Zac1, an Sp1-like protein, regulates human p21{sup WAF1/Cip1} gene expression in HeLa cells
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan, ROC (China)
- Division of Gastroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan, ROC (China)
- Department of Biochemistry, National Defense Medical Center, Taipei 114, Taiwan, ROC (China)
- Division of Cardiology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan, ROC (China)
Zac1 functions as both a transcription factor and a transcriptional cofactor for p53, nuclear receptors (NRs) and NR coactivators. Zac1 might also act as a transcriptional repressor via the recruitment of histone deacetylase 1 (HDAC1). The ability of Zac1 to interact directly with GC-specific elements indicates that Zac1 possibly binds to Sp1-responsive elements. In the present study, our data show that Zac1 is able to interact directly with the Sp1-responsive element in the p21{sup WAF1/Cip1} gene promoter and enhance the transactivation activity of Sp1 through direct physical interaction. Our data further demonstrate that Zac1 might enhance Sp1-specific promoter activity by interacting with the Sp1-responsive element, affecting the transactivation activity of Sp1 via a protein-protein interaction, or competing the HDAC1 protein away from the pre-existing Sp1/HDAC1 complex. Finally, the synergistic regulation of p21{sup WAF1/Cip1} gene expression by Zac1 and Sp1 is mediated by endogenous p53 protein and p53-responsive elements in HeLa cells. Our work suggests that Zac1 might serve as an Sp1-like protein that directly interacts with the Sp1-responsive element to oligomerize with and/or to coactivate Sp1.
- OSTI ID:
- 22212258
- Journal Information:
- Experimental Cell Research, Vol. 317, Issue 20; Other Information: Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0014-4827
- Country of Publication:
- United States
- Language:
- English
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