Does palmitoylation target estrogen receptors to plasma membrane caveolae?

The human nuclear estrogen receptors (i.e., ERalpha and ERbeta), as other transcriptional factors, regulate cellular processes inducing genomic events. In addition, the binding of 17beta-estradiol to ERs induces different membrane initiating non-genomic signaling. The non-genomic effects of ER are independent of transcriptional activity of the receptor and have been attributed to membrane ERs belonging to a signaling complex localized in caveolae. Here, we postulate that S-acylation of cysteine residue(s) present in the ligand binding domain of ERalpha and ERbeta may play a critical role in the membrane caveolar localization of the receptor and in the formation of the 'steroid signalosome'.