This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Johnson, J. S. Articles by Engel, D. A. Search for Related Content PubMed PubMed Citation Articles by Johnson, J. S. Articles by Engel, D. A.

Adenovirus Protein VII Condenses DNA, Represses Transcription, and Associates with Transcriptional Activator E1A

Department of Microbiology, University of Virginia Health System, Charlottesville, Virginia 22908

Received 22 December 2003/ Accepted 16 February 2004

Adenovirus protein VII is the major protein component of the viral nucleoprotein core. It is highly basic, and an estimated 1070 copies associate with each viral genome, forming a tightly condensed DNA-protein complex. We have investigated DNA condensation, transcriptional repression, and specific protein binding by protein VII. Xenopus oocytes were microinjected with mRNA encoding HA-tagged protein VII and prepared for visualization of lampbrush chromosomes. Immunostaining revealed that protein VII associated in a uniform manner across entire chromosomes. Furthermore, the chromosomes were significantly condensed and transcriptionally silenced, as judged by the dramatic disappearance of transcription loops characteristic of lampbrush chromosomes. During infection, the protein VII-DNA complex may be the initial substrate for transcriptional activation by cellular factors and the viral E1A protein. To investigate this possibility, mRNAs encoding E1A and protein VII were comicroinjected into Xenopus oocytes. Interestingly, whereas E1A did not associate with chromosomes in the absence of protein VII, expression of both proteins together resulted in significant association of E1A with lampbrush chromosomes. Binding studies with proteins produced in bacteria or human cells or by in vitro translation showed that E1A and protein VII can interact in vitro. Structure-function analysis revealed that an N-terminal region of E1A is responsible for binding to protein VII. These studies define the in vivo functions of protein VII in DNA binding, condensation, and transcriptional repression and indicate a role in E1A-mediated transcriptional activation of viral genes.

This article has been cited by other articles:

• Haruki, H., Okuwaki, M., Miyagishi, M., Taira, K., Nagata, K. (2006). Involvement of Template-Activating Factor I/SET in Transcription of Adenovirus Early Genes as a Positive-Acting Factor. J. Virol. 80: 794-801 [Abstract] [Full Text]  
• Xue, Y., Johnson, J. S., Ornelles, D. A., Lieberman, J., Engel, D. A. (2005). Adenovirus Protein VII Functions throughout Early Phase and Interacts with Cellular Proteins SET and pp32. J. Virol. 79: 2474-2483 [Abstract] [Full Text]