Mechanism of Histone H1-stimulated Glucocorticoid Receptor Dna Binding in Vivo.
From: Dept. of Cell and Molecular Biology, Karolinska Institutet, SE-17177 Stockholm, Sweden.
Molecular and cellular biology
- Publish Date: Mar 2007
- ISSN: 0270-7306
- Volume: 27
- Issue: 6
- Pages: 2398-410
- Medium: Print
- Language: English
- Citation (JAMA): Belikov Sergey, Astrand Carolina, Wrange Orjan, et al. Mechanism of Histone H1-stimulated Glucocorticoid Receptor Dna Binding in Vivo.. Mol. Cell. Biol. Mar 2007;27:2398-410
Abstract
Xenopus oocytes lack somatic linker histone H1 but contain an oocyte-specific variant, B4. The glucocorticoid receptor (GR) inducible mouse mammary tumor virus (MMTV) promoter was reconstituted in Xenopus oocytes to address the effects of histone H1. The expression of Xenopus H1A (H1) via cytoplasmic mRNA injection resulted in H1 incorporation into in vivo assembled chromatin based on (i) the appearance of a chromatosome stop, (ii) the increased nucleosome repeat length (NRL), and (iii) H1-DNA binding assayed by chromatin immunoprecipitation (ChIP). The H1 effect on the NRL was saturable and hence represents H1-binding to a specific site. A subsaturating level of H1 enhanced the hormone-dependent binding of GR to the glucocorticoid response elements (GREs) and the hormone-dependent MMTV transcription while it reduced the access to DNA as revealed by micrococcal nuclease (MNase) analysis. These H1 effects were lost at higher levels of H1. ChIP and MNase analysis revealed a hormone-dependent dissociation of H1 from the activated chromatin domain. The proposed mechanism of H1-induced GR binding is based on two effects: (i) a GR-induced asymmetric distribution of H1 in favor of inactive chromatin and (ii) an H1-induced reduction in DNA access. These effects results in increased concentration of free GR and, hence, in increased GR-GRE binding.
Mesh Headings (Keywords): Animals, Base Sequence, Chromatin, DNA, Genes, Reporter, Histones, Hormones, Humans, Mammary Tumor Virus, Mouse, Molecular Sequence Data, Nucleosomes, Oocytes, Promoter Regions (Genetics), Protein Binding, Rats, Receptors, Glucocorticoid, Swine, Transcription, Genetic, Xenopus laevis
Check for Full Text / PubMed Unique Identifier (PMID): 17210632
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.