BRCA2-dependent and independent formation of RAD51 nuclear foci

Tarsounas, Madalena; Davies, Derek; West, Stephen C.

doi:10.1038/sj.onc.1206263

Cited by 175 publications

(154 citation statements)

References 41 publications

Supporting

Mentioning

142

Contrasting

Unclassified

Order By: Relevance

“…Thus, it is of interest to study whether c-ABL has any effects on in vivo behaviors of self-association-defective RAD51 mutants. Since RAD51filament formation in vivo is a complex cellular process, especially in higher vertebrate cells, requiring transport to and assembly in chromatin, before RAD51 nucleoprotein filament formation on damaged DNA [14,20], we examined effects of c-ABL on nuclear transport or chromatin association of RAD51. HA-tagged RAD51-WT or RAD51-R167G was transiently co-expressed with Flag-tagged active (wt) or kinase-dead (kd) c-ABL in 293T cells, and cells were fractionated into cytoplasmic, nuclear and chromatin-associated fractions.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

c-ABL tyrosine kinase stabilizes RAD51 chromatin association

Shimizu

Popova

Fleury

et al. 2009

Biochemical and Biophysical Research Communications

View full text Add to dashboard Cite

In this paper, by using self-association defective RAD51 mutants, we show that the phosphorylation of RAD51 by c-ABL stabilizes RAD51 chromatin association. This activation is abolished by replacement of Tyr-315 with Phe, indicating that the phosphorylation of Tyr-315 is the origin of this activation. However, c-ABL cannot restore the defect of the self-association defective mutants in IR-induced nuclear focus formation, suggesting that c-ABL functions during the early phase of RAD51 chromatin assembly, before RAD51 nucleo-protein filament formation. Our findings thus suggest a new model for the regulation of early steps of homologous recombination repair.We are very happy if you kindly consider our manuscript for possible publication in AbstractThe assembly of RAD51 recombinase on DNA substrates at sites of breakage is essential for their repair by homologous recombination repair (HRR). The signaling pathway that triggers RAD51 assembly at damage sites to form subnuclear foci is unclear. Here, we provide evidence that c-ABL, a tyrosine kinase activated by DNA damage which phosphorylates RAD51 on Tyr-315, works at a previously unrecognized, proximal step to initiate RAD51 assembly. We first show that c-ABL associates with chromatin after DNA damage in a manner dependent on its kinase activity. Using RAD51 mutants that are unable to oligomerize to form a nucleoprotein filament, we separate RAD51 assembly on DNA to form foci into two steps: stable chromatin association followed by oligomerization. We show that phosphorylation on Tyr-315 by c-ABL is required for chromatin association of oligomerization-defective RAD51 mutants, but is insufficient to restore oligomerization. Our findings suggest a new model for the regulation of early steps of HRR.

show abstract

Section: Resultsmentioning

confidence: 99%

“…Transient transfection were performed by using FuGENE 6 Transfection Reagent (Roche). Subcellular fractionation was carried out essentially as described [14].…”

Section: Methodsmentioning

confidence: 99%

c-ABL tyrosine kinase stabilizes RAD51 chromatin association

Shimizu

Popova

Fleury

et al. 2009

Biochemical and Biophysical Research Communications

View full text Add to dashboard Cite

show abstract

“…It also directly interacts with the recombinase and could participate in its nuclear localization (Davies et al, 2001;Pellegrini et al, 2004). However, nuclear foci of Rad51 are also observed during S phase independently of the presence of Brca2, suggesting that distinct pathways, requiring different proteins, could contribute to Rad51 foci formation in S phase or following DNA-damaging treatments (Tarsounas et al, 2003). Brca1 colocalizes with Rad51 in S phase and following DNA-damaging treatments (Scully et al, 1997), but this interaction is thought to be indirect and mediated by Brca2 (Venkitaraman, 2002).…”

Section: Introductionmentioning

confidence: 99%

DNA damage induce γ-tubulin–RAD51 nuclear complexes in mammalian cells

et al. 2005

View full text Add to dashboard Cite

Rad51 protein plays an essential role in recombination repair of DNA double-strand breaks and DNA crosslinking adducts. It is part of complexes which can vary with the stage of the cell cycle and the nature of the DNA lesions. During a search for Rad51-associated proteins in CHO nuclear extracts of S-phase cells by mass spectrometry of proteins immunoprecipitated with Rad51 antibodies, we identified a centrosomal protein, c-tubulin. This association was confirmed by the reverse immunoprecipitation with c-tubulin antibodies. Both proteins copurified from HeLa cells nuclear extracts following a tandem affinity purification of double-tagged Rad51. Immunofluorescence analysis showed colocalization of both Rad51 and c-tubulin in discrete foci in mammalian cell nuclei. The number of colocalized foci and their overlapping area increased in the presence of DNA damage produced by genotoxic treatments either during S phase or in exponentially growing cells. These variations did not result from an overall stress because microtubule cytoskeleton poisons devoid of direct interactions with DNA, such as taxol or colcemid, did not lead to an increase of this association. The recruitment of Rad51 and c-tubulin in the same nuclear complex suggests a link between DNA recombination repair and the centrosome function during the cell cycle.

show abstract

“…They are also in agreement with the results of Tutt et al (2001) who found that gene conversion was significantly reduced in BRCA2-deficient cells, while levels of SCE were only slightly reduced. Previously, it has been reported that RAD51 foci are formed in BRCA2-deficient cells in the S phase of the cell cycle (Tarsounas et al, 2003), suggesting that these cells may still repair DSBs at replication forks. It has also been shown that DSBs induced at replication forks preferentially trigger SCE rather than gene conversion (Arnaudeau et al, 2001;Saleh-Gohari and Helleday, unpublished).…”

Section: Suppressed Short Tract Gene Conversion (Stgc) But Not Sce Imentioning

confidence: 99%

“…Furthermore, translocation of the RAD51 protein to the nucleus is dependent on BRCA2 (Davies et al, 2001), and RAD51 foci fail to form in response to DNA damage in BRCA2-defective cells (Kraakman-van der Zwet et al, 2002). However, it has been shown that some RAD51 foci form independent of a functional BRCA2 protein during the S phase of the cell cycle, although damage-induced RAD51 foci fail to form in the same BRCA2-deficient cells (Tarsounas et al, 2003). From these data it has been suggested that there may be two ways to form RAD51 foci, dependent or independent of a functional BRCA2 protein.…”

mentioning

confidence: 99%

Strand invasion involving short tract gene conversion is specifically suppressed in BRCA2-deficient hamster cells

Saleh‐Gohari

Helleday

2004

Oncogene

View full text Add to dashboard Cite

The BRCA2 tumour suppressor protein is involved in maintaining genetic stability through its role in homologous recombination (HR), where it mediates RAD51-dependent strand invasion. Here, we show that BRCA2-defective cells are not completely impaired in HR by strand invasion although the spontaneous HR rate is 10-fold lower than that in wild-type cells. Furthermore, a DNA double-strand break (DSB) triggers HR repair by strand invasion also in BRCA2-defective cells, but less efficiently. Thus, either the strand invasion pathway(s) in which BRCA2 operates is still operative in the absence of a functional BRCA2, albeit at a reduced frequency, or there is a separate pathway for strand invasion still functional in BRCA2-deficient cells. Consistent with the latter hypothesis, we show that HR events occurring in BRCA2-defective cells differ from HR events in wild-type cells. These data suggest that BRCA2-defective hamster cells are impaired in short tract gene conversion but maintain proficiency in sister chromatid exchange.

show abstract

BRCA2-dependent and independent formation of RAD51 nuclear foci

Cited by 175 publications

References 41 publications

c-ABL tyrosine kinase stabilizes RAD51 chromatin association

c-ABL tyrosine kinase stabilizes RAD51 chromatin association

DNA damage induce γ-tubulin–RAD51 nuclear complexes in mammalian cells

Strand invasion involving short tract gene conversion is specifically suppressed in BRCA2-deficient hamster cells

Contact Info

Product

Resources

About