USF2 is connected to GAAAATATGATA element and associates with androgen receptor‐dependent transcriptional regulation in prostate

BACKGROUND We have previously identified a GAAAATATGATA binding site (pros) of a transcription factor involved in prostatic and androgen‐dependent gene regulation. We now purified the potential factors interacting with the pros and characterized their co‐operation with the androgen receptor (AR). METHODS Sequence‐specific DNA affinity chromatography, mass‐spectrometry, electromobility shift assays, supershifts, glutathione‐ S ‐transferase pull‐downs, and transient transfections. RESULTS Several proteins bound to the pros site, but only upstream stimulatory factor 2 (USF2) was confirmed to be part of the transcription factor complex. Weak interaction was detected between AR and the transcription factor complex. Physical proximity between the androgen response element (ARE) and the pros was shown to be important for their co‐operation. In the presence of pros and androgen, AR achieves its maximal efficiency even at low concentrations. CONCLUSIONS The protein complex binding to the GAAAATATGATA site does not have a significant independent function, but may interact with AR if GAAAATATGATA is physically close to the ARE and enhances the transactivation function of AR. © 2004 Wiley‐Liss, Inc.