Previous Article | Next Article ![]()
Journal of Virology, June 2003, p. 6255-6264, Vol. 77, No. 11
0022-538X/03/$08.00+0 DOI: 10.1128/JVI.77.11.6255-6264.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.
Jihong Yang,1 Keqin Gregg,2 Alain Nepveu,3 Jaquelin P. Dudley,2 and Patrick Hearing1*
Department of Molecular Genetics and Microbiology, School of Medicine, Stony Brook University, Stony Brook, New York 11794,1 Section of Molecular Genetics and Microbiology, University of Texas at Austin, Austin, Texas 78705,2 Molecular Oncology Group, McGill University Health Center, Montreal, Quebec, Canada H3A 1A13
Received 23 October 2002/ Accepted 25 February 2003
Adenovirus (Ad) type 5 DNA packaging is initiated in a polar fashion from the left end of the genome. The packaging process is dependent upon the cis-acting packaging domain located between nucleotides 194 and 380. Seven A/T-rich repeats have been identified within this domain that direct packaging. A1, A2, A5, and A6 are the most important repeats functionally and share a bipartite sequence motif. Several lines of evidence suggest that there is a limiting trans-acting factor(s) that plays a role in packaging. Two cellular activities that bind to minimal packaging domains in vitro have been previously identified. These binding activities are P complex, an uncharacterized protein(s), and chicken ovalbumin upstream promoter transcription factor (COUP-TF). In this work, we report that a third cellular protein, octamer-1 protein (Oct-1), binds to minimal packaging domains. In vitro binding analyses and in vivo packaging assays were used to examine the relevance of these DNA binding activities to Ad DNA packaging. The results of these experiments reveal that COUP-TF and Oct-1 binding does not play a functional role in Ad packaging, whereas P-complex binding directly correlates with packaging function. We demonstrate that P complex contains the cellular protein CCAAT displacement protein (CDP) and that full-length CDP is found in purified virus particles. In addition to cellular factors, previous evidence indicates that viral factors play a role in the initiation of viral DNA packaging. We propose that CDP, in conjunction with one or more viral proteins, binds to the packaging sequences of Ad to initiate the encapsidation process.
Present address: Division of Hematology/Oncology, Children's Hospital Medical Center, Cincinnati, OH 45229.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»