Hormone activation induces nucleosome positioning in vivo.
The mouse mammary tumor virus (MMTV) promoter is induced by glucocorticoid hormone. A robust hormone- and receptor-dependent activation could be reproduced in Xenopus laevis oocytes. The homogeneous response in this system allowed a detailed analysis of the transition in chromatin structure following hormone activation. This revealed two novel findings: hormone activation led to the establishment of specific translational positioning of nucleosomes despite the lack of significant positioning in the inactive state; and, in the active promoter, a subnucleosomal particle encompassing the glucocorticoid receptor (GR)-binding region was detected. The presence of only a single GR-binding site was sufficient for the structural transition to occur. Both basal promoter elements and ongoing transcription were dispensable. These data reveal a stepwise process in the transcriptional activation by glucocorticoid hormone.
Belikov
S
S
Laboratory of Molecular Genetics, Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institutet, SE-17177 Stockholm, Sweden.
Gelius
B
B
Almouzni
G
G
Wrange
O
O
D000818:Animals; D005260:Female; D005786:Gene Expression Regulation; D005938:Glucocorticoids / Q000235:genetics* / Q000378:metabolism; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics*; D051379:Mice; D009707:Nucleosomes / Q000235:genetics* / Q000378:metabolism; D009865:Oocytes; D011401:Promoter Regions, Genetic; D014982:Xenopus laevis
D005938:Glucocorticoids; D009707:Nucleosomes