Steroid Receptors-AP-1 Interaction: Cross-Coupling of Signal Transduction Pathways
This chapter considers two main signal transduction pathways: the effects of steroid hormones and growth promoting substances on a cell. It reviews the efforts to understand cross-talk between these two signaling pathways and discusses divergent findings to find out whether the reported inconsistencies are real or have been generated by the use of different experimental systems. Steroid hormones are naturally occurring cyclopentanophenanthrene molecules that regulate diverse processes such as homeostasis, reproduction, development, and differentiation. Steroid hormone receptors regulate their own activity through repression of the timely production of their ligands by derivatives of the central nervous system and through negative regulation of their synthesis. Various lines of evidence suggest that the steroid receptor pathway interacts with the signal transduction pathway for growth-promoting factors. The cross-talk between steroid hormone receptors and other transcription factors is not limited to the Glucocorticoid receptors and activator protein nor does it always result in negative regulation of gene expression.