Polyproline and Tat transduction peptides in the study of the rapid actions of steroid receptors

Cellular responses to signals require the action of a myriad of protein networks, which are regulated by protein/protein associations [1]. Rapid actions of steroid hormones are also subject to this regulation. They induce direct association of steroid receptors with different proteins (e.g., growth factor receptors, signaling effectors, scaffold proteins, transcription factors). These multi-molecular complexes drive signaling activation and finally trigger basic hormonal effects. Receptor/protein associations are attracting increased interest concerning their role in hormone action as well as their potential use as therapeutic targets in hormonal diseases.

► Hormone induced receptor/protein association is a token of the rapid steroid action. ► AR-derived peptides inhibit the AR association with the Src kinase. ► Inhibition of AR/Src interaction causes failure of androgen-dependent DNA synthesis. ► A ERα derived peptide prevents the receptor association with CRM-1 nuclear exportin. ► Sequestering ERα in the nuclei inhibits hormone-induced DNA synthesis.