Previous Article | Next Article 
Journal of Virology, September 2004, p. 9924-9935, Vol. 78, No. 18
0022-538X/04/$08.00+0 DOI: 10.1128/JVI.78.18.9924-9935.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
Diverse Roles for E4orf3 at Late Times of Infection Revealed in an E1B 55-Kilodalton Protein Mutant Background
Robin N. Shepard and David A. Ornelles*
Department of Microbiology and Immunology, School of Medicine, Wake Forest University, Winston-Salem, North Carolina
Received 25 November 2003/
Accepted 15 May 2004
Species C human adenovirus mutants that fail to express open reading frame 3 of early region 4 (E4orf3) are phenotypically indistinguishable from the wild-type virus when evaluated in cells cultured in vitro. However, E4orf3 gene function has been productively studied in the context of additional viral mutations. This study identifies diverse roles for the E4orf3 protein that are evident in the absence of early region 1B 55-kDa protein (E1B-55K) function. In an E1B-55K-deficient background, the E4orf3 protein promotes viral replication by increasing both the burst size and the probability that an infected cell will produce virus. Early viral gene expression is not impaired in E1B-55K/E4orf3 double mutant virus-infected cells. Cells infected with the double mutant virus accumulated concatemers of viral DNA. However, the E1B-55K/E4orf3 double mutant virus did not replicate any better in MO59J cells, in which viral DNA concatemers did not accumulate, than in MO59K cells, in which viral DNA concatemers were produced, suggesting that viral DNA concatenation is not the primary growth defect of the E1B-55K/E4orf3 double mutant virus. Accumulation of viral mRNA in the nucleus and cytoplasm of E1B-55K/E4orf3 double mutant virus-infected cells was severely reduced compared to that on wild-type virus-infected cells. Thus, in an E1B-55K mutant background, the E4orf3 protein promotes the accumulation of late viral RNA and enhances late gene expression. Finally, within the context of an E1B-55K mutant virus, the E4orf3 protein acts to suppress host cell translation and preserve the viability of cells at moderately late times of infection.
* Corresponding author. Mailing address: Department of Microbiology and Immunology, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1064. Phone: (336) 716-9332. Fax: (336) 716-9928. E-mail: ornelles{at}wfubmc.edu.
Journal of Virology, September 2004, p. 9924-9935, Vol. 78, No. 18
0022-538X/04/$08.00+0 DOI: 10.1128/JVI.78.18.9924-9935.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
This article has been cited by other articles:
-
Schwartz, R. A., Lakdawala, S. S., Eshleman, H. D., Russell, M. R., Carson, C. T., Weitzman, M. D.
(2008). Distinct Requirements of Adenovirus E1b55K Protein for Degradation of Cellular Substrates. J. Virol.
82: 9043-9055
[Abstract]
[Full Text]
-
Lakdawala, S. S., Schwartz, R. A., Ferenchak, K., Carson, C. T., McSharry, B. P., Wilkinson, G. W., Weitzman, M. D.
(2008). Differential Requirements of the C Terminus of Nbs1 in Suppressing Adenovirus DNA Replication and Promoting Concatemer Formation. J. Virol.
82: 8362-8372
[Abstract]
[Full Text]
-
Ullman, A. J., Hearing, P.
(2008). Cellular Proteins PML and Daxx Mediate an Innate Antiviral Defense Antagonized by the Adenovirus E4 ORF3 Protein. J. Virol.
82: 7325-7335
[Abstract]
[Full Text]
-
Ullman, A. J., Reich, N. C., Hearing, P.
(2007). Adenovirus E4 ORF3 Protein Inhibits the Interferon-Mediated Antiviral Response. J. Virol.
81: 4744-4752
[Abstract]
[Full Text]
-
Yondola, M. A., Hearing, P.
(2007). The Adenovirus E4 ORF3 Protein Binds and Reorganizes the TRIM Family Member Transcriptional Intermediary Factor 1 Alpha. J. Virol.
81: 4264-4271
[Abstract]
[Full Text]
-
Woo, J. L., Berk, A. J.
(2007). Adenovirus Ubiquitin-Protein Ligase Stimulates Viral Late mRNA Nuclear Export. J. Virol.
81: 575-587
[Abstract]
[Full Text]
-
Timpe, J. M., Verrill, K. C., Trempe, J. P.
(2006). Effects of Adeno-Associated Virus on Adenovirus Replication and Gene Expression during Coinfection.. J. Virol.
80: 7807-7815
[Abstract]
[Full Text]
-
Liu, Y., Shevchenko, A., Shevchenko, A., Berk, A. J.
(2005). Adenovirus Exploits the Cellular Aggresome Response To Accelerate Inactivation of the MRN Complex. J. Virol.
79: 14004-14016
[Abstract]
[Full Text]
-
Araujo, F. D., Stracker, T. H., Carson, C. T., Lee, D. V., Weitzman, M. D.
(2005). Adenovirus Type 5 E4orf3 Protein Targets the Mre11 Complex to Cytoplasmic Aggresomes. J. Virol.
79: 11382-11391
[Abstract]
[Full Text]
-
Stracker, T. H., Lee, D. V., Carson, C. T., Araujo, F. D., Ornelles, D. A., Weitzman, M. D.
(2005). Serotype-Specific Reorganization of the Mre11 Complex by Adenoviral E4orf3 Proteins. J. Virol.
79: 6664-6673
[Abstract]
[Full Text]
Copyright © 2004 by the American Society for Microbiology. All rights reserved.