FIGURE 1.

ARA55 enhances AR transcriptional activity but inhibits TR4 activity. A, ARA55 enhances AR transcriptional activity but inhibits TR4 transcriptional activity. Left panel, 293T cells were cotransfected with pSG5-AR, MMTV-luc, and pCDNA3-flagARA55 as indicated (the ratio of AR to ARA55 was 1:3) using Superfect according to the manual instructions. After 16 h, the cells were treated with vehicle or dihydrotestosterone for an additional day and then harvested for AR luciferase assay. Right panel, 293T cells were cotransfected with pCMX-TR4, HCR-luc, and pcDNA3-flagARA55 as indicated (the ratio of TR4 to ARA55 was 1:3). After 24 h, the cells were harvested, and TR4 luciferase activity was examined. B, ARA55 reduces the mRNA expression level of CD36, a target gene of TR4. Hep1-6 cells were cotransfected with pCDNA3-flagTR4 and pCDNA4-HisARA55 as indicated. After 24 h, the cells were harvested, and CD36 mRNA levels were examined by real time RT-PCR. 18 S rRNA level was used as the internal control, and the CD36 mRNA expression in control cells (with empty vector) was set as 1. The data represent the means ± S.D. of triplicate samples. C, ARA55 reduces the protein level of CD36. Hep1-6 cells were cotransfected with pCDNA3flagTR4 and pCDNA4HisARA55 as indicated. After 24 h, the cells were harvested, and the protein levels of CD36 as well as TR4 and ARA55 were examined by Western blot analysis. GAPDH served as the loading control. DHT, dihydrotestosterone; IB, immunoblot.