ATP hydrolysis by the viral RNA sensor RIG-I prevents unintentional recognition of self-RNA
ATP hydrolysis by the viral RNA sensor RIG-I prevents unintentional recognition of self-RNA
复制标题
DOI：
10.7554/elife.10859
复制
发表时间：
2015-11-26
期刊：
影响因子：
7.7
通讯作者：
Hopfner, Karl-Peter
中科院分区：
文献类型：
--
作者：
Laessig, Charlotte;Matheisl, Sarah;Hopfner, Karl-Peter
胞质抗病毒先天免疫传感器RIG-I通过一种尚未完全了解的机制将含有病毒双链(DS)RNA的5‘-三磷酸或二磷酸RNA与自身RNA区分开来，该机制涉及RIG-I的RNA转位酶结构域对ATP的水解。最近发现的ATPase基序突变可能导致多系统疾病Singleton-Merten综合征(SMS)和干扰素水平增加，这表明RIG-I信号转导错误。在这里，我们报告了短信突变的表型，这是一种允许结合三磷酸腺苷但阻止水解性的突变。ATPase缺陷的RIG-I通过内源RNA构成信号，并与自身RNA共同纯化，即使是从病毒感染的细胞中也是如此。生化研究和冷冻电子显微镜证实，60S的核糖体扩展片段是一种主要的自身RNA，它稳定地与ATPase缺陷的RIG-I结合。ATP水解取代了野生型RIG-I从这个自我RNA，但不从5‘三磷酸dsRNA。我们的结果表明，ATP水解阻止了对自身RNA的识别，并表明SMS突变通过延长RNA结合时间导致了无意的信号传递。
The cytosolic antiviral innate immune sensor RIG-I distinguishes 5' tri- or diphosphate containing viral double-stranded (ds) RNA from self-RNA by an incompletely understood mechanism that involves ATP hydrolysis by RIG-I's RNA translocase domain. Recently discovered mutations in ATPase motifs can lead to the multi-system disorder Singleton-Merten Syndrome (SMS) and increased interferon levels, suggesting misregulated signaling by RIG-I. Here we report that SMS mutations phenocopy a mutation that allows ATP binding but prevents hydrolysis. ATPase deficient RIG-I constitutively signals through endogenous RNA and co-purifies with self-RNA even from virus infected cells. Biochemical studies and cryo-electron microscopy identify a 60S ribosomal expansion segment as a dominant self-RNA that is stably bound by ATPase deficient RIG-I. ATP hydrolysis displaces wild-type RIG-I from this self-RNA but not from 5' triphosphate dsRNA. Our results indicate that ATP-hydrolysis prevents recognition of self-RNA and suggest that SMS mutations lead to unintentional signaling through prolonged RNA binding.