Cloning, expression analysis and functional characterization of an interleukin-1 receptor-associated kinase 4 from Apostichopus japonicus
Cloning, expression analysis and functional characterization of an interleukin-1 receptor-associated kinase 4 from Apostichopus japonicus
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刺参白细胞介素 1 受体相关激酶 4 的克隆、表达分析和功能表征
DOI：
10.1016/j.molimm.2018.08.006
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发表时间：
2018
影响因子：
3.6
通讯作者：
Li Chenghua
中科院分区：
文献类型：
--
作者：
Cui Yi;Jiang Liting;Xing Ronglian;Wang Zhengdong;Wang Zhenhui;Shao Yina;Zhang Weiwei;Zhao Xuelin;Li Chenghua
白介素1受体相关激酶4(IRAK4)是TLR介导的宿主免疫功能中的一个关键因子。本研究通过RACE方法从刺参中鉴定了一个IRAK4同源分子，命名为AjIRAK4。AjIRAK4基因全长为2024bp，含有一个1311bp的开放阅读框，编码一个436个氨基酸残基的多聚蛋白，具有典型的死亡结构域(10-113aa)和激活区(160-426aa)。AjIRAK4的mRNA转录本在所有受检组织中呈结构性表达，其中肌肉中的表达最高(是体腔细胞的7.20倍)。病原性脾弧菌攻击和脂多糖暴露均能显著上调AjIRAK4基因的表达。在体外和活体中沉默AjIRAK4可以在mRNA和蛋白水平上抑制TLR成员的表达，这表明AjIRAK4是海参TLR级联反应的重要组成部分。更重要的是，通过特异性siRNA敲除AjIRAK4基因后，体内外体腔细胞凋亡率分别增加了1.82倍和1.95倍。综上所述，我们的研究结果提示，AjIRAK4可能通过TLR级联途径作为体腔细胞的凋亡调节因子。
Interleukin 1 receptor-associated kinase 4 (IRAK4) is a key factor in TLR-mediated host immune function. In this study, an IRAK4 homologue molecule was identified fromApostichopus japonicus(designated as AjIRAK4) by RACE approach. The full-length cDNA of AjIRAK4 was of 2024 bp containing an open reading frame of 1311 bp encoding a 436-amino-acid (aa) residue polyprotein with the typical death domain (10-113aa) and the kinase domain (160-426aa). The mRNA transcripts of AjIRAK4 displayed constitutively expressed in all examined tissues with highest expression in the muscles (7.20-fold increase compared to the coelomocytes). The pathogenVibrio splendiduschallenge and LPS exposure could both significantly up-regulate the mRNA expression of AjIRAK4. Silencing AjIRAK4in vitroandin vivocould inhibit the expression of TLR members at mRNA and protein levels, suggesting AjIRAK4 was an important component of TLR cascade in sea cucumber. More importantly, knockdown of AjIRAK4 by specific siRNA resulted in the significant promotion of coelomocyte apoptosis by 1.82-fold increasein vitroand 1.95-foldin vivo. Taken together, all our results suggested that AjIRAK4 might be served as coelomocyte apoptosis regulatorviaTLR cascade.