Chromatin remodeler Fun30 promotes efficient DSB end resection and recombination during yeast meiosis
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ABSTRACT:
ORGANISM(S): Saccharomyces cerevisiae
PROVIDER: GSE221377 | GEO | 2023/05/01
REPOSITORIES: GEO
Similar Datasets
Project description:Resection, nucleolytic processing of DSB ends is necessary to generate 3' single-stranded DNA tails (ssDNA) for homologous recombination (HR). Meiotic recombination initiated by Spo11 induced double-strand breaks (DSBs) is essential for the accurate segregation of homologous chromosomes. After cleavage, Spo11 stays covalently linked to the DSB ends, which requires MRX/Sae2 incision on broken molecules to allow following Exo1-mediated resection. Exonuclease I activity is inhibited by nucleosome bound DNA in vitro. To ensure resection proceeds, resection machineries must overcome chromatin barrier. Here we show that DSB dependent enrichment of Fun30 proteins at hotspots and meiotic axes.
2023-05-01 | GSE221033 | GEO
Project description:Chromosomal double-strand breaks (DSBs) are resected by 5’-nucleases to form 3’ single-strand DNA (ssDNA) substrates for binding by homologous recombination and DNA damage checkpoint proteins. Two redundant pathways of extensive resection were described both in cells and in vitro, one relying on Exo1 exonuclease and the other on Sgs1 helicase and Dna2 nuclease. However, it remains unknown how resection proceeds within the context of chromatin where histones and histone-bound proteins represent barriers for resection enzymes. Here, we have identified the yeast nucleosome remodeling enzyme Fun30 as novel factor promoting DSB end resection. Fun30 is the major nucleosome remodeler promoting extensive Exo1- and Sgs1-dependent resection of DSBs while the RSC and INO80 chromatin remodeling complexes play redundant roles with Fun30 in resection adjacent to DSB ends. ATPase and helicase domains of Fun30, which are needed for nucleosome remodeling, are also required for resection. Fun30 is robustly recruited to DNA breaks and spreads around the DSB coincident with resection. Fun30 becomes less important for resection in the absence of the histone-bound Rad9 checkpoint adaptor protein known to block 5’ strand processing and in the absence of either histone H3 K79 methylation or γ-H2A, which mediate recruitment of the Rad9 . Together these data suggest that Fun30 helps to overcome the inhibitory effect of Rad9 on DNA resection.
2012-10-04 | GSE38601 | GEO
Project description:Chromosomal double-strand breaks (DSBs) are resected by 5M-bM-^@M-^Y-nucleases to form 3M-bM-^@M-^Y single-strand DNA (ssDNA) substrates for binding by homologous recombination and DNA damage checkpoint proteins. Two redundant pathways of extensive resection were described both in cells and in vitro, one relying on Exo1 exonuclease and the other on Sgs1 helicase and Dna2 nuclease. However, it remains unknown how resection proceeds within the context of chromatin where histones and histone-bound proteins represent barriers for resection enzymes. Here, we have identified the yeast nucleosome remodeling enzyme Fun30 as novel factor promoting DSB end resection. Fun30 is the major nucleosome remodeler promoting extensive Exo1- and Sgs1-dependent resection of DSBs while the RSC and INO80 chromatin remodeling complexes play redundant roles with Fun30 in resection adjacent to DSB ends. ATPase and helicase domains of Fun30, which are needed for nucleosome remodeling, are also required for resection. Fun30 is robustly recruited to DNA breaks and spreads around the DSB coincident with resection. Fun30 becomes less important for resection in the absence of the histone-bound Rad9 checkpoint adaptor protein known to block 5M-bM-^@M-^Y strand processing and in the absence of either histone H3 K79 methylation or M-NM-3-H2A, which mediate recruitment of the Rad9 . Together these data suggest that Fun30 helps to overcome the inhibitory effect of Rad9 on DNA resection. Genome-wide expression profiling of Yeast gene expression in two cell type including the wild type and a FUN30 knockout cell, each cell type is tested in two duplicates. Test relative gene integration efficiency in yeast genome-wide homozygous diploid deletion mutants.
2012-10-04 | E-GEOD-38601 | biostudies-arrayexpress
Project description:Exonucleolytic resection is a critical step in repair of DNA double-strand breaks (DSBs) via homologous recombination, but resection mechanisms are not well understood, particularly in mammalian meiosis. Here, we use a genome-wide, nucleotide-resolution analysis to define the molecular structure of resected DSBs in mouse spermatocytes. Resection tracts averaged 1100 nucleotides on each side of a DSB, but with a broad distribution and substantial fine-scale heterogeneity at individual hotspots. Surprisingly, eliminating the nuclease activity of EXO1 only modestly decreased resection lengths, thus EXO1 is not the major 5′→3′ exonuclease in mouse meiosis. In contrast, the DSB-responsive kinase ATM proved to be a key regulator of both the initiation and extension of resection. In wild type, apparent intermolecular recombination intermediates clustered near to but offset from DSB positions, consistent with joint molecules with incompletely invaded 3′ ends. Finally, we provide evidence for PRDM9-dependent chromatin remodeling leading to increased accessibility at recombination sites. Our findings give insight into the mechanisms of DSB processing and repair in meiotic chromatin.
2020-07-10 | GSE141850 | GEO
Project description:DNA double-strand breaks (DSBs) initiate meiotic recombination. Past DSB-mapping studies have used rad50S or sae2? mutants, which are defective in break processing, to accumulate DSBs, and report large (= 50 kb) “DSB-hot” regions that are separated by “DSB-cold” domains of similar size. Substantial recombination occurs in some DSB-cold regions, suggesting that DSB patterns are not normal in rad50S or sae2? mutants. We therefore developed novel methods that detect DSBs using ssDNA enrichment and microarray hybridization, and that use background-based normalization to allow cross-comparison between array datasets, to map genome-wide the DSBs that accumulate in processing-capable, repair-defective dmc1î and dmc1î rad51î mutants. DSBs were observed at known hotspots, but also in most previously-identified “DSB-cold” regions, including near centromeres and telomeres. While about 40% of the genome is DSB-cold in rad50S mutants, analysis of meiotic ssDNA from dmc1? shows that most of these regions have significant DSB activity. Thus, DSBs are distributed much more uniformly than was previously believed. Southern-blot assays of DSBs in selected regions in dmc1?, rad50S and wild-type cells confirm these findings. Comparisons of DSB signals in dmc1, dmc1 rad51, and dmc1 spo11 mutant strains identify Dmc1 as the primary strand transfer activity genome-wide, and Spo11-induced lesions as initiating all meiotic recombination. Keywords: DSB mapping, ChIP-chip, single strand DNA , BND cellulose We use two different strategies to map the genome-wide distribution of meiotic DSBs in the yeast Saccharomyces cerevisiae. The first is a chromatin immunoprecipitation (ChIP) based approach that targets the Spo11p protein, which remains covalently attached to DSB ends in the rad50S mutant background. The second approach involves BND cellulose enrichment of the single strand DNA (ssDNA) recombination intermediate formed by end-resection at DSB sites following Spo11p removal. We use dmc1 and dmc1 rad51 mutants that accumulates meiotic single strand DNA intermediates
2007-12-30 | E-GEOD-8981 | biostudies-arrayexpress
Project description:Programed DNA double-strand breaks (DSBs) catalyzed by the topoisomerase II-like enzymes, SPO11 and TOPVIBL, initiate meiotic recombination. Following DSB formation, the MRE11-RAD50-NBS1/Xrs2 (MRN/X) complex, along with EXO1 and DNA2, cleave the SPO11-DNA to generate 3′ single-stranded DNA (ssDNA) ends, which are prerequisite for meiotic DSB repair. In both yeast and mammals, MRE11 exhibits endonucleolytic cleavage of the 5′ terminated DNA strand in the vicinity of the DSBs and exonucleolytic resection from 3′ to 5′ towards the DSB ends. RAD50 is a structure maintenance of chromosome (SMC) related protein that contains one ATPase domain at its N- and C- terminal ends, respectively, Zn hook, and anti-parallel coiled coils. RAD50 plays a crucial role in facilitating the MRE11 nuclease activity on DSBs by ATP binding and hydrolysis. However, the in vivo function of Rad50 in mammalian germ cells, particularly its in vivo role in the resection of meiotic DSB ends at the molecular level remains elusive. Here, we performed END-seq with synchronized zygotene spermatocytes from control and germ cell specific Rad50 mutant (Rad50-sKO) mice. We find that the number of formed DSB in the mutant spermatocytes was reduced compared to control spermatocytes (6 636 DSBs in Rad50-sKO spermatocytes vs 8 168 in control spermatocytes) and abnormal DSB end resection occurred in mutant spermatocytes (DSB end resection length: 1 279 nts in Rad50-sKO spermatocytes vs 1 923 nts in control spermatocytes). Thus, RAD50 is essential for DSB formation and end resection during mammalian meiosis.
2024-04-02 | GSE262706 | GEO
Project description:Meiotic recombination is initiated by genome-wide SPO11-induced double-strand breaks (DSBs) that are processed by MRE11-mediated release of SPO11-bound oligonucleotides (SPO11-oligos). The DSB is then resected and loaded with DMC1/RAD51 filaments that invade homologous chromosome templates. In most mammals, DSB locations (“hotspots”) are determined by the DNA sequence specificity of the PRDM9 DNA binding zinc finger array. Here, we demonstrate the first direct detection of meiotic DSBs in vertebrates by performing END-seq on mouse spermatocytes using low sample input. We find that DMC1 limits both the minimum and maximum length of ssDNA produced at all hotspots, whereas 53BP1, BRCA1 and EXO1 play a surprisingly minimal role in meiotic resection. Through enzymatic modifications to the END-seq protocol that mimic the in vivo processing of SPO11, we identify a novel meiotic recombination intermediate (RI) with SPO11 still bound to the 3’ end via a small stretch of dsDNA (“SPO11-RI”) that is dependent on the presence of PRDM9. We propose that SPO11-RI is generated because chromatin-bound PRDM9 blocks MRE11 from releasing SPO11 via 3’-5’ resection. SPO11-RI is present at all hotspots and correlates with the localization and frequency of crossovers and noncrossovers. In Atm–/– spermatocytes, multiple DSBs at the same hotspot reduces SPO11-RI formation, while unresected DNA-bound SPO11 accumulates because of defective MRE11 initiation. Thus in addition to their global roles in governing SPO11 breakage, ATM and PRDM9 are critical local regulators of mammalian SPO11 processing.
2020-02-20 | GSE138915 | GEO
Project description:The DNA double-strand breaks that initiate homologous recombination during meiosis are subject to extensive 5ʹâ??3â?² exonucleolytic processing. This resection is a central and conserved feature of recombination, yet its mechanism is poorly understood. Using a purpose-made deep-sequencing method, namely S1Seq, we mapped meiotic resection endpoints genome-wide at high spatial resolution in Saccharomyces cerevisiae. Generating full-length resection tracts requires Exo1 exonuclease activity and the DNA-damage responsive kinase Tel1, but not the helicase Sgs1. Tel1 is also required for efficient and timely initiation of resection. We find that distributions of resection endpoints at individual genomic loci display pronounced heterogeneity that reflects a tendency for nucleosomes to block Exo1 in vivo, yet modeling experiments indicate that Exo1 digests chromatin with high apparent processivity and at rates approaching those for naked DNA in vitro. This paradox points to nucleosome destabilization or eviction as a determining feature of the meiotic resection landscape. 36 samples total: two biological replicate S1Seq maps of S.cerevisiae for each genetic background and time point in meiosis
2016-08-06 | E-GEOD-85253 | biostudies-arrayexpress
Project description:DNA double-strand breaks (DSBs) initiate meiotic recombination. Past DSB-mapping studies have used rad50S or sae2? mutants, which are defective in break processing, to accumulate DSBs, and report large (= 50 kb) “DSB-hot” regions that are separated by “DSB-cold” domains of similar size. Substantial recombination occurs in some DSB-cold regions, suggesting that DSB patterns are not normal in rad50S or sae2? mutants. We therefore developed novel methods that detect DSBs using ssDNA enrichment and microarray hybridization, and that use background-based normalization to allow cross-comparison between array datasets, to map genome-wide the DSBs that accumulate in processing-capable, repair-defective dmc1î and dmc1î rad51î mutants. DSBs were observed at known hotspots, but also in most previously-identified “DSB-cold” regions, including near centromeres and telomeres. While about 40% of the genome is DSB-cold in rad50S mutants, analysis of meiotic ssDNA from dmc1? shows that most of these regions have significant DSB activity. Thus, DSBs are distributed much more uniformly than was previously believed. Southern-blot assays of DSBs in selected regions in dmc1?, rad50S and wild-type cells confirm these findings. Comparisons of DSB signals in dmc1, dmc1 rad51, and dmc1 spo11 mutant strains identify Dmc1 as the primary strand transfer activity genome-wide, and Spo11-induced lesions as initiating all meiotic recombination. Keywords: DSB mapping, ChIP-chip, single strand DNA , BND cellulose
2007-12-31 | GSE8981 | GEO
Project description:DNA double-strand breaks (DSBs) can be repaired by several pathways. In eukaryotes, repair pathway choice – the cellular decision making underlying DSB repair – occurs at the level of DSB resection and is controlled by the cell cycle. Upon cell cycle-dependent activation, cyclin-dependent kinases (CDKs) phosphorylate resection proteins and thereby stimulate DSB resection and repair by homologous recombination (HR). Here, we identify Dbf4-dependent kinase (DDK) as a second major cell cycle regulator of DNA end resection. Using inducible genetic and chemical inhibition of DDK in budding yeast and human cells, we show that DNA resection and HR require activation by DDK. Mechanistically, DDK catalyzes phosphorylation of at least two resection nucleases. Via phosphorylation of the Mre11 activator Sae2 it promotes activation of resection initiation, via phosphorylation of the Dna2 nuclease it promotes long-range resection. Notably, synthetic activiation of DDK allows limited resection and HR in G1 cells, suggesting that DDK is a key component of DSB repair decision making.
2024-02-22 | GSE233549 | GEO