Androgen Receptor

After binding to androgenic hormones such as testosterone and dihydrotestosterone, the androgen receptor (AR, NR3C4, nuclear receptor subfamily 3, group C, member 4) as a nuclear receptor can be activated and then translocate into nucleus. Activated AR can interact with caveolae resultling in the activation of Erk, PI3K, SRC and Akt signaling pathways. Growth factors such as insulin-like growth-factor-1 (IGF-1), keratinocyte growth factor (KGF) and epidermal growth factor (EGF), and receptor-tyrosine kinases (RTKs) such as HER-2/neu can activate AR independently of androgens via mitogen activated protein kinases (MAPK) and Akt pathways. RTKs and G-protein coupled receptors (GPCRs) are also found concentrated in caveolae, where AR may have roles in activation of these receptors. GPCRs can also phosphorylate AR independently of androgen via MEK1/2 and ERK1/2.