Prostate Cell Specific Regulation of Androgen Receptor Phosphorylation in Vivo

摘要

We propose that AR phosphorylation at serines 213 and 650 regulate differential target gene expression and recruitment to gene promoters via altered interaction with other cellular transcription factors. To test this hypothesis we have conducted yeast two-hybrid analysis with the N-terminus of wild type AR as well as AR S213A and AR S213E variants. Our preliminary analysis indicates that the screen is preferentially isolating proteins with a known role in gene transcription and we are currently assessing the phosphorylation-dependence of the putative AR interacting proteins. Additionally, we have generated PC3 cells stably transfected with wild type, S650A and S650E AR. We have shown that the cells activate endogenous target genes in response to androgens and are currently investigating classes of genes affected by differential AR phosphorylation. Further, we have optimized conditions to isolate pools of hyper- and hypo-phosphorylated AR in order to isolate proteins that interact with AR in a phosphorylation-dependent manner. These proteins were identified via mass spectrometry.