Strand exchange activity of human recombination protein Rad52

Kumar, Jaspal Kaur; Gupta, Ravindra C.

doi:10.1073/pnas.0403416101

Cited by 29 publications

(15 citation statements)

References 50 publications

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“…Although biochemical studies clearly implicate mammalian RAD52 in homologous recombinational repair of ionizing radiation-induced DNA damage (34)(35)(36), this view is challenged by the mild phenotype exhibited by cells and mice with RAD52 defects (14,17) and by the marked delay in the colocalization of RAD52 and RAD51 foci after ionizing radiation (Figs. 1C and 2B).…”

Section: Resultsmentioning

confidence: 99%

Distinct RAD51 Associations with RAD52 and BCCIP in Response to DNA Damage and Replication Stress

et al. 2008

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RAD51 has critical roles in homologous recombination (HR) repair of DNA double-strand breaks (DSB) and restarting stalled or collapsed replication forks. In yeast, Rad51 function is facilitated by Rad52 and other ''mediators.'' Mammalian cells express RAD52, but BRCA2 may have supplanted RAD52 in mediating RAD51 loading onto ssDNA. BCCIP interacts with BRCA2, and both proteins are important for RAD51 focus formation after ionizing radiation and HR repair of DSBs. Nonetheless, mammalian RAD52 shares biochemical activities with yeast Rad52, including RAD51 binding and single-strand annealing, suggesting a conserved role in HR. Because RAD52 and RAD51 associate, and RAD51 and BCCIP associate, we investigated the colocalization of RAD51 with BCCIP and RAD52 in human cells. We found that RAD51 colocalizes with BCCIP early after ionizing radiation, with RAD52 later, and there was little colocalization of BCCIP and RAD52. RAD52 foci are induced to a greater extent by hydroxyurea, which stalls replication forks, than by ionizing radiation. Using fluorescence recovery after photo bleaching, we show that RAD52 mobility is reduced to a greater extent by hydroxyurea than ionizing radiation. However, BCCIP showed no changes in mobility after hydroxyurea or ionizing radiation. We propose that BCCIP-dependent repair of DSBs by HR is an early RAD51 response to ionizing radiation-induced DNA damage, and that RAD52-dependent HR occurs later to restart a subset of blocked or collapsed replication forks. RAD52 and BRCA2 seem to act in parallel pathways, suggesting that targeting RAD52 in BRCA2-deficient tumors may be effective in treating these tumors. [Cancer Res 2008;68(8):2699-707]

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Section: Resultsmentioning

confidence: 99%

Distinct RAD51 Associations with RAD52 and BCCIP in Response to DNA Damage and Replication Stress

et al. 2008

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“…We next investigated whether the physical interaction between RAD52 and OGG1 translated into a functional interaction. RAD52 has two enzymatic activities: single-strand DNA annealing (23,28) and DNA strand exchange (4,20). Both activities are relevant to its role in homologous recombination and DSB repair.…”

Section: Rad52 Interacts With Ogg1-␣ and -␤ In Vitro And In Vivomentioning

confidence: 99%

The Recombination Protein RAD52 Cooperates with the Excision Repair Protein OGG1 for the Repair of Oxidative Lesions in Mammalian Cells

Souza-Pinto

Maynard

Hashiguchi

et al. 2009

Molecular and Cellular Biology

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Oxidized bases are common types of DNA modifications. Their accumulation in the genome is linked to aging and degenerative diseases. These modifications are commonly repaired by the base excision repair (BER) pathway. Oxoguanine DNA glycosylase (OGG1) initiates BER of oxidized purine bases. A small number of protein interactions have been identified for OGG1, while very few appear to have functional consequences. We report here that OGG1 interacts with the recombination protein RAD52 in vitro and in vivo. This interaction has reciprocal functional consequences as OGG1 inhibits RAD52 catalytic activities and RAD52 stimulates OGG1 incision activity, likely increasing its turnover rate. RAD52 colocalizes with OGG1 after oxidative stress to cultured cells, but not after the direct induction of double-strand breaks by ionizing radiation. Human cells depleted of RAD52 via small interfering RNA knockdown, and mouse cells lacking the protein via gene knockout showed increased sensitivity to oxidative stress. Moreover, cells depleted of RAD52 show higher accumulation of oxidized bases in their genome than cells with normal levels of RAD52. Our results indicate that RAD52 cooperates with OGG1 to repair oxidative DNA damage and enhances the cellular resistance to oxidative stress. Our observations suggest a coordinated action between these proteins that may be relevant when oxidative lesions positioned close to strand breaks impose a hindrance to RAD52 catalytic activities.Oxidative DNA damage is generated at high levels in mammalian cells, even in cells not exposed to exogenous sources of reactive oxygen species. Several kinds of DNA modifications are formed upon oxidative stress (8). The most prevalent modifications, quantitatively, are single-strand breaks and oxidized bases. Clustered DNA damage, when two or more modifications are closely positioned in opposite strands, is detectable after gamma irradiation and has recently been shown to be generated by normal oxidative metabolism (3,35). One unique aspect of such clustered lesions is that they can be converted into double-strand breaks (DSB) if a DNA glycosylase removes the two opposite bases and an apurinic/apyrimidinic (AP)-endonuclease cleaves the resulting abasic sites. Thus, although quantitatively minor, DSB are possible outcomes of oxidative DNA damage.

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“…RAD52 is largely conserved throughout eukaryotes, and both the human and yeast Rad52 proteins stimulate the replacement of replication protein A with Rad51 on single-stranded DNA (4,29,39,45). Additionally, Rad52 promotes DNA annealing and strand exchange between a DNA duplex and complementary single-stranded DNA (14,21,27). Three-dimensional structures of the N terminus of human RAD52 (hRAD52) reveal a multimeric ring containing a positively charged surface groove that has been suggested to bind single-stranded DNA (15, 40).…”

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confidence: 99%

Cells Expressing Murine RAD52 Splice Variants Favor Sister Chromatid Repair

Thorpe

Marrero

Savitzky

et al. 2006

Molecular and Cellular Biology

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The RAD52 gene is essential for homologous recombination in the yeast Saccharomyces cerevisiae. RAD52 is the archetype in an epistasis group of genes essential for DNA damage repair. By catalyzing the replacement of replication protein A with Rad51 on single-stranded DNA, Rad52 likely promotes strand invasion of a double-stranded DNA molecule by single-stranded DNA. Although the sequence and in vitro functions of mammalian RAD52 are conserved with those of yeast, one difference is the presence of introns and consequent splicing of the mammalian RAD52 pre-mRNA. We identified two novel splice variants from the RAD52 gene that are expressed in adult mouse tissues. Expression of these splice variants in tissue culture cells elevates the frequency of recombination that uses a sister chromatid template. To characterize this dominant phenotype further, the RAD52 gene from the yeast Saccharomyces cerevisiae was truncated to model the mammalian splice variants. The same dominant sister chromatid recombination phenotype seen in mammalian cells was also observed in yeast. Furthermore, repair from a homologous chromatid is reduced in yeast, implying that the choice of alternative repair pathways may be controlled by these variants. In addition, a dominant DNA repair defect induced by one of the variants in yeast is suppressed by overexpression of RAD51, suggesting that the Rad51-Rad52 interaction is impaired.Homology-directed repair (HDR) allows cells to repair DNA double-strand breaks (DSBs) in an error-free way and is a key mechanism for maintaining genome integrity in all eukaryotes (11,48, 52). RAD52 is an essential gene for HDR in the yeast Saccharomyces cerevisiae (20,30,46). Identified as one member of an epistasis group of radiation-sensitive yeast mutants, rad52 strains are defective in HDR, the major DSB repair pathway in yeast. RAD52 is largely conserved throughout eukaryotes, and both the human and yeast Rad52 proteins stimulate the replacement of replication protein A with Rad51 on single-stranded DNA (4,29,39,45). Additionally, Rad52 promotes DNA annealing and strand exchange between a DNA duplex and complementary single-stranded DNA (14,21,27). Three-dimensional structures of the N terminus of human RAD52 (hRAD52) reveal a multimeric ring containing a positively charged surface groove that has been suggested to bind single-stranded DNA (15, 40). Relative to the N terminus of Rad52, the C terminus is poorly conserved between homologs. The C terminus of Rad52 is essential for its interaction with Rad51, a bacterial RecA homolog (26, 37). Consistent with its ability to bind both itself and other DNA repair proteins, Rad52 forms discrete nuclear foci both spontaneously and in response to DNA damage, and these DNA repair centers are the sites of DSB repair (23)(24)(25)32).Although yeast RAD52 plays a critical role in HDR, surprisingly, RAD52 knockout mice are resistant to DNA damage (35). However, it is likely that mammalian RAD52 is important for DNA repair, as its activities are conserved with yeast Rad52; in ad...

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Strand exchange activity of human recombination protein Rad52

Cited by 29 publications

References 50 publications

Distinct RAD51 Associations with RAD52 and BCCIP in Response to DNA Damage and Replication Stress

Distinct RAD51 Associations with RAD52 and BCCIP in Response to DNA Damage and Replication Stress

The Recombination Protein RAD52 Cooperates with the Excision Repair Protein OGG1 for the Repair of Oxidative Lesions in Mammalian Cells

Cells Expressing Murine RAD52 Splice Variants Favor Sister Chromatid Repair

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