Correction: The BRCT Domain of PARP-1 Is Required for Immunoglobulin Gene Conversion
| العنوان: | Correction: The BRCT Domain of PARP-1 Is Required for Immunoglobulin Gene Conversion |
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| المؤلفون: | Shunichi Takeda, Ben Buelow, Marcia Paddock, Andrew M. Scharenberg |
| المصدر: | PLoS Biology, Vol 16, Iss 3, p e1002621 (2018) PLoS Biology |
| بيانات النشر: | Public Library of Science (PLoS), 2018. |
| سنة النشر: | 2018 |
| مصطلحات موضوعية: | 0301 basic medicine, Immunoglobulin gene, Biochemistry/Replication and Repair, Mutation, General Immunology and Microbiology, QH301-705.5, DNA repair, General Neuroscience, Protein domain, Biology, medicine.disease_cause, Biochemistry, DNA-binding protein, General Biochemistry, Genetics and Molecular Biology, Protein–protein interaction, Cell biology, 03 medical and health sciences, 030104 developmental biology, BRCT domain, medicine, Gene conversion, Biology (General), Immunology/Genetics of the Immune System, General Agricultural and Biological Sciences, Research Article |
| الوصف: | During affinity maturation, genomic integrity is maintained through specific targeting of DNA mutations. The DNA damage sensor PARP-1 helps determine whether a DNA lesion results in faithful or mutagenic repair. Genetic variation at immunoglobulin (Ig) gene variable regions in B-cells is created through a multi-step process involving deamination of cytosine bases by activation-induced cytidine deaminase (AID) and their subsequent mutagenic repair. To protect the genome from dangerous, potentially oncogenic effects of off-target mutations, both AID activity and mutagenic repair are targeted specifically to the Ig genes. However, the mechanisms of targeting are unknown and recent data have highlighted the role of regulating mutagenic repair to limit the accumulation of somatic mutations resulting from the more widely distributed AID-induced lesions to the Ig genes. Here we investigated the role of the DNA damage sensor poly-(ADPribose)-polymerase-1 (PARP-1) in the repair of AID-induced DNA lesions. We show through sequencing of the diversifying Ig genes in PARP-1−/− DT40 B-cells that PARP-1 deficiency results in a marked reduction in gene conversion events and enhanced high-fidelity repair of AID-induced lesions at both Ig heavy and light chains. To further characterize the role of PARP-1 in the mutagenic repair of AID-induced lesions, we performed functional analyses comparing the role of engineered PARP-1 variants in high-fidelity repair of DNA damage induced by methyl methane sulfonate (MMS) and the mutagenic repair of lesions at the Ig genes induced by AID. This revealed a requirement for the previously uncharacterized BRCT domain of PARP-1 to reconstitute both gene conversion and a normal rate of somatic mutation at Ig genes, while being dispensable for the high-fidelity base excision repair. From these data we conclude that the BRCT domain of PARP-1 is required to initiate a significant proportion of the mutagenic repair specific to diversifying antibody genes. This role is distinct from the known roles of PARP-1 in high-fidelity DNA repair, suggesting that the PARP-1 BRCT domain has a specialized role in assembling mutagenic DNA repair complexes involved in antibody diversification. Author Summary To produce a limitless diversity of antibodies within the constraints of a finite genome, activated B cells introduce random mutations into antibody genes through a process of targeted DNA damage and subsequent mutagenic repair. At the same time, the rest of the genome must be protected from mutagenesis to prevent off-target mutations which can lead to the development of lymphoma or leukemia. How antibody genes are specifically targeted is still largely unknown. A potential player in this process is the DNA-damage-sensing enzyme PARP-1, which recruits DNA repair enzymes to sites of damage. Using a chicken B cell lymphoma cell line because it has only a single PARP isoform and constitutively mutates its antibody genes, we compared the types of mutations accumulated in PARP-1−/− cells to wild type. We found that in cells lacking PARP-1, the major pathway of mutagenic repair was disrupted and fewer mutations than normal were introduced into their antibody genes. To identify what might be important for mutagenesis, we tested different factors for their ability to rescue this mutagenic deficiency and found a role for the BRCT (BRCA1 C-terminal) domain of PARP-1, a consensus protein domain known to be involved in directing protein-protein interactions. Our evidence suggests that PARP-1 may be interacting with another hypothetical protein via its BRCT domain that is required for the mutagenic rather than faithful repair of DNA lesions in the antibody genes. |
| تدمد: | 1545-7885 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::207764a0100f030f35d9ded47339ea47Test https://doi.org/10.1371/journal.pbio.1002621Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....207764a0100f030f35d9ded47339ea47 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15457885 |
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