Double-strand break repair by homologous recombination in primary mouse somatic cells requires BRCA1 but not the ATM kinase Journal Article
| Authors: | Kass, E. M.; Helgadottir, H. R.; Chen, C. C.; Barbera, M.; Wang, R.; Westermark, U. K.; Ludwig, T.; Moynahan, M. E.; Jasin, M. |
| Article Title: | Double-strand break repair by homologous recombination in primary mouse somatic cells requires BRCA1 but not the ATM kinase |
| Abstract: | Homology-directed repair (HDR) is a critical pathway for the repair of DNA double-strand breaks (DSBs) in mammalian cells. Efficient HDR is thought to be crucial for maintenance of genomic integrity during organismal development and tumor suppression. However, most mammalian HDR studies have focused on transformed and immortalized cell lines. We report here the generation of a Direct Repeat (DR)-GFP reporter-based mouse model to study HDR in primary cell types derived from diverse lineages. Embryonic and adult fibroblasts from these mice as well as cells derived from mammary epithelium, ovary, and neonatal brain were observed to undergo HDR at I-SceI endonuclease-induced DSBs at similar frequencies. When the DR-GFP reporter was crossed into mice carrying a hypomorphic mutation in the breast cancer susceptibility gene Brca1, a significant reduction in HDR was detected, showing that BRCA1 is critical for HDR in somatic cell types. Consistent with an HDR defect, Brca1 mutant mice are highly sensitive to the cross-linking agent mitomycin C. By contrast, loss of the DSB signaling ataxia telangiectasia-mutated (ATM) kinase did not significantly alter HDR levels, indicating that ATM is dispensable for HDR. Notably, chemical inhibition of ATM interfered with HDR. The DR-GFP mouse provides a powerful tool for dissecting the genetic requirements of HDR in a diverse array of somatic cell types in a normal, nontransformed cellular milieu. |
| Keywords: | signal transduction; controlled study; gene mutation; dna-binding proteins; nonhuman; flow cytometry; animal cell; dna recombination; mouse; mammalia; animals; cell cycle proteins; mice; mus; dna repair; somatic cell; cancer susceptibility; breast cancer; embryo; green fluorescent protein; brca1 protein; cell type; models, animal; ovary; protein-serine-threonine kinases; tumor suppressor proteins; newborn; fibroblast; fibroblasts; atm protein; breast epithelium; dna breaks, double-stranded; double stranded dna break; green fluorescent proteins; electroporation; saccharomyces cerevisiae proteins; endonuclease; mitomycin; concentration (parameters); repetitive sequences, nucleic acid; ataxia telangiectasia; reduction; cross linking; brca1 associated ring domain protein 1; deoxyribonucleases, type ii site-specific; recombinational dna repair |
| Journal Title: | Proceedings of the National Academy of Sciences of the United States of America |
| Volume: | 110 |
| Issue: | 14 |
| ISSN: | 0027-8424 |
| Publisher: | National Academy of Sciences |
| Date Published: | 2013-04-02 |
| Start Page: | 5564 |
| End Page: | 5569 |
| Language: | English |
| PROVIDER: | scopus |
| PMCID: | PMC3619303 |
| PUBMED: | 23509290 |
| DOI: | 10.1073/pnas.1216824110 |
| DOI/URL: | |
| Notes: | --- - "Export Date: 1 May 2013" - "CODEN: PNASA" - ":doi 10.1073/pnas.1216824110" - "Source: Scopus" |
Altmetric
Citation Impact
BMJ Impact Analytics
Related MSK Work