RT Journal Article SR Electronic T1 Tripartite Motif Containing 24 Acts as a Novel Coactivator of the Constitutive Active/Androstane Receptor JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 46 OP 52 DO 10.1124/dmd.117.077693 VO 46 IS 1 A1 Yuichiro Kanno A1 Yuki Kure A1 Saori Kobayashi A1 Mariko Mizuno A1 Yumi Tsuchiya A1 Naoya Yamashita A1 Kiyomitsu Nemoto A1 Yoshio Inouye YR 2018 UL http://dmd.aspetjournals.org/content/46/1/46.abstract AB The constitutive androstane receptor (CAR) is a nuclear receptor that acts as a transcription factor for a variety of genes, including genes encoding xenobiotic, steroid, and drug-metabolizing enzymes and transporters. Transactivation of a target gene by a transcription factor is generally mediated through the concerted and stepwise recruitment of various proteins termed coregulators, including coactivators and corepressors. In this study, TRIM24 (also known as transcriptional intermediary factor 1 alpha) was found to interact with the CAR. TRIM24 enhanced the CAR-dependent transactivation in reporter assays using the direct repeat-4 motif, a binding site of the CAR. This enhancement was synergistically augmented in the presence of steroid receptor coactivator (SRC) 1 or SRC2, both of which are coactivators of the CAR. In addition, TRIM24 was recruited to the CAR-binding element of the CYP2B6 promoter together with the CAR. We also noted that knockdown of TRIM24 suppressed CAR-induced CYP2B6 mRNA expression in HepTR/CAR and HepaRG cells and suppressed CAR-induced CYP3A4 mRNA expression in HepaRG cells but not HepTR/CAR cells. From these results, we suggest that TRIM24 is a novel coactivator of the CAR that is involved in cell- and/or promoter- selective transactivation.