DAX1 suppresses FXR transactivity as a novel co-repressor
J Li, Y Lu, R Liu, X Xiong, Z Zhang, X Zhang… - Biochemical and …, 2011 - Elsevier
J Li, Y Lu, R Liu, X Xiong, Z Zhang, X Zhang, G Ning, X Li
Biochemical and biophysical research communications, 2011•ElsevierBile acid receptor FXR (farnesoid X receptor) is a key regulator of hepatic bile acid, glucose
and lipid homeostasis through regulation of numerous genes involved in the process of bile
acid, triglyceride and glucose metabolism. DAX1 (dosage-sensitive sex reversal adrenal
hypoplasia congenital critical region on X chromosome, gene 1) is an atypical member of
the nuclear receptor family due to lack of classical DNA-binding domains and acts primarily
as a co-repressor of many nuclear receptors. Here, we demonstrated that DAX1 is co …
and lipid homeostasis through regulation of numerous genes involved in the process of bile
acid, triglyceride and glucose metabolism. DAX1 (dosage-sensitive sex reversal adrenal
hypoplasia congenital critical region on X chromosome, gene 1) is an atypical member of
the nuclear receptor family due to lack of classical DNA-binding domains and acts primarily
as a co-repressor of many nuclear receptors. Here, we demonstrated that DAX1 is co …
Bile acid receptor FXR (farnesoid X receptor) is a key regulator of hepatic bile acid, glucose and lipid homeostasis through regulation of numerous genes involved in the process of bile acid, triglyceride and glucose metabolism. DAX1 (dosage-sensitive sex reversal adrenal hypoplasia congenital critical region on X chromosome, gene 1) is an atypical member of the nuclear receptor family due to lack of classical DNA-binding domains and acts primarily as a co-repressor of many nuclear receptors. Here, we demonstrated that DAX1 is co-localized with FXR in the nucleus and acted as a negative regulator of FXR through a physical interaction with FXR. Our study showed that over-expression of DAX1 down-regulated the expression of FXR target genes, whereas knockdown of DAX1 led to their up-regulation. Furthermore, three LXXLL motifs in the N-terminus of DAX1 were required for the full repression of FXR transactivation. In addition, our study characterized that DAX1 suppresses FXR transactivation via competing with co-activators such as SRC-1 and PGC-1α. In conclusion, DAX1 acts as a co-repressor to negatively modulate FXR transactivity.
Elsevier
