title: Biological characterization of noninfectious HIV-1 particles lacking the envelope protein.
abstract: To understand the role of the HIV-1 envelope protein in the assembly of virus, we constructed a proviral clone of HIV-1 where the methionine initiator codon of the env gene was substituted with a translational stop codon. Upon DNA transfection into permissive cells in culture, this clone produces virus-like particles similar in size to parental virus but are noninfectious in human T-cells, promonocytic cells, and primary macrophages. This mutant readily recombines with a deletion mutant provirus lacking the entire gag-pol region producing a recombinant virus that is infectious. Substitution of the same initiator methionine codon with valine results in a leaky missense mutant provirus capable of a low level of Env protein synthesis that leads to a productive infection. Thus, the prototype initiation codon AUG is dispensable for virus infectivity. Further, the expression of the envelope protein is not a prerequisite for the assembly of the virus particles in the HIV-1 system. These noninfectious envelope-less particles revert readily to wild-type phenotype upon cotransfection with Env-producing plasmid DNAs.
authors.affiliation: Laboratory of Tumor Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: M R
authors.initials: MR
authors.lastname: Sadaie
authors.forename: V S
authors.initials: VS
authors.lastname: Kalyanaraman
authors.forename: R
authors.initials: R
authors.lastname: Mukopadhayaya
authors.forename: E
authors.initials: E
authors.lastname: Tschachler
authors.forename: R C
authors.initials: RC
authors.lastname: Gallo
authors.forename: F
authors.initials: F
authors.lastname: Wong-Staal
mesh_terms: D000818:Animals; D002522:Chlorocebus aethiops; D004252:DNA Mutational Analysis; D003673:Defective Viruses / Q000254:growth & development*; D015686:Gene Products, env / Q000235:genetics*; D015752:Genes, env; D016655:HIV Core Protein p24 / Q000378:metabolism; D015658:HIV Infections / Q000382:microbiology; D015497:HIV-1 / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D066298:In Vitro Techniques; D008264:Macrophages / Q000382:microbiology; D014407:Tumor Cells, Cultured; D014779:Virus Replication
chemical_list: D015686:Gene Products, env; D016655:HIV Core Protein p24