A novel myeloid differentiation factor 88 homolog, SpMyD88, exhibiting SpToll-binding activity in the mud crab Scylla paramamosain
A novel myeloid differentiation factor 88 homolog, SpMyD88, exhibiting SpToll-binding activity in the mud crab Scylla paramamosain
复制标题
一种新型骨髓分化因子 88 同源物 SpMyD88，在泥蟹 Scylla paramamosain 中表现出 SpToll 结合活性。
DOI：
10.1016/j.dci.2012.11.011
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发表时间：
2013-04-01
影响因子：
2.9
通讯作者：
Kang, Wei
中科院分区：
文献类型：
--
作者：
Li, Xin-Cang;Zhu, Lei;Kang, Wei
髓样分化因子88 （MyD88）是Toll或Toll样受体（TLR）信号通路的重要调节因子。在本研究中，我们鉴定了一种新的甲壳动物MyD88同源物SpMyD88，并分析了它与SpToll的结合活性。SpMyD88全长2933 bp，开放阅读框全长1419 bp，编码472个氨基酸的蛋白。无信号肽预测。一个死亡结构域（残基19-103），一个Toll/白细胞介素-1受体（TIR）结构域（残基156-297）和一个c端延伸结构域（残基298-472）也被发现。在由无脊椎动物和脊椎动物MyD88同源物构建的系统发育树中，包括SpMyD88在内的节肢动物MyD88形成了一个包含独特CTE结构域的集群。SpToll与人类TLR4具有最高的同源性。这两个受体被分组成基于保守的TIR结构域构建的树簇。SpToll与其他具有潜在抗菌活性的对虾tlr关系密切。SpMyD88在血细胞、鳃、肝胰腺和眼柄中高表达。经哈维弧菌攻毒后，血细胞中SpMyD88和SpToll均显著升高，而金黄色葡萄球菌仅使SpMyD88升高。此外，下拉实验表明SpMyD88与SpToll具有结合活性。这些结果表明SpMyD88和SpToll参与了泥蟹对革兰氏阴性菌的防御系统。(C) 2012 Elsevier Ltd.版权所有。
Myeloid differentiation factor 88 (MyD88) is an essential regulator in the Toll or Toll-like receptor (TLR) signaling pathway. In the current study, we characterized a novel crustacean MyD88 homolog, SpMyD88, and analyzed its binding activity with SpToll. The full-length cDNA sequence of SpMyD88 is 2933 bp, with a 1419 bp open reading frame encoding a 472-amino acid protein. No signal peptide was predicted. A death domain (residues 19-103), a Toll/interleukin-1 receptor (TIR) domain (residues 156-297), and a C-terminal extension (CTE) domain (residues 298-472) were also found. In a phylogenetic tree constructed with MyD88 homologs from both invertebrates and vertebrates, arthropod MyD88s including SpMyD88 formed a cluster containing a unique CTE domain. SpToll shared the highest identity with human TLR4. These two receptors were grouped into a cluster of a tree constructed based on the conserved TIR domains. SpToll also had a close relationship with other shrimp TLRs that possess potential antibacterial activity. SpMyD88 was highly expressed in the hemocytes, gills, hepatopancreas, and eye stalks. Upon challenge with Vibrio harveyi, both SpMyD88 and SpToll were significantly increased in the hemocytes, whereas only SpMyD88 was elevated by Staphylococcus aureus. In addition, a pull-down assay demonstrated that SpMyD88 showed a binding activity with SpToll. These results suggest that SpMyD88 and SpToll are involved in the defense system of mud crabs against Gram-negative bacteria. (C) 2012 Elsevier Ltd. All rights reserved.