Ajuba Preferentially Binds LXRα/RXRγ Heterodimer to Enhance LXR Target Gene Expression in Liver Cells.
Mol Endocrinol
; 29(11): 1608-18, 2015 Nov.
Article
en En
| MEDLINE
| ID: mdl-26389695
ABSTRACT
The liver X receptors (LXRs) are important regulators of lipid, cholesterol, and glucose homeostasis by transcriptional regulation of many key genes in these processes, and the transcriptional activities of LXRs are finely controlled by cooperating with retinoid X receptors and many other coregulators. Here, we report that the LIM protein Ajuba binds to the hinge and the ligand binding domains of LXRα via its C-terminal tandem LIM motifs and enhances LXR target gene expression in liver cells. Depletion of Ajuba in HepG2 cells and in mouse primary hepatocytes decreases LXR target gene expression, whereas stable expression of Ajuba in HepG2 cells results in increased expression of these genes. Mechanistic investigations found that Ajuba selectively interacts with LXRα/retinoid X receptor-γ heterodimer to form a ternary complex, which displays a higher transactivation activity to LXR target genes. Moreover, Ajuba and LXR mutually affect their DNA binding activity at endogenous target chromatins and the cooperation between Ajuba and LXRα is dependent on the functional LXR response elements located in the target promoters. Together, our studies demonstrate that Ajuba is a novel coactivator for LXRs and may play important role in lipid and glucose metabolism.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Activación Transcripcional
/
Regulación de la Expresión Génica
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Receptor gamma X Retinoide
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Receptores Nucleares Huérfanos
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Proteínas con Dominio LIM
Límite:
Animals
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Humans
/
Male
Idioma:
En
Revista:
Mol Endocrinol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
ENDOCRINOLOGIA
Año:
2015
Tipo del documento:
Article