title: Part of the C-terminal tail of the envelope gp41 transmembrane glycoprotein of human immunodeficiency virus type 1 is exposed on the surface of infected cells and is involved in virus-mediated cell fusion.
abstract: The C-terminal tail of the gp41 transmembrane glycoprotein of the human immunodeficiency virus type 1 (HIV-1) virion is usually thought to be inside the virion, but it has been shown recently that part of the tail is exposed on the virion exterior. Here, using a panel of antibodies, it was demonstrated that the same part of the tail is exposed on the surface of HIV-1-infected C8166 lymphoblastoid cells and HeLa cells infected with a gp41-expressing vaccinia virus recombinant. Both types of infected cell failed to react with p17 matrix protein-specific IgGs until permeabilized with saponin, confirming the integrity of the plasma membrane. Cell-surface exposure of the gp41 tail was independently demonstrated by inhibition of HIV-1-mediated cell-cell fusion by one of the gp41 tail-specific antibodies. These data also implicate the exposed region of the gp41 C-terminal tail either directly or indirectly in the viral fusion process. Its surface exposure suggests that the gp41 C-terminal tail may be a candidate for immune intervention or chemotherapy of infection.
authors.affiliation: Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Linda
authors.initials: L
authors.lastname: Cheung
authors.affiliation: Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Lesley
authors.initials: L
authors.lastname: McLain
authors.affiliation: Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Hollier
authors.affiliation: Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Reading
authors.affiliation: Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Dimmock
mesh_terms: D002459:Cell Fusion; D002460:Cell Line; D002461:Cell Line, Transformed; D002473:Cell Wall / Q000378:metabolism; D015700:HIV Envelope Protein gp41 / Q000737:chemistry / Q000378:metabolism*; D015497:HIV-1 / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D013601:T-Lymphocytes / Q000378:metabolism / Q000821:virology; D014779:Virus Replication
chemical_list: D015700:HIV Envelope Protein gp41