摘要
昆虫杆状病毒在感染宿主的过程中产生2种结构和功能不同,但遗传物质完全一致的病毒粒子表型,即出芽型病毒粒子(BV)和包涵体衍生型病毒粒子(ODV)。在昆虫中肠碱性环境下释放出的ODV通过其表面囊膜上高度保守的经口感染因子(PIF)介导感染中肠上皮细胞,引发原发性感染。已有研究发现,由经口感染因子PIF1、PIF2、PIF3和P74组成的多分子复合物在ODV入侵昆虫中肠上皮细胞的过程中发挥重要作用。最近有研究报道其他囊膜蛋白如PIF4、PIF5和PIF6,可与已知的PIF互作促进ODV感染。进一步的研究发现,PIF4和P95(AC83)也是PIF复合物的组分,PIF4能与PIF1、PIF2、PIF3形成稳定的复合物,而P95和P74与这个复合物的结合并不紧密。通过蛋白质组分析发现,其他3种蛋白质——AC5、AC68(PIF6)和AC108(SF58的同系物)也与PIF复合物有关。揭示ODV入侵昆虫中肠上皮细胞时复合物的形成与构象变化,PIF的潜在受体及其复合物识别宿主细胞受体的过程,将是阐明杆状病毒PIFs及其复合物介导ODV病毒感染机制的重要研究内容。
Insect baculovirus produces two kinds of enveloped virion phenotypes named budded virus（BV） and occlusion-derived virus（ODV） which have different structures and functions but identical genetic substance during infection.ODV infects insect midgut epithelial cells under alkaline condition mediated by highly conserved per os infectivity factors（PIFs） on its envelope,causing primary infection.Previous studies reported that a multimolecular complex composed of PIF1,PIF2,PIF3 and P74 play an essential role during ODV entry into insect midgut epithelial cells.Recently,more proteins were identified,including PIF4,PIF5,and PIF6,which might work in concert with previously known PIFs to facilitate ODV infection.Further studies revealed that PIF4 and P95（AC83） were also components of the PIF complex.PIF4 could form a stable complex with PIF1,PIF2 and PIF3,while P95 and P74 were more loosely associated with this complex.Three other proteins,AC5,AC68（PIF6）,and AC108（homologue of SF58）,were also found by the proteomic analysis to be associated with the PIF complex.Future efforts could be devoted to identify the host receptors of the PIF complex as well as the formation and putative sequential conformational changes of the complex during ODV entry.These works are essential for elucidating the infection mechanism of ODV mediated by baculovirus PIFs and their complex.
出处
《蚕业科学》
CAS
CSCD
北大核心
2014年第4期730-736,共7页
ACTA SERICOLOGICA SINICA
基金
国家自然科学基金项目(No.31272506)
浙江省自然科学基金重点项目(No.Z14C170002)
