杨扇舟蛾颗粒体病毒经口侵染因子PIF0~PIF6间分子互作的酵母双杂交验证

为阐明杨扇舟蛾颗粒体病毒(Clostera anachoreta granulovirus,ClanGV)的口服侵染机制,利用酵母双杂交技术,通过双向互作方法研究了ClanGV的经口侵染因子PIF0、PIF1、PIF2、PIF3、PIF4、PIF5和PIF6之间的分子互作情况。自激活试验证明,PIF5的重组诱饵载体(B5)有自激活现象,其它重组诱饵载体均无自激活现象。酵母双杂交试验结果表明,ClanGV的4个经口侵染因子PIF1～PIF4之间存在双向互作现象,而且这4个蛋白均能同时与自身发生互作,暗示这4个经口侵染因子有可能是以二聚体或多聚体的形式存在并发挥功能。在ClanGV经口侵染因子间的6组单向互作中,PIF5作为捕获载体时分别能与PIF1、PIF3和PIF4发生互作,PIF6作为诱饵载体时分别能与PIF3和PIF4发生互作,PIF0作为捕获载体时能与PIF4发生互作。表明ClanGV的经口侵染因子像核型多角体病毒(nucleopolyhedrovirus,NPV)一样,在病毒粒子表面通过分子互作形成复合体并在病毒的经口侵染过程中发挥功能。

Verification of the molecular interactions among per os infectivity factors (PIF0-PIF6) of Clostera anachoreta granulovirus by the yeast two-hybrid system

In order to elucidate the mechanism of oral infection of Clostera anachoreta granulovirus (ClanGV), the protein interactions of per os infectivity factors (PIFs) of ClanGV (PIF0, PIF1, PIF2, PIF3, PIF4, PIF5 and PIF6) were studied by yeast two-hybrid technique. Self-activation experiments demonstrated that only the recombinant bait vector (B5) of PIF5 had self-activation in this study. The results of yeast two-hybrid indicated that PIF1, PIF2, PIF3 and PIF4 of ClanGV had two-way interactions between any two proteins; these proteins could interact with itself, which suggested that these PIFs might be present with dimers or polymers in complex. In addition, this study also explained six groups of unidirectional interactions between ClanGV PIFs: as a trap vector, PIF5 could interact with PIF1, PIF3 and PIF4, respectively; as a bait vector, PIF6 had interactions with PIF3 and PIF4, respectively, and as a trap vector, PIF0 could interact with PIF4. This study indicated that the PIFs formed a complex on the surface of ClanGV virions by molecular interactions and played an important role in the course of oral infection, which was similar to nucleopolyhedrovirus (NPV).