在鱼类中关于转化生长因子β -激活激酶1(TAK1)在天然免疫反应中的功能研究较少。为了探究TAK1在斑马鱼天然免疫中的功能, 本文克隆并获得了一种斑马鱼tak1剪接异构体(Drtak1), 其开放阅读框含有1 737个核苷酸, 编码578个氨基酸, 其中包括N端的丝氨酸/苏氨酸蛋白激酶结构域和C端的卷曲螺旋结构部。通过免疫荧光试验, 证实DrTAK1是一种胞质蛋白。双荧光素酶报告试验显现在EPC细胞中单转DrTAK1不能诱导IFN的产生, 但与IRF7共转时能显著提高其诱导干扰素启动子表达的能力。本文研究结果首次在斑马鱼中发现TAK1能正向调控IRF7介导的天然免疫反应, 为后续DrTAK1功能研究奠定了基础。

There are few reports on the function of transforming growth factor β-activated kinase 1(TAK1) in innate immune response in fish. To explore the role of zebrafish TAK1(Danio rerio TAK1, DrTAK1) in innate immune, a new splicing isoforms of Drtak1 has been cloned and characterized in this study. The open reading frame (ORF) of the Drtak1 has 1 737 nt, which can encode 578 amino acids. DrTAK1 includes a N-terminal serine/threonine protein kinases (S/TKc) and a C-terminal coiled-coil region. The results of immunofluorescence showed that DrTAK1 is a cytoplasmic protein. Over-expression of DrTAK1 in EPC cells down-regulates the activity of IFN promoter in luciferase reporter assay in EPC cells. However when co-transferred with zebrafish IRF7, the DrTAK1 can obviously promote the IFN-activation ability of IRF7. The data in this study showed that the DrTAK1 positively regulated IRF7-mediated innate immune responses for the first time in zebrafish, and it laid the foundation for subsequent DrTAK1 research.