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Transcriptional activation of a constitutive heterochromatic domain of the human genome in response to heat shock.

Authors :
Nicoletta, Rizzi
Marco, Denegri
Ilaria, Chiodi
Margherita, Corioni
Rut, Valgardsdottir
Fabio, Cobianchi
Silvano, Riva
Giuseppe, Biamonti
Source :
Molecular Biology of the Cell; February 2004, Vol. 15 Issue: 2 p543-51, 9p
Publication Year :
2004

Abstract

Heat shock triggers the assembly of nuclear stress bodies that contain heat shock factor 1 and a subset of RNA processing factors. These structures are formed on the pericentromeric heterochromatic regions of specific human chromosomes, among which chromosome 9. In this article we show that these heterochromatic domains are characterized by an epigenetic status typical of euchromatic regions. Similarly to transcriptionally competent portions of the genome, stress bodies are, in fact, enriched in acetylated histone H4. Acetylation peaks at 6 h of recovery from heat shock. Moreover, heterochromatin markers, such as HP1 and histone H3 methylated on lysine 9, are excluded from these nuclear districts. In addition, heat shock triggers the transient accumulation of RNA molecules, heterogeneous in size, containing the subclass of satellite III sequences found in the pericentromeric heterochromatin of chromosome 9. This is the first report of a transcriptional activation of a constitutive heterochromatic portion of the genome in response to stress stimuli.

Details

Language :
English
ISSN :
10591524 and 19394586
Volume :
15
Issue :
2
Database :
Supplemental Index
Journal :
Molecular Biology of the Cell
Publication Type :
Periodical
Accession number :
ejs7035429