杆状病毒核心基因gp41在BV和ODV形成过程中的作用机制研究

gp41是杆状病毒的核心基因，定位于ODV囊膜和核衣壳之间的皮层结构。我们的初步研究发现，AcMNPV GP41定位在细胞内核膜环带区；缺失GP41导致大量核衣壳滞留在核内无法产生BV，同时核衣壳无法正确包埋形成ODV。生物信息学分析发现，GP41含有多个 O-糖基化和磷酸化位点、亮氨酸拉链和一段富含亮氨酸的潜在核输出信号。这些证据提示，GP41很可能在病毒的装配及核孔运输过程中发挥重要作用。本项目拟深入解析GP41的结构与功能，包括：对重要结构位点进行截短和突变，构建一系列瞬时表达载体及重组病毒；分析这些突变体的亚细胞定位、对重组病毒BV和ODV感染性及形态发生的影响；通过蛋白相互作用等方法揭示GP41与宿主细胞核输出蛋白Exportin（CRM1）可能存在的相互作用。本研究有望深入解析GP41在BV、ODV形成过程中的作用，对进一步研究以杆状病毒为模型的昆虫细胞核孔运输机制有重要意义。

Known as one of the baculovirus core genes, GP41 resides in the tegument region between the envelope membrane and the capsid. Our preliminary study analysed the cellular location of AcMNPV GP41, showing it located in the ring zone close to the inner nuclear membrane. We also found that gp41 knock-out AcMNPV produced nucleocapsids were retained in nucleus, thus no BVs produced, and nucleocapsids failed to be enveloped to become matured ODVs. Bio-informatics analysis showed that GP41 possesses multiple O-glycosylation sites and phosphorylation sites, leucine zippers and one potential motif of leucing-rich nuclear export signal. All these suggested that GP41 is important for virus assembly and transport through nuclear pores. This subject is going to further investigate the structure and functions of GP41, including to construct a series of transient expression vectors and recombinant bacmids carrying GP41s with truncations and/or mutations at important sites, to characterize the influences of truncated and mutated GP41s on the cellular distribution, virus infectivity and BV and ODV morphogenesis, and to analyse the possible interactions between GP41 and the exportin (CRM1) in host cells. It is very promising to clarify the function and mechanism of GP41 in BV and ODV morphogenesis, which will be of important significance for taking baculovirus as models to further study the nuclear pore transport pathway in insect cells.