Figure 6. TRIM23 does not affect PPARγ2 transcriptional activity.
(A) TRIM23 does not affect PPARγ-mediated transcriptional activity in HEK293T cells. The peroxisome proliferator-activated receptor response element firefly luciferase reporter vector (PPRE–Luc), pGL4.74 renilla luciferase reporter plasmid, and expression vectors encoding TRIM23 and Pparg were transfected into HEK293T cells and the cells were incubated in culture medium containing 10% charcoal-treated fetal bovine serum for 24 hr. Cells were incubated with or without troglitazone (2 μM) for 24 hr, harvested, and quantified firefly luciferase and renilla luciferase mRNA with real-time PCR. The data represent means ± s.d. from three independent experiments. (B) TRIM23 does not promote SUMOylation of PPARγ2. An in vivo assay for SUMOylation of PPARγ2 by TRIM23 was performed. Expression vectors encoding FLAG-PPARγ2, Myc-TRIM23, and HA-SUMO1 were transfected into HEK293T cells. Cell lysates were immunoprecipitated with anti-FLAG antibody and then immunoblot analysis was performed to detect modifications of PPARγ2.