Transcriptional Bursting and Co-bursting Regulation by Steroid Hormone Release Pattern and Transcription Factor Mobility

The binding of the glucocorticoid receptor (GR to GR regulatory elements (GREs) over constant treatment with 600nM corticosterone (Cort) changes over time in a locus-specific manner. We show this by comparing GR binding at 0h, 1h, and 12h after Cort treatment. This finding is further corroborated by the reduced dwell times of GR over time measured by single molecule tracking (SMT) as well as by the reduced RNA bust duration and frequency observed at the GR-mediated mouse mammary tumor promoter (MMTV) transcription sites (TSs). We examined the Cort-mediated effects on GR binding patterns