期刊论文详细信息
MOLECULAR AND CELLULAR ENDOCRINOLOGY 卷:299
Ligand-selective transactivation and transrepression via the glucocorticoid receptor: Role of cofactor interaction
Article
Ronacher, Katharina2  Hadley, Katie1  Avenant, Chanel1  Stubsrud, Elisabeth2  Simons, S. Stoney, Jr.3  Louw, Ann2  Hapgood, Janet P.1,2 
[1] Univ Cape Town, Dept Mol & Cell Biol, ZA-7700 Rondebosch, South Africa
[2] Univ Stellenbosch, Dept Biochem, ZA-7602 Matieland, South Africa
[3] NIDDK CEB, Steroid Hormontes Sect, NIH, Bethesda, MD 20892 USA
关键词: Glucocorticoid receptor;    Cofactor;    Transactivation;    Transrepression;   
DOI  :  10.1016/j.mce.2008.10.008
来源: Elsevier
PDF
【 摘 要 】

The mechanisms that determine ligand-selective transcriptional responses by the glucocorticoid receptor (GR) are not fully understood. Using a wide panel of GR ligands, we investigated the relationships between the potency and maximal response for transactivation via a glucocorticoid response element (GRE) and transrepression via both nuclear factor KB (NF kappa B) and activator protein-1 (AP-1) sites, relative binding affinity for the GR, as well as interaction with both coactivators and corepressors. The results showed ligand-selective differences in potency and efficacy for each promoter, as well as for a particular ligand between the three promoters. Ligand potency correlated with relative affinity for the GR for agonists and partial agonists in transactivation but not for transrepression. Maximal response was unrelated to relative affinity of ligand for GR for both transactivation and transrepression. A good and significant correlation between full length coactivator binding in two-hybrid assays and efficacy as well as potency of different receptor-steroid complexes for both transactivation and transrepression supports a major role for coactivator recruitment in determination of ligand-selective transcriptional activity. Furthermore, ligand-selective GR binding to GRIP-1, as determined by both two-hybrid and DNA pull down assays. correlated positively with ligand-selective efficacy for transactivation of both a synthetic GRE reporter with expressed GR as well as of an endogenous gene via endogenous GR. The receptor interacting domain of the corepressor SMRT exhibited strong interaction with both agonists and partial agonists, similar to the results for coactivators, suggesting a possible role for SMRT in activation of transcription. However, there was no correlation between ligand affinity for the GR and cofactor interaction. These results provide strong quantitative biochemical support for a model in which GR-mediated ligand-selective differential interaction with GRIP-1. SRC-1 A. NCoR and SMRT is a major determinant of ligand-selective and promoter-specific differences in potency and efficacy, for both transactivation and transrepression. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

【 授权许可】

Free   

【 预 览 】
附件列表
Files Size Format View
10_1016_j_mce_2008_10_008.pdf 1292KB PDF download
  文献评价指标  
  下载次数:0次 浏览次数:0次