Estrogen action and cytoplasmic signaling pathways. Part II: the role of growth factors and phosphorylation in estrogen signaling.

In recent years, distinct signaling pathways involving specific complexes of cytoplasmic proteins have been shown to orchestrate estrogen action. These pathways might supplement or augment genomic effects of estrogen that are attributable to transcriptional activation by liganded receptor. Signals might be transduced through phosphorylation of the estrogen receptors (ERs), or indirectly through effects upon transcriptional coactivators or cell receptors. Estrogen signaling is coupled to growth factor signaling with feedback mechanisms directly impacting function of growth factor receptors. These signaling pathways regulate important physiological processes, such as cell growth and apoptosis. Here, we focus on cytoplasmic signaling pathways leading to activation of ERs.