Nucleic Acids Research Advance Access originally published online on July 8, 2008
Nucleic Acids Research 2008 36(13):4510-4520; doi:10.1093/nar/gkn419
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Nucleic Acids Research, 2008, Vol. 36, No. 13 4510-4520
© 2008 The Author(s)
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Gene Regulation, Chromatin and Epigenetics |
Requirement of histone deacetylase1 (HDAC1) in signal transducer and activator of transcription 3 (STAT3) nucleocytoplasmic distribution
1Department of Internal Medicine, 2Department of Biochemistry and Molecular Biology, 3Department of Microbiology and Immunology and 4The Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, TX 77555-1060, USA
*To whom correspondence should be addressed. Tel: +1 409 772 2824; Fax: +1 409 772 8709; Email: suray{at}utmb.edu
Received May 13, 2008. Revised June 13, 2008. Accepted June 16, 2008.
Signal Transducer and Activator of Transcription 3 (STAT3) is a transcription factor that plays a crucial role in interleukin-6 (IL-6) signaling, mediating the acute-phase induction of the human Angiotensinogen (hAGT) gene in hepatocytes. We showed earlier that IL-6 induces acetylation of the STAT3 NH2-terminus by the recruitment of the p300 coactivator. We had also observed a physical interaction of STAT3 and Histone Deacetylase1 (HDAC1) in an IL-6-dependent manner that leads to transcriptional repression. In this study, we sought to elucidate the mechanism by which HDAC1 controls STAT3 transcriptional activity. Here, we mapped the interacting domains of both STAT3 and HDAC1 and found that the COOH-terminal domain of HDAC1 is necessary for IL-6-induced STAT3 transcriptional repression, whereas the NH2-terminal acetylation domain of STAT3 is required for HDAC1 binding. Interestingly, over expression of HDAC1 in HepG2 cells leads to significantly reduced amounts of nuclear STAT3 after IL-6 induction, whereas silencing of HDAC1 resulted in accumulation of total and acetylated STAT3 in the nucleus. We have found that HDAC1 knockdown also interferes with the responsiveness of the STAT3-dependent MCP1 target gene expression to IL-6, as confirmed by real-time RT–PCR analysis. Together, our study reveals the novel functional consequences of IL-6-induced STAT3-HDAC1 interaction on nucleocytoplasmic distribution of STAT3.