This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lin, X.
Right arrow Articles by Hunter, E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lin, X.
Right arrow Articles by Hunter, E.

 Previous Article  |  Next Article 

Journal of Virology, June 2003, p. 7067-7077, Vol. 77, No. 12
0022-538X/03/$08.00+0     DOI: 10.1128/JVI.77.12.7067-7077.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

Progressive Truncations C Terminal to the Membrane-Spanning Domain of Simian Immunodeficiency Virus Env Reduce Fusogenicity and Increase Concentration Dependence of Env for Fusion

Xiaoxu Lin,1,{dagger} Cynthia A. Derdeyn,1 Robert Blumenthal,2 John West,1 and Eric Hunter1*

Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama 35294,1 Section of Membrane Structure and Function, Laboratory of Experimental and Computational Biology, National Cancer Institute—Frederick Cancer Research and Development Center, Frederick, Maryland 217022

Received 21 November 2002/ Accepted 24 March 2003

The simian immunodeficiency virus (SIV) transmembrane (TM) protein, gp41, has multiple functions, which include anchoring the glycoprotein complex in the lipid envelope of the virus and mediating fusion of the virus and host cell membranes. Recently, a series of mutants of the SIVmac239 TM protein that have truncations at the carboxyl terminus of the membrane-spanning domain (MSD) have been characterized (J. T. West, P. Johnston, S. R. Dubay, and E. Hunter, J. Virol. 75:9601-9612, 2001). These mutants retained membrane anchorage but demonstrated reduced fusogenicity and infectivity as the MSD length was shortened. We have established a novel three-color fluorescence assay, which allows qualitative confocal and quantitative flow cytometric analyses, to further characterize the nature of the fusion defect in five of the MSD mutants: TM185, TM186, TM187, TM188, and TM189. Our analysis showed that each mutant could mediate complete lipid and aqueous dye transfer at early time points after effector and target cell mixing. No hemifusion with only lipid dye flux was detected. However, another intermediate fusion stage, which appears to involve small-fusion-pore formation that allowed small aqueous dye transfer but prevented the exchange of large cytoplasmic components, was identified infrequently in mutant-Env-expressing cell and target cell mixtures. Quantitative flow cytometric analysis of these mutants demonstrated that the TM187, TM188, and TM189 mutants were significantly more fusogenic than TM185 and TM186 but remained significantly impaired compared to the wild type. Moreover, fusion efficiency showed an increased dependence on the expression level of glycoproteins, suggesting that, for these mutants, formation of an active fusion complex was an increasingly stochastic event.

* Corresponding author. Mailing address: Department of Microbiology, The University of Alabama at Birmingham, 256 Bevill Biomedical Res. Bldg., 845 19th St. South, Birmingham, AL 35294-2170. Phone: (205) 934-4321. Fax: (205) 934-1640. E-mail: ehunter{at}uab.edu.

{dagger} Present address: Department of Microbiology and Immunology, Emory University, Atlanta, GA 30329.

Journal of Virology, June 2003, p. 7067-7077, Vol. 77, No. 12
0022-538X/03/$08.00+0     DOI: 10.1128/JVI.77.12.7067-7077.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Yue, L., Shang, L., Hunter, E. (2009). Truncation of the Membrane-Spanning Domain of Human Immunodeficiency Virus Type 1 Envelope Glycoprotein Defines Elements Required for Fusion, Incorporation, and Infectivity. J. Virol. 83: 11588-11598 [Abstract] [Full Text]  
  • Shang, L., Yue, L., Hunter, E. (2008). Role of the Membrane-Spanning Domain of Human Immunodeficiency Virus Type 1 Envelope Glycoprotein in Cell-Cell Fusion and Virus Infection. J. Virol. 82: 5417-5428 [Abstract] [Full Text]  
  • Montero, M., van Houten, N. E., Wang, X., Scott, J. K. (2008). The Membrane-Proximal External Region of the Human Immunodeficiency Virus Type 1 Envelope: Dominant Site of Antibody Neutralization and Target for Vaccine Design. Microbiol. Mol. Biol. Rev. 72: 54-84 [Abstract] [Full Text]  
  • Cote, M., Zheng, Y.-M., Albritton, L. M., Liu, S.-L. (2008). Fusogenicity of Jaagsiekte Sheep Retrovirus Envelope Protein Is Dependent on Low pH and Is Enhanced by Cytoplasmic Tail Truncations. J. Virol. 82: 2543-2554 [Abstract] [Full Text]  
  • Murphy, S. L., Gaulton, G. N. (2007). TR1.3 Viral Pathogenesis and Syncytium Formation Are Linked to Env-Gag Cooperation. J. Virol. 81: 10777-10785 [Abstract] [Full Text]  
  • Miyauchi, K., Komano, J., Yokomaku, Y., Sugiura, W., Yamamoto, N., Matsuda, Z. (2005). Role of the Specific Amino Acid Sequence of the Membrane-Spanning Domain of Human Immunodeficiency Virus Type 1 in Membrane Fusion. J. Virol. 79: 4720-4729 [Abstract] [Full Text]  
  • Abrahamyan, L. G., Mkrtchyan, S. R., Binley, J., Lu, M., Melikyan, G. B., Cohen, F. S. (2005). The Cytoplasmic Tail Slows the Folding of Human Immunodeficiency Virus Type 1 Env from a Late Prebundle Configuration into the Six-Helix Bundle. J. Virol. 79: 106-115 [Abstract] [Full Text]  
  • York, J., Romanowski, V., Lu, M., Nunberg, J. H. (2004). The Signal Peptide of the Junin Arenavirus Envelope Glycoprotein Is Myristoylated and Forms an Essential Subunit of the Mature G1-G2 Complex. J. Virol. 78: 10783-10792 [Abstract] [Full Text]  
  • Matsuyama, S., Delos, S. E., White, J. M. (2004). Sequential Roles of Receptor Binding and Low pH in Forming Prehairpin and Hairpin Conformations of a Retroviral Envelope Glycoprotein. J. Virol. 78: 8201-8209 [Abstract] [Full Text]  
  • Bar, S., Alizon, M. (2004). Role of the Ectodomain of the gp41 Transmembrane Envelope Protein of Human Immunodeficiency Virus Type 1 in Late Steps of the Membrane Fusion Process. J. Virol. 78: 811-820 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»