Dihydroxyacetone kinase (DAK) functions as a negative regulator of melanoma differentiation-associated gene 5 (MDA5)-mediated interferon (IFN) production in human. To explore its role in teleost fish, DAK homologue of black carp (Mylopharyngodon piceus) has been cloned and characterized in this paper. The transcription of black carp DAK (bcDAK) variated in host cells in response to LPS, poly (I:C) and virus stimulation, and bcDAK was majorly distributed in the cytoplasm. Overexpressed bcDAK in EPC cells showed little IFN promoter-inducing ability in the reporter assay and no antiviral activity in plaque assay. When co-expressed with black carp MDA5 (bcMDA5) in EPC cells, bcDAK obviously inhibited bcMDA5-mediated IFN promoter transcription in reporter assay and the antiviral activity in plaque assay. The knockdown of bcDAK enhanced the antiviral activity of the host cells. The association between bcDAK and bcMDA5 has been identified through immunofluorescent staining and co-immunoprecipitation (co-IP) assay. Thus, the data generated in this study support the conclusion that black carp DAK interacts with MDA5 and negatively regulates MDA5-mediated antiviral signaling.

二羟丙酮激酶 (DAK) 作为黑色素瘤分化相关基因 5 (MDA5) 介导的人类干扰素 (IFN) 产生的负调节因子发挥作用。为了探索它在硬骨鱼中的作用，黑鲤（Mylopharyngodon piceus ）的 DAK 同源物) 已在本文中被克隆和表征。黑鲤DAK（bcDAK）的转录在宿主细胞中响应LPS、poly（I：C）和病毒刺激而发生变化，bcDAK主要分布在细胞质中。在 EPC 细胞中过表达的 bcDAK 在报告基因测定中显示出很少的 IFN 启动子诱导能力，而在斑块测定中没有抗病毒活性。当与 EPC 细胞中的黑鲤 MDA5 (bcMDA5) 共表达时，bcDAK 在报告基因检测中明显抑制 bcMDA5 介导的 IFN 启动子转录和在斑块检测中的抗病毒活性。bcDAK 的敲低增强了宿主细胞的抗病毒活性。bcDAK 和 bcMDA5 之间的关联已通过免疫荧光染色和免疫共沉淀 (co-IP) 测定法确定。因此，