NAP-I is a functional homologue of TAF-I that is required for replication and transcription of the adenovirus genome in a chromatin-like structure
Article first published online: 30 OCT 2003
Blackwell Science Ltd, Oxford
Genes to Cells
Volume 1, Issue 12, pages 1045–1056, December 1996
How to Cite
Kawase, H., Okuwaki, M., Miyaji, M., Ohba, R., Handa, H., Ishimi, Y., Fujii-Nakata, T., Kikuchi, A. and Nagata, K. (1996), NAP-I is a functional homologue of TAF-I that is required for replication and transcription of the adenovirus genome in a chromatin-like structure. Genes to Cells, 1: 1045–1056. doi: 10.1046/j.1365-2443.1996.d01-223.x
- Issue published online: 30 OCT 2003
- Article first published online: 30 OCT 2003
- Cited By
Background: For the activation of replication and transcription from DNA in a chromatin structure, a variety of factors are thought to be needed that alter the chromatin structure. Template activating factor-I (TAF-I) has been identified as such a host factor required for replication of the adenovirus (Ad) genome complexed with viral basic core proteins (Ad core). TAF-I also stimulates transcription from the Ad core DNA.
Results: Using mutant TAF-I proteins, we have demonstrated that the acidic stretch present in the carboxyl terminal region is essential for the stimulation of transcription from the Ad core. A genomic footprinting experiment with restriction endonuclease has revealed that TAF-I causes a structural change in the Ad core. TAF-I has been shown to have significant amino acid similarity to nucleosome assembly protein-I (NAP-I), which is involved in the formation of the chromatin structure. We have shown that TAF-I can be substituted by NAP-I in the activation of the cell-free Ad core transcription system. Two of the tripartite acidic regions and the region homologous to TAF-I in NAP-I are required for the maximal TAF-I activity of NAP-I. Furthermore, TAF-I has been shown to have NAP-I activity, and the acidic region of TAF-I is required for this activity.
Conclusions: Since TAF-I causes the structural change of the Ad core and thereby activates transcription, TAF-I is thought to be one of the proteins which is involved in chromatin remodeling. NAP-I is structurally related to TAF-I and functionally substitutes for TAF-I. Furthermore, TAF-I has NAP-I activity. These observations suggest that this type of molecule has dual functions, possibly by participating in facilitating the assembly of the chromatin structure as well as perturbing the chromatin structure to allow transcription to proceed.