Differential regulation of testosterone vs. 5alpha-dihydrotestosterone by selective androgen response elements.

There are two major physiological androgens, testosterone (T), and 5alpha-dihydrotestosterone (DHT), which induce different responses in mammals. These androgens regulate the target gene transcription via binding to and activating the same androgen receptor (AR). The molecular mechanisms that differ between these two very close androgens through the same AR protein to target the distinct genomic responses remain unknown. Using yeast genetic selection, we identified two kinds of androgen response elements (ARE), which could respond differentially to T vs. DHT. These two AREs also show different T- vs. DHT-induced AR transactivation in mammalian Chinese hamster ovary (CHO) cells in terms of copy number and comparisons with the classic mouse mammary tumor virus ARE. Together, our results suggest that the selective ARE sequence may play an important role in the differential T- vs. DHT-induced AR transactivation.