Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2004-7-21
pubmed:abstractText
BRCA1 is involved in maintaining genomic integrity and, as a regulator of the G2/M checkpoint, contributes to DNA repair and cell survival. The overexpression of BRCA1 elicits diverse cellular responses including apoptosis due to the stimulation of specific signaling pathways. BRCA1 is normally regulated by protein turnover, but is stabilized by BARD1 which can recruit BRCA1 to the nucleus to form a ubiquitin E3 ligase complex involved in DNA repair or cell survival. Here, we identify BARD1 as a regulator of BRCA1-dependent apoptosis. Using transfected MCF-7 breast cancer cells, we found that BRCA1-induced apoptosis was independent of p53 and was stimulated by BRCA1 nuclear export. Conversely, BARD1 reduced BRCA1-dependent apoptosis by a mechanism involving nuclear sequestration. Regulation of apoptosis by BARD1 was reduced by BRCA1 cancer mutations that disrupt Ub ligase function. Transfection of BRCA1 N-terminal peptides that disrupted the cellular BRCA1-BARD1 interaction caused a loss of nuclear BRCA1 that correlated with increased apoptosis in single cell assays, but did not alter localization or expression of endogenous BARD1. Reducing BARD1 levels by siRNA caused a small increase in apoptosis. Our findings identify a novel apoptosis inhibitory function of BARD1 and suggest that nuclear retention of BRCA1-BARD1 complexes contributes to both DNA repair and cell survival.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0014-4827
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
298
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
661-73
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:15265711-Active Transport, Cell Nucleus, pubmed-meshheading:15265711-Apoptosis, pubmed-meshheading:15265711-BRCA1 Protein, pubmed-meshheading:15265711-Breast Neoplasms, pubmed-meshheading:15265711-Carcinoma, pubmed-meshheading:15265711-Cell Line, Tumor, pubmed-meshheading:15265711-Cell Nucleus, pubmed-meshheading:15265711-Cell Survival, pubmed-meshheading:15265711-DNA Repair, pubmed-meshheading:15265711-Down-Regulation, pubmed-meshheading:15265711-Humans, pubmed-meshheading:15265711-Macromolecular Substances, pubmed-meshheading:15265711-Mutation, pubmed-meshheading:15265711-Peptide Fragments, pubmed-meshheading:15265711-Transfection, pubmed-meshheading:15265711-Tumor Suppressor Protein p53, pubmed-meshheading:15265711-Tumor Suppressor Proteins, pubmed-meshheading:15265711-Ubiquitin-Protein Ligases
pubmed:year
2004
pubmed:articleTitle
BARD1 regulates BRCA1 apoptotic function by a mechanism involving nuclear retention.
pubmed:affiliation
Westmead Institute for Cancer Research, Westmead Millennium Institute at Westmead Hospital, University of Sydney, Westmead, 2145 New South Wales, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't