Open AccessPosttranslational Modifications within the HIV-1 Envelope Glycoprotein Which Restrict Virus Assembly and CD4-Dependent Infection
Author(s) -
Sheryl Haggerty,
Michael P. Dempsey,
Michael Bukrinsky,
Lin Guo,
Mario Stevenson
Publication year - 1991
Publication title -
aids research and human retroviruses
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.993
H-Index - 92
eISSN - 1931-8405
pISSN - 0889-2229
DOI - 10.1089/aid.1991.7.501
Subject(s) - glycoprotein , biology , virology , tropism , virus , herpesvirus glycoprotein b , mutant , glycosylation , viral replication , viral entry , viral envelope , mutation , mutagenesis , microbiology and biotechnology , genetics , gene
Alterations in two highly conserved N-linked glycosylation sites within the gp120 envelope glycoprotein of human immunodeficiency virus type I (HIV-1) implicated in the phenotype of a noncytopathic HIV-1 variant were introduced independently and in combination into a cytopathic, infectious HIV-1 clone by site-specific mutagenesis. Neither mutation affected the synthesis of HIV-1 envelope glycoproteins. However, one of the mutations restricted the ability of HIV-1 envelope to localize on the cell membrane and thus markedly impaired virus assembly. The HIV-1 assembly defect could be overcome in trans if site-specific mutants were packaged in HeLa cells constitutively producing wild-type HIV-1 envelope glycoprotein. In addition to inefficient virus assembly, this mutation impaired the ability of the virus to infect CD4+ T cells, but did not affect CD4-independent infection of muscle cells. These results suggest additional functions of posttranslational modification in virus replication (i.e., envelope glycoprotein transport). Given that such modifications can restrict CD4-mediated uptake without affecting CD4-independent uptake, variations in posttranslational env processing between different HIV-1 genotypes may affect virus tropism in vivo.