Fig 10. A model for HCPro-VCS interaction in PVA infection.

We present here a hypothetical model of a core complex, which contains both HCPro and VCS and guides PVA RNA through the different stages of infection. We propose that after PVA RNA is released from the viral replication complex it connects with HCPro. HCPro then recruits VCS to assist in the formation of multiprotein complexes. The composition of these complexes probably varies depending on the infection stage. Interaction between HCPro and VCS is required for the formation of PGs, which form to suppress RNA silencing and to enable active PVA translation. Finally, the multiprotein complex formed around HCPro-VCS seals the PVA particles. This is essential for both the stability of PVA RNA within particles and the systemic spread of PVA infection.