THE CYTOPLASMIC AND TRANSMEMBRANE DOMAINS OF THE VACCINIA VIRUS B5R PROTEIN TARGET A CHIMERIC HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 GLYCOPROTEIN TO THE OUTER ENVELOPE OF NASCENT VACCINIA VIRIONS
E. Katz et al., THE CYTOPLASMIC AND TRANSMEMBRANE DOMAINS OF THE VACCINIA VIRUS B5R PROTEIN TARGET A CHIMERIC HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 GLYCOPROTEIN TO THE OUTER ENVELOPE OF NASCENT VACCINIA VIRIONS, Journal of virology, 71(4), 1997, pp. 3178-3187
The outer envelope of the extracellular form of vaccinia virus (EEV) i
s derived from the Golgi membrane and contains at least six viral prot
eins. Transfection studies indicated that the EEV protein encoded by t
he B5R gene associates with Golgi membranes when synthesized in the ab
sence of other viral products, a domain swapping strategy was then use
d to investigate the possibility that the B5R protein contains an EEV
targeting signal. We constructed chimeric genes encoding the human imm
unodeficiency virus (HIV) type 1 glycoprotein with the cytoplasmic and
transmembrane domains replaced by the corresponding 42-amino-acid C-t
erminal segment of the B5R protein. Recombinant vaccinia viruses that
stably express a chimeric B5R-HIV protein or a control HIV envelope pr
otein with the original cytoplasmic and transmembrane domains were iso
lated. Cells infected with recombinant vaccinia viruses that expressed
either the unmodified or the chimeric HIV envelope protein formed syn
cytia with cells expressing the CD4 receptor for HIV. However, biochem
ical and microscopic studies demonstrated that the HIV envelope protei
ns with the B5R cytoplasmic and transmembrane domains were preferentia
lly targeted to the EEV. These data are consistent with the presence o
f EEV localization signals in the cytoplasmic and transmembrane domain
s of the B5R protein.