Nuclear Role for Human Argonaute-1 as an Estrogen-dependent Transcription Coactivator

In mammals, argonaute (AGO) proteins have been characterized for their roles in small RNA-mediated post-transcriptional and also in transcriptional gene silencing. We report here a different role for AGO1 in estradiol-triggered transcriptional activation in human cells. We show that in MCF-7 mammary gland cells AGO1 associates to transcriptional enhancers of estrogen receptor alpha (ERa) and that this association is upregulated by treating the cells with estrogen (E2), displaying a positive correlation with the activation of these enhancers. Overall design: Examination of AGO1 binding to chromatin in vehicle or estradiol treated MCF7 cells