Cytoplasmic domain truncation enhances fusion activity by the exterior glycoprotein complex of human immunodeficiency virus type 2 in selected cell types.

Journal Article (Journal Article)

To investigate the glycoprotein determinants of viral cytopathology, we constructed chimeric env genes between a noncytopathic strain of human immunodeficiency virus type 2 (HIV-2), designated HIV-2/ST, and a highly fusogenic and cytopathic variant derived from this virus. Expression of the resulting chimeric glycoproteins indicated that efficient syncytium formation in the human T-cell line Sup T1 mapped to the C-terminal region of the transmembrane (TM) glycoprotein subunit. In this region, the wild-type and cytopathic ST glycoproteins differed by only four amino acids and by the presence of a premature termination codon in the cytopathic variant. Subsequent site-directed mutagenesis indicated that the cytoplasmic domain truncation was responsible for the enhanced fusion activity. This modification, however, increased the fusion activity of the glycoprotein only in Sup T1 cells (in which the ST variant arose) but not in Molt 4 clone 8 or peripheral blood mononuclear cells. These observations indicate that the length of the cytoplasmic domain of the HIV-2 glycoprotein modulates the fusion activity of the exterior glycoprotein complex in a cell-specific manner. Such adaptability appears to permit the emergence of fusogenic variants during HIV-2 passage in vitro and may also regulate viral growth or cytopathic effects in selected cell types during natural infection in vivo.

Full Text

Duke Authors

Cited Authors

  • Mulligan, MJ; Yamshchikov, GV; Ritter, GD; Gao, F; Jin, MJ; Nail, CD; Spies, CP; Hahn, BH; Compans, RW

Published Date

  • June 1992

Published In

Volume / Issue

  • 66 / 6

Start / End Page

  • 3971 - 3975

PubMed ID

  • 1583738

Pubmed Central ID

  • PMC241192

International Standard Serial Number (ISSN)

  • 0022-538X

Digital Object Identifier (DOI)

  • 10.1128/JVI.66.6.3971-3975.1992


  • eng

Conference Location

  • United States