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病毒入侵是病毒感染宿主细胞的第一步,涉及病毒与宿主细胞受体的结合、膜融合等过程,而这些过程是由病毒的囊膜蛋白所介导.已知昆虫杆状病毒中存在GP64和F2种不同类型的囊膜蛋白.感染鳞翅目昆虫的核型多角体病毒(NPV)中的Group Ⅰ组病毒同时具有F蛋白和GP64蛋白的同源物,但是F蛋白不是膜融合蛋白;GroupⅡ组NPV和颗粒病毒(GV)以及感染双翅目昆虫的病毒仅有F蛋白的同源物,而在感染膜翅目昆虫的病毒中,这2种蛋白质的同源物均不存在.F蛋白又可分为Fa和Fb2类.在GroupⅡ组NPV中,Fa是出芽型病毒粒子的膜融合蛋白,能介导低pH依赖的膜融合;而在Group Ⅰ组NPV中,Fb蛋白的功能目前尚不明确,其膜融合活性被认为在进化历程中被GP64所取代.本文重点综述昆虫杆状病毒囊膜蛋白F的研究进展.“,”Viral entry is the first key step for virus infection,which involves receptor binding and membrane fusion mediated by viral envelope proteins.In the family Baculoviridae,two different envelope proteins named GP64 and F have been identified.Group Ⅰ NPVs (nuclear polyhedron viruses) which can infect Lepidoptera insects have homologs of both GP64 and F,but F is not a membrane fusion protein.Group Ⅱ NPVs,GVs (granulosis virus) and viruses hostile to Diptera insects only have homologs of F,whereas the viruses corresponding to hymenoptera insects have homologs of neither GP64 nor F.F protein is divided into two categories,Fa and Fb.Fa is an membrane fusion protein of budded virion in Group Ⅱ NPVs.It can mediate low-pH-dependent membrane fusion.In Group Ⅰ NPVs,the function of Fb has not been elucidated and its fusion activity is speculated to be replaced by GP64 during evolution.This article reviews major research progress in envelope protein F of baculovirus.