苏云金芽孢杆菌vip2A(c)基因在昆虫细胞中的表达

利用苜蓿丫纹夜蛾核多角体病毒(Autographacalifornicamulticapsidnucleopolyhedrovirus,AcMNPV)Bac-to-Bac表达系统在粉蚊夜蛾(Trichoplusiani)TnHi5细胞中表达了GFP与Vip2A(c)酶活成分区域的融合蛋白(GV2融合蛋白),研究了该蛋白对昆虫细胞和病毒产生的影响。Bac-gfpDNA转染48h后部分TnHi5细胞已经检测到荧光,48￣120h出现荧光的细胞数目增加,最后70%左右的细胞都有较强的荧光。而Bac-gv2DNA转染后2￣5d仅有极少TnHi5细胞出现荧光且多呈零散分布,推测这可能是由于杆状病毒极晚期表达的GV2融合蛋白中的Vip2A对细胞骨架成分肌动蛋白进行ADP-核糖基化,从而影响了芽生型病毒粒子(BV)的正常产生或限制了BV在其它细胞间的传播。

Expression of vip2A(c) Gene from Bacillus thuringiensis in Insect Cell

The recombinant Bac-gv2 DNA was obtained by inserting a fused gfp gene with Bacillus thuringiensis vip2A(c) gene encoding possible enzymatic component under the control of the polyhedrin gene promoter of the baculovirus Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). Trichoplusia ni cell line TnHi5 was transfected with Bac-gfp and Bac-gv2 DNAs respectively. Fluorescent cells expressing the fusion protein GV2 were much fewer than those expressing GFP alone, and did not obviously increase in number from 2 to 5 days after transfection. This results show that Vip2A fusion protein may have an ADP-ribosylating activity on cell skeleton actin and exert an influence on insect cell, the production and diffusion of the budded virus.