Open AccessVaccinia Virus F12L Protein Is Required for Actin Tail Formation, Normal Plaque Size, and Virulence
Author(s) -
Weihong Zhang,
Diane Wilcock,
Geoffrey L. Smith
Publication year - 2000
Publication title -
journal of virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.617
H-Index - 292
eISSN - 1070-6321
pISSN - 0022-538X
DOI - 10.1128/jvi.74.24.11654-11662.2000
Subject(s) - biology , virus , virology , mutant , vaccinia , vp40 , gene , poxviridae , virulence , microbiology and biotechnology , hemagglutinin (influenza) , viral envelope , orthopoxvirus , viral matrix protein , recombinant dna , genetics
Vaccinia virus gene F12L is shown to encode a 65-kDa protein that is synthesized early and late during infection and that is not modified by glycosylation. Computational sequence comparison revealed that related proteins are encoded by all sequenced chordopoxviruses. A virus deletion mutant lacking the F12L gene (vΔF12L) and a revertant virus with the F12L gene reinserted into the deletion mutant (vF12L-rev) were constructed and analyzed. A version of the F12L gene with a C-terminal amino acid tag derived from the influenza virus hemagglutinin and that is recognized by a monoclonal antibody was also inserted into the F12L locus of vΔF12L. Loss of the F12L protein reduced the formation of IMV 2-fold, but there was a dramatic (99.5%) reduction in actin tail formation, and the levels of cell-associated enveloped virus and extracellular enveloped virus were reduced 8- to 11-fold and 7-fold, respectively. Consistent with the lack of actin tail formation, vΔF12L produced a very small plaque. The vΔF12L virus was severely attenuated in vivo, such that a dose of vΔF12L 10,000-fold greater than the dose of wild-type virus that induced severe disease was unable to induce disease in mice infected intranasally.