家蚕核型多角体病毒的互作同源重复区结合蛋白的鉴定

Identification of proteins binding to interacting homologous regions in Bombyx mori nucleopolyhedrovirus

摘要:

家蚕核型多角体病毒(Bombyx mori nucleopolyhedrovirus, BmNPV)的同源重复区(homologous regions, hrs)已被证明可作为病毒转录的增强子以及DNA复制的起始位点。本研究旨在解析BmNPV基因组中hrs的蛋白结合特征及其对病毒的调控机制。通过DNA pull-down联合液相色谱-串联质谱(liquid chromatography-tandem mass spectrometry, LC-MS/MS)技术，对4个高频互作的hrs区域(hr1、hr2L、hr3、hr5)进行了系统性分析，分别成功鉴定到215?612个特异性结合蛋白。结果表明，这些hrs区域不仅能结合大量宿主蛋白，还与多个病毒蛋白存在相互作用，其中15个蛋白可同时结合4个hrs区域。进一步分析显示，67.3%的结合蛋白具有多价结合特性，表明hrs可能通过共享结合蛋白来协调病毒基因组的调控功能。本研究的结果不仅有助于阐明BmNPV的hrs在病毒调控方面的重要作用，还为家蚕抗病毒策略的研发提供了新的靶点，同时为深入理解杆状病毒与宿主的互作关系提供了理论参考。

Abstract:

The homologous regions (hrs) of Bombyx mori nucleopolyhedrovirus (BmNPV) have been demonstrated to function as transcriptional enhancers and initiation sites of DNA replication. This study aimed to elucidate the protein-binding characteristics of hrs in the BmNPV genome and their regulatory mechanisms in viral infection. Using DNA pull-down coupled with LC-MS/MS, we systematically analyzed four highly interactive hrs (hr1, hr2L, hr3, and hr5), successfully identifying 215?612 specific binding proteins for each region. Our findings revealed that these hrs not only bind to with numerous host proteins but also with multiple viral proteins. Notably, 15 proteins exhibited binding affinity to all four hrs, which suggested that these core interacting proteins may play pivotal roles in hrs-mediated regulation. Further analysis demonstrated that 67.3% of the binding proteins possessed multivalent binding properties, indicating that hrs may coordinate viral genome regulation through shared protein interaction networks. These results provide significant insights into the crucial regulatory functions of hrs in BmNPV infection, offer potential targets for developing antiviral strategies in silkworms, and contribute to a deeper understanding of baculovirus-host interactions at the molecular level.