CAREER:RNA conformational dynamics in the regulation of microRNA biogenesis

RNA是三种主要的生物大分子之一，对所有已知的生命形式都至关重要（另外两种是DNA和蛋白质）。虽然多年来人们认为RNA在细胞中只有三种主要作用，但现在人们知道，RNA的作用要广泛得多，也有趣得多。MicroRNAs是一类进化上保守的小的非编码rna。它们调节着60%以上的蛋白质基因，在所有生物过程中起着关键的调节作用。由于它们在基因调控中的核心作用，microrna本身受到严格调控。该项目将研究两种不同的microrna的构象动力学如何控制特定蛋白质辅助因子的识别以调节其加工途径。该项目的结果将为这些重要基因调控的调控提供重要的机制见解。该项目将扩展RNA-蛋白相互作用的现有知识，加深对RNA构象动力学在生物学中的功能作用的理解。该项目将整合研究和教育，以支持本科生和研究生以及代表性不足的高中生在STEM原则方面的科学培训和教育。将为高中生开发一个以年度科学论坛和暑期研究实习为特色的校园项目。在当地高中开展外展活动，开发创新的STEM教学方法。MicroRNA的生物发生是一个动态调控的过程。在典型的生物发生途径中，初级和前体microrna的顶端环区域起着关键的调控作用。然而，这些RNA元件具有高度的柔韧性，无法通过传统的结构生物学技术进行高分辨率的结构研究。包括PI在内的核酸核磁共振波谱学的最新发展，为表征高度灵活rna的复杂构象动力学和转变开辟了新的途径。该项目将进一步发展和应用这些核磁共振方法，以及生化和计算方法，以了解通过特定rna -蛋白质相互作用调节microRNA生物发生的机制。以microRNA-1和microRNA-21为模型系统，本项目将可视化microRNA前体中的RNA构象动力学，并阐明蛋白质辅助因子在microRNA生物发生中的调节作用的结构和分子基础。结果将用于评估本项目的中心假设，即初级和前体microrna的顶端环区域动态采样不同的构象以识别蛋白质，并且这些动态可能被调整以影响蛋白质- rna相互作用以指导生物发生途径。

RNA is one of the three major biological macromolecules that are essential for all known forms of life (along with DNA and proteins). While for many years RNA was believed to have only three major roles in the cell, it is now known that the roles adopted by RNA are much broader and interesting. MicroRNAs are a class of evolutionarily conserved, small noncoding RNAs. They regulate more than 60% of all protein genes, and serve as critical regulators in all biological processes. Due to their central role in gene regulation, microRNAs themselves are tightly regulated. This project will investigate how conformational dynamics in two distinct microRNAs control recognition of specific protein cofactors to regulate their processing pathways. Results of this project will provide important mechanistic insights into the regulation of these essential gene regulators. This project will expand the current knowledge of RNA-protein interactions and deepen the understanding of the functional roles of RNA conformational dynamics in biology. Research and education will be integrated in this project to support scientific training and education of undergraduate and graduate students as well as underrepresented high-school students in STEM principles. An on-campus program will be developed for high-school students featuring an annual scientific forum and summer research internships. Outreach activities to local high schools will be carried out to develop innovative STEM teaching approaches.MicroRNA biogenesis is a dynamic and regulated process. During the canonical biogenesis pathway, the apical-loop regions of primary and precursor microRNAs play critical regulatory roles. However, these RNA elements are highly flexible and have evaded high-resolution structural study by conventional structural biology techniques. Recent developments in nucleic acid NMR spectroscopy, including those from the PI, have opened new avenues to characterize complex conformational dynamics and transitions in highly flexible RNAs. This project will further develop and apply these NMR methods, together with biochemical and computational approaches, to understand the mechanism by which microRNA biogenesis is regulated via specific RNA-protein interactions. Using microRNA-1 and microRNA-21 as model systems, this project will visualize RNA conformational dynamics in microRNA precursors and elucidate the structural and molecular basis for the regulatory roles of protein cofactors in microRNA biogenesis. Results will be used to evaluate the central hypothesis of this project that the apical-loop regions of primary and precursor microRNAs dynamically sample distinct conformations for protein recognition and that these dynamics may be tuned to affect protein-RNA interactions to direct biogenesis pathways.