Catalytic acyl transfer modification of nuclear receptors and detection by in-gel labeling

Abstract

Androgen receptor (AR) signaling plays a central role in prostate development and homeostasis as well as the progression of prostate cancer (PCa). Upon hormone binding, AR enters nucleus and induces down-stream expression of specific genes. Post-translational modification of AR could alter this signaling process and serve as an alternate approach in PCa treatment. ☐ In this study, we prepared N-acetylcysteamine (NAC) mimicking a charged CoA as an alkyne group substrate. As the structure of SAMT has been reported to act as an acyl transfer catalyst, we combined its structure with a ligand for AR and perform proximity-directed protein labeling to modify a lysine residue on AR. Efficiency and specificity of the labeling are evaluated with fluorogenic click reaction in vitro and in cell. The in-solution and in-gel detection limit are assessed, against small molecule reference and Bovine Serum Albumin (BSA) reference, respectively. ☐ Our result indicated that with the method discussed, the proximity-directed labeling has not been able to deliver a satisfactory efficiency and selectivity. The methods still show great potential and needs further diagnosis and optimization.