise which RNAs should be decoded and which should not. Our current understanding is that these two types of RNA look very much alike. Many non-coding RNAs are present in neurons and changes in their levels can lead to neuronal cells losing their function, ultimately resulting neurological conditions e.g. Alzheimer's disease. It is therefore important to understand what these non-coding RNAs are doing. This project will demonstrate which RNAs are coding and non-coding in human neurons. I hypothesise that there are specific protein factors that bind to coding RNAs to mark them for translation and other proteins that mark non-coding RNAs for other activities. I will test this hypothesis and find out which proteins act to distinguish coding and non-coding RNAs, and to discover the biological effect of disrupting these RNA-protein complexes. For this study, I will use novel sequencing techniques, which I contributed to the development of, to determine which RNAs are non-coding and which are coding in human neurons. Once we know which are which, I will isolate examples of coding and non-coding RNA from cells and look for differences in the proteins that they bind. I propose to perform purification of non-coding and coding RNPs in both Drosophila S2 tissue culture cells and cultured human neurons. To demonstrate the biological importance of these RNPs, I will use genetic tools and create fly strains; disruptions to the RNPs will be assessed in the developing fruit fly. I will execute experiments both in the model organism, the fruit fly (Drosophila melanogaster) and cultured human neurons. Combining these two models I will look to see if the mechanisms used by cells to differentiate coding and non-coding RNAs are conserved between flies and humans. Fruit flies are ideal for assessing the biological impact of disrupting non-coding RNAs because extensive genetic tools are available. Identifying which RNAs are coding and which are non-coding in human neurons is essential because the RNPs we identify could be important for neuronal function. Characterising cytoplasmic non-coding RNAs in neurons will help further our understanding of how mis-regulation of gene expression in neurons can result in neurological conditions e.g. reduced neural specification. This work will unlock important mechanistic understanding of how cells distinguish between coding and non-coding RNAs, which will advance our understanding of the molecular basis of neurological conditions.