ERCC6L2 suppresses chromosome translocation
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE281505 | GEO | 2024/11/20
REPOSITORIES: GEO
Similar Datasets
Project description:DNA-PKcs is a crucial component of the non-homologous end joining (NHEJ) repair machinery. To investigate its function in human cell lines, we conducted a study using K562 and HEK293T cell lines. We introduced twinned DNA double-strand breaks (DSBs) or genome-wide DSBs into these cell lines via nucleofection and transfection, respectively. Subsequently, we employed high-throughput genome translocation sequencing (HTGTS) to capture the translocation events (i.e., ligation between "prey(s)" and "bait") and the rejoining events (i.e., direct repair within the "bait" locus) under different conditions, including with or without DNA-PKcs inhibition or deletion. We quantified the number of translocation events by normalizing them to the number of rejoining events, denoted as TL. Interestingly, DNA-PKcs inhibition led to an increase in TL, indicating a higher frequency of translocations. However, it is important to note that chromosomal translocations still predominantly relied on NHEJ despite DNA-PKcs inhibition. Furthermore, we observed that DNA-PKcs deletion resulted in an elevated utilization of microhomology in translocation formation. Nevertheless, NHEJ remained the primary mechanism driving translocation events.These findings provide valuable insights into the role of DNA-PKcs in the repair pathways involved in translocation events in human cell lines. The utilization of HTGTS allowed us to comprehensively analyze the effects of DNA-PKcs inhibition and deletion, shedding light on the interplay between NHEJ and alternative repair mechanisms in translocation formation.
2023-09-01 | GSE232940 | GEO
Project description:ERCC6L2 suppresses chromosome translocation
| PRJNA1184159 | ENA
Project description:Structurally complex genomic regions, such as centromeres, are inherently difficult to duplicate. The mechanism that underlies centromere inheritance is not well understood, and one of the key questions relates to the reassembly of centromeric chromatin following DNA replication. Here we define the SNF2 ATPase ERCC6L2 as a key regulator of this process. ERCC6L2 accumulates at centromeres and promotes efficient deposition of core centromeric factors. Our genomic analyses show that ERCC6L2 deficiency erodes centromeric chromatin, leading to unrestrained replication of centromeric DNA. We also establish that, beyond centromeres, ERCC6L2 facilitates replication at genomic repeats and non-canonical DNA structures. Notably, ERCC6L2 interacts with the major DNA replication factor PCNA through an atypical peptide, presented here as a co-crystal structure. Finally, we examine ERCC6L2 activities at DNA breaks, and show that it acts to restrict end resection independently of the 53BP1-REV7-Shieldin complex. Our observations allow us to propose a mechanistic model of ERCC6L2 activity, which reconciles its seemingly distinct functions in DNA repair and DNA replication. Together, these findings provide a new molecular context for studies linking ERCC6L2 to human disease.
2023-04-10 | GSE226154 | GEO
Project description:Structurally complex genomic regions, such as centromeres, are inherently difficult to duplicate. The mechanism that underlies centromere inheritance is not well understood, and one of the key questions relates to the reassembly of centromeric chromatin following DNA replication. Here we define the SNF2 ATPase ERCC6L2 as a key regulator of this process. ERCC6L2 accumulates at centromeres and promotes efficient deposition of core centromeric factors. Our genomic analyses show that ERCC6L2 deficiency erodes centromeric chromatin, leading to unrestrained replication of centromeric DNA. We also establish that, beyond centromeres, ERCC6L2 facilitates replication at genomic repeats and non-canonical DNA structures. Notably, ERCC6L2 interacts with the major DNA replication factor PCNA through an atypical peptide, presented here as a co-crystal structure. Finally, we examine ERCC6L2 activities at DNA breaks, and show that it acts to restrict end resection independently of the 53BP1-REV7-Shieldin complex. Our observations allow us to propose a mechanistic model of ERCC6L2 activity, which reconciles its seemingly distinct functions in DNA repair and DNA replication. Together, these findings provide a new molecular context for studies linking ERCC6L2 to human disease.
2023-04-10 | GSE226152 | GEO
Project description:Despite the inclusion of inherited myeloid malignancies as a separate entity in the WHO Classification, our understanding of the etiology of familial leukemia remains limited. ERCC6L2-deficiency is a rare, life-threatening inherited condition that gives rise to bone marrow failure (BMF), myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) resulting from germline mutations in DNA repair factor ERCC6L2. Here we employ a lentiviral shRNA approach to functionally characterize the impact of ERCC6L2 loss on hematopoietic stem/progenitor cells (HSPCs) and mesenchymal stromal cells (MSCs). By combining cell culture assays and transcriptomic analysis of knockdown and ERCC6L2-mutated patient cells, we find that ERCC6L2-deficiency reduces HSPC clonogenic potential and delays erythropoiesis, while in MSCs it induces a significant lineage skewing, with increased osteogenesis and suppressed adipogenesis. Altogether, we demonstrate that ERCC6L2-deficiency impacts both hematopoietic and stromal compartments, and that our ex vivo model recapitulates patient phenotypes, providing a robust system to study germline mutations in hematological malignancies.
2022-09-26 | GSE190542 | GEO
Project description:We identified robust cleavage by non-canonically-targeted SpCas9 that target protospacer with a few bases from the canonical NGG PAM in biochemistry assay. To determine whether this spaced SpCas9 cleavage exists in human cells, we employed high-throughput genome-wide translocation sequencing (LAM-HTGTS) using SpCas9 with three independent canonical sgRNAs served as bait (bait-A, bait-L and bait-D) to compared the cleavage activities of canonically-targeted and non-canonically-targeted SpCas9 in eight locus (RAG1B-D, RAG1K-O) in chromosome 11. We found that almost all 1bp-target shifted SpCas9 generated substantial DSBs as the canonical controls. While detected less frequently, 2bp-targeted shifted SpCas9 generated significant amounts of DSBs in RAG1D and RAG1L locus. These findings underscore the spaced PAM-mediated DSBs occurred in living cells.
2022-02-28 | GSE192459 | GEO
Project description:We describe a robust linear amplification-mediated high-throughput genome-wide translocation sequencing (HTGTS) method that identifies endogenous or ectopic "prey" DNA double-stranded breaks (DSBs) across the human genome based on their translocation to "bait" DSBs generated by engineered nucleases. HTGTS with different Cas9:gRNA or TALEN-nuclease on-target baits revealed off-target hotspots for given nucleases that ranged from few or none to dozens or more, and greatly extended known off-target numbers for certain previously characterized engineered nucleases by more than 10-fold. Beyond various types of nuclease off-target collateral damage, we also identified collateral damage in the form of translocations between bona fide nuclease targets on homologous chromosomes. Based on frequent non-specific DSBs making any given human chromosome an HTGTS hotspot region for bait DSBs within it, we found that HTGTS also reveals wide-spread, low-level DSB-generating activities of engineered nucleases. Finally, HTGTS confirmed that the Cas9D10A paired nickase approach suppresses off-targets genome-wide and suggested other strategies to enhance desired nuclease activities.
2014-11-29 | GSE57283 | GEO
Project description:ERCC6L2 mitigates replication stress and promotes centromere stability
| PRJNA939098 | ENA
Project description:During B cell development, RAG endonuclease cleaves immunoglobulin heavy chain (IgH) V, D, and J gene segments and orchestrates their fusion as deletional events that assemble a V(D)J exon in the same transcriptional orientation as adjacent Cμ constant region exons. In mice, six additional sets of constant region exons (CHs) lie 100-200kb downstream in the same transcriptional orientation as V(D)J and Cμ exons. Long repetitive switch (S) regions precede Cμ and downstream CHs. In mature B cells, class switch recombination (CSR) generates different antibody classes by replacing Cμ with a downstream CH. Activation Induced Cytidine Deaminase (AID) initiates CSR by promoting deamination lesions within Sμ and a downstream acceptor S region; these lesions are converted into DNA double strand breaks (DSBs) by general DNA repair factors. Productive CSR must occur in a deletional orientation by joining the upstream end of an Sμ DSB to the downstream end of an acceptor S region DSB. However, the relative frequency of deletional to inversional CSR junctions had not been measured. Thus, whether orientation-specific joining is a programmed mechanistic feature of CSR as it is for V(D)J recombination and, if so, how this is achieved was unknown. To address this question, we adapted high throughput genome wide translocation sequencing (HTGTS) into a highly sensitive DSB end-joining assay and applied it to endogenous AID-initiated S region DSBs. We find that CSR indeed is programmed to occur in a productive deletional orientation and does so via an unprecedented mechanism that involves in cis IgH organizational features in combination with frequent S region DSBs initiated by AID. We further implicate ATM-dependent DSB response (DSBR) factors in enforcing this mechanism and provide a solution to the enigma of why CSR is so reliant on the 53BP1 DSBR factor. We performed high-throughput genome-wide translocation sequencing (HTGTS) with different B cell genotypes that induces either I-SceI or AID-initiated DSBs as bait to study their joining pattern to AID-initiated S region breaks Please note that the 'ΔSγ1_2xI/ΔSµ_2xI-3' raw data files were analyzed twice with different reference assemblies to address specific points, and associated with both 'ΔSγ1_2xI_ΔSµ_2xI-3'.txt and Sγ1_2xI_ΔSµ_2xI-3'_trans-Sm.txt processed data files. As for the reference genome mm9_129_IgHC, it is a custom built generated based on mm9 (Bl6 line based mouse genome) and the partial genome sequence of another mouse line 129sv. It is not currently available in any public database however can be easily obtained either from the authors or self-built using information provided in the associated manuscript.
2015-08-26 | E-GEOD-71005 | biostudies-arrayexpress
Project description:We recently discovered 27 recurrent DNA double-strand break (DSB) clusters (RDCs) in mouse neural stem/progenitor cells (NSPCs). Most RDCs occurred across long, late-replicating RDC genes and were found only after mild inhibition of DNA replication. RDC genes share intriguing characteristics, including encoding surface proteins that organize brain architecture and neuronal junctions, and are genetically implicated in neuropsychiatric disorders and/or cancers. RDC identification relies on high-throughput genome-wide translocation sequencing (HTGTS), which maps recurrent DSBs based on their translocation to "bait" DSBs in specific chromosomal locations. Cellular heterogeneity in 3D genome organization allowed unequivocal identification of RDCs on 14 different chromosomes using HTGTS baits on three mouse chromosomes. Additional candidate RDCs were also implicated, however, suggesting that some RDCs were missed. To more completely identify RDCs, we exploited our finding that joining of two DSBs occurs more frequently if they lie on the same cis chromosome. Thus, we used CRISPR/Cas9 to introduce specific DSBs into each mouse chromosome in NSPCs that were used as bait for HTGTS libraries. This analysis confirmed all 27 previously identified RDCs and identified many new ones. NSPC RDCs fall into three groups based on length, organization, transcription level, and replication timing of genes within them. While mostly less robust, the largest group of newly defined RDCs share many intriguing characteristics with the original 27. Our findings also revealed RDCs in NSPCs in the absence of induced replication stress, and support the idea that the latter treatment augments an already active endogenous process.
2018-01-19 | GSE106822 | GEO