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.
The outer envelope of the extracellular form of vaccinia virus (EEV) is derived from the Golgi membrane and contains at least six viral proteins. Transfection studies indicated that the EEV protein encoded by the B5R gene associates with Golgi membranes when synthesized in the absence of other viral products. A domain swapping strategy was then used to investigate the possibility that the B5R protein contains an EEV targeting signal. We constructed chimeric genes encoding the human immunodeficiency virus (HIV) type 1 glycoprotein with the cytoplasmic and transmembrane domains replaced by the corresponding 42-amino-acid C-terminal segment of the B5R protein. Recombinant vaccinia viruses that stably express a chimeric B5R-HIV protein or a control HIV envelope protein with the original cytoplasmic and transmembrane domains were isolated. Cells infected with recombinant vaccinia viruses that expressed either the unmodified or the chimeric HIV envelope protein formed syncytia with cells expressing the CD4 receptor for HIV. However, biochemical and microscopic studies demonstrated that the HIV envelope proteins with the B5R cytoplasmic and transmembrane domains were preferentially targeted to the EEV. These data are consistent with the presence of EEV localization signals in the cytoplasmic and transmembrane domains of the B5R protein.
Katz
E
E
Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892-0445, USA.
Wolffe
E J
EJ
Moss
B
B
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001692:Biological Transport; D019556:COS Cells; D002460:Cell Line; D002462:Cell Membrane; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D003593:Cytoplasm; D004591:Electrophoresis, Polyacrylamide Gel; D015686:Gene Products, env / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D014616:Vaccinia virus / Q000235:genetics / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism*
D015686:Gene Products, env; D008562:Membrane Glycoproteins; D011993:Recombinant Fusion Proteins; D014759:Viral Envelope Proteins; C074512:42kDa protein, Vaccinia virus