A role for histones H2A/H2B in chromatin folding and transcriptional repression.
AUTOR(ES)
Hansen, J C
RESUMO
Histone octamers or histone H3/H4 tetramers were reconstituted onto either closed circular plasmids containing a single Xenopus 5S rRNA gene or a reiterated array of Lytechinus 5S rRNA genes. All "reconstitutes" were found to undergo both Na(+)-dependent and Mg(2+)-dependent compaction. However, in each case, the compaction of nucleosomal templates containing H2A/H2B was much more extensive than compaction of templates containing only H3/H4 tetramers. Inclusion of 5 mM MgCl2 in the transcription buffer increased the level of compaction of nucleosomal templates and led to a marked inhibition of both transcription initiation and elongation by RNA polymerase III. The inhibitory effect of Mg2+ was reduced significantly when DNA templates contained only H3/H4 tetramers, consistent with their lesser extent of Mg(2+)-dependent compaction. Thus, the removal of histones H2A/H2B from nucleosomal arrays enhances gene activity, in part because of decreased levels of chromatin folding.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=43366Documentos Relacionados
- Conservation of histone H2A/H2B intergene regions: a role for the H2B specific element in divergent transcription.
- A novel labeling technique reveals a function for histone H2A/H2B dimer tail domains in chromatin assembly in vivo
- Role for ADA/GCN5 products in antagonizing chromatin-mediated transcriptional repression.
- Histones H2A and H2B are neighbors along DNA in chromatin: characterization of subnucleosomal particles containing H2A+H2B.
- Functional analysis of histones H2A and H2B in transcriptional repression in Saccharomyces cerevisiae.
