RETRACTED: Repressive domain of unliganded human estrogen receptor α associates with Hsc70 (Retracted article. See vol. 18, pg. 1145, 2013)

Estrogen receptor (ER) is a hormone-inducible transcription factor as a member of the nuclear receptor gene superfamily. Unliganded ER is transcriptionally silent and capable of DNA binding; however, it is unable to suppress the basal activity of the target gene promoters, unlike non-steroid hormone receptors that associate with corepressors in the absence of their cognate ligands. To study the molecular basis of how unliganded human ER alpha is maintained silent in gene regulation upon the target gene promoters, we biochemically searched interactants for hER alpha, and identified heat shock protein 70 (Hsc70). Hsc70 appeared to associate with the N-terminal hormone binding E domain, that also turned out a transcriptionally repressive domain. Competitive association of Hsc70 with a best known coactivator p300 was observed. Thus, these findings suggest that Hsc70 associates with unliganded hER alpha, and thereby deters hER alpha from recruiting transcriptional coregulators, presumably as a component of chaperone complexes.