The Histone Chaperone Asf1 Increases the Rate of Histone Eviction at the Yeast PHO5 and PHO8 Promoters
Autor: | Philipp Korber, Ulrike J. Schermer, Wolfram Hörz, Tim Luckenbach, Dorothea Blaschke, Andrea Schmid, Slobodan Barbarić |
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Rok vydání: | 2006 |
Předmět: |
Transcriptional Activation
Saccharomyces cerevisiae Proteins Acid Phosphatase Cell Cycle Proteins Saccharomyces cerevisiae Biology Biochemistry Chromatin remodeling Histones Histone H1 Gene Expression Regulation Fungal Histone H2A Histone methylation Histone code Histone octamer Promoter Regions Genetic Molecular Biology chromatin remodeling yeast PHO5 promoter yeast PHO8 promoter transcriptional regulation Adenosine Triphosphatases Genetics Cell Biology Alkaline Phosphatase Chromatin Assembly and Disassembly Mi-2/NuRD complex Cell biology DNA-Binding Proteins Histone methyltransferase Molecular Chaperones Transcription Factors |
Zdroj: | Journal of Biological Chemistry. 281:5539-5545 |
ISSN: | 0021-9258 |
DOI: | 10.1074/jbc.m513340200 |
Popis: | Eukaryotic gene expression starts off from a largely obstructive chromatin substrate that has to be rendered accessible by regulated mechanisms of chromatin remodeling. The yeast PHO5 promoter is a well known example for the contribution of positioned nucleosomes to gene repression and for extensive chromatin remodeling in the course of gene induction. Recently, the mechanism of this remodeling process was shown to lead to the disassembly of promoter nucleosomes and the eviction of the constituent histones in trans. This finding called for a histone acceptor in trans and thus made histone chaperones likely to be involved in this process. In this study we have shown that the histone chaperone Asf1 increases the rate of histone eviction at the PHO5 promoter. In the absence of Asf1 histone eviction is delayed, but the final outcome of the chromatin transition is not affected. The same is true for the coregulated PHO8 promoter where induction also leads to histone eviction and where the rate of histone loss is reduced in asf1 strains as well, although less severely. Importantly, the final extent of chromatin remodeling is not affected. We have also presented evidence that Asf1 and the SWI/SNF chromatin remodeling complex work in distinct parallel but functionally overlapping pathways, i.e. they both contribute toward the same outcome without being mutually strictly dependent. |
Databáze: | OpenAIRE |
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