Nucleic Acids Research Advance Access originally published online on March 15, 2008
Nucleic Acids Research 2008 36(8):2639-2653; doi:10.1093/nar/gkn117
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Nucleic Acids Research, 2008, Vol. 36, No. 8 2639-2653
© 2008 The Author(s)
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Molecular Biology |
Determinants of a transcriptionally competent environment at the GM-CSF promoter
1Menzies Research Institute, University of Tasmania, Private Bag 58, Hobart 7001, Tasmania and 2Division of Molecular Biosciences, John Curtin School of Medical Research, Australian National University, ACT, Australia
*To whom correspondence should be addressed. Tel: 613 62262670; Fax: 613 62262703; Email: A.F.Holloway{at}utas.edu.au
Received September 18, 2007. Revised February 26, 2008. Accepted February 29, 2008.
Granulocyte macrophage-colony stimulating factor (GM-CSF) is produced by T cells, but not B cells, in response to immune signals. GM-CSF gene activation in response to T-cell stimulation requires remodelling of chromatin associated with the gene promoter, and these changes do not occur in B cells. While the CpG methylation status of the murine GM-CSF promoter shows no correlation with the ability of the gene to respond to activation, we find that the basal chromatin environment of the gene promoter influences its ability to respond to immune signals. In unstimulated T cells but not B cells, the GM-CSF promoter is selectively marked by enrichment of histone acetylation, and association of the chromatin-remodelling protein BRG1. BRG1 is removed from the promoter upon activation concomitant with histone depletion and BRG1 is required for efficient chromatin remodelling and transcription. Increasing histone acetylation at the promoter in T cells is paralleled by increased BRG1 recruitment, resulting in more rapid chromatin remodelling, and an associated increase in GM-CSF mRNA levels. Furthermore, increasing histone acetylation in B cells removes the block in chromatin remodelling and transcriptional activation of the GM-CSF gene. These data are consistent with a model in which histone hyperacetylation and BRG1 enrichment at the GM-CSF promoter, generate a chromatin environment competent to respond to immune signals resulting in gene activation.
Present address: Brettingham-Moore K. H., Murdoch Childrens Research Institute, Royal Children's Hospital, Victoria, Australia
The authors wish it to be known that, in their opinion, the first two authors should be regarded as joint First Authors