The vaccinia virus F17R protein interacts with actin

We have examined the possible role of the F17R protein in vaccinia virus-induced rearrangements of the host actin cytoskeleton. F17R is localized to vaccinia-induced actin tails late during infection. The recombinant vaccinia strain vRO11k is able to induce actin tails that are indistinguishable from controls in the absence of F17R expression. The association of vaccinia and myxoma virus F17R with the actin cytoskeleton in the absence of additional viral factors suggests a basic region in the N-terminal half of the protein is important for this interaction. A peptide corresponding to this region efficiently bundles actin filaments in vitro, confirming that the protein interacts directly with actin. Our results show F17R is not required for actin tail formation and highlight the difficulty in discriminating functional actin-binding proteins from those that associate by virtue of their basic nature.