State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
Virol J. 2013 Apr 27;10:133. doi: 10.1186/1743-422X-10-133.
Aquareovirus particle is comprised of central core and outer capsid, which is built by seven structural proteins (VP1-VP7). The protein VP6 has been identified to be a clamp protein of stabilizing inner core frame VP3, and bridging outer shell protein VP5. However, the biological properties of VP6 in viral life cycle remain unknown.
The recombinant VP6 (rVP6) of aquareovirus was expressed in E. coli, and the polyclonal antibody against VP6 was generated by using purified rVP6 in this study. Following the preparation of VP6 antibody, the VP6 component in aquareovirus infected cells and purified viral particles was detected by Immunoblotting (IB) assay. Furthermore, using Immunofluorescence (IF) microscopy, singly transfected VP6 protein was observed to exhibit a diffuse distribution mainly in the cytoplasm, while it appeared inclusion phenotype in infected cells. Meanwhile, inclusion structures were also identified when VP6 was coexpressed with nonstructural protein NS80 in cotransfected cells.
VP6 can be recruited by NS80 to its inclusions in both infected and transfected cells. The colocalization of VP6 and NS80 is corresponding to their homologous proteins σ2 and μNS in MRV. Our results suggest that VP6 may play a significant role in viral replication and particle assembly.
空心病毒颗粒由中央核心和外壳组成，外壳由七种结构蛋白（VP1-VP7）构成。VP6 蛋白已被鉴定为稳定内部核心框架 VP3 的夹蛋白，并连接外壳蛋白 VP5。然而，VP6 在病毒生命周期中的生物学特性尚不清楚。
本研究在大肠杆菌中表达了空心病毒的重组 VP6（rVP6），并使用纯化的 rVP6 制备了针对 VP6 的多克隆抗体。制备 VP6 抗体后，通过免疫印迹（IB）检测感染细胞和纯化病毒颗粒中的 VP6 成分。此外，通过免疫荧光（IF）显微镜观察，单独转染的 VP6 蛋白呈弥散分布，主要位于细胞质中，而在感染细胞中则表现出包涵体形态。同时，当 VP6 与非结构蛋白 NS80 在共转染细胞中共同表达时，也鉴定出包涵体结构。
VP6 可被 NS80 募集到其在感染和转染细胞中的包涵体中。VP6 和 NS80 的共定位与 MRV 中的同源蛋白 σ2 和 μNS 相对应。我们的结果表明，VP6 可能在病毒复制和颗粒组装中发挥重要作用。
