FIG. 2.

The PRL distal enhancer contains an RXR/TR binding site. (A) PRL luciferase reporter constructs containing the indicated combinations of the proximal promoter (−422/+34), the distal enhancer (−1530/−1831), or basal sequences (−36/+34) were transfected into GH4C1 cells, and reporter activity was determined after 48 h in control cells and in cells treated with 5 nM T3 or 1 μM 9-cis-RA. Results are expressed relative to the values obtained in the untreated cells transfected with the longest construct. The TRE is depicted as a shaded rectangle adjacent to the ERE. Black boxes, binding sites for GHF-1/Pit-1. (B) Mobility shift assays with in vitro-translated TRα, RXR, and RAR (1 μl) and an oligonucleotide encompassing the sequence from −1551 to −1573 of the PRL distal enhancer.