RNA binding activates RIG-I by releasing an autorepressed signaling domain
RNA binding activates RIG-I by releasing an autorepressed signaling domain
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DOI：
10.1126/sciadv.aax3641
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发表时间：
2019-10-01
期刊：
影响因子：
13.6
通讯作者：
Pyle, A. M.
中科院分区：
文献类型：
--
作者：
Dickey, T. H.;Song, B.;Pyle, A. M.
视黄酸诱导基因I （RIG-I）先天免疫受体是一个重要的免疫治疗靶点，但我们缺乏监测其体外激活的物理基础的方法。我们认识上的这一差距导致了对rig - 1激活机制的困惑，以及发现激动剂和拮抗剂的困难。因此，我们创建了一种新的基于荧光共振能量转移的方法，利用蛋白质的双位点特异性荧光标记来测量RIG-I的体外激活。这种方法使我们能够测量在RIG-I激活的第一步释放信号域的构象变化，从而有可能理解刺激配体的作用。我们发现仅RNA就足以使信号域脱出，脱出是可逆的，三磷酸腺苷在这一过程中起次要作用。这些发现有助于解释自身免疫性疾病中的RIG-I功能障碍，并为设计靶向RIG-I的治疗方法提供信息。
The retinoic acid-inducible gene I (RIG-I) innate immune receptor is an important immunotherapeutic target, but we lack approaches for monitoring the physical basis for its activation in vitro.This gap in our understanding has led to confusion about mechanisms of RIG-I activation and difficulty discovering agonists and antagonists. We therefore created a novel fluorescence resonance energy transfer-based method for measuring RIG-I activation in vitro using dual site-specific fluorescent labeling of the protein. This approach enables us to measure the conformational change that releases the signaling domain during the first step of RIG-I activation, making it possible to understand the role of stimulatory ligands. We have found that RNA alone is sufficient to eject the signaling domain, ejection is reversible, and adenosine triphosphate plays but a minor role in this process. These findings help explain RIG-I dysfunction in autoimmune disease, and they inform the design of therapeutics targeting RIG-I.