Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1178638 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| Other | ||||
| SRR31169324_1.fastq.gz | Fastqsanger.gz | |||
| SRR31169324_2.fastq.gz | Fastqsanger.gz | |||
| SRR31169326_1.fastq.gz | Fastqsanger.gz | |||
| SRR31169326_2.fastq.gz | Fastqsanger.gz |
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Project description:DNA polymerase theta (Pol-theta)-mediated end-joining (TMEJ) repairs DNA double-strand breaks and confers resistance to genotoxic agents. How Pol-theta is regulated at the molecular level to exert TMEJ remains unknown. We find that Pol-theta interacts with and is PARylated by PARP1 in vitro and in cells. PARP1 recruits Pol-theta to the vicinity of DNA damage via PARylation dependent liquid demixing, however, PARylated Pol-theta (PAR-Pol-theta) cannot perform TMEJ due to its inability to bind DNA. PARG-mediated de-PARylation of Pol-theta reactivates its DNA binding and end-joining activities in vitro. Consistent with this, PARG is essential for TMEJ in cells and the temporal recruitment of PARG to DNA damage corresponds with TMEJ activation and dissipation of PARP1 and PAR. These studies support a two-step spatiotemporal mechanism of TMEJ regulation. First, PARP1 PARylates Pol-theta and facilitates its recruitment to DNA damage sites in an inactivated state. PARG subsequently activates TMEJ by removing repressive PAR marks on Pol-theta.
| MSV000092839 | MassIVE
Project description:In homologous recombination deficient cells, polymerase theta (Pol θ)-mediated end-joining (TMEJ) repairs replicative DNA breaks during mitosis through interactions with RHINO and TOPBP1. V(D)J recombination and class switch recombination (CSR) rely on DNA breakage in G1-phase B lymphocytes and repair by non-homologous end-joining (NHEJ). In this study, we assayed CSR in primary B cells deficient in XRCC4, SHLD1, and Pol θ. We found that B cells deficient in both XRCC4 and Pol θ, or SHLD1 and Pol θ, exhibit an increased rate of IgH breaks, while retaining CSR levels similar to those of B cells deficient in XRCC4 or SHLD1. We show that in XRCC4- or SHLD1-deficient B cells, Pol θ promotes the formation of aberrant recombination products characterized by exacerbated double-strand break (DSB) end resection, inversion and microhomology, and that these end-joining events occur independently of RHINO. Furthermore, we find that TMEJ of RAG-generated DSBs is also independent of RHINO and concomitant to S/G2 entry. Based on these results, we propose that in the absence of NHEJ, TMEJ repairs persistent G1-phase DSBs in S/G2, rather than in mitosis.
2025-08-26 | GSE306291 | GEO
Project description:Roles for DNA Polymerase Theta mediated end-joining
| PRJNA324723 | ENA
Project description:Polymerase theta-mediated end-joining repairs persistent G1-induced DNA breaks in S/G2.
| PRJNA1310422 | ENA
Project description:To generate antibodies with different effector functions, B cells undergo Immunoglobulin class switch recombination (CSR). The ligation step of CSR is usually mediated by the classical non-homologous end-joining (cNHEJ) pathway. In cNHEJ-deficient cells, a remarkable ~25% CSR can be achieved by the alternative end-joining (A-EJ) pathway that preferentially uses microhomology (MH) at the junctions. While A-EJ mediated repair of endonuclease generated breaks requires DNA end-resection, we show that CtIP-mediated DNA end-resection is dispensable for A-EJ-mediated CSR using cNHEJ-deficient B cells. High-throughput sequencing analyses revealed that loss of ATM/ATR phosphorylation of CtIP at T855 or ATM kinase inhibition suppress resection without altering the MH-pattern of the A-EJ-mediated switch junctions. Moreover, we found that ATM kinase promotes Alt-EJ mediated CSR by suppressing inter-chromosomal translocations independent of end-resection. Finally, temperol analyses reveal that MHs are enriched in early internal deletions even in cNHEJ-proficient B cells. Thus, we propose that repetitive IgH switch regions represent favoriate substrates for MH-mediated end-joining contributing to the robustness and resection-indepndence of A-EJ-mediated CSR.
2020-09-18 | GSE156392 | GEO
Project description:Replication stress, if not effectively and timely addressed, could result in DNA damage in mitosis. However, it remains unknown the relationship between mitotic DNA damage and other mitotic events such as nuclear envelope (NE) breakdown and reassembly. Here we report that replication stress could generate NE rupture. Rather than de novo formation, the rupture per se is a result of nuclear envelope reassembly defect (NERD) in mitosis. Repair of mitotic DNA damage by DNA polymerase theta (Polθ), a key microhomology-mediated end joining (MMEJ) factor, suppresses NERD. Furthermore, exacerbated NERD is observed in multiple conditions of synthetic lethality, suggesting NERD might be a general consequence of synthetic lethality. In addition, genomic mapping of LADs identifies a population of RESS-LADs (replication stress-sensitive LADs). Replication stress causes the loss of CFSs at RESS-LADs, likely due to the sustained phosphorylation of Lamin A/C at the NE rupture sites. Altogether, our findings establish a novel link between replication stress-induced genome instability and nuclear vulnerability.
2025-08-16 | GSE271990 | GEO
Project description:IgH class switch recombination (CSR) in B lymphocytes switches IgH constant regions to change antibody functions. CSR is initiated by DNA double strand breaks (DSBs) within a donor IgH switch (S) region and a downstream acceptor S region. CSR is completed by fusing donor and acceptor S region DSB ends by classical non-homologous end-joining (C-NHEJ) and, in its absence, by alternative end-joining (A-EJ) that is more biased to use longer junctional micro-homologies (MHs). Deficiency for DSB response (DSBR) factors, including ATM and 53BP1, variably impair CSR end-joining, with 53BP1 deficiency having the greatest impact. However, studies of potential impact of DSBR factor deficiencies on MH-mediated CSR end-joining have been technically limited. We now use a robust DSB joining assay to elucidate impacts of deficiencies for DSBR factors on CSR and chromosomal translocation junctions in primary mouse B cells and CH12F3 B lymphoma cells. Compared to wild-type, CSR and c-Myc to S region translocation junctions in the absence of 53BP1, and to a lesser extent other DSBR factors, have increased MH-utilization; indeed, 53BP1-deficient MH-profiles resemble those associated with C-NHEJ deficiency. Yet, translocation junctions between c-Myc DSB and general DSBs genome-wide are not MH-biased in ATM-deficient versus wild-type CH12F3 cells and less biased in 53BP1- and C-NHEJ-deficient cells than CSR junctions or c-Myc to S region translocation junctions. We discuss potential roles of DSBR factors in suppressing increased MH-mediated DSB end-joining and features of S regions that may render their DSBs prone to MH-biased end-joining in the absence of DSBR factors.
2018-01-08 | GSE106922 | GEO