Song Xuan, Zhang Zijian, Wang Sheng, Li Haoyang, Zuo Hongliang, Xu Xiaopeng, Weng Shaoping, He Jianguo, Li Chaozheng
MOE Key Laboratory of Aquatic Product Safety, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China.
MOE Key Laboratory of Aquatic Product Safety, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Provice Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, PR China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, PR China.
Fish Shellfish Immunol. 2015 Jun;44(2):662-73. doi: 10.1016/j.fsi.2015.03.031. Epub 2015 Apr 1.
The JAK/STAT signaling pathways are conserved in evolution and mediate diversity immune responses to virus infection. In the present study, a Janus kinase (designated as LvJAK) gene was cloned and characterized from Litopenaeus vannamei. LvJAK contained the characteristic JAK homology domain (JH domain) from JH1 to JH7 and showed 19% identity (34% similarity) and 21% identity (35% similarity) to Drosophila Hopscotch protein and Human JAK2 protein, respectively. The mRNA of LvJAK was highly expressed in hepatopancreas of L. vannamei and its expression level was prominently upregulated after the stimulation of Poly (I:C) and white spot syndrome virus (WSSV) challenges. There were 10 putative STAT binding motifs in the promoter region of LvJAK, and it could be regulated by LvJAK self or (and) LvSTAT, suggesting that LvJAK is the JAK/STAT pathway target gene and could function as a positive regulator to form a positive feedback loop. In addition, the silencing of LvJAK caused higher mortality rate and virus load, suggesting that LvJAK could play an important role in defense against WSSV. This is the first report about the complete set of JAK/STAT proteins in shrimp and the results provide the evidence of the positive feedback loop mediated by JAK protein present in the JAK/STAT pathway in invertebrates.
JAK/STAT信号通路在进化过程中保守，并介导对病毒感染的多种免疫反应。在本研究中，从凡纳滨对虾中克隆并鉴定了一个Janus激酶（命名为LvJAK）基因。LvJAK包含从JH1到JH7的特征性JAK同源结构域（JH结构域），与果蝇Hopscotch蛋白和人类JAK2蛋白的同一性分别为19%（相似性为34%）和21%（相似性为35%）。LvJAK的mRNA在凡纳滨对虾的肝胰腺中高表达，在Poly（I:C）刺激和白斑综合征病毒（WSSV）攻击后其表达水平显著上调。LvJAK启动子区域有10个假定的STAT结合基序，它可能受LvJAK自身或（和）LvSTAT调控，这表明LvJAK是JAK/STAT通路的靶基因，可作为正调节因子形成正反馈环。此外，LvJAK的沉默导致更高的死亡率和病毒载量，表明LvJAK在抵御WSSV中可能发挥重要作用。这是关于对虾中JAK/STAT蛋白全套的首次报道，结果为无脊椎动物JAK/STAT通路中存在的由JAK蛋白介导的正反馈环提供了证据。
