Aquareovirus protein VP6 colocalizes with NS80 protein in infected and transfected cells

Background: 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. Results: 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. Conclusions: 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 sigma 2 and mu NS in MRV. Our results suggest that VP6 may play a significant role in viral replication and particle assembly.