Expression of the highly conserved vaccinia virus E6 protein is required for virion morphogenesis.
The vaccinia virus E6R gene (VACVWR062) is conserved in all members of the poxvirus family and encodes a protein associated with the mature virion. We confirmed this association and provided evidence for an internal location. An inducible mutant that conditionally expresses E6 was constructed. In the absence of inducer, plaque formation and virus production were severely inhibited in several cell lines, whereas some replication occurred in others. This difference could be due to variation in the stringency of repression, since we could not isolate a stable deletion mutant even in the more "permissive" cells. Under non-permissive conditions, viral late proteins were synthesized but processing of core proteins was inefficient, indicative of an assembly block. Transmission electron microscopy of sections of cells infected with the mutant in the absence of inducer revealed morphogenetic defects with crescents and empty immature virions adjacent to dense inclusions of viroplasm. Mature virions were infrequent and cores appeared to have lucent centers.
Resch
Wolfgang
W
Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-3210, USA.
Weisberg
Andrea S
AS
Moss
Bernard
B
D000595:Amino Acid Sequence; D000818:Animals; D002522:Chlorocebus aethiops; D017124:Conserved Sequence; D004279:DNA, Viral / Q000235:genetics; D015967:Gene Expression Regulation, Viral; D020043:Genes, Essential; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D014616:Vaccinia virus / Q000235:genetics / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure; D014709:Vero Cells; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014771:Virion / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure*; D019065:Virus Assembly; D014779:Virus Replication
D004279:DNA, Viral; D014764:Viral Proteins