scholarly journals Lack of Effect of Cytoplasmic Tail Truncations on Human Immunodeficiency Virus Type 2 ROD Env Particle Release Activity

1999 ◽  
Vol 73 (1) ◽  
pp. 778-782 ◽  
Author(s):  
Stephan P. Bour ◽  
Claudia Aberham ◽  
Christèle Perrin ◽  
Klaus Strebel
Keyword(s):  
Human Immunodeficiency Virus ◽  
Biological Activity ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Amino Acid Level ◽  
Cytoplasmic Tail ◽  
Site Directed Mutagenesis ◽  
Particle Release ◽  
Immunodeficiency Virus

ABSTRACT In addition to its role in receptor binding, the envelope glycoprotein of certain human immunodeficiency virus type 2 (HIV-2) isolates, including ROD10, exhibits a biological activity that enhances the release of HIV-2, HIV-1, and simian immunodeficiency virus particles from infected cells. The present study aims at better defining the functional domains involved in this biological activity. To this end, we have characterized the envelope protein of the ROD14 isolate of HIV-2, which, despite 95% homology with the ROD10 envelope at the amino acid level, is unable to enhance viral particle release. Site-directed mutagenesis showed that the presence of a truncation in the cytoplasmic tail of the ROD14 envelope was not responsible for the lack of activity, as previously reported for the HIV-2 ST isolate (G. D. Ritter, Jr., G. Yamshchikov, S. J. Cohen, and M. J. Mulligan, J. Virol. 70:2669–2673, 1996). Similarly, several modifications of the length of the ROD10 envelope cytoplasmic tail did not impair its ability to enhance particle release, suggesting that, in the case of the HIV-2 ROD isolate, particle release activity is not regulated by the length of the cytoplasmic tail.

scholarly journals Cellular Membrane-Binding Ability of the C-Terminal Cytoplasmic Domain of Human Immunodeficiency Virus Type 1 Envelope Transmembrane Protein gp41

2001 ◽  
Vol 75 (20) ◽  
pp. 9925-9938 ◽  
Author(s):  
Steve S.-L. Chen ◽  
Sheau-Fen Lee ◽  
Chin-Tien Wang
Keyword(s):  
Amino Acids ◽  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Membrane Binding ◽  
Cytoplasmic Tail ◽  
Cellular Membrane ◽  
C Terminus ◽  
Immunodeficiency Virus

ABSTRACT The amphipathic α-helices located in the cytoplasmic tail of the envelope (Env) transmembrane glycoprotein gp41 of human immunodeficiency virus type 1 have been implicated in membrane association and cytopathicity. Deletion of the last 12 amino acids in the C terminus of this domain severely impairs infectivity. However, the nature of the involvement of the cytoplasmic tail in Env-membrane interactions in cells and the molecular basis for the defect in infectivity of this mutant virus are still poorly understood. In this study we examined the interaction of the cytoplasmic tail with membranes in living mammalian cells by expressing a recombinant cytoplasmic tail fragment and an Escherichia coli β-galactosidase/cytoplasmic tail fusion protein, both of them lacking gp120, the gp41 ectodomain, and the transmembrane region. We found through cell fractionation, in vivo membrane flotation, and confocal immunofluorescence studies that the cytoplasmic tail contained determinants to be routed to a perinuclear membrane region in cells. Further mapping showed that each of the three lentivirus lytic peptide (LLP-1, LLP-2, and LLP-3) sequences conferred this cellular membrane-targeting ability. Deletion of the last 12 amino acids from the C terminus abolished the ability of the LLP-1 motif to bind to membranes. High salt extraction, in vitro transcription and translation, and posttranslational membrane binding analyses indicated that the β-galactosidase/LLP fusion proteins were inserted into membranes via the LLP sequences. Subcellular fractionation and confocal microscopy studies revealed that each of the LLP motifs, acting in a position-independent manner, targeted non-endoplasmic reticulum (ER)-associated β-galactosidase and enhanced green fluorescence protein to the ER. Our study provides a basis for the involvement of the gp41 cytoplasmic tail during Env maturation and also supports the notion that the membrane apposition of the C-terminal cytoplasmic tail plays a crucial role in virus-host interaction.

Human immunodeficiency virus type 2 envelope glycoprotein: Differential CD4 interactions of soluble gpl20 versus the assembled envelope complex

Virology ◽  
1992 ◽  
Vol 187 (1) ◽  
pp. 233-241 ◽  
Author(s):  
Mark J. Mulligan ◽  
G.Douglas Ritter ◽  
Margery A. Chaikinj ◽  
Galina V. Yamshchikov ◽  
Prasanna Kumar ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Envelope Glycoprotein ◽  
Immunodeficiency Virus
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