Global chromatin compaction limits the strength of the DNA damage response.
J Cell Biol
; 178(7): 1101-8, 2007 Sep 24.
Article
in En
| MEDLINE
| ID: mdl-17893239
ABSTRACT
In response to DNA damage, chromatin undergoes a global decondensation process that has been proposed to facilitate genome surveillance. However, the impact that chromatin compaction has on the DNA damage response (DDR) has not directly been tested and thus remains speculative. We apply two independent approaches (one based on murine embryonic stem cells with reduced amounts of the linker histone H1 and the second making use of histone deacetylase inhibitors) to show that the strength of the DDR is amplified in the context of "open" chromatin. H1-depleted cells are hyperresistant to DNA damage and present hypersensitive checkpoints, phenotypes that we show are explained by an increase in the amount of signaling generated at each DNA break. Furthermore, the decrease in H1 leads to a general increase in telomere length, an as of yet unrecognized role for H1 in the regulation of chromosome structure. We propose that slight differences in the epigenetic configuration might account for the cell-to-cell variation in the strength of the DDR observed when groups of cells are challenged with DNA breaks.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
DNA Damage
/
Chromatin
/
Chromatin Assembly and Disassembly
Limits:
Animals
Language:
En
Journal:
J Cell Biol
Year:
2007
Type:
Article
Affiliation country:
Spain