Arockiaraj Jesu, Sathyamoorthi Akila, Kumaresan Venkatesh, Palanisamy Rajesh, Chaurasia Mukesh Kumar, Bhatt Prasanth, Gnanam Annie J, Pasupuleti Mukesh, Arasu Abirami
Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur, Chennai, 603 203, Tamil Nadu, India,
Mol Biol Rep. 2014 Aug;41(8):5299-309. doi: 10.1007/s11033-014-3401-5. Epub 2014 May 24.
In this study, we have reported a first murrel interferon regulatory factor-1 (designated as Murrel IRF-1) which is identified from a constructed cDNA library of striped murrel Channa striatus. The identified sequence was obtained by internal sequencing method from the library. The Murrel IRF-1 varies in size of the polypeptide from the earlier reported fish IRF-1. It contains a DNA binding domain along with a tryptophan pentad repeats, a nuclear localization signal and a transactivation domain. The homologous analysis showed that the Murrel IRF-1 had a significant sequence similarity with other known fish IRF-1 groups. The phylogenetic analysis exhibited that the Murrel IRF-1 clustered together with IRF-1 members, but the other members including IRF-2, 3, 4, 5, 6, 7, 8, 9 and 10 were clustered individually. The secondary structure of Murrel IRF-1 contains 27% α-helices (85 aa residues), 5.7% β-sheets (19 aa residues) and 67.19% random coils (210 aa residues). Furthermore, we predicted a tertiary structure of Murrel IRF-1 using I-Tasser program and analyzed the structure on PyMol surface view. The RNA structure of the Murrel IRF-1 along with its minimum free energy (-284.43 kcal/mol) was also predicted. The highest gene expression was observed in spleen and its expression was inducted with pathogenic microbes which cause epizootic ulcerative syndrome in murrels such as fungus, Aphanomyces invadans and bacteria, Aeromonas hydrophila, and poly I:C, a viral RNA analog. The results of cell protection assay suggested that the Murrel IRF-1 regulates the early defense response in C. striatus. Moreover, it showed Murrel IRF-1 as a potential candidate which can be developed as a therapeutic agent to control microbial infections in striped murrel. Overall, these results indicate the immune importance of IRF-1, however, the interferon signaling mechanism in murrels upon infection is yet to be studied at proteomic level.
在本研究中，我们报道了首个从构建的条纹鳢（Channa striatus）cDNA文库中鉴定出的鳢干扰素调节因子-1（命名为Murrel IRF-1）。通过对文库进行内部测序获得了鉴定出的序列。Murrel IRF-1的多肽大小与先前报道的鱼类IRF-1不同。它包含一个DNA结合结构域以及一个色氨酸五联体重复序列、一个核定位信号和一个反式激活结构域。同源性分析表明，Murrel IRF-1与其他已知的鱼类IRF-1组具有显著的序列相似性。系统发育分析显示，Murrel IRF-1与IRF-1成员聚集在一起，但其他成员包括IRF-2、3、4、5、6、7、8、9和10则单独聚集。Murrel IRF-1的二级结构包含27%的α-螺旋（85个氨基酸残基）、5.7%的β-折叠（19个氨基酸残基）和67.19%的无规卷曲（210个氨基酸残基）。此外，我们使用I-Tasser程序预测了Murrel IRF-1的三级结构，并在PyMol表面视图上分析了该结构。还预测了Murrel IRF-1的RNA结构及其最小自由能（-284.43千卡/摩尔）。在脾脏中观察到最高的基因表达，并且其表达在致病微生物如真菌、侵袭性丝囊霉菌和细菌嗜水气单胞菌以及病毒RNA类似物聚肌胞苷酸（poly I:C）诱导下，这些致病微生物会在鳢中引起流行性溃疡综合征。细胞保护试验结果表明，Murrel IRF-1调节条纹鳢的早期防御反应。此外，它表明Murrel IRF-1是一种潜在的候选物，可开发为控制条纹鳢微生物感染的治疗剂。总体而言，这些结果表明了IRF-1在免疫方面的重要性，然而，鳢在感染时的干扰素信号传导机制在蛋白质组学水平上仍有待研究。
