Cloning and characterization of two lipopolysaccharide-binding protein/bactericidal permeability-increasing protein (LBP/BPI) genes from the sea cucumber Apostichopus japonicus with diversified function in modulating ROS production
Cloning and characterization of two lipopolysaccharide-binding protein/bactericidal permeability-increasing protein (LBP/BPI) genes from the sea cucumber Apostichopus japonicus with diversified function in modulating ROS production
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DOI：
10.1016/j.dci.2015.04.015
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发表时间：
2015-09-01
影响因子：
2.9
通讯作者：
Li, Ye
中科院分区：
文献类型：
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作者：
Shao, Yina;Li, Chenghua;Li, Ye
脂多糖结合蛋白和杀菌通透性增加蛋白（LBP/BPI）在革兰氏阴性菌感染后细胞信号的调节中起着重要作用。本研究利用RACE技术从仿刺参（Apostichopus）中克隆了LBP/BPI基因的两个亚型（分别命名为AjLBP/BPI 1和AjLBP/BPI 2）。AjLBP/BPI 1和AjLBP/BPI 2的cDNA全长分别为1479和1455 bp，分别编码492和484个氨基酸残基的分泌蛋白。AjLBP/BPI 1和AjLBP/BPI 2推导的氨基酸序列中信号肽、两个BPI/LBP/CETP和一个中心结构域完全保守。系统发育分析进一步支持AjLBP/BPI 1和AjLBP/BPI 2属于无脊椎动物LBP/BPI家族的新成员。空间表达分析显示AjLBP/BPI 1和AjLBP/BPI 2在所有检测的组织中普遍表达，其中AjLBP/BPI 1的表达量较大。脾裂弧菌攻击和LPS刺激均能显著上调AjLBP/BPI 1和AjLBP/BPI 2的mRNA表达，且AjLBP/BPI 2的表达上调早于AjLBP/BPIL。因此，未分类的AjToll而不是AjTIR 3的表达水平与AjLBP/BPI 1的表达水平密切相关。沉默AjToll也抑制了培养的体腔细胞中ROS的产生。这些结果表明，AjLBP/BPI 1和AjLBP/BPI 2在细菌介导的海参免疫应答中可能发挥不同的作用，AjLBP/BPI 1通过调节AjToll级联反应抑制海参体腔细胞ROS的产生。(C)2015爱思唯尔有限公司版权所有。
Lipopolysaccharide-binding protein and bactericidal permeability-increasing protein (LBP/BPI) play crucial role in modulating cellular signals in response to Gram-negative bacteria infection. In the present study, two isoforms of LBP/BPI genes (designated as AjLBP/BPI1 and AjLBP/BPI2, respectively) were cloned from the sea cucumber Apostichopus japonicus by RACE approach. The full-length cDNAs of AjLBP/BPI1 and AjLBP/BPI2 were of 1479 and 1455 bp and encoded two secreted proteins of 492 and 484 amino acid residues, respectively. Signal peptide, two BPI/LBP/CETP and one central domain were totally conserved in the deduced amino acid of AjLBP/BPI1 and AjLBP/BPI2. Phylogentic analysis further supported that AjLBP/BPI1 and AjLBP/BPI2 belonged to new members of invertebrates LBP/BPI family. Spatial expression analysis revealed that both AjLBP/BPI1 and AjLBP/BPI2 were ubiquitously expressed in all examined tissues with the larger magnitude in AjLBP/BPI1. The Vibrio splenfidus challenge and LPS stimulation could significantly up-regulate the mRNA expression of both AjLBP/BPI1 and AjLBP/BPI2, with the increase of AjLBP/BPI2 expression occurred earlier than that of AjLBP/BPIL More importantly, we found that LPS induced ROS production was markedly depressed after AjLBP/BPI1 knock-down, but there was no significant change by AjLBP/BPI2 silencing. Consistently, the expression level of unclassified AjToll, not AjTIR3, was tightly correlated with that of AjLBP/BPI1. Silencing the AjToll also depressed the ROS production in the cultured coelomocytes. All these results indicated that AjLBP/BPI1 and AjLBP/BPI2 probably played distinct roles in bacterial mediating immune response in sea cucumber, and AjLBP/BPI1 depressed coelomocytes ROS production via modulating AjToll cascade. (C) 2015 Elsevier Ltd. All rights reserved.