CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China.
Fish Shellfish Immunol. 2018 Apr;75:365-373. doi: 10.1016/j.fsi.2018.02.027. Epub 2018 Feb 15.
The eukaryotic initiation factor 2 alpha subunit (eIF2α) is a key translation regulator that plays an important role in different cellular pressures and stimuli, including virus infection. In the present study, an eIF2α homolog (EceIF2α) from the orange-spotted grouper (Epinephelus coioides) was cloned and its roles during fish viral infection were characterized. EceIF2α encodes a putative protein of 315 amino acid residues, and shares a high degree of similarity with eIF2αs from other species. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that EceIF2α was distributed in all examined tissues. Both of the expression levels of EceIF2α in the spleen and head kidney of E. coioides were up-regulated when challenged with polyinosine-polycytidylic acid (poly[I:C]). EceIF2α was abundantly distributed in both the cytoplasm and nucleus in grouper spleen (GS) cells. Over-expression of EceIF2α improved the expression of red-spotted grouper nervous necrosis virus (RGNNV) genes in GS cells. In addition, EceIF2α depressed the activation of NK-κB and IFN-β. Furthermore, dephosphorylation inhibitor treatment led to a significant decrease of RGNNV gene transcription. Taken together, these results suggest that EceIF2α might be involved in the fish immune response to virus challenge.
真核起始因子 2α 亚基（eIF2α）是一种关键的翻译调节因子，在不同的细胞压力和刺激下发挥重要作用，包括病毒感染。本研究从卵形鲷（Epinephelus coioides）克隆了一个 eIF2α 同源物（EceIF2α），并对其在鱼类病毒感染过程中的作用进行了表征。EceIF2α 编码一个由 315 个氨基酸残基组成的假定蛋白，与其他物种的 eIF2α 具有高度相似性。定量实时聚合酶链反应（qRT-PCR）分析表明，EceIF2α分布在所有检测的组织中。当卵形鲷受到多聚肌苷酸-多聚胞苷酸（poly[I:C]）刺激时，其脾脏和头肾中的 EceIF2α 表达水平均上调。EceIF2α 在卵形鲷脾脏（GS）细胞的细胞质和细胞核中均大量分布。EceIF2α 的过表达可提高 GS 细胞中红鳍东方鲀神经坏死病毒（RGNNV）基因的表达。此外，EceIF2α 抑制了 NK-κB 和 IFN-β 的激活。此外，磷酸酶抑制剂处理导致 RGNNV 基因转录显著减少。综上所述，这些结果表明 EceIF2α 可能参与鱼类对病毒挑战的免疫反应。
