Hormone-induced enhancer assembly requires an optimal level of hormone receptor multivalent interactions

Transcription factors (TFs) activate enhancers to drive cell-specific gene expression in response to signals, but our understanding of enhancer assembly in signaling events is incomplete. Here we show that Androgen Receptor (AR), a steroid hormone signaling-regulated transcription factor, forms phase-separated condensates in response to androgen to activate enhancers. We demonstrate that the intrinsically disordered NTD of AR drives condensate formation and that NTD deletion or aromatic residue mutation reduces AR self-association and abolishes AR transcriptional activity. AR NTD can be substituted by some IDRs from other proteins for AR condensation capacity and transactivation function. Extending the polyQ tract within AR NTD strengthens AR phase separation and also leads to impaired transcriptional activity. PolyQ expansion does not affect AR binding on enhancers, but instead impairs enhancer assembly. These results suggest that AR phase separation mediates enhancer assembly, and an optimal level of AR condensation is required for its proper function in mediating AR-AR homotypic and AR-cofactor heterotypic interactions to regulate transcription in response to signals. Our study supports that alteration of the fine-tuned protein condensation might underlie AR-related human pathologies, therefore providing novel molecular insights for potential therapeutic strategies to treat prostate cancer and other AR-involved diseases by targeting AR condensation. Overall design: Assay for Transposase-Accessible Chromatin followed by high throughput sequencing (ATAC-seq) for checking chromatin accessibilities for LNCaP cells with different treatments or with the rescue tests for different AR cDNAs.