CAREER:RNA conformational dynamics in the regulation of microRNA biogenesis

RNA是已知生命形式所必需的三大生物大分子之一（沿着的还有DNA和蛋白质）。 虽然多年来RNA被认为在细胞中只有三个主要角色，但现在已知RNA所扮演的角色更广泛和有趣。 MicroRNA是一类进化上保守的小的非编码RNA。它们调节所有蛋白质基因的60%以上，并在所有生物过程中充当关键调节剂。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microRNA的构象动力学如何控制特定蛋白质辅因子的识别，以调节其加工途径。该项目的结果将为这些必需基因调节因子的调节提供重要的机制见解。该项目将扩展目前对RNA-蛋白质相互作用的认识，并加深对RNA构象动力学在生物学中的功能作用的理解。研究和教育将被纳入该项目，以支持科学培训和本科生和研究生教育，以及在STEM原则代表性不足的高中学生。将为高中生开发一个校内项目，包括年度科学论坛和夏季研究实习。我们将在当地高中开展外展活动，以开发创新的STEM教学方法。MicroRNA生物合成是一个动态和受调控的过程。在经典的生物发生途径中，初级和前体microRNA的顶环区域起着关键的调节作用。然而，这些RNA元件是高度灵活的，并回避了高分辨率的结构研究，通过传统的结构生物学技术。核酸NMR光谱学的最新进展，包括PI的进展，为表征高度灵活的RNA中复杂的构象动力学和转变开辟了新的途径。该项目将进一步开发和应用这些NMR方法，以及生物化学和计算方法，以了解通过特定的RNA-蛋白质相互作用调节microRNA生物合成的机制。该项目将使用microRNA-1和microRNA-21作为模型系统，可视化microRNA前体中的RNA构象动力学，并阐明蛋白质辅因子在microRNA生物发生中的调节作用的结构和分子基础。结果将用于评估该项目的中心假设，即初级和前体microRNA的顶环区域动态地对蛋白质识别的不同构象进行采样，并且这些动态可以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.