不同BmNPV株系来源orf126基因对外源蛋白表达的增强功能分析

Enhancing Effect of orf126 Gene from Different Strains of BmNPV on Heteroprotein Expression

杆状病毒表达系统广泛用于表达具有生物活性的外源蛋白,提高其表达效率具有重要意义。为了研究家蚕核型多角体病毒(Bombyx morinucleopolyhedrovirus,BmNPV)orf126基因对外源蛋白表达的影响,分别将陕西株和广东株BmNPV的orf126与荧光素酶报告基因克隆到Bac-to-Bac供体质粒中,并转座至敲除了orf126基因的BmNPV Bacmid中,转染家蚕细胞后,获得携带不同BmNPV株系来源orf126的2种重组病毒。表达比较试验结果显示,2种病毒在不同细胞系中表达的荧光素酶活性有显著差异,携带广东株orf126的病毒在BmN细胞中表达的荧光素酶活性显著低于携带陕西株orf126的病毒,而在Bm5细胞中则相反,表明不同BmNPV株系来源的orf126对外源蛋白的表达增强作用依赖于宿主细胞类型。研究结果为改造杆状病毒表达载体提供了策略。

Baculovirus expression vector system has been wildly used for expressing heteroprotein with high bioactivity. It is of great significance to enhance its expression efficiency. To confirm the enhancing effect of orf126 gene from Bombyx mori nucleopolyhedrovirus(BmNPV)on heteroprotein expression,orf126 gene from Shaanxi strain of BmNPV(SX126)and Guangdong strain of BmNPV(GD126)and luciferase reporter gene were cloned into donor vector of Bac-to-Bac to generate recombinant BmNPV Bacmids by transferring donor vectors into orf126 null Bacmid. Therefore,2 kinds of recombinant viruses with orf126 from different strains of BmNPV were obtained by transfecting BmN cells and then compared. The results demonstrated that there was significant difference in luciferase activity between different cell lines infected by 2 kinds of viruses. Virus carrying GD126 gene produced less luciferase in BmN than that carrying SX126,however,the virus carrying GD126 produced more luciferase in Bm5 cells than that carrying SX126,which indicated that the enhancing effect of orf126 from different strains of BmNPV on expression of heteroprotein depended on the type of host cell. This study provides a new strategy to modify baculovirus expression vector system.