Chromosomal Mcm2-7 distribution and the genome replication program in species from yeast to humans
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ABSTRACT:
ORGANISM(S): Mus musculus x Mus spretus Saccharomyces cerevisiae Schizosaccharomyces pombe Homo sapiens
PROVIDER: GSE150800 | GEO | 2021/05/18
REPOSITORIES: GEO
Similar Datasets
Project description:The minichromosome maintenance complex (MCM) DNA helicase is an important replicative factor during DNA replication. The proper chromatin loading of MCM is a key step to ensure replication initiation during G1/S phase. Because replication initiation is regulated by multiple biological cues, additional changes to MCM may provide deeper understanding towards this event. Here, we uncover that the histidine methyltransferase SETD3 promotes DNA replication in an enzymatic activity dependent manner. Nascent-strand sequencing (NS-seq) shows that SETD3 regulates replication initiation, as depletion of SETD3 attenuates early replication origins firing. Mechanistically, biochemical experiments reveal that SETD3 binds MCM mainly during G1/S phase, which is required for CDT1-mediated chromatin loading of MCM. The MCM loading relies on the histidine-459 methylation (H459me) on MCM7 that is catalyzed by SETD3. Impairment of H459 methylation attenuates DNA synthesis and chromatin loading of MCM. Furthermore, we show that CDK2 phosphorylates SETD3 at Serine-21 during the G1/S phase, which is required for DNA replication and cell cycle progression. These findings demonstrate a novel mechanism by which SETD3 methylates MCM to regulate replication initiation.
2024-03-12 | GSE243937 | GEO
Project description:Chromosomal translocations result from joining of DNA double-strand breaks (DSBs) and frequently cause cancer. Yet, the steps linking DSB formation to DSB ligation remain undeciphered. We report that DNA replication timing (RT) directly regulates lymphomagenic Myc translocations during antibody maturation in B-cells downstream of DSBs and independently of DSB frequency. Depletion of minichromosome-maintenance (MCM) complexes alters replication origin activity, decreases translocations and abrogates global RT. Ablating a single origin at Myc causes an early-to-late RT switch, loss of translocations and reduced nuclear proximity with a translocation partner locus, phenotypes that were reversed by restoring early RT. Disruption of shared early RT also reduced tumorigenic translocations in human leukemic cells. Thus, RT constitutes a new, unprecedented mechanism in translocation biogenesis linking DSB formation to DSB ligation
2022-09-13 | PXD034446 | Pride
Project description:There are approximately 500 known origins of replication in the yeast genome, and the process by which DNA replication initiates at these locations is well understood. In particular, these sites are made competent to initiate replication by loading of the Mcm replicative helicase prior to the start of S phase; thus, "a site to which MCM is bound in G1" might be considered to provide an operational definition of a replication origin. By fusing a subunit of Mcm to micrococcal nuclease, a technique referred to as "Chromatin Endogenous Cleavage", we previously showed that known origins are typically bound by a single Mcm double hexamer, loaded adjacent to the ARS consensus sequence (ACS). Here we extend this analysis from known origins to the entire genome, identifying candidate Mcm binding sites whose signal intensity varies over at least 3 orders of magnitude. Published data quantifying the production of ssDNA during S phase showed clear evidence of replication initiation among the most abundant 1600 of these sites, with replication activity decreasing in concert with Mcm abundance and disappearing at the limit of detection of ssDNA. Three other hallmarks of replication origins were apparent among the most abundant 5,500 sites. Specifically, these sites (1) appeared in intergenic nucleosome-free regions that were flanked on one or both sides by well-positioned nucleosomes; (2) were flanked by ACSs; and (3) exhibited a pattern of GC skew characteristic of replication initiation. Furthermore, the high resolution of this technique allowed us to demonstrate a strong bias for detecting Mcm double-hexamers downstream rather than upstream of the ACS, which is consistent with the directionality of Mcm loading by Orc that has been observed in vitro. We conclude that DNA replication origins are at least 3-fold more abundant than previously assumed, and we suggest that replication may occasionally initiate in essentially every intergenic region. These results shed light on recent reports that as many as 15% of replication events initiate outside of known origins, and this broader distribution of replication origins suggest that S phase in yeast may be less distinct from that in humans than is widely assumed.
2023-09-05 | GSE242131 | GEO
Project description:The hexameric DNA helicase MCM (Mcm2-7) is a central regulatory target in eukaryotic replication. Chromatin-bound MCM is kept inactive during G1 phase and subsequently activated in S phase to initiate replication. During this transition, the only known chemical change on the Mcm2-7 proteins is the gain of multi-site phosphorylation that promotes recruitment of co-factors. As replication initiation is tied intimately to multiple biological cues, additional changes on these proteins can provide a second regulatory point. Here we describe a new MCM modification cycle mediated by SUMO that enables a negative regulation of replication initiation. We show that all MCM subunits undergo sumoylation upon loading at origins in G1 phase prior to MCM phosphorylation. Then bulk MCM sumoylation is lost as MCM phosphorylation rises. The pattern of MCM sumoylation suggests a negative role in replication. Indeed, increasing MCM sumoylation delays genome-wide replication initiation. Mechanistically, this is partly due to enhancing the recruitment of a conserved phosphatase that delays MCM phosphorylation and activation. By revealing a new MCM modification cycle and its role in replication, our findings suggest a new model, in which MCM sumoylation counterbalances kinase-based regulation to ensure accurate control of replication initiation.
2016-02-01 | GSE70407 | GEO
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-2’-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
2007-03-05 | GSE6523 | GEO
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:Many cancers originate from misregulation of gene expression caused by chromosomal translocations which result from ligation of DNA double-strand breaks (DSBs). Indeed, translocations may be causal in ~20% of human cancer morbidity 1. Although the sources of DSBs are numerous2-5, we have virtually no knowledge of the steps linking DSB formation to DSB ligation. Here, we show that early replication timing of translocation partner loci, mediated by the activity of replication origins, is a critical regulator of lymphomagenic Myc translocations generated by activation-induced deaminase (AID) during antibody maturation in B-cells. Reduced levels of the replicative helicase, the minichromosome maintenance (MCM) complex6, impairs translocation genesis, decreases firing of replication origins at AID target genes and globally abrogates the replication timing program without altering cell proliferation, gene expression or genome architecture. Strikingly, deleting a single origin of replication at Myc induces a switch from early-to-late replication at Myc with concomitantly impaired translocation frequency. This phenotype is reversed by restoring early replication at Myc thereby demonstrating a direct, causal role of replication origin activity and replication timing in translocation genesis. Finally, this replication timing-mediated step acts downstream of DSBs and is independent of DSB frequency, constituting a novel regulatory step in translocation biogenesis.
2022-09-15 | GSE161817 | GEO
Project description:Many cancers originate from misregulation of gene expression caused by chromosomal translocations which result from ligation of DNA double-strand breaks (DSBs). Indeed, translocations may be causal in ~20% of human cancer morbidity 1. Although the sources of DSBs are numerous2-5, we have virtually no knowledge of the steps linking DSB formation to DSB ligation. Here, we show that early replication timing of translocation partner loci, mediated by the activity of replication origins, is a critical regulator of lymphomagenic Myc translocations generated by activation-induced deaminase (AID) during antibody maturation in B-cells. Reduced levels of the replicative helicase, the minichromosome maintenance (MCM) complex6, impairs translocation genesis, decreases firing of replication origins at AID target genes and globally abrogates the replication timing program without altering cell proliferation, gene expression or genome architecture. Strikingly, deleting a single origin of replication at Myc induces a switch from early-to-late replication at Myc with concomitantly impaired translocation frequency. This phenotype is reversed by restoring early replication at Myc thereby demonstrating a direct, causal role of replication origin activity and replication timing in translocation genesis. Finally, this replication timing-mediated step acts downstream of DSBs and is independent of DSB frequency, constituting a novel regulatory step in translocation biogenesis.
2022-09-15 | GSE171623 | GEO
Project description:Many cancers originate from misregulation of gene expression caused by chromosomal translocations which result from ligation of DNA double-strand breaks (DSBs). Indeed, translocations may be causal in ~20% of human cancer morbidity 1. Although the sources of DSBs are numerous2-5, we have virtually no knowledge of the steps linking DSB formation to DSB ligation. Here, we show that early replication timing of translocation partner loci, mediated by the activity of replication origins, is a critical regulator of lymphomagenic Myc translocations generated by activation-induced deaminase (AID) during antibody maturation in B-cells. Reduced levels of the replicative helicase, the minichromosome maintenance (MCM) complex6, impairs translocation genesis, decreases firing of replication origins at AID target genes and globally abrogates the replication timing program without altering cell proliferation, gene expression or genome architecture. Strikingly, deleting a single origin of replication at Myc induces a switch from early-to-late replication at Myc with concomitantly impaired translocation frequency. This phenotype is reversed by restoring early replication at Myc thereby demonstrating a direct, causal role of replication origin activity and replication timing in translocation genesis. Finally, this replication timing-mediated step acts downstream of DSBs and is independent of DSB frequency, constituting a novel regulatory step in translocation biogenesis.
2022-09-15 | GSE161821 | GEO