ALBERT

Description: 〈p〉Publication date: Available online 29 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology〈/p〉 〈p〉Author(s): Hengwei Deng, Xiaopeng Xu, Lei Hu, Jingjing Li, Dandan Zhou, Shanshan Liu, Panpan Luo, Jianguo He, Shaoping Weng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉JAK/STAT signaling pathways are associated with the innate immune system and play important roles in mediating immune responses to virus infection. In this study, a Janus kinase gene from 〈em〉Scylla paramamosain〈/em〉 (〈em〉Sp〈/em〉JAK) was cloned and characterized. The full length of 〈em〉Sp〈/em〉JAK mRNA contains a 5′ untranslated region (UTR) of 304 bp, an open reading frame of 3300 bp and a 3′ UTR of 302 bp. The 〈em〉Sp〈/em〉JAK protein contains seven characteristic JAK homology domains (JH1 to JH7) and showed 60% identity (78% similarity), 20% identity (35% similarity), and 21% identity (37% similarity) to the 〈em〉Litopenaeus vannamei〈/em〉 JAK (〈em〉Lv〈/em〉JAK) protein, the 〈em〉Drosophila melanogaster〈/em〉 hopscotch protein, and the 〈em〉Homo sapiens〈/em〉 JAK2 protein, respectively. The mRNA of 〈em〉Sp〈/em〉JAK showed high expression in the brain and nerve but low expression in the hemocyte and muscle. Moreover, the expression of 〈em〉Sp〈/em〉JAK was significantly upregulated by stimulation with mud crab reovirus (MCRV), poly(I:C), and 〈em〉Vibrio parahaemolyticus〈/em〉. 〈em〉Sp〈/em〉JAK significantly activated the STAT of 〈em〉S. paramamosain〈/em〉 (〈em〉Sp〈/em〉STAT) to translocate to the nucleus of 〈em〉Drosophila〈/em〉 Schneider 2 cells. 〈em〉Sp〈/em〉JAK significantly enhanced the activity of the promoter of the WSSV wsv069 gene that was activated significantly by 〈em〉Sp〈/em〉STAT by acting on the STAT-binding DNA motif. These results suggest that 〈em〉Sp〈/em〉JAK activates the JAK/STAT pathway. Furthermore, silencing 〈em〉Sp〈/em〉JAK 〈em〉in vivo〈/em〉 resulted in the high mortality rate of MCRV-infected mud crabs and increased the viral load in tissues. Hence, 〈em〉Sp〈/em〉JAK could play an important role in defense against MCRV in mud crab.〈/p〉〈/div〉 〈/div〉