Understanding double-stranded RNA recognition in human cells

项目总结 对双链RNA(DsRNA)结构的特异性识别是关键生物学基础 从发育到抗病毒免疫反应的过程，并涉及一系列dsRNA- 结合蛋白。生化和结构研究描绘了这些蛋白质是如何相互作用的 然而，对于模型配体，他们在细胞中遇到的dsRNA要复杂得多。此外，几乎没有 已知细胞如何调控dsRNA识别。我实验室的目标是了解 DsRNA结合蛋白与细胞中的天然dsRNA相互作用，连接 DsRNA识别对细胞dsRNA的识别和调控。在未来五年，我们将 重点研究microRNA(MiRNA)生物发生中的dsRNA识别和先天性免疫传感。 在miRNA生物发生过程中，微处理器识别并切割发夹状结构 长转录本称为初级miRNAs(pri-miRNAs)。我之前的研究建立了一个统一的模型 发现一个最佳的miRNA发夹可以增强一个人Pri-miRNA的切割 同一转录本上的次优miRNA发夹--称为簇辅助。因为几乎 40%的人类miRNAs以簇的形式存在，其中许多与疾病有关，并受到 簇辅助，我们建议剖析miRNA中的这一基本调控机制 使用生化、单分子和结构方法的生物发生。双链RNA的识别 通过RIG-I和MDA5等先天免疫感受器启动抗病毒反应。最新研究 表明内源性dsRNA也可以激活这些感受器，有时会导致 自身炎症性和自身免疫性疾病。因此，对自身dsRNA的识别需要 受到修饰、降解或屏蔽内源性dsRNA的蛋白质的限制。建立在我们的 在dsRNA识别和处理方面的专业知识，我们将1)开发新的生化方法来 鉴定先天免疫感受器的dsrna配体；2)开发新的遗传筛选方法 目的：确定先天免疫中限制自身dsRNA感知的因素。这些研究将结合在一起 提供关于细胞dsRNA是如何被感知和调节的至关重要的见解，具有治疗性 对癌症、自身免疫和传染病的影响。

PROJECT SUMMARY Specific recognition of double-stranded RNA (dsRNA) structures underlies key biological processes from development to antiviral immune responses, and involves a host of dsRNA- binding proteins. Biochemical and structural studies have delineated how these proteins interact with model ligands, yet dsRNAs that they encounter in cells are far more complex. Moreover, little is known about how cells regulate dsRNA recognition. The goal of my lab is to understand how dsRNA-binding proteins interact with natural dsRNAs in cells, connecting biochemical models of dsRNA recognition to cellular dsRNA recognition and regulation. In the next five years, we will focus on dsRNA recognition in microRNA (miRNA) biogenesis and innate immune sensing. During miRNA biogenesis, Microprocessor recognizes and cleaves hairpin-like structures from long transcripts called primary miRNAs (pri-miRNAs). My previous research built a unifying model of human pri-miRNA and discovered that an optimal miRNA hairpin enhances the cleavage of a suboptimal miRNA hairpin on the same transcript—known as cluster assistance. Because nearly 40% of human miRNAs reside in clusters, with many implicated in diseases and influenced by cluster assistance, we propose to dissect this fundamental regulatory mechanism in miRNA biogenesis using biochemical, single-molecule, and structural approaches. Recognition of dsRNA by innate immune sensors such as RIG-I and MDA5 initiates antiviral responses. Recent studies show that endogenous dsRNAs can also activate these sensors, sometimes resulting in autoinflammatory and autoimmune diseases. The recognition of self dsRNAs therefore needs to be restricted by proteins that modify, degrade or shield endogenous dsRNAs. Building on our expertise in dsRNA recognition and processing, we will 1) develop new biochemical methods to identify dsRNA ligands of innate immune sensors, and 2) develop new genetic screen methods to identify factors that restrict self dsRNA sensing in innate immunity. Together these studies will provide crucial insights into how cellular dsRNAs are sensed and regulated, with therapeutic implications for cancer, autoimmune and infectious diseases.