Premium
Fate of linear and supercoiled multinucleosomic templates during transcription.
Author(s) -
HeggelerBordier B.,
SchildPoulter C.,
Chapel S.,
Wahli W.
Publication year - 1995
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1995.tb07254.x
Subject(s) - rna polymerase ii , biology , transcription (linguistics) , microbiology and biotechnology , t7 rna polymerase , rna polymerase , transcription bubble , nucleosome , transcription factor ii d , polymerase , chromatin , rna polymerase i , rna polymerase ii holoenzyme , general transcription factor , rna , promoter , rna dependent rna polymerase , dna , biochemistry , gene expression , gene , linguistics , philosophy , escherichia coli , bacteriophage
Electron microscopy was used to monitor the fate of reconstituted nucleosome cores during in vitro transcription of long linear and supercoiled multinucleosomic templates by the prokaryotic T7 RNA polymerase and the eukaryotic RNA polymerase II. Transcription by T7 RNA polymerase disrupted the nucleosomal configuration in the transcribed region, while nucleosomes were preserved upstream of the transcription initiation site and in front of the polymerase. Nucleosome disruption was independent of the topology of the template, linear or supercoiled, and of the presence or absence of nucleosome positioning sequences in the transcribed region. In contrast, the nucleosomal configuration was preserved during transcription from the vitellogenin B1 promoter with RNA polymerase II in a rat liver total nuclear extract. However, the persistence of nucleosomes on the template was not RNA polymerase II‐specific, but was dependent on another activity present in the nuclear extract. This was demonstrated by addition of the extract to the T7 RNA polymerase transcription reaction, which resulted in retention of the nucleosomal configuration. This nuclear activity, also found in HeLa cell nuclei, is heat sensitive and could not be substituted by nucleoplasmin, chromatin assembly factor (CAF‐I) or a combination thereof. Altogether, these results identify a novel nuclear activity, called herein transcription‐dependent chromatin stabilizing activity I or TCSA‐I, which may be involved in a nucleosome transfer mechanism during transcription.