Laboratory of Molecular Virology and Immunology, Department of Aquaculture, The College of Life Science, National Taiwan Ocean University, No. 2, Beining Road, Keelung 202, Taiwan.
Laboratory of Molecular Virology and Immunology, Department of Aquaculture, The College of Life Science, National Taiwan Ocean University, No. 2, Beining Road, Keelung 202, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, No. 2, Beining Road, Keelung 202, Taiwan.
Fish Shellfish Immunol. 2017 Dec;71:116-126. doi: 10.1016/j.fsi.2017.09.080. Epub 2017 Oct 7.
ADARs are RNA editing catalysts that bind double-stranded RNA and convert adenosine to inosine, a process that can lead to destabilization of dsRNA structures and suppression of mRNA translation. In mammals, ADAR1 genes are involved in various cellular pathways, including interferon (IFN)-mediated response. However, the function of fish ADAR1 remains unclear. We report here the cloning of ADAR1 in Malabar grouper (Epinephelus malabaricus) (MgADAR1) and its response to various immune stimulants. The MgADAR1 cDNA is 5371-bp long, consisting of an open reading frame encoding a putative protein of 1381 amino acids, a 235-nt 5'-terminal untranslated region (UTR), and a 990-nt 3'-UTR. The deduced amino acid sequence exhibits signature features of a chitin synthesis regulation domain, two Z-DNA-binding domains (Z alpha), three dsRNA binding motifs (DSRM) and one tRNA-specific and dsRNA adenosine deaminase domain (ADEAMc). MgADAR1 mRNA expressed ubiquitously in tissues of healthy Malabar grouper, with elevated levels in the brain, gills and eyes. In response to poly (I: C), the MgADAR1 mRNA level was significantly up-regulated in the brain and spleen, but not head kidney. Upon nervous necrosis virus (NNV) infection the level of MgADAR1 increased in the brain, whereas Mx increased in the brain, spleen and head kidney. Induction of MgADAR1 by poly (I: C) and NNV was also observed in vitro. Additionally, the expression of MgADAR1 was upregulated by recombinant grouper IFN in grouper cells. These data indicate an intricate interplay between ADAR1 and NNV infection in grouper as MgADAR1 might be regulated in a tissue-specific manner.
ADARs 是 RNA 编辑催化剂，可结合双链 RNA 并将腺苷转化为肌苷，该过程可导致 dsRNA 结构不稳定和 mRNA 翻译抑制。在哺乳动物中，ADAR1 基因参与多种细胞途径，包括干扰素 (IFN) 介导的反应。然而，鱼类 ADAR1 的功能尚不清楚。我们在此报告在马拉巴尔石斑鱼 (Epinephelus malabaricus) (MgADAR1) 中克隆 ADAR1 及其对各种免疫刺激物的反应。MgADAR1 cDNA 长 5371bp，由一个开放阅读框编码，该框编码一个推定的 1381 个氨基酸的蛋白质，一个 235nt 的 5'非翻译区 (UTR) 和一个 990nt 的 3'UTR。推导的氨基酸序列显示出壳聚糖合成调节域、两个 Z-DNA 结合域 (Z alpha)、三个双链 RNA 结合基序 (DSRM) 和一个 tRNA 特异性和双链 RNA 腺苷脱氨酶域 (ADEAMc) 的特征。MgADAR1 mRNA 在健康马拉巴尔石斑鱼的组织中广泛表达，在大脑、鳃和眼睛中表达水平较高。在 poly (I: C) 反应后，MgADAR1 mRNA 水平在大脑和脾脏中显著上调，但在头肾中没有上调。在神经坏死病毒 (NNV) 感染后，MgADAR1 在大脑中的水平增加，而 Mx 在大脑、脾脏和头肾中增加。poly (I: C) 和 NNV 诱导 MgADAR1 的表达也在体外观察到。此外，重组石斑鱼 IFN 在石斑鱼细胞中上调了 MgADAR1 的表达。这些数据表明 ADAR1 与 NNV 感染之间在石斑鱼中存在复杂的相互作用，因为 MgADAR1 可能以组织特异性方式受到调节。
