Preferential localization of human origins of DNA replication at the 5' end of expressed genes
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Jack Zhu
PROVIDER: E-GEOD-10917 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Short nascent strands purification coupled to next-generation sequencing allowed us to identify replication origins on human genome in an extensive way, by mapping replication origins in 4 different cell types, IMR-90 fibroblasts, hESC H9 cells, iPSC Th Cl-4 cells and HeLa cells. We demonstrated the existence of a cell type-specific reprogrammable signature of the cell identity revealed by specific efficiencies of conserved origin positions and not by the selection of cell-type specific subsets of origins. 4 different cell types were analyzed. For each cell types, 2 different biological replicates of short nascent strands at replication origins were purified. Each SNS sample was sequencing at least one time.
2012-07-01 | E-GEOD-37757 | biostudies-arrayexpress
Project description:DNA replication of eukaryotic chromosomes initiates at a number of discrete loci, called replication origins. Distribution and regulation of origins are important for complete duplication of the genome. Here, we determined locations of Orc1 and Mcm6, components of pre-replicative complex (pre-RC), on whole genome of Schizosaccharomyces pombe using a high-resolution tiling array. Pre-RC sites were identified in 460 intergenic regions, where Orc1 and Mcm6 colocalized. By mapping of 5-bromo-2â-deoxyuridine (BrdU)-incorporated DNA in the presence of hydroxyurea (HU), 307 pre-RC sites were identified as early-firing origins. In contrast, 153 pre-RC sites without BrdU incorporation were considered to be late and/or inefficient origins. Early and late origins tend to distribute separately in large chromosome regions. Inactivation of replication checkpoint by deletion of Cds1 resulted in BrdU incorporation with HU specifically at the late origins. An origin-exchange experiment showed that replication timing was not intrinsic to origin but dependent on its surrounding region. Interestingly, pericentromeric heterochromatin and the silent mating type locus replicated in the presence of HU, while the inner centromere or subtelomeric heterochromatin did not. Notably, MCM did not bind to inner centromeres where ORC was located. Thus, replication is differentially regulated in chromosome domains. Keywords: ChIP-chip analysis Experiment Design: ⢠The goal of the experiment â Genome-wide localization of ORC and MCM binding sites and identification of replication origins in Shizosaccaromyces pombe ⢠A brief description of the experiment (e.g., the abstract from the related publication) DNA replication of eukaryotic chromosomes initiates at a number of discrete loci, called replication origins. Distribution and regulation of origins are important for complete duplication of the genome. Here, we determined locations of Orc1 and Mcm6, components of pre-replicative complex (pre-RC), on whole genome of Schizosaccharomyces pombe using a high-resolution tiling array. Pre-RC sites were identified in 460 intergenic regions, where Orc1 and Mcm6 colocalized. By mapping of 5-bromo-2â-deoxyuridine (BrdU)-incorporated DNA in the presence of hydroxyurea (HU), 307 pre-RC sites were identified as early-firing origins. In contrast, 153 pre-RC sites without BrdU incorporation were considered to be late and/or inefficient origins. Early and late origins tend to distribute separately in large chromosome regions. Inactivation of replication checkpoint by deletion of Cds1 resulted in BrdU incorporation with HU specifically at the late origins. An origin-exchange experiment showed that replication timing was not intrinsic to origin but dependent on its surrounding region. Interestingly, pericentromeric heterochromatin and the silent mating type locus replicated in the presence of HU, while the inner centromere or subtelomeric heterochromatin did not. Notably, MCM did not bind to inner centromeres where ORC was located. Thus, replication is differentially regulated in chromosome domains. ⢠Keywords, for example, time course, cell type comparison, array CGH (the use of MGED ontology terms is recommended). Mitosis, Cell cycle, Schizosaccharomyces pombe, Whole-genome, Tiling array, Chromosome II, III array, Orc1, Orc4, Mcm6, BrdU-labeling, cds1Î. ⢠Experimental factors Distribution of the Orc1 and Mcm6 in WT in G1 phase (S. pombe). Distribution of the Orc4 in WT in asynchronous cells (S. pombe). Distribution of BrdU-incorporated DNA in WT and in cds1 deletion mutant in S phase in the presence of HU (S. pombe). ⢠Experimental design ChIP analysis: In all cases, hybridization data for ChIP fraction was compared with WCE (whole cell extract) fraction. Pombe whole-genome tiling array were used. BrdU analysis: Hybridization data for BrdU fraction (replicated DNA) was compared with Whole fraction (unreplicated DNA) or hybridization data for BrdU fraction of cds1Î cells was compared with that of WT cells. Pombe whole-genome tiling array were used. ⢠Quality control steps taken Different subunits of the same complex. Confirmation of several loci by q-PCR. Checking the BrdU-labeled DNA fraction in CsCl gradient by q-PCR or slot-blot analysis. ⢠Links to the publication, any supplemental websites or database accession numbers. GSE6523 Samples used, extract preparation and labelling: ⢠The origin of each biological sample ChIP analysis: Schizosaccharomyces pombe nda3-KM311 cdc10-129 strain harboring pREP81-cdc18 and pREP42-cdt1. BrdU analysis: Schizosaccharomyces pombe wild type (cdc25-22 nmt1-TK) and cds1Î strains. ⢠Manipulation of biological samples and protocols used ChIP analysis: Chromatin immunoprecipitation (ChIP) in G1 arrested cells or asynchronous cells were performed as previously described (Takahashi et al., 2003, EMBO). Hybridization to Affimetrix high-density oligonucleotide array of S. pombe chromosomes 2 and 3 and whole genome tiling array of S. pombe was performed essentially as previously described (Katou et al., 2003, nature) (Lengronne et al., 2004, nature). BrdU analysis: Growing cdc25-22 cells expressing Thymidine Kinase were arrested at G2/M boundary and released in the presence of BrdU and HU. BrdU was incorporated in nascent DNA in following S phase. The genomic DNA was digested by HaeIII and BrdU-labeled DNA was purified in CsCl density gradient centrifugation. Hybridization to Affimetrix high-density oligonucleotide array of S. pombe whole genome tiling array was performed essentially as previously described (Katou et al., 2003, nature) (Lengronne et al., 2004, nature).
2010-06-11 | E-GEOD-6523 | biostudies-arrayexpress
Project description:We report the application of single-molecule-based sequencing technology for high-throughput profiling of DNA replication origins in K562 mammalian cells. We have optimized a specific method of peak detection adapted to the signal produced by the sequencing of short nascent strands (SNS) that are specific of replication initiation, with the aim to have both a good sensitivity and specificity. We demonstrated the existence of the spatiao-temporal program of DNA replication driven by a specific epigenetic signature. K562 human cells; five samples subjected to SNS-Seq.
2014-05-01 | E-GEOD-46189 | biostudies-arrayexpress
Project description:Genomic mapping of DNA replication origins (ORIs) in mammals provides a powerful means for understanding the regulatory complexity of our genome. Here we combine a genome-wide approach to identify preferential sites of DNA replication initiation at 0.4% of the mouse genome with detailed molecular analysis at distinct classes of ORIs according to their location relative to the genes. Our study reveals that 85% of the replication initiation sites in mouse embryonic stem (ES) cells are associated with transcriptional units. Nearly half of the identified ORIs map at promoter regions and, interestingly, ORI density strongly correlates with promoter density, reflecting the coordinated organisation of replication and transcription in the mouse genome. Detailed analysis of ORI activity showed that CpG island promoter-ORIs are the most efficient ORIs in ES cells and both ORI specification and firing efficiency are maintained across cell types. Remarkably, the distribution of replication initiation sites at promoter-ORIs exactly parallels that of transcription start sites (TSS) suggesting a co-evolution of the regulatory regions driving replication and transcription. Moreover, we found that promoter-ORIs are significantly enriched in CAGE tags derived from early embryos relative to all promoters. This association implies that transcription initiation early in development sets the probability of ORI activation unveiling a new hallmark in ORI efficiency regulation in mammalian cells. Two biological replicates of lambda-exonuclease treated short nascent strands (100-600 or 300-800 nt in length) were co-hybridised with genomic DNA from the same cells to tiled genomic array covering 10.1 Mb of the mouse genome (Agilent Technologies)
2010-05-22 | E-GEOD-15082 | biostudies-arrayexpress
Project description:Mini-chromosome maintenance (MCM) proteins are loaded to chromatin during G1-phase and define potential locations of DNA replication initiation. MCM protein deficiency results in genome instability and high rates of cancer in mouse models. Here we develop a method of nascent strand capture and release and show that MCM2 deficiency reduces DNA replication initiation in gene rich regions of the genome. DNA structural properties are shown to correlate with sequence motifs associated with replication origins and with locations that are preferentially affected by MCM2 deficiency. Reduced nascent strand density correlates with sites of recurrent focal CNVs in tumors arising in MCM2-deficient mice, consistent with a direct relationship between sites of reduced DNA replication initiation and genetic damage. Between 10 and 90% of human tumors, depending on type, carry heterozygous loss or mutation of one or more Mcm2-7 genes which is expected to compromise DNA replication origin licensing and result in elevated rates of genome damage at a subset of gene rich locations. Mcm2 deficient vs. wild type
2015-01-14 | E-GEOD-64933 | biostudies-arrayexpress
Project description:Chromatin organization must be maintained during cell proliferation to preserve cellular identity and genome integrity. However, DNA replication results in transient displacement of DNA bound proteins, and it is unclear how they regain access to newly replicated DNA. Using quantitative MS-based proteomics coupled to Nascent Chromatin Capture, we provide time resolved binding kinetics for thousands of proteins behind replisomes of mid-S replicated regions. This shows that most proteins regain access within the first 15 minutes after the passage of the fork. In contrast, 25% of the identified proteins do not, and this delay cannot be inferred from their known function, physicochemical properties, or nuclear abundance. A sample treated with nocodazole to block the cell cycle progression. The comparison between a normal cell cycle progression and a nocodazole treated sample shows that the reassociation onto chromatin of proteins with a delayed restoration can be regulated by the cell cycle progression and/or the post-replication time. In addition, we provide evidence that DNA replication not only disrupts but also promotes recruitment of transcription factors and chromatin remodellers, providing a significant advance in understanding how DNA replication could contribute to programmed changes of cell memory. Data available in this entry are related with the supplementary table 5 from our manuscript.
2023-02-02 | PXD038113 | Pride
Project description:Although histone modifications have been implicated in many DNA-dependent processes, their precise role in DNA replication remains poorly understood. Here, we show that the regulation of histone H4-K20 methylation states, in particular for the monomethylation, is a critical determinant of licensing and time activation of replication origins in mammalian cells. Two experimental condition : shRNA LUC cells (control) versus siRNA Prset-7 cells
2016-07-01 | E-GEOD-69083 | biostudies-arrayexpress
Project description:Although histone modifications have been implicated in many DNA-dependent processes, their precise role in DNA replication remains poorly understood. Here, we show that the regulation of histone H4-K20 methylation states, in particular for the trimethylation, is a critical determinant of licensing and time activation of replication origins in mammalian cells. WT cells versus suv4-20h KO cells, and non-induced cells versus induced cells
2016-07-01 | E-GEOD-69084 | biostudies-arrayexpress
Project description:Chromatin organization must be maintained during cell proliferation to preserve cellular identity and genome integrity. However, DNA replication results in transient displacement of DNA bound proteins, and it is unclear how they regain access to newly replicated DNA. Using quantitative MS-based proteomics coupled to Nascent Chromatin Capture, we provide time resolved binding kinetics for thousands of proteins behind replisomes of mid-S replicated regions. This shows that most proteins regain access within the first 15 minutes after the passage of the fork. In contrast, 25% of the identified proteins do not, and this delay cannot be inferred from their known function, physicochemical properties, or nuclear abundance. Here, we provide data where we impaired the H3K27me3 restoration to analyse its impact into chromatin restoration. To this aim, we used the EPZ-6438 inhibitor, which blocks the histone methyltransferase EZH2. Two time-points are analysed by NCC along the cell cycle in late replicated regions: nascent chromatin, just after the passage of the fork, and a sample 16 hours later, in late G1 phase. Our data support that H3K27me3 have an important role in chromatin restoration. Data available in this entry are related with the supplementary table 6 from our manuscript.
2023-02-02 | PXD038376 | Pride
Project description:Faithful inheritance of the large eukaryotic genomes requires the orchestrated activation of multiple DNA replication origins. Although origin activation is mechanistically conserved among eukaryotes, how replication origins are specified and selected for activation in each S-phase seem to differ across the model systems studied. Here we provide a complete analysis of the nucleosomal landscape and replication programme of the human parasite Leishmania major, building on a better evolutionary understanding of replication organization in Eukarya. We found that active transcription is a driving force for the nucleosomal organization of L. major genome, and that both the spatial and the temporal programme of DNA replication can be explained as associated to RNA polymerase kinetics, without the need to invoke specific regulatory mechanisms. This simple scenario likely provides these organisms with the flexibility and robustness to deal with the continuous environmental changes that impose alterations in their genetic programmes during their parasitic life cycle stages. Our findings also suggest that coupling replication initiation to transcription elongation could be an ancient solution used by eukaryotic cells for origin maintenance Replication intitiation sites were defined using two replicates of short nascent strands of increasing sizes (F4 and F5) purified through three rounds of Lambda-exonuclease digestion, and a genomic DNA control (Ctrl). Nucleosome landscape was determined using two replicates of mononucleosomal-DNA derived from MNase-digested chromatin
2016-06-10 | E-GEOD-81991 | biostudies-arrayexpress