Huang Ping-Han, Huang Ting-Yi, Cai Pei-Si, Chang Li-Kwan
Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan.
Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
J Virol. 2017 Feb 28;91(6). doi: 10.1128/JVI.02314-16. Print 2017 Mar 15.
Yin Yang 1 (YY1) is a multifunctional zinc finger transcription factor that regulates many key cellular processes. In this study, we report the cloning of YY1 from shrimp (LvYY1). This study shows that LvYY1 is ubiquitously expressed in shrimp tissues, and knockdown of LvYY1 expression by double-stranded RNA (dsRNA) injection in white spot syndrome virus (WSSV)-infected shrimp reduced both mRNA levels of the WSSV immediate early gene as well as overall copy numbers of the WSSV genome. The cumulative mortality rate of infected shrimp also declined with LvYY1 dsRNA injection. Using an insect cell model, we observed that LvYY1 activates expression, and a mutation introduced into the promoter subsequently repressed this capability. Moreover, reporter assay results suggested that LvYY1 is involved in basal transcriptional regulation via an interaction with TATA-binding protein (LvTBP). Electrophoretic mobility shift assay (EMSA) results further indicated that LvYY1 binds to a YY1-binding site in the region between positions -119 and -126 in the promoter. Chromatin immunoprecipitation analysis also confirmed that LvYY1 binds to the promoter in WSSV-infected shrimp. Taken together, these results indicate that WSSV uses host LvYY1 to enhance expression via a YY1-binding site and the TATA box in the promoter, thereby facilitating lytic activation and viral replication. WSSV has long been a scourge of the shrimp industry and remains a serious global threat. Thus, there is a pressing need to understand how the interactions between WSSV and its host drive infection, lytic development, pathogenesis, and mortality. Our successful cloning of YY1 (LvYY1) led to the elucidation of a critical virus-host interaction between LvYY1 and the WSSV immediate early gene We observed that LvYY1 regulates expression via a consensus YY1-binding site and TATA box. LvYY1 was also found to interact with TATA-binding protein (LvTBP), which may have an effect on basal transcription. Knockdown of LvYY1 expression inhibited transcription and subsequently reduced viral DNA replication and decreased cumulative mortality rates of WSSV-infected shrimp. These findings are expected to contribute to future studies involving WSSV-host interactions.
阴阳1（YY1）是一种多功能锌指转录因子，可调节许多关键的细胞过程。在本研究中，我们报道了对虾YY1（LvYY1）的克隆。本研究表明，LvYY1在对虾组织中普遍表达，通过向感染白斑综合征病毒（WSSV）的对虾注射双链RNA（dsRNA）来敲低LvYY1的表达，可降低WSSV立即早期基因的mRNA水平以及WSSV基因组的总体拷贝数。注射LvYY1 dsRNA后，受感染对虾的累积死亡率也有所下降。利用昆虫细胞模型，我们观察到LvYY1激活了表达，而引入到启动子中的一个突变随后抑制了这种能力。此外，报告基因检测结果表明，LvYY1通过与TATA结合蛋白（LvTBP）相互作用参与基础转录调控。电泳迁移率变动分析（EMSA）结果进一步表明，LvYY1与启动子中-119至-126位之间区域的一个YY1结合位点结合。染色质免疫沉淀分析也证实，LvYY1在感染WSSV的对虾中与启动子结合。综上所述，这些结果表明，WSSV利用宿主LvYY1通过启动子中的一个YY1结合位点和TATA框来增强表达，从而促进裂解激活和病毒复制。WSSV长期以来一直是对虾养殖业的一大祸害，并且仍然是一个严重的全球威胁。因此，迫切需要了解WSSV与其宿主之间的相互作用如何驱动感染、裂解发育、发病机制和死亡率。我们成功克隆了YY1（LvYY1），从而阐明了LvYY1与WSSV立即早期基因之间关键的病毒-宿主相互作用。我们观察到，LvYY1通过一个共有YY1结合位点和TATA框调节表达。还发现LvYY1与TATA结合蛋白（LvTBP）相互作用，这可能对基础转录有影响。敲低LvYY1的表达抑制了转录，随后减少了病毒DNA复制，并降低了感染WSSV的对虾的累积死亡率。这些发现有望为未来涉及WSSV-宿主相互作用的研究做出贡献。
