State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, China.
State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, China; College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
Dev Comp Immunol. 2021 Sep;122:104105. doi: 10.1016/j.dci.2021.104105. Epub 2021 Apr 17.
Mammalian Nemo-like kinase (NLK) plays important roles in multiple biological processes including immune response; however, the roles of teleost NLK remain largely unknown. In the present study, the NLK homolog (bcNLK) of black carp (Mylopharyngodon piceus) has been cloned and characterized. The coding region of bcNLK consists of 1427 nucleotides and encodes 476 amino acid, including two low complexity region (LCR) domains at the N-terminus and a serine/threonine protein kinase catalytic (S-TKc) domain in the middle region. The transcription of bcNLK are promoted after spring viremia of carp virus (SVCV) infection and poly (I:C) stimulation in host cells, but not post LPS treatment. bcNLK exhibits weak impact on the transcription of interferon (IFN) promoter in the reporter assay, however, black carp MAVS (bcMAVS)-mediated IFN promoter transcription is remarkably dampened by bcNLK. The interaction between bcNLK and bcMAVS is detected through the co-immunoprecipitation assay. Accordingly, the plaque assay results show that bcMAVS-mediated antiviral ability is impaired by bcNLK. Moreover, knockdown of bcNLK in host cells leads to the enhanced antiviral ability against SVCV. All these data support the conclusion that black carp NLK associates with MAVS and inhibited MAVS-mediated antiviral signaling.
哺乳动物 Nemo 样激酶 (NLK) 在包括免疫反应在内的多种生物学过程中发挥着重要作用；然而，鱼类 NLK 的作用在很大程度上尚不清楚。在本研究中，克隆并鉴定了草鱼 (Mylopharyngodon piceus) 的 NLK 同源物 (bcNLK)。bcNLK 的编码区由 1427 个核苷酸组成，编码 476 个氨基酸，包括 N 端的两个低复杂度区 (LCR) 域和中间的丝氨酸/苏氨酸蛋白激酶催化 (S-TKc) 域。bcNLK 的转录在宿主细胞中受到鲤春病毒血症病毒 (SVCV) 感染和聚肌苷酸 (poly (I:C)) 刺激的促进，但不受 LPS 处理的影响。bcNLK 在报告基因检测中对干扰素 (IFN) 启动子的转录影响较弱，但 bcNLK 显著抑制了草鱼 MAVS (bcMAVS) 介导的 IFN 启动子转录。通过共免疫沉淀实验检测到 bcNLK 与 bcMAVS 之间的相互作用。因此，噬斑实验结果表明，bcMAVS 介导的抗病毒能力被 bcNLK 削弱。此外，宿主细胞中 bcNLK 的敲低导致对 SVCV 的抗病毒能力增强。所有这些数据都支持草鱼 NLK 与 MAVS 结合并抑制 MAVS 介导的抗病毒信号通路的结论。
