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 Mahalingam, S.
Right arrow Articles by Hahn, B. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Mahalingam, S.
Right arrow Articles by Hahn, B. H.

 Previous Article  |  Next Article 

Journal of Virology, January 2001, p. 362-374, Vol. 75, No. 1
0022-538X/01/$04.00+0   DOI: 10.1128/JVI.75.1.362-374.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.

Functional Analysis of the Simian Immunodeficiency Virus Vpx Protein: Identification of Packaging Determinants and a Novel Nuclear Targeting Domain

Sundarasamy Mahalingam,1,dagger Brian Van Tine,1 Mario L. Santiago,2 Feng Gao,1 George M. Shaw,1,2,3 and Beatrice H. Hahn1,2,*

Departments of Medicine1 and Microbiology2 and Howard Hughes Medical Institute,3 University of Alabama at Birmingham, Birmingham, Alabama 35294

Received 24 July 2000/Accepted 9 October 2000

The vpx gene products of human immunodeficiency virus type 2 (HIV-2) and of the closely related simian immunodeficiency viruses from sooty mangabeys (SIVsm) and macaques (SIVmac) comprise a 112-amino-acid virion-associated protein that is critical for efficient virus replication in nondividing cells such as macrophages. When expressed in the absence of other viral proteins, Vpx localizes to the nuclear membrane as well as to the nucleus; however, in the context of virus replication Vpx is packaged into virions via interaction with the p6 domain of the Gag precursor polyprotein (p55gag). To identify the domains essential for virion incorporation and nuclear localization, site-directed mutations were introduced into the vpx gene of SIVsmPBj1.9 and functionally analyzed. Our results show that (i) mutation of two highly conserved L74 and I75 residues impaired both virion incorporation and nuclear localization of Vpx; (ii) substitution of conserved H82, G86, C87, P103, and P106 residues impaired Vpx nuclear localization but not virion incorporation; (iii) mutations of conserved Y66, Y69, and Y71 residues impaired virion incorporation but not the translocation of Vpx to the nucleus; and (iv) a mutation at E30 (predicted to disrupt an N-terminal alpha -helix) had no effect on either virion incorporation or nuclear localization of Vpx. Importantly, mutations in Vpx which impaired nuclear localization also reduced virus replication in macaque macrophages, suggesting an important role of the carboxyl terminus of Vpx in nuclear translocation of the viral preintegration complex. Analyzing this domain in greater detail, we identified a 26-amino-acid (aa 60 to 85) fragment that was sufficient to mediate the transport of a heterologous protein (green fluorescent protein [GFP]) to the nucleus. Taken together, these results indicate that virion incorporation and nuclear localization are encoded by two partially overlapping domains in the C-terminus of Vpx (aa 60 to 112). The identification of a novel 26-amino-acid nuclear targeting domain provides a new tool to investigate the nuclear import of the HIV-2/SIV preintegration complex.

* Corresponding author. Mailing address: Departments of Medicine and Microbiology, University of Alabama at Birmingham, LHRB 613, 701 19th St. South, Birmingham, AL 35294. Phone: (205) 934-0412. Fax: (205) 934-1580. E-mail: bhahn{at}uab.edu.

dagger Laboratory of Molecular Virology, Center for DNA Fingerprinting and Diagnostics, Nacharam, Hyderabad 500 076, India.

Journal of Virology, January 2001, p. 362-374, Vol. 75, No. 1
0022-538X/01/$04.00+0   DOI: 10.1128/JVI.75.1.362-374.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Bergamaschi, A., Ayinde, D., David, A., Le Rouzic, E., Morel, M., Collin, G., Descamps, D., Damond, F., Brun-Vezinet, F., Nisole, S., Margottin-Goguet, F., Pancino, G., Transy, C. (2009). The Human Immunodeficiency Virus Type 2 Vpx Protein Usurps the CUL4A-DDB1DCAF1 Ubiquitin Ligase To Overcome a Postentry Block in Macrophage Infection. J. Virol. 83: 4854-4860 [Abstract] [Full Text]  
  • Goujon, C., Arfi, V., Pertel, T., Luban, J., Lienard, J., Rigal, D., Darlix, J.-L., Cimarelli, A. (2008). Characterization of Simian Immunodeficiency Virus SIVSM/Human Immunodeficiency Virus Type 2 Vpx Function in Human Myeloid Cells. J. Virol. 82: 12335-12345 [Abstract] [Full Text]  
  • Cheng, X., Belshan, M., Ratner, L. (2008). Hsp40 Facilitates Nuclear Import of the Human Immunodeficiency Virus Type 2 Vpx-Mediated Preintegration Complex. J. Virol. 82: 1229-1237 [Abstract] [Full Text]  
  • Singhal, P. K., Rajendra Kumar, P., Subba Rao, M. R. K., Mahalingam, S. (2006). Nuclear Export of Simian Immunodeficiency Virus Vpx Protein. J. Virol. 80: 12271-12282 [Abstract] [Full Text]  
  • Singhal, P. K., Kumar, P. R., Rao, M. R. K. S., Kyasani, M., Mahalingam, S. (2006). Simian Immunodeficiency Virus Vpx Is Imported into the Nucleus via Importin Alpha-Dependent and -Independent Pathways. J. Virol. 80: 526-536 [Abstract] [Full Text]  
  • Rajendra Kumar, P., Singhal, P. K., Subba Rao, M. R. K., Mahalingam, S. (2005). Phosphorylation by MAPK Regulates Simian Immunodeficiency Virus Vpx Protein Nuclear Import and Virus Infectivity. J. Biol. Chem. 280: 8553-8563 [Abstract] [Full Text]  
  • Mueller, S. M., Jung, R., Weiler, S., Lang, S. M. (2004). Vpx proteins of SIVmac239 and HIV-2ROD interact with the cytoskeletal protein {alpha}-actinin 1. J. Gen. Virol. 85: 3291-3303 [Abstract] [Full Text]  
  • Zander, K., Sherman, M. P., Tessmer, U., Bruns, K., Wray, V., Prechtel, A. T., Schubert, E., Henklein, P., Luban, J., Neidleman, J., Greene, W. C., Schubert, U. (2003). Cyclophilin A Interacts with HIV-1 Vpr and Is Required for Its Functional Expression. J. Biol. Chem. 278: 43202-43213 [Abstract] [Full Text]  
  • Hu, J., Switzer, W. M., Foley, B. T., Robertson, D. L., Goeken, R. M., Korber, B. T., Hirsch, V. M., Beer, B. E. (2003). Characterization and Comparison of Recombinant Simian Immunodeficiency Virus from Drill (Mandrillus leucophaeus) and Mandrill (Mandrillus sphinx) Isolates. J. Virol. 77: 4867-4880 [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»