Abstract：
The suppressor of cytokine signaling (SOCS) proteins family have twelve members including eight known mammalian SOCS members (CISH, SOCS1-7) and four new discovery members (SOCS3b, SOCS5b, SOCS8 and SOCS9) that is regarded as a classic feedback inhibitor of cytokine signaling. Although the function of the mammalian SOCS proteins have been well studied, little is known about the roles of SOCS in fish during viral infection. In this study, the molecular characteristics of SOCS9 from orange-spotted grouper (Epinephelus coioides, EcSOCS9) is investigated. The EcSOCS9 protein encoded 543 amino acids with typical SH2 (389-475aa) and SOCS_box (491-527aa), sharing high identities with reported fish SOCS9. EcSOCS9 was expressed in all detected tissues and highly expressed in kidney. After red-spotted grouper nervous necrosis virus (RGNNV) infection, the expression of EcSOCS9 was significantly induced in vitro. Furthermore, EcSOCS9 overexpression enhanced RGNNV replication, promoted virus-induced mitophagy that evidenced by the increased level of LC3-Ⅱ, BCL2, PGAM5 and decreased level of BNIP3 and FUNDC1. Besides, EcSOCS9 overexpression suppressed the expression levels of ATP6, CYB, ND4, ATP level and induced ROS level. The expression levels of interferon (IFN) related factors (IRF1, IRF3, IRF7, P53), inflammatory factors (IL1-β, IL8, TLR2, TNF-α) and IFN-3, ISRE, NF-κB, AP1 activities were also reduced by overexpressing EcSOCS9. These date suggests that EcSOCS9 impacts RGNNV infection through modulating mitophagy, regulating the expression levels of IFN- related and inflammatory factors, which will expand our understanding of fish immune responses during viral infection.
摘要：
细胞因子信号传导抑制因子（SOCS）蛋白家族有12个成员，包括8个已知的哺乳动物SOCS成员（CISH，SOCS1-7)和四个新的发现成员(SOCS3b，SOCS5b,SOCS8和SOCS9），被认为是细胞因子信号传导的经典反馈抑制剂。尽管哺乳动物SOCS蛋白的功能已经得到了很好的研究,人们对SOCS在病毒感染期间在鱼类中的作用知之甚少。在这项研究中,橙色斑点石斑鱼（Epinepheluscoioides，EcSOCS9)进行了调查。EcSOCS9蛋白编码543个氨基酸，具有典型的SH2（389-475aa）和SOCS_box（491-527aa），与报告的鱼类SOCS9共享高身份。EcSOCS9在所有检测到的组织中均有表达，在肾脏中高度表达。红斑石斑鱼神经坏死病毒（RGNNV）感染后，体外显著诱导EcSOCS9的表达。此外，EcSOCS9过表达增强RGNNV复制,促进病毒诱导的线粒体自噬，证明LC3-Ⅱ水平升高，BCL2、PGAM5和BNIP3及FUNDC1程度下降。此外,EcSOCS9过表达抑制ATP6、CYB、ND4、ATP程度与引诱ROS程度有关。干扰素(IFN)相关因子(IRF1、IRF3、IRF7、P53)的表达水平,炎症因子(IL1-β，IL8、TLR2、TNF-α)和IFN-3、ISRE、NF-κB,过表达EcSOCS9也降低了AP1活性。这些数据表明EcSOCS9通过调节线粒体自噬影响RGNNV感染，调节IFN-γ相关因子和炎症因子的表达水平,这将扩大我们对病毒感染期间鱼类免疫反应的理解。
