TY - JOUR
T1 - Negative regulation of tshα target gene by thyroid hormone involves histone acetylation and corepressor complex dissociation
AU - Wang, Dongqing
AU - Xia, Xianmin
AU - Liu, Ying
AU - Oetting, Alexis
AU - Walker, Robert L.
AU - Zhu, Yuelin
AU - Meltzer, Paul
AU - Cole, Philip A.
AU - Shi, Yun Bo
AU - Yen, Paul M.
PY - 2009/5
Y1 - 2009/5
N2 - Currently, little is known about histone modifications and molecular mechanisms of negatively regulated transcription. In pituitary cells, thyroid hormone (T 3) decreased transcription, and surprisingly increased histone acetylation, of TSHα promoter. This increase was mediated directly by thyroid hormone receptor. Histone acetylation of H3K9 and H3K18 sites, two modifications usually associated with transcriptional activation, occur in negative regulation of TSHα promoter. T 3also caused release of a corepressor complex composed of histone deacetylase 3 (HDAC3), trans- ducin β-like protein 1, and nuclear receptor coprepressor (NCoR)/ silencing mediator for retinoic and thyroid hormone receptor from TSHα promoter in chromatin immunoprecipitation assays. NCoR and HDAC3 overexpression selectively increased ligand-independent basal transcription. Two histone acetyltransferase inhibitors increased overall transcription but did not abrogate negative regulation or NCoR/HDAC3 complex release by T 3. Chromatin immunoprecipitation analyses of an endogenous positively regulated target gene showed increased histone acetylation and corepressor complex release with T 3 treatment. Finally, microarray analyses suggested there is a subset of negatively regulated genes with increased histone acetylation. These findings demonstrate the critical role of NCoR/HDAC3 complex in negative regulation of TSHα gene expression and show that similar complexes and overlapping epigenetic modifications can participate in both negative and positive transcriptional regulation
AB - Currently, little is known about histone modifications and molecular mechanisms of negatively regulated transcription. In pituitary cells, thyroid hormone (T 3) decreased transcription, and surprisingly increased histone acetylation, of TSHα promoter. This increase was mediated directly by thyroid hormone receptor. Histone acetylation of H3K9 and H3K18 sites, two modifications usually associated with transcriptional activation, occur in negative regulation of TSHα promoter. T 3also caused release of a corepressor complex composed of histone deacetylase 3 (HDAC3), trans- ducin β-like protein 1, and nuclear receptor coprepressor (NCoR)/ silencing mediator for retinoic and thyroid hormone receptor from TSHα promoter in chromatin immunoprecipitation assays. NCoR and HDAC3 overexpression selectively increased ligand-independent basal transcription. Two histone acetyltransferase inhibitors increased overall transcription but did not abrogate negative regulation or NCoR/HDAC3 complex release by T 3. Chromatin immunoprecipitation analyses of an endogenous positively regulated target gene showed increased histone acetylation and corepressor complex release with T 3 treatment. Finally, microarray analyses suggested there is a subset of negatively regulated genes with increased histone acetylation. These findings demonstrate the critical role of NCoR/HDAC3 complex in negative regulation of TSHα gene expression and show that similar complexes and overlapping epigenetic modifications can participate in both negative and positive transcriptional regulation
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U2 - 10.1210/me.2008-0389
DO - 10.1210/me.2008-0389
M3 - Article
C2 - 19196836
AN - SCOPUS:66649119535
SN - 0888-8809
VL - 23
SP - 600
EP - 609
JO - Molecular Endocrinology
JF - Molecular Endocrinology
IS - 5
ER -