Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2010-10-19
pubmed:abstractText
The pathway involving Bre1-dependent monoubiquitination of histone H2B lysine 123, which leads to Dot1-dependent methylation of histone H3 lysine 79 (H3K79me2), has been implicated in survival after exposure to ionizing radiation in Saccharomyces cerevisiae. We found that depletion of mammalian homologs of Bre1 compromises the response to ionizing radiation, leading to increased radiosensitivity and a G(2)/M checkpoint defect. The deficiency in Bre1a/b function was also associated with increased sensitivity to crosslinking drugs and defective formation of Rad51 foci in mouse cells, suggesting a defect in homologous recombinational repair analogous to that seen in Saccharomyces. In budding yeast, H3K79me2 is important for the recruitment of the checkpoint signaling protein Rad9 to sites of double-strand breaks (DSBs). However, in mammalian cells, 53BP1 (the Rad9 ortholog) in addition to H3K79me2 recognizes a different residue, H4K20me2, and some studies argue that it is H4K20me2 and not H3K79me2 that is the preferred target for 53BP1. We show here that depletion of Bre1b specifically reduced dimethylation of H3K79 without affecting dimethylation of H4K20. Thus our data suggest that the observed defects in the radiation response of Bre1a/b-deficient cells are associated with reduced H3K79me2 and not with H4K20me2.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1938-5404
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
174
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
558-65
pubmed:dateRevised
2011-11-1
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Deficiency in Bre1 impairs homologous recombination repair and cell cycle checkpoint response to radiation damage in mammalian cells.
pubmed:affiliation
Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305-5152, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural