Estrogen Signaling: A Subtle Balance Between ERα and ERβ

The influence of chromatin on the transcriptional activities of ERα and ERβ. Both ER subtypes exhibit comparable activity on naked DNA, but differential activity on chromatin templates. ERα strongly activates transcription on chromatin templates, whereas chromatin structure is very restrictive for transcription mediated by ERβ. These differences may be due to the inability of ERβ to recruit a stable preinitiation complex to chromatin templates, demonstrating that chromatin represents an important regulatory aspect of ER-mediated gene expression.