DAX1 suppresses FXR transactivity as a novel co-repressor

► DAX1 is co-localized with FXR and interacts with FXR. ► DAX1 acts as a negative regulator of FXR. ► Three LXXLL motifs in the N-terminus of DAX1 were required. ► DAX1 suppresses FXR transactivation by competing with co-activators.