In vitro transcription enhancement by purified derivatives of the glucocorticoid receptor

Science  21 Jul 1989:
Vol. 245, Issue 4915, pp. 298-301
DOI: 10.1126/science.2473529


Mammalian glucocorticoid receptors enhance transcription from linked promoters by binding to glucocorticoid response element (GRE) DNA sequences. Understanding the mechanism of receptor action will require biochemical studies with purified components. Enhancement was observed in vitro with derivatives of the receptor that were expressed in Escherichia coli, purified, and added to a cell-free extract from Drosophila embryo nuclei. Transcription from promoters linked to one or multiple GREs was selectively enhanced by as much as six times. The effect was weaker with only one GRE, and enhancement was abolished by a point mutation that inactivates the GRE in vivo.