M蛋白是新城疫病毒（NDV）感染细胞期间唯一能通过自身携带的核定位信号（NLS）进入细胞核的病毒蛋白，但NLS介导的M蛋白细胞核定位的分子机制及功能尚不清楚。大量的文献表明，具有核定位特征的蛋白质分子进入细胞核除了依赖自身携带的NLS，还需要细胞内核转运受体蛋白的参与。因此，我们推测核转运受体蛋白可能参与了M蛋白的细胞核定位及其功能的发挥。为证实该假说，本项目通过鉴定与M蛋白入核相关的核转运受体蛋白，研究核转运蛋白缺失对M蛋白细胞核定位的影响，阐明M蛋白细胞核定位的分子机制；研究核转运受体蛋白缺失导致M蛋白细胞核定位功能丧失对NDV复制和致病性的影响，以及通过基因芯片筛选并分析NDV感染后的细胞核内差异表达基因，综合解析M蛋白细胞核定位在NDV感染中的功能。项目研究结果对揭示NDV M蛋白细胞核定位的分子机制及功能具有重要意义，可为后续研究M蛋白在NDV复制和致病机制中的作用提供理论依据。

The M protein is demonstrated to localize in the nucleus of Newcastle disease virus (NDV) infected cells through a bipartite nuclear localization signal (NLS). However, the molecular mechanism and definite function of M’s nuclear localization meidated by NLS are unclear. Previous studies have shown that in addition to the owned NLS in proteins possessing the nuclear localization characteristics, cellular nuclear transport receptor proteins are also involved in this process. We speculated that nuclear transport receptor proteins might participate in the functions of M protein in the nucleus. To verify this hypothesis, the nuclear transport receptor proteins related to M’s nuclear translocation were identified to clarify the molecular mechanism of the nuclear localization of M protein. Moreover, the deficiency of nuclear transport receptor proteins to the replication and pathogenicity of NDV and to the influence of differential expression genes screened by gene microarray in the nucleus of NDV-infected cells were also investigated to elaborate the functions of M’s nuclear localization. This project is important to reveal the molecular mechanism and function of the nuclear localization of NDV M protein, which will provide theoretical basis for further studying the roles of M protein in the replication and pathogenic mechanism of NDV.