Ae. Wallberg et al., Recruitment of the SWI-SNF chromatin remodeling complex as a mechanism of gene activation by the glucocorticoid receptor tau 1 activation domain, MOL CELL B, 20(6), 2000, pp. 2004-2013
The SWI-SNF complex has been shown to alter nucleosome conformation in an A
TP-dependent manner, leading to increased accessibility of nucleosomal DNA
to transcription factors. In this study, we show that the SWI-SNF complex c
an potentiate the activity of the glucocorticoid receptor (GR) through the
N-terminal transactivation domain, tau 1, in both yeast and mammalian cells
. GR-sl can directly interact with purified SWI-SNF complex, and mutations
in tau 1 that affect the transactivation activity in vivo also directly aff
ect tau 1 interaction with SWI-SNF. Furthermore, the SWI-SNF complex can st
imulate tau 1-driven transcription from chromatin templates in vitro, Taken
together, these results support a model in which the GR can directly recru
it the SWI-SNF complex to target promoters during glucocorticoid-dependent
gene activation. We also provide evidence that the SWI-SNF and SAGA complex
es represent independent pathways of tau 1-mediated activation but play ove
rlapping roles that are able to compensate for one another under some condi
tions.