Biophysics of Regulatory RNAs and RNPs

项目摘要 非编码RNA是真核生物中多种生物过程的关键调节因子。microRNA是一个家族， 以序列依赖性方式在转录后调节基因表达的小的非编码RNA。 大约1,000种人类microRNA似乎控制着超过一半的人类基因组的表达。 信使RNA。偏离稳态microRNA表达水平，降低或增强 这些基因表达与癌症、糖尿病、心脏病和神经退行性疾病等有关。到 为了维持适当的microRNA表达水平，真核细胞必须严格控制微RNA的酶促加工， 主要和前体microRNA元件。然而，这种严格调控背后的分子决定因素 microRNA的生物合成机制尚未完全了解。在这个提议中，我们将探索顺式（RNA结构）和 反式（蛋白质结合伴侣）调节microRNA生物发生。在研究领域1中，我们将探索 let-7 microRNA家族成员的转录后调控。处理近似 let-7 microRNA的一半由蛋白质伴侣Lin 28介导。这个家庭的其他成员是 受其他通常未知的因素影响。我们将确定RNA修饰的程度，RNA 结构和RNA动力学可以作为调节触发器来控制这些其他家族的加工 成员在研究领域2中，我们将研究oncomiR-1的差异加工， 在许多癌症中富集的microRNA。我们将在细胞内进行化学探测研究， 细胞蛋白质，并阐明了控制亚结构域加工的结构开关。我们的长期目标 是确定单独的和与调节蛋白复合的oncomiR-1的三级结构。总的来说， 这些研究将有助于阐明高度调节的生产的分子决定因素， microRNAs。相对于蛋白质，RNA结构仍然是不确定的，导致我们的研究中的不对称性。 对RNA折叠和功能的机械理解。我们希望， 在这些研究中开发的将广泛适用于其他调控RNA和蛋白质-RNA的研究 配合物这种增强的结构洞察力将告知RNA结构如何直接调节生物学特性。 活性，并将为开发新的RNA靶向治疗方法铺平道路。

Project Summary Non-coding RNAs are key regulators of diverse biological processes in eukaryotes. MicroRNAs are a family of small non-coding RNAs that post-transcriptionally regulate gene expression in a sequence-dependent manner. Approximately 1,000 human microRNAs appear to control the expression of more than half of all human messenger RNAs. Deviations from homeostatic microRNA expression levels, either reduced or enhanced expression, have been linked to cancers, diabetes, heart and neurodegenerative diseases, among others. To maintain proper microRNA expression levels, eukaryotic cells must tightly control the enzymatic processing of primary and precursor microRNA elements. However, the molecular determinants underlying this strict regulation of microRNA biogenesis are not fully understood. In this proposal we will explore both cis (RNA structure) and trans (protein binding partners) regulators of microRNAs biogenesis. In Research Area 1, we will explore the post-transcriptional regulation of members of the let-7 family of microRNAs. The processing of approximately half of the let-7 microRNAs is mediated by a protein partner, Lin28. The other members of this family are regulated by other, often unknown factors. We will determine the extent to which RNA modification, RNA structure, and RNA dynamics can serve as regulatory triggers to control the processing of these other family members. In Research Area 2, we will examine the differential processing of oncomiR-1, a polycistronic primary microRNA that is enriched in many cancers. We will conduct in cell chemical probing studies, identify associated cellular proteins, and elucidate a structural switch that controls processing of a subdomain. Our long-term goal is to determine the tertiary structure of oncomiR-1 alone and in complex with regulatory proteins. Collectively, these studies will help elucidate the molecular determinants underlying the highly-regulated production of microRNAs. RNA structures remain underdetermined relative to proteins, leading to an asymmetry in our mechanistic understanding of RNA folding and function. We expect that the methodology and approach developed in these studies will be broadly applicable to studies of other regulatory RNAs and protein-RNA complexes. This enhanced structural insight will inform on how RNA structure can directly regulate biological activity and will pave the way for the development of novel RNA-targeted therapeutics.