Fig. 3.

Intramolecular folding precedes association of AR and ERα monomers but not PPARγ2. FRET was determined in HeLa cells expressing AR (A), ERα (B), or PPARγ2(C) as fusions with CFP–NR and NR–YFP (association) or CFP–NR–YFP (folding). Images were collected every minute at 37°C. DHT (10 nM), estradiol (10 nM), or GW1929 (100 nM) was added 30 sec after the fourth image; an additional 26 images were captured starting 30 sec after the addition of ligand. The mean CFP–NR/NR–YFP or CFP–NR–YFP FRET in the nucleus (nuc; blue diamonds or red squares) and in the cytoplasm (cyto; pink diamonds or green squares) are shown from 12 or 47 cells (AR), 6 or 14 cells (ERα), and 8 or 11 cells (PPARγ2). Error bars represent the SEM.