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Keith W Caldecott - One of the best experts on this subject based on the ideXlab platform.
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versatility in phospho dependent molecular recognition of the XRCC1 and xrcc4 dna damage scaffolds by aprataxin family fha domains
DNA Repair, 2015Co-Authors: Amy L Cherry, Keith W Caldecott, Timothy J Nott, Geoffrey Kelly, Stuart L Rulten, Stephen J SmerdonAbstract:Aprataxin, aprataxin and PNKP-like factor (APLF) and polynucleotide kinase phosphatase (PNKP) are key DNA-repair proteins with diverse functions but which all contain a homologous forkhead-associated (FHA) domain. Their primary binding targets are casein kinase 2-phosphorylated forms of the XRCC1 and XRCC4 scaffold molecules which respectively coordinate single-stranded and double-stranded DNA break repair pathways. Here, we present the high-resolution X-ray structure of a complex of phosphorylated XRCC4 with APLF, the most divergent of the three FHA domain family members. This, combined with NMR and biochemical analysis of aprataxin and APLF binding to singly and multiply-phosphorylated forms of XRCC1 and XRCC4, and comparison with PNKP reveals a pattern of distinct but overlapping binding specificities that are differentially modulated by multi-site phosphorylation. Together, our data illuminate important differences between activities of the three phospho-binding domains, in spite of a close evolutionary relationship between them.
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APLF (C2orf13) is a novel human protein involved in the cellular response to chromosomal DNA strand breaks.
Molecular and Cellular Biology, 2007Co-Authors: Natasha Iles, Stuart L Rulten, Sherif F. El-khamisy, Keith W CaldecottAbstract:Aprataxin and polynucleotide kinase (PNK) are DNA end processing factors that are recruited into the DNA single- and double-strand break repair machinery through phosphorylation-specific interactions with XRCC1 and XRCC4, respectively. These interactions are mediated through a divergent class of forkhead-associated (FHA) domain that binds to peptide sequences in XRCC1 and XRCC4 that are phosphorylated by casein kinase 2 (CK2). Here, we identify the product of the uncharacterized open reading frame C2orf13 as a novel member of this FHA domain family of proteins and we denote this protein APLF (aprataxin- and PNK-like factor). We show that APLF interacts with XRCC1 in vivo and in vitro in a manner that is stimulated by CK2. Yeast two-hybrid analyses suggest that APLF also interacts with the double-strand break repair proteins XRCC4 and XRCC5 (Ku86). We also show that endogenous and yellow fluorescent protein-tagged APLF accumulates at sites of H2O2 or UVA laser-induced chromosomal DNA damage and that this is achieved through at least two mechanisms: one that requires the FHA domain-mediated interaction with XRCC1 and a second that is independent of XRCC1 but requires a novel type of zinc finger motif located at the C terminus of APLF. Finally, we demonstrate that APLF is phosphorylated in a DNA damage- and ATM-dependent manner and that the depletion of APLF from noncycling human SH-SY5Y neuroblastoma cells reduces rates of chromosomal DNA strand break repair following ionizing radiation. These data identify APLF as a novel component of the cellular response to DNA strand breaks in human cells.
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the ataxia oculomotor apraxia 1 gene product has a role distinct from atm and interacts with the dna strand break repair proteins XRCC1 and xrcc4
DNA Repair, 2004Co-Authors: Paula M Clements, Mariaceu Moreira, Malcolm A R Taylor, Claire Breslin, Limei Ju, Pawel Bieganowski, Philip J Byrd, Emma D. Deeks, Charles Brenner, Keith W CaldecottAbstract:Ataxia-oculomotor apraxia 1 (AOA1) is an autosomal recessive neurodegenerative disease that is reminiscent of ataxia-telangiectasia (A-T). AOA1 is caused by mutations in the gene encoding aprataxin, a protein whose physiological function is currently unknown. We report here that, in contrast to A-T, AOA1 cell lines exhibit neither radioresistant DNA synthesis nor a reduced ability to phosphorylate downstream targets of ATM following DNA damage, suggesting that AOA1 lacks the cell cycle checkpoint defects that are characteristic of A-T. In addition, AOA1 primary fibroblasts exhibit only mild sensitivity to ionising radiation, hydrogen peroxide, and methyl methanesulphonate (MMS). Strikingly, however, aprataxin physically interacts in vitro and in vivo with the DNA strand break repair proteins XRCC1 and XRCC4. Aprataxin possesses a divergent forkhead associated (FHA) domain that closely resembles the FHA domain present in polynucleotide kinase, and appears to mediate the interactions with CK2-phosphorylated XRCC1 and XRCC4 through this domain. Aprataxin is therefore physically associated with both the DNA single-strand and double-strand break repair machinery, raising the possibility that AOA1 is a novel DNA damage response-defective disease.
Antonia Velázquez - One of the best experts on this subject based on the ideXlab platform.
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association studies of ogg1 XRCC1 xrcc2 and xrcc3 polymorphisms with differentiated thyroid cancer
Mutation Research, 2011Co-Authors: Wilserandres Garciaquispes, Giselle Perezmachado, Abdelmounaim Akdi, Susana Pastor, Fina Biarnes, Joan Castell, Antonia Velázquez, Pere GalofreAbstract:Abstract The role of the DNA repair genes OGG1 , XRCC1 , XRCC2 and XRCC3 on differentiated thyroid cancer (DTC) susceptibility was examined in 881 individuals (402 DTC and 479 controls). DNA repair genes were proposed as candidate genes, since the current data indicate that exposure to ionizing radiation is the only established factor in the development of thyroid cancer, especially when it occurs in early stages of life. We have genotyped DNA repair genes involved in base excision repair (BER) ( OGG1 , Ser326Cys; XRCC1 , Arg280His and Arg399Gln), and homologous recombination repair (HRR) ( XRCC2 , Arg188His and XRCC3 , ISV-14G). Genotyping was carried out using the iPLEX (Sequenom) technique. Multivariate logistic regression analyses were performed in a case-control study design. From all the studied polymorphism, only a positive association (OR = 1.58, 95% CI 1.05–2.46, P = 0.027) was obtained for XRCC1 (Arg280His). No associations were observed for the other polymorphisms. No effects of the histopathological type of tumor were found when the DTC patients were stratified according to the type of tumor. It must be emphasized that this study include the greater patients group, among the few studies carried out until now determining the role of DNA repair genes in thyroid cancer susceptibility.
Eduardo Antônio Donadi - One of the best experts on this subject based on the ideXlab platform.
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efficiency of the dna repair and polymorphisms of the XRCC1 xrcc3 and xrcc4 dna repair genes in systemic lupus erythematosus
Lupus, 2008Co-Authors: Carmen Lucia Bassi, Danilo J Xavier, Gustavo Martelli Palomino, Patricia Nicolucci, Elza Tiemi Sakamotohojo, Christiane Pienna Soares, Eduardo Antônio DonadiAbstract:Impaired DNA repair efficiency in systemic lupus erythematosus (SLE) patients has been reported in some studies, mainly regarding the repair of oxidative damage, but little is known about repair kinetics towards primarily single-stranded DNA breaks. In the present study, we aimed to investigate: (a) the efficiency of SLE peripheral blood leucocytes in repairing DNA damage induced by ionizing radiation and (b) the association of DNA repair gene (XRCC1 Arg399Gln, XRCC3 Thr241Met and XRCC4 Ile401Thr) polymorphisms in SLE patients, considering the whole group, or stratified sub-groups according to clinical and laboratory features. A total of 163 SLE patients and 125 healthy controls were studied. The kinetics of DNA strand break repair was evaluated by the comet assay, and genotyping for DNA repair genes was performed by PCR-RFLP. Compared with controls, SLE leucocytes exhibited decreased efficiency of DNA repair evaluated at 30 min following irradiation. A significant association with DNA repair gene polymor...
Michael Weinfeld - One of the best experts on this subject based on the ideXlab platform.
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domain analysis of pnkp XRCC1 interactions influence of genetic variants of XRCC1
Journal of Biological Chemistry, 2019Co-Authors: Rajam S. Mani, Inbal Mermershtain, Ismail Abdou, Mesfin Fanta, Michael J. Hendzel, J Mark N Glover, Michael WeinfeldAbstract:Polynucleotide kinase/phosphatase (PNKP) and X-ray repair cross-complementing 1 (XRCC1) are key proteins in the single-strand DNA break repair pathway. Phosphorylated XRCC1 stimulates PNKP by binding to its forkhead-associated (FHA) domain, whereas nonphosphorylated XRCC1 stimulates PNKP by interacting with the PNKP catalytic domain. Here, we have further studied the interactions between these two proteins, including two variants of XRCC1 (R194W and R280H) arising from single-nucleotide polymorphisms (SNPs) that have been associated with elevated cancer risk in some reports. We observed that interaction of the PNKP FHA domain with phosphorylated XRCC1 extends beyond the immediate, well-characterized phosphorylated region of XRCC1 (residues 515-526). We also found that an XRCC1 fragment, comprising residues 166-436, binds tightly to PNKP and DNA and efficiently activates PNKP's kinase activity. However, interaction of either of the SNP-derived variants of this fragment with PNKP was considerably weaker, and their stimulation of PNKP was severely reduced, although they still could bind DNA effectively. Laser microirradiation revealed reduced recruitment of PNKP to damaged DNA in cells expressing either XRCC1 variant compared with PNKP recruitment in cells expressing WT XRCC1 even though WT and variant XRCC1s were equally efficient at localizing to the damaged DNA. These findings suggest that the elevated risk of cancer associated with these XRCC1 SNPs reported in some studies may be due in part to the reduced ability of these XRCC1 variants to recruit PNKP to damaged DNA.
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Domain analysis of PNKP–XRCC1 interactions: Influence of genetic variants of XRCC1
The Journal of biological chemistry, 2018Co-Authors: Rajam S. Mani, Inbal Mermershtain, Ismail Abdou, Mesfin Fanta, Michael J. Hendzel, J. N. Mark Glover, Michael WeinfeldAbstract:Polynucleotide kinase/phosphatase (PNKP) and X-ray repair cross-complementing 1 (XRCC1) are key proteins in the single-strand DNA break repair pathway. Phosphorylated XRCC1 stimulates PNKP by binding to its forkhead-associated (FHA) domain, whereas nonphosphorylated XRCC1 stimulates PNKP by interacting with the PNKP catalytic domain. Here, we have further studied the interactions between these two proteins, including two variants of XRCC1 (R194W and R280H) arising from single-nucleotide polymorphisms (SNPs) that have been associated with elevated cancer risk in some reports. We observed that interaction of the PNKP FHA domain with phosphorylated XRCC1 extends beyond the immediate, well-characterized phosphorylated region of XRCC1 (residues 515-526). We also found that an XRCC1 fragment, comprising residues 166-436, binds tightly to PNKP and DNA and efficiently activates PNKP's kinase activity. However, interaction of either of the SNP-derived variants of this fragment with PNKP was considerably weaker, and their stimulation of PNKP was severely reduced, although they still could bind DNA effectively. Laser microirradiation revealed reduced recruitment of PNKP to damaged DNA in cells expressing either XRCC1 variant compared with PNKP recruitment in cells expressing WT XRCC1 even though WT and variant XRCC1s were equally efficient at localizing to the damaged DNA. These findings suggest that the elevated risk of cancer associated with these XRCC1 SNPs reported in some studies may be due in part to the reduced ability of these XRCC1 variants to recruit PNKP to damaged DNA.
Eliane Pedra Dias - One of the best experts on this subject based on the ideXlab platform.
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Association of Polymorphisms in the DNA Repair Genes XRCC1 and XRCC3 with Systemic Lupus Erythematosus
The Open Rheumatology Journal, 2019Co-Authors: Cristhiane Almeida Leite Da Silva, Marcial Francis Galera, Regiane R. Festi, Mariano Martinez Espinosa, Vander Fernandes, Paula Henriques Blaskievicz, Eliane Pedra DiasAbstract:Background: Evidence suggests that DNA damage is implicated in the development of Systemic Lupus Erythematosus (SLE). Objective: Investigate the possible association of polymorphisms in the DNA repair genes XRCC1 and XRCC3 with SLE and its clinical and laboratory features. Methods: This is a case-control study comparing the polymorphisms in the DNA repair genes XRCC1 and XRCC3 in SLE patients and control individuals. Genotyping for DNA repair genes was performed by polymerase chain reaction-restriction fragment length polymorphism in 76 patients and 82 healthy control individuals. Results: Our data indicated that the genotype frequencies in patients with the XRCC1 Arg399Gln and XRCC3 Thr241Met polymorphisms were similar to those observed in the control group (p > 0.05). However, the frequencies of the 399Gln allele (p = 0.023, OR = 0.58, 95% CI = 0.36–0.93) and 241Met allele (p = 0.0039, OR = 0.59, 95% CI = 0.36–0.98) were significantly lower in the patients than those in the control subjects. Conclusion: We demonstrated that 399Gln and 241Met alleles may play a protective role in SLE susceptibility.
