| Title: | Coactivators p300 and PCAF Physically and Functionally Interact with the Foamy Viral Trans-activator |
| Author: |
Bannert, Helmut; Muranyi, Walter; Ogryzko, Vasily V; Flügel, Rolf M; Nakatani, Yoshihiro Pat
Note: Order does not necessarily reflect citation order of authors. |
| Citation: | Bannert, Helmut, Walter Muranyi, Vasily V. Ogryzko, Yoshihiro Nakatani, and Rolf M. Flügel. 2004. Coactivators p300 and PCAF physically and functionally interact with the foamy viral trans-activator. BMC Molecular Biology 5: 16. |
| Full Text & Related Files: |
517496.pdf (732.1Kb; PDF)
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| Abstract: | Background: Foamy virus Bel1/Tas trans-activators act as key regulators of gene expression and directly bind to Bel1 response elements (BRE) in both the internal and the 5'LTR promoters leading to strong transcriptional trans-activation. Cellular coactivators interacting with Bel1/Tas are unknown to date. Results: Transient expression assays, co-immunoprecipitation experiments, pull-down assays, and Western blot analysis were used to demonstrate that the coactivator p300 and histone acetyltransferase PCAF specifically interact with the retroviral trans-activator Bel1/Tas in vivo. Here we show that the Bel1/Tas-mediated trans-activation was enhanced by the coactivator p300, histone acetyltransferases PCAF and SRC-1 based on the crucial internal promoter BRE. The Bel1/Tas-interacting region was mapped to the C/H1 domain of p300 by co-immunoprecipitation and pull-down assays. In contrast, coactivator SRC-1 previously reported to bind to the C-terminal domain of p300 did not directly interact with the Bel1 protein but nevertheless enhanced Bel1/Tas-mediated trans-activation. Cotransfection of Bel1/Tas and p300C with an expression plasmid containing the C/H1domain partially inhibited the p300C-driven trans-activation. Conclusion: Our data identify p300 and PCAF as functional partner molecules that directly interact with Bel1/Tas. Since the acetylation activities of the three coactivators reside in or bind to the C-terminal regions of p300, a C/H1 expression plasmid was used as inhibitor. This is the first report of a C/H1 domain-interacting retroviral trans-activator capable of partially blocking the strong Bel1/Tas-mediated activation of the C-terminal region of coactivator p300. The potential mechanisms and functional roles of the three histone and factor acetyltransferases p300, PCAF, and SRC-1 in Bel1/Tas-mediated trans-activation are discussed. |
| Published Version: | doi:10.1186/1471-2199-5-16 |
| Other Sources: | http://www.ncbi.nlm.nih.gov/pmc/articles/PMC517496/pdf/ |
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| Citable link to this page: | http://nrs.harvard.edu/urn-3:HUL.InstRepos:4878055 |
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