Guo Minglan, Wei Jingguang, Zhou Yongcan, Qin Qiwei
Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China.
Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, PR China.
Dev Comp Immunol. 2016 Dec;65:169-181. doi: 10.1016/j.dci.2016.06.009. Epub 2016 Jul 13.
C-Jun N-terminal kinases (JNKs), a subgroup of serine-threonine protein kinases that activated by phosphorylation, are involve in physiological and pathophysiological processes. JNK3 is one of JNK proteins involved in JNK3 signaling transduction. In the present study, two JNK3 isoforms, Ec-JNK3 X1 and Ec-JNK3 X2, were cloned from orange-spotted grouper, Epinephelus coioides. Both Ec-JNK3 X1 and Ec-JNK3 X2 were mainly expressed in liver, gill, skin, brain and muscle of juvenile grouper. The relative expression of Ec-JNK3 X2 mRNA was much higher in muscle and gill than that of Ec-JNK3 X1. Isoform-specific immune response to challenges was revealed by the expression profiles in vivo. Immunofluorescence staining indicated that JNK3 was localized in the cytoplasm of grouper spleen (GS) cells and shown immune response to SGIV infection in vitro. Over-expressing Ec-JNK3 X1 and/or Ec-JNK3 X2 inhibited the SGIV infection and replication and the SGIV-induced apoptosis. To achieve the antiviral and anti-apoptosis activities, JNK3 promoted the activation of genes ISRE and type I IFN in the antiviral IFN signaling pathway, and inhibited the activation of transcription factors NF-κB and p53 relating to apoptosis, respectively. Ec-JNK3 X2 showed stronger activities in antivirus and anti-apoptosis than that of Ec-JNK3 X1. Our results not only define the characterization of JNK3 but also reveal new immune functions and the molecular mechanisms of JNK3 on iridoviruses infection and the virus-induced apoptosis.
c-Jun氨基末端激酶（JNKs）是丝氨酸-苏氨酸蛋白激酶的一个亚组，通过磷酸化激活，参与生理和病理生理过程。JNK3是参与JNK3信号转导的JNK蛋白之一。在本研究中，从斜带石斑鱼（Epinephelus coioides）中克隆了两种JNK3亚型，即Ec-JNK3 X1和Ec-JNK3 X2。Ec-JNK3 X1和Ec-JNK3 X2主要在幼年石斑鱼的肝脏、鳃、皮肤、脑和肌肉中表达。Ec-JNK3 X2 mRNA在肌肉和鳃中的相对表达量远高于Ec-JNK3 X1。体内表达谱揭示了亚型特异性的免疫应答。免疫荧光染色表明，JNK3定位于石斑鱼脾脏（GS）细胞的细胞质中，并在体外对SGIV感染表现出免疫应答。过表达Ec-JNK3 X1和/或Ec-JNK3 X2可抑制SGIV的感染和复制以及SGIV诱导的凋亡。为实现抗病毒和抗凋亡活性，JNK3分别促进抗病毒IFN信号通路中ISRE和I型IFN基因的激活，并抑制与凋亡相关的转录因子NF-κB和p53的激活。Ec-JNK3 X2在抗病毒和抗凋亡方面表现出比Ec-JNK3 X1更强的活性。我们的研究结果不仅明确了JNK3的特性，还揭示了JNK3对虹彩病毒感染和病毒诱导凋亡的新免疫功能及分子机制。
