Expression characterization, genomic structure and function analysis of fish ubiquitin-specific protease 18 (USP18) genes
Expression characterization, genomic structure and function analysis of fish ubiquitin-specific protease 18 (USP18) genes
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鱼类泛素特异性蛋白酶 18 (USP18) 基因的表达表征、基因组结构和功能分析
DOI：
10.1016/j.dci.2015.05.003
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发表时间：
2015-10-01
影响因子：
2.9
通讯作者：
Gui, Jian-Fang
中科院分区：
文献类型：
--
作者：
Chen, Chen;Zhang, Yi-Bing;Gui, Jian-Fang
在哺乳动物中，USP 18（泛素特异性蛋白酶18）是干扰素（IFN）诱导蛋白，并且在病毒感染后调节IFN应答中起作用。本研究首先从感染病毒的鲫鱼囊胚胚胎细胞中克隆了USP 18同源基因，随后在包括斑马鱼在内的其他鱼类中也发现了USP 18同源基因。所有鱼类USP 18基因都有10个外显子和9个内含子，与非鱼类脊椎动物的toll外显子和10个内含子相当。表达分析表明，鱼USP 18显着诱导在体外和体内的IFN和IFN刺激。利用启动子驱动的荧光素酶报告基因系统对鱼类USP 18基因表达的分子机制进行了研究，结果表明鱼类USP 18基因是一个典型的干扰素刺激基因（ISG）。细胞内poly（I：C）诱导的斑马鱼USP 18表达是通过RLR-IFN途径调控的，这与鱼类USP 18基因启动子含有两个典型的IFN刺激反应元件（ISREs）的事实相一致。进一步的突变分析表明，远距离ISRE基序主要有助于鱼类IFN和IFN刺激诱导斑马鱼USPI 8。在功能上，鱼USP 18抑制poly（I：C）和IFN触发的一个共同的ISRE启动子的激活，并减弱了一些ISG的转录表达，包括Stat 1和PKZ的重组IFN。最后，我们发现鱼USP 18蛋白在细胞质中表达，并表现出与ISG 15相互作用的能力。这些结果表明，鱼类USPI 8可能发挥其类似于哺乳动物同系物的功能。(C)2015爱思唯尔有限公司版权所有。
In mammals, USP18 (ubiquitin-specific protease 18) is an interferon (IFN) inducible protein and plays a role in regulation of IFN response upon viral infection. In this study, we first cloned a USP18 homologous gene from virally-infected crucian carp (Carassius auratus) blastula embryonic (CAB) cells, and later found in other fish species including zebrafish. All fish USP18 genes have 10 exons and 9 introns comparable toll exons and 10 introns in non-fish vertebrates. Expression analysis revealed that fish USP18 was significantly induced in vitro and in vivo by IFN and IFN stimuli. Using promoter-driven luciferase reporter assay system to explore the molecular mechanism underlying fish USP18 expression, fish USP18 was identified as a typical interferon (IFN)-stimulated gene (ISG). Intracellular poly(I:C)-triggered zebrafish USP18 expression was regulated through RLR-IFN pathway, which was consistent with the fact that fish USP18 gene promoter contained two typical IFN-stimulated response elements (ISREs). Further mutation assays revealed that the distant ISRE motif primarily contributed to the induction of zebrafish USPI8 by fish IFN and IFN stimuli. Functionally, fish USP18 inhibited poly(I:C)- and IFN-triggered activation of a common ISRE-containing promoter, and attenuated transcriptional expression of some ISGs including Stat1 and PKZ by recombinant IFN. Finally, we found that fish USP18 protein was expressed in cytoplasm and exhibited an ability to interact with ISG15. These results indicate that fish USPI8 likely exerts its function similar to mammalian homologs. (C) 2015 Elsevier Ltd. All rights reserved.