Interaction between vaccinia virus extracellular virus envelope A33 and B5 glycoproteins
Interaction between vaccinia virus extracellular virus envelope A33 and B5 glycoproteins
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DOI：
10.1128/jvi.00598-06
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发表时间：
2006-09-01
影响因子：
5.4
通讯作者：
Blasco, Rafael
中科院分区：
文献类型：
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作者：
Perdiguero, Beatriz;Blasco, Rafael
牛痘病毒的细胞外形式通过用细胞质膜包裹获得其外包膜，所述细胞质膜含有至少七种病毒编码的蛋白质，其中四种是糖蛋白。我们研究了牛痘病毒A33糖蛋白与蛋白质A34、A36、B5、F12和F13之间的相互作用。首先，当myc表位标记的A33与其他包膜蛋白组合表达时，A33与B5和A36共定位，表明直接A33-B5和A33-A36相互作用在没有感染的情况下发生。通过将带有myc标签的A33版本（A33 mye）导入A33缺陷型痘苗病毒中，构建了重组痘苗病毒（vA 33 Rmyc）。A33 myc部分恢复了空斑形成，并与感染细胞中的包膜病毒体共定位。用vA 33 Rmyc感染的细胞的提取物进行的共免疫沉淀实验证实了A33与A36和B5的物理缔合的存在。其中，A33-115的相互作用是一个新的发现，而A33和A36之间的相互作用已经被表征。使用表达B5蛋白的突变形式的牛痘病毒的集合来研究与A33相互作用所需的B5的结构域。B5蛋白质的胞质结构域和大部分胞外结构域（但不是跨膜结构域）都被标记为与A33结合。B5和A33细胞外部分的突变增强了细胞外病毒的释放，但并不影响两者之间的相互作用。相反，用水泡性口炎病毒G糖蛋白的B5跨膜结构域取代B5跨膜结构域阻止了与A33的结合。对病毒突变体的免疫荧光实验表明，B5是将A33有效靶向进入有包膜病毒粒子所必需的。这些结果表明B5的跨膜结构域是A33-B5相互作用的主要决定因素，并表明蛋白质-蛋白质相互作用在决定病毒包膜的组成中至关重要。
The extracellullar form of vaccinia virus acquires its outer envelope by wrapping with cytoplasmic membranes that contain at least seven virus-encoded proteins, of which four are glycoproteins. We searched for interactions between the vaccinia virus A33 glycoprotein and proteins A34, A36, B5, F12, and F13. First, when myc epitope-tagged A33 was expressed in combination with other envelope proteins, A33 colocalized with B5 and A36, suggesting that direct A33-B5 and A33-A36 interactions occur in the absence of infection. A recombinant vaccinia virus (vA33Rmyc) was constructed by introduction of the myc-tagged A33 version (A33mye) into A33-deficient vaccinia virus. A33myc partially restored plaque formation and colocalized with enveloped virions in infected cells. Coimmoprecipitation experiments with extracts of vA33Rmyc-infected cells confirmed the existence of a physical association of A33 with A36 and B5. Of these, the A33-115 interaction is a novel finding, whereas the interaction between A33 and A36 has been previously characterized. A collection of vaccinia viruses expressing mutated versions of the B5 protein was used to investigate the domain(s) of B5 required for interaction with A33. Both the cytoplasmic domain and most of the extracellular domain, but not the transmembrane domain, of the B5 protein were dispensable for binding to A33. Mutations in the extracellular portions of B5 and A33 that enhance extracellular virus release did not affect the interaction between the two. In contrast, substituting the B5 transmembrane domain with that of the vesicular stomatitis virus G glycoprotein prevented the association with A33. Immunofluorescence experiments on virus mutants indicated that B5 is required for efficient targeting of A33 into enveloped virions. These results point to the transmembrane domain of B5 as the major determinant of the A33-B5 interaction and demonstrate that protein-protein interactions are crucial in determining the composition of the virus envelope.