PMID: 20086010 , Related PDB ids: 3L3X, 3L3Z

Authors:

Zhou XE, Suino-Powell KM, Li J, He Y, Mackeigan JP, Melcher K, Yong EL, Xu HE

Title:

Identification of SRC3/AIB1 as a preferred coactivator for hormone-activated androgen receptor.

Journal:

J Biol Chem. 2010 Mar 19;285(12):9161-71. Epub 2010 Jan 19.

Abstract:

Transcription activation by androgen receptor (AR), which depends on recruitment of coactivators, is required for the initiation and progression of prostate cancer, yet the mechanisms of how hormone-activated AR interacts with coactivators remain unclear. This is because AR, unlike any other nuclear receptor, prefers its own N-terminal FXXLF motif to the canonical LXXLL motifs of coactivators. Through biochemical and crystallographic studies, we identify that steroid receptor coactivator-3 (SRC3) (also named as amplified in breast cancer-1 or AIB1) interacts strongly with AR via synergistic binding of its first and third LXXLL motifs. Mutagenesis and functional studies confirm that SRC3 is a preferred coactivator for hormone-activated AR. Importantly, AR mutations found in prostate cancer patients correlate with their binding potency to SRC3, corroborating with the emerging role of SRC3 as a prostate cancer oncogene. These results provide a molecular mechanism for the selective utilization of SRC3 by hormone-activated AR, and they link the functional relationship between AR and SRC3 to the development and growth of prostate cancer.