Expression and partial characterisation of rabbit haemorrhagic disease virus non-structural proteins

The intracellular replication and molecular virulence mechanisms of Rabbit haemorrhagic disease virus (RHDV) are poorly understood, mainly due to the lack of an effective cell culture system for this virus. To increase our understanding of RHDV molecular biology, the subcellular localisation of recombinant non-structural RHDV proteins was investigated in transiently transfected rabbit kidney (RK-13) cells. We provide evidence for oligomerisation of p23, and an ability of the viral protease to cleave the p16:p23 junction in trans, outside the context of the nascent polyprotein chain. Notably, expression of the viral polymerase alone and in the context of the entire RHDV polyprotein resulted in a redistribution of the Golgi network. This suggests that, similar to other positive-strand RNA viruses, RHDV may recruit membranes of the secretory pathway during replication, and that the viral polymerase may play a critical role during this process.