Rabbit hemorrhagic disease virus: Genome organization and polyprotein processing of a calicivirus studied after transient expression of cDNA constructs

Rabbit hemorrhagic disease virus (RHDV) belongs to the family Caliciviridae . Studies on this virus are hampered by the lack Of a convenient cell cultu re system. To study viral protein expression a cDNA construct containing th e entire protein-coding region of the virus was established and used for tr ansient expression studies. After metabolic labeling of transfected cells a nd immunoprecipitation with a set of RHDV-specific antisera a variety of po lypeptides were identified and assigned to defined regions of the viral gen ome. The consensus sequences of already identified or putative proteolytic cleavage sites in the viral polyprotein were changed by the introduction of mutations into the expression construct. Expression of these mutated const ructs and analysis of the protein patterns allowed us to identify novel cle avage sites in the polyprotein and revealed the first details regarding the order of polyprotein processing. (C) 2000 Academic Press.