Identification and Characterization of a Novel Androgen Receptor

The androgen receptor (AR) is a member of the steroid receptor superfamily that binds to the androgen re-sponse element to regulate target gene transcription. AR may need to interact with some selected coregula-tors for maximal or proper androgen function. Here we report the isolation of a new AR coregulator with a calculated molecular mass of 267 kDa named the andro-gen receptor-associated protein 267- (ARA267-). ARA267- contains 2427 amino acids, including one Su-(var)3-9, Enhancer-of-zeste, and Trithorax (SET) do-main, two LXXLL motifs, three nuclear translocation signal (NLS) sequences, and four plant homodomain (PHD) finger domains. Northern blot analyses reveal that ARA267- is expressed predominantly in the lymph node as 13- and 10-kilobase transcripts. HepG2 is th