载脂蛋白B mRNA编辑酶催化样蛋白3F在PRRSV复制中的作用机制研究

PRRSV是危害养猪业的重要动物病原，载脂蛋白B mRNA编辑酶催化样蛋白3F (APOBEC3F)是mRNA处理小体的重要组件成分。前期研究发现过表达APOBEC3F于Marc-145 细胞，PRRSV N基因转录水平显著下调；siRNA干扰细胞内APOBEC3F，PRRSV N基因转录水平则明显上调。本项目拟在前期研究基础上开展以下研究：（1）利用空斑形态试验、病毒生长曲线、基因沉默等方法分析APOBEC3F对PRRSV空斑形态变化、病毒滴度、RNA转录和复制速率等特性的影响。（2）采用免疫共沉淀、Pull down、激光共聚焦、凝胶阻滞等试验技术探寻与APOBEC3F相互作用的PRRSV病毒成分及其区域。（3）通过鉴定PRRSV是否包装APOBEC3F，探索APOBEC3F对PRRSV基因突变效应，深入阐明APOBEC3F在PRRSV复制中的作用及其机制，为PRRSV防控提供思路。

Abstract: Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) is an important pathogen that is extremely harmful to the pig industry. The apolipoprotein B mRNA editing enzyme catalytic protein 3F (APOBEC3F) is a core component of mRNA processing body. In our previous studies, we found that the transcriptional level of PRRSV N gene was significantly down-regulated in the APOBEC3F overexpressed Marc145 cells while significantly up-regulated in the APOBEC3F knockdown cells. However, the potential regulatory mechanisms of APOBEC3F in this event remain unknown. Therefore, we here aim to elucidate this by carrying out the following experiments: (1) To explore the roles of AOBEC3F in plaque morphology, virus titer, RNA transcription and replication of PRRSV in the AOBEC3F overexpression and knockdown cells; (2) To identify the potential proteins as well as their critical domains of PRRSV interacting with APOBEC3F using co-immunoprecipitation, Pull down, confocal fluorescence and gel block; (3) To investigate the mutation effect of APOBEC3F on PRRSV genes. This work will be helpful to better understand the biological roles and mechanisms of APOBEC3F in PRRSV infection, thereby providing novel insights in prevention and control of PRRS in the pig industry.