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 Parker, S. D.
Right arrow Articles by Hunter, E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Parker, S. D.
Right arrow Articles by Hunter, E.

 Previous Article  |  Next Article 

Journal of Virology, January 2000, p. 784-795, Vol. 74, No. 2
0022-538X/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

A Cell-Line-Specific Defect in the Intracellular Transport and Release of Assembled Retroviral Capsids

Scott D. Parker1 and Eric Hunter2,*

Division of Infectious Diseases, Department of Medicine,1 and Department of Microbiology,2 University of Alabama at Birmingham, Birmingham, Alabama 35294

Received 15 July 1999/Accepted 12 October 1999

Retrovirus assembly involves a complex series of events in which a large number of proteins must be targeted to a point on the plasma membrane where immature viruses bud from the cell. Gag polyproteins of most retroviruses assemble an immature capsid on the cytoplasmic side of the plasma membrane during the budding process (C-type assembly), but a few assemble immature capsids deep in the cytoplasm and are then transported to the plasma membrane (B- or D-type assembly), where they are enveloped. With both assembly phenotypes, Gag polyproteins must be transported to the site of viral budding in either a relatively unassembled form (C type) or a completely assembled form (B and D types). The molecular nature of this transport process and the host cell factors that are involved have remained obscure. During the development of a recombinant baculovirus/insect cell system for the expression of both C-type and D-type Gag polyproteins, we discovered an insect cell line (High Five) with two distinct defects that resulted in the reduced release of virus-like particles. The first of these was a pronounced defect in the transport of D-type but not C-type Gag polyproteins to the plasma membrane. High Five cells expressing wild-type Mason-Pfizer monkey virus (M-PMV) Gag precursors accumulate assembled immature capsids in large cytoplasmic aggregates similar to a transport-defective mutant (MA-A18V). In contrast, a larger fraction of the Gag molecules encoded by the M-PMV C-type morphogenesis mutant (MA-R55W) and those of human immunodeficiency virus were transported to the plasma membrane for assembly and budding of virions. When pulse-labeled Gag precursors from High Five cells were fractionated on velocity gradients, they sedimented more rapidly, indicating that they are sequestered in a higher-molecular-mass complex. Compared to Sf9 insect cells, the High Five cells also demonstrate a defect in the release of C-type virus particles. These findings support the hypothesis that host cell factors are important in the process of Gag transport and in the release of enveloped viral particles.

* Corresponding author. Mailing address: Department of Microbiology, University of Alabama at Birmingham, 908 20th St. So., Birmingham, AL 35294. Phone: (205) 934-4321. Fax: (205) 934-1640. E-mail: Ehunter{at}UAB.edu.

Journal of Virology, January 2000, p. 784-795, Vol. 74, No. 2
0022-538X/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Andersen, K. B., Diep, H. A., Zedeler, A. (2006). Murine leukemia virus transmembrane protein R-peptide is found in small virus core-like complexes in cells. J. Gen. Virol. 87: 1583-1588 [Abstract] [Full Text]  
  • Abdurahman, S., Hoglund, S., Goobar-Larsson, L., Vahlne, A. (2004). Selected amino acid substitutions in the C-terminal region of human immunodeficiency virus type 1 capsid protein affect virus assembly and release. J. Gen. Virol. 85: 2903-2913 [Abstract] [Full Text]  
  • Serhan, F., Jourdan, N., Saleun, S., Moullier, P., Duisit, G. (2002). Characterization of Producer Cell-Dependent Restriction of Murine Leukemia Virus Replication. J. Virol. 76: 6609-6617 [Abstract] [Full Text]  
  • Parker, S. D., Hunter, E. (2001). Activation of the Mason-Pfizer monkey virus protease within immature capsids invitro. Proc. Natl. Acad. Sci. USA 10.1073/pnas.251460998v1 [Abstract] [Full Text]  
  • Parker, S. D., Wall, J. S., Hunter, E. (2001). Analysis of Mason-Pfizer Monkey Virus Gag Particles by Scanning Transmission Electron Microscopy. J. Virol. 75: 9543-9548 [Abstract] [Full Text]  
  • Eastman, S. W., Linial, M. L. (2001). Identification of a Conserved Residue of Foamy Virus Gag Required for Intracellular Capsid Assembly. J. Virol. 75: 6857-6864 [Abstract] [Full Text]  
  • Tritel, M., Resh, M. D. (2001). The Late Stage of Human Immunodeficiency Virus Type 1 Assembly Is an Energy-Dependent Process. J. Virol. 75: 5473-5481 [Abstract] [Full Text]  
  • Bieniasz, P. D., Cullen, B. R. (2000). Multiple Blocks to Human Immunodeficiency Virus Type 1 Replication in Rodent Cells. J. Virol. 74: 9868-9877 [Abstract] [Full Text]  
  • Rumlova-Klikova, M., Hunter, E., Nermut, M. V., Pichova, I., Ruml, T. (2000). Analysis of Mason-Pfizer Monkey Virus Gag Domains Required for Capsid Assembly in Bacteria: Role of the N-Terminal Proline Residue of CA in Directing Particle Shape. J. Virol. 74: 8452-8459 [Abstract] [Full Text]  
  • Parker, S. D., Hunter, E. (2001). Activation of the Mason-Pfizer monkey virus protease within immature capsids invitro. Proc. Natl. Acad. Sci. USA 98: 14631-14636 [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»