Estradiol (E2)- and tamoxifen (Tmx)-bound ER-alpha (ERα) interact differentially with histone deacetylases 1 and 3 (HDACs 1 and 3). Issue 174 (November 2017) - Sharma, Dharmendra
Highlights: Treatment with estradiol (E2) or tamoxifen (Tmx) fails to alter deacetylase activity. E2 treatment decreases interaction of the estrogen receptor with histone deacetylase 3 but not 1. Only knockdown of HDAC3 permits decreased inhibition of transcription by Tmx. Abstract: Although ERα activation properties have been intensively studied, this is not the case for their repressive properties. In this report, the ERα ligand binding domain (LBD) is shown to interact both with a deacetylase function and with HDAC1 and HDAC3. Ligands do not affect binding to the deacetylase activity or to HDAC1. In distinction, E2 reduced LBD binding to HDAC3, whereas Tmx had no effect. Knock-down of either HDAC1 or 3 led to increased transcriptional activity by both HDACs, presumably by decreased repression. In distinction, only HDAC3 knock-down led to increased activity in the presence of Tmx. In summary, ERα differentially interacts with HDACs 1 and 3 to regulate transcriptional activity.