College of Animal Science and Technology, Northwest A&F University, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Yangling 712100, China.
Fish Shellfish Immunol. 2011 Jan;30(1):317-23. doi: 10.1016/j.fsi.2010.11.010. Epub 2010 Nov 13.
IPS-1 (interferon-β promoter stimulator 1), also known as MAVS/VISA/Cardif, plays a central role in antiviral immunity. In this manuscript, we cloned and characterized IPS-1 from grass carp Ctenopharyngodon idella (designated as CiIPS-1). The CiIPS-1 cDNA is 2412 bp long and consists of a 5' untranslated region (UTR) of 124 bp, a 3' UTR of 497 bp with three cytokine RNA instability motifs (ATTTA) and a polyadenylation signal (AATAAA), and an open reading frame (ORF) of 1791 bp encoding a polypeptide of 596 amino acids with a calculated molecular mass of 64.1 kDa and a theoretical isoelectric point of 4.79. Structural analysis showed that the CiIPS-1 protein contained an N-terminal CARD (caspase activation and recruitment domain), a central proline-rich domain, a putative TRAF2-binding motif and a C-terminal transmembrane domain. Similarity analysis of the deduced amino acid sequence of the CiIPS-1 by MatGAT software revealed that the CiIPS-1 shared 27.8-76.4% identity and 47.4-85.2% similarity with other known piscine IPS-1 sequences. The CiIPS-1 mRNA was constitutively expressed in the examined tissues, higher in spleen, and was induced by grass carp reovirus (GCRV) injection by semi-quantitative RT-PCR assay. Quantitative real-time RT-PCR analysis revealed that the CiIPS-1 mRNA expression was rapidly and significantly up-regulated in vivo and in vitro after GCRV infection, and the CiIPS-1 transcripts were also significantly enhanced in vitro post the synthetic double stranded RNA polyinosinic-polycytidylic potassium salt (poly(I:C)) stimulation. These results indicated that CiIPS-1 was an inducible acute-phase protein and involved in the immune reaction to GCRV in grass carp.
IPS-1（干扰素-β启动子刺激物 1），也称为 MAVS/VISA/Cardif，在抗病毒免疫中发挥核心作用。在本手稿中，我们从草鱼（Ctenopharyngodon idella）克隆并鉴定了 IPS-1（命名为 CiIPS-1）。CiIPS-1 cDNA 长 2412bp，包含 124bp 的 5'非翻译区（UTR）、497bp 的 3'UTR，其中含有三个细胞因子 RNA 不稳定性基序（ATTTA）和一个多聚腺苷酸化信号（AATAAA），以及一个编码 596 个氨基酸的开放阅读框（ORF），理论分子量为 64.1kDa，理论等电点为 4.79。结构分析表明，CiIPS-1 蛋白含有一个 N 端 CARD（半胱天冬酶激活和募集结构域）、一个中央富含脯氨酸的结构域、一个假定的 TRAF2 结合基序和一个 C 端跨膜结构域。使用 MatGAT 软件对 CiIPS-1 推导的氨基酸序列进行相似性分析表明，CiIPS-1 与其他已知的鱼类 IPS-1 序列具有 27.8-76.4%的同一性和 47.4-85.2%的相似性。半定量 RT-PCR 检测结果显示，CiIPS-1 在检测的组织中持续表达，在脾脏中表达量较高，且在注射草鱼呼肠孤病毒（GCRV）后可诱导表达。定量实时 RT-PCR 分析表明，在 GCRV 感染后 CiIPS-1 的转录物在体内和体外迅速显著上调，在体外经合成双链 RNA 聚肌苷酸-聚胞苷酸钾盐（poly(I:C))刺激后 CiIPS-1 转录物也显著增强。这些结果表明 CiIPS-1 是一种诱导型急性期蛋白，参与草鱼对 GCRV 的免疫反应。
