Virus Inhibitory Protein (Viperin)

The deduced 361-amino acid protein has a calculated molecular mass of 42.1 kD. Viperin contains an N-terminal leucine zipper motif and a domain associated with iron-sulfur cluster coordination. Viperin shares significant homology with Best5, which is expressed during rat osteoblast differentiation, and Vig1, which is induced in rainbow trout infected with a fish rhabdovirus. The N-terminal leucine zipper motifs display the least homology. Western blot analysis of IFNG-treated macrophages and transfected HeLa cells revealed a major band of 43 kD and a minor band of 35 kD.HCMV infection caused redistribution of the induced viperin from its normal endoplasmic reticulum association, first to the Golgi apparatus and then to cytoplasmic vacuoles containing gB and the HCMV structural protein pp28.