Structural basis for RIG-I and MDA-5 mediated antiviral response

我们研究了RIG-I样蛋白的激活、调节和抑制的结构和生化机制， 解旋酶在抗病毒干扰素反应中的作用。RIG-I和相关的MDA 5蛋白检测病毒RNA， 启动信号转导级联以刺激先天免疫。病毒对抗自身的分子基础 RIG-I和MDA 5对RNA的分化尚不清楚，但对于理解RNA的内在分化具有重要意义。 我们细胞的抗病毒功能。我们结合了X射线晶体学，小角X射线散射 和生物化学技术来了解RIG-I如何识别病毒RNA模式的关键原理， RIG-I的ATP结合和水解用于模式识别过程，最后用于病毒如何 蛋白质抑制剂干扰模式识别和激活。基于现有的X射线衍射晶体 我们的目的是在第一个目的中推导出RIG-1的解旋酶结构域的结构。该结构将指导 通过病毒模式分析RIG-I的活化机制。我们将致力于从分子水平 ATP酶识别5'三磷酸RNA以及双链RNA的决定簇， RIG-I的调节域。我们将讨论RIG-I的调节结构域以及ATP酶结构域如何 是机械地联系在一起的，并测试RIG-I将几种模式整合成一个活跃的“信号”的假设 关于”构造。然后，我们将致力于推导出这种“信号”的详细分子和机制图 关于“使用多学科和协作方法构建RIG-I”。该方法将包括 ATP依赖性模式识别和RIG-I翻译后修饰之间的相互联系，我们将 解决这些翻译后修饰是否表现出“信号开启”构象。最后我们将 旨在揭示病毒如何通过使用针对MDA 5的蛋白质抑制剂来抵消MDA 5信号传导。 总之，预期的结果将促进我们对特定和校对模式的理解 RIG-I样解旋酶在分子机制和原子水平上识别病毒RNA。

We address the structural and biochemical mechanisms of activation, regulation and inhibition of RIG-I like helicases in the antiviral interferon response. RIG-I and the related MDA5 protein detect viral RNA and initiate a signal transduction cascade to stimulate innate immunity. The molecular basis for virus versus self RNA differentiation by RIG-I and MDA5 is not understood, but of central importance to understand intrinsic antiviral functions of our cells. We use a combination of X-ray crystallography, small angle X-ray scattering and biochemical techniques to understand key principles of how RIG-I recognizes viral RNA patterns, how ATP binding and hydrolysis by RIG-I is used in the process of pattern recognition and finally, how viral protein inhibitors interfere with pattern recognition and activation. Based on existing, X-ray diffracting crystals we aim at deriving in the first aim a structure of the helicase domain of RIG-I. This structure will guide the analysis of the mechanism of activation of RIG-I by viral patterns. We will aim at deriving molecular determinants for the recognition of 5' triphosphate RNA as well as double stranded RNA by the ATPase and regulatory domains of RIG-I. We will address how regulatory domains as well as ATPase domain of RIG-I are mechanistically linked and test the hypothesis that RIG-I integrates several patterns into an active "signal on" conformation. We will then aim at deriving a detailed molecular and mechanistic picture of this "signal on" conformation of RIG-I using a multidisciplinary and collaborative approach. This apprach will include the interlink between ATP dependent pattern recognition and posttranslational modification of RIG-I and we will address whether these posttranslational modifications manifest the "signal on" conformation. Finally, we will aim at revealing how viruses counteract MDA5 signalling by using a proteinaceous inhibitor against MDA5. All in all, the expected outcome will advance our understanding of the specific and proofread pattern recognition of viral RNA by RIG-I like helicases at the molecular mechanistic and atomic level.