Fig. 2.

A proposed model of the AR signaling pathway depicting the potential role of SGTA in the foldosome complex. In the absence of androgen, the AR is located in the cytoplasm in association with the foldosome complex. Maturation of the nascent AR is a dynamic process that involves three stages: early, intermediate, and mature. At each stage, HSPs and co-chaperones with distinct roles bind to or are released from the foldosome complex in order to stabilize and fold the protein into a conformation that is competent to bind ligand. SGTA binds to HSP70 and can mediate its ATPase activity. In addition, SGTA binds directly to microtubules, thus retaining the AR in the cytoplasm. Androgen binding results in a conformational change of the AR, an exchange of TPR-containing proteins, and initiation of nuclear translocation. In the nucleus, the AR is able to bind to response elements in target genes. Subsequently, cofactors, chaperones, co-chaperones, and other transcriptional machinery are recruited in order to mediate gene transcription. Darker shading for SGTA protein indicates better evidence for that particular interaction. D dynein, TM transcriptional machinery