新城疫病毒（NDV）M蛋白是一种具有核质穿梭特征的多功能病毒蛋白。目前已有许多关于NDV M蛋白与细胞蛋白互作的研究，但是转录调节因子与M蛋白互作对NDV复制的影响还未见报道。课题组前期利用酵母双杂交系统筛选到NDV M蛋白与转录调节因子BRD2存在相互作用，进一步利用荧光共定位、免疫共沉淀和pull-down技术证实两者具有相互作用，但是这种互作在NDV复制中的作用尚不清楚。本项目通过开展M蛋白与BRD2互作结构域的鉴定，研究M蛋白中与BRD2互作关键氨基酸位点突变对NDV复制和致病性的影响，探讨NDV感染或干扰BRD2表达对BRD2转录复合物以及BRD2调控的信号通路中关键蛋白表达的影响，解析BRD2以及M蛋白通过BRD2调控的信号通路在NDV复制中的作用，以此阐明M蛋白与BRD2互作调控NDV复制的作用机制。本研究工作对深入了解NDV或其它相关病毒M蛋白细胞核定位的功能具有重要意义。

Newcastle disease virus (NDV) M protein is a multifunctional and nucleocytoplasmic shuttling protein. Up to now, numerous studies have reported the interactions between NDV M protein and cellular proteins, but the effect of transcriptional regulatory factors interacting with M protein on the replication of NDV is unknown. We previously demonstrate that transcriptional regulatory factor BRD2 was screened to interact with NDV M protein using yeast two-hybrid system, and this interaction was subsequently confirmed by fluorescence co-localization, co-immunoprecipitation and pull-down assays. However, the role of the interaction between M and BRD2 in the replication of NDV remains unclear. This project planned to identify the interaction domains between M and BRD2, study the effect of the mutation of key amino acids that interact with BRD2 in the M protein on the replication and pathogenicity of NDV, investigate the impact of NDV infection or BRD2 suppression on the expression of BRD2 transcription complex and the key protein expression of BRD2-regulated signaling pathways, and analyze the role of BRD2 and the signaling pathway regulated by M and BRD2 interaction in NDV replication. The results obtained from this project could reveal the mechanism of the effect of M and BRD2 interaction on the replication of NDV. The research work will be of great importance in understanding the nuclear localization functions of M protein for NDV and other related viruses.