Department of Center Laboratory, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510700, China.
Fish Shellfish Immunol. 2019 Mar;86:474-479. doi: 10.1016/j.fsi.2018.11.070. Epub 2018 Nov 30.
RIG-I-like receptors (RLRs) play a key role in antiviral and inflammatory responses. Increasing evidence indicates that ubiquitination is crucial for regulation of RIG-I signaling pathway. Several ubiquitin ligases were reported to be involved in RIG-I-mediated signal transduction. In the present study, we demonstrated zebrafish RING finger protein 135 (zbRNF135) was a critical player in the regulation of RIG-I signaling pathway. zbRNF135 mRNA was widely expressed in different tissues of zebrafish. The expression of zbRNF135 was up-regulated post poly(I:C) treatment in vivo and in vitro. Furthermore, the expression profiles of RIG-I signaling pathway related genes (LGP2, MDA5, RIG-I, MAVS, TRAF3, IRF3 and IRF7), together with its downstream molecules (IFN1, ISG15, Mx and PKR), were up-regulated by overexpression of zbRNF135 in ZF4 cells. Luciferase and ubiquitination assays revealed that overexpression of zbRNF135 facilitated zebrafish RIG-I (zbRIG-I)-mediated IFN1 promoter activation by mediating K63-linked ubiquitination of zbRIG-I. The co-immunoprecipitation assay showed that zbRNF135 specifically interacted with zbRIG-I. Our study indicated that zbRNF135 participated in innate immune response through modulating RIG-I signaling pathway.
RLR 样受体（RLRs）在抗病毒和炎症反应中发挥关键作用。越来越多的证据表明，泛素化对于 RIG-I 信号通路的调节至关重要。已有报道称几种泛素连接酶参与 RIG-I 介导的信号转导。在本研究中，我们证实 zebrafish RING finger protein 135（zbRNF135）是 RIG-I 信号通路调节的关键因子。zbRNF135 mRNA 在斑马鱼不同组织中广泛表达。zbRNF135 在体内和体外经 poly(I:C)处理后表达上调。此外，RIG-I 信号通路相关基因（LGP2、MDA5、RIG-I、MAVS、TRAF3、IRF3 和 IRF7）及其下游分子（IFN1、ISG15、Mx 和 PKR）的表达谱在 ZF4 细胞中 zbRNF135 的过表达下上调。荧光素酶和泛素化测定表明，zbRNF135 的过表达通过介导 zbRIG-I 的 K63 连接泛素化促进了 zebrafish RIG-I（zbRIG-I）介导的 IFN1 启动子激活。共免疫沉淀试验表明，zbRNF135 与 zbRIG-I 特异性相互作用。我们的研究表明，zbRNF135 通过调节 RIG-I 信号通路参与先天免疫反应。
