An S-phase checkpoint gated by Bms1 and Ttf1 at the rDNA loci
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA736321 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR14766502.fastq.gz | Fastqsanger.gz | |||
| SRR14766503.fastq.gz | Fastqsanger.gz |
Items per page: 5 1 - 2 of 2 |
Similar Datasets
Project description:During S-phase, active rDNA transcription conflicts with rDNA replication along hundreds of copies of tandemly arrayed rDNA genes. Ttf1 prevents conflicting collisions by binding to specific ‘Sal-boxes’, thus forming replication-fork-barriers. However, understanding of how Ttf1 is displaced from ‘Sal-boxes’ to allow replication-fork progression remains elusive. Here we report that Bms1, a nucleolar GTPase, interacts with Ttf1 to disassociate the Ttf1-DNA complex. GTPase-activity compromised zebrafish Bms1 mutants display ‘Sal-boxes’ accumulation of Ttf1 and resultant replication-fork stall. However, genomic DNA undergo over-replication that in turn activates DNA-damage response and arrests cell cycle at the S-phase, causing a small liver in bms1 mutants. We propose that Ttf1 and Bms1 together impose a nucleolar checkpoint on cell cycle progression through balancing S-phase rDNA transcription and replication.
2022-02-02 | GSE176455 | GEO
Project description:Following radiation damage, cells resume ribosome biogenesis for survival. We combined chromatin immunoprecipitation (ChIP) with mass spectrometry to identify key binding partners of RPA194 (the major subunit of RNA polI) at the rDNA loci in response to irradiation.
2023-07-20 | PXD041472 | Pride
Project description:In the baker’s yeast Saccharomyces cerevisiae, NuA4 and SWR1-C, two multisubunit complexes, are involved in histone acetylation and chromatin remodeling, respectively. Eaf1 is the assembly platform subunit of NuA4, Swr1 is the assembly platform and catalytic subunit of SWR1-C, while Swc4, Yaf9, Arp4 and Act1 form a functional module, and is present in both NuA4 and SWR1 complexes. ACT1 and ARP4 are essential for cell survival. Deletion of SWC4, but not YAF9, EAF1 or SWR1 results in a severe growth defect, but the underlying mechanism remains largely unknown. Here, we show that swc4Δ, but not yaf9Δ, eaf1Δ, or swr1Δ cells display defects in DNA ploidy and chromosome segregation, suggesting that the defects observed in swc4Δ cells are independent of NuA4 or SWR1-C integrity. Swc4 is enriched in the nucleosome-free regions (NFRs) of the genome, including characteristic regions of RDN5s, tDNAs and telomeres, independently of Yaf9, Eaf1 or Swr1. In particular, rDNA, tDNA and telomere loci are more unstable and prone to recombination in the swc4Δ cells than in wild-type cells. Taken together, we conclude that the chromatin associated Swc4 protects nucleosome-free chromatin of rDNA, tDNA and telomere loci to ensure genome integrity.
2023-05-31 | GSE233269 | GEO
Project description:The transition from pluripotent to somatic states marks a critical checkpoint in mammalian development. How this is regulated remains largely unresolved. Here we report the identification of SS18 by whole genome CRISPR screen as a checkpoint regulator. SS18 regulates pluripotent to somatic transition or PST by relocating from pluripotent loci to somatic ones accompanied by corresponding chromatin closing-opening and remodeling of SS18-centric protein complexes. Mechanistically, SS18 forms phase separation granules (PSG) with an intrinsically disordered region (IDR) rich in tyrosine (Y), which, once mutated, no longer form PSG nor rescue SS18-/- defect in PST. These results reveal that rapid cell fate decision can be achieved by massive redistribution of chromatin remodeling37 complexes through phase separation.
2021-05-18 | GSE135397 | GEO
Project description:The transition from pluripotent to somatic states marks a critical checkpoint in mammalian development. How this is regulated remains largely unresolved. Here we report the identification of SS18 by whole genome CRISPR screen as a checkpoint regulator. SS18 regulates pluripotent to somatic transition or PST by relocating from pluripotent loci to somatic ones accompanied by corresponding chromatin closing-opening and remodeling of SS18-centric protein complexes. Mechanistically, SS18 forms phase separation granules (PSG) with an intrinsically disordered region (IDR) rich in tyrosine (Y), which, once mutated, no longer form PSG nor rescue SS18-/- defect in PST. These results reveal that rapid cell fate decision can be achieved by massive redistribution of chromatin remodeling37 complexes through phase separation.
2021-05-18 | GSE135395 | GEO
Project description:Across eukaryotes, checkpoints maintain the order of cell cycle events in the face of DNA damage or incomplete replication. Although a wide array of DNA lesions activates the checkpoint kinases, whether and how this response differs in different phases of the cell cycle remains poorly understood. The S-phase checkpoint for example results in the slowing of replication, which in the budding yeast Saccharomyces cerevisiae is caused by Rad53 kinase-dependent inhibition of the initiation factors Sld3 and Dbf4. Despite this, we show here that Rad53 phosphorylates both of these substrates throughout the cell cycle at the same sites as in S-phase, suggesting roles for this pathway beyond S-phase. Indeed we show that Rad53-dependent inhibition of Sld3 and Dbf4 limits re-replication in G2/M phase, preventing inappropriate gene amplification events. In addition we show that inhibition of Sld3 and Dbf4 after DNA damage in G1 phase prevents premature replication initiation at all origins at the G1/S transition. This study redefines the scope and specificity of the ‘S-phase checkpoint’ with implications for understanding the roles of this checkpoint in the majority of cancers that lack proper cell cycle controls.
2021-01-14 | GSE163571 | GEO
Project description:Across eukaryotes, checkpoints maintain the order of cell cycle events in the face of DNA damage or incomplete replication. Although a wide array of DNA lesions activates the checkpoint kinases, whether and how this response differs in different phases of the cell cycle remains poorly understood. The S-phase checkpoint for example results in the slowing of replication, which in the budding yeast Saccharomyces cerevisiae is caused by Rad53 kinase-dependent inhibition of the initiation factors Sld3 and Dbf4. Despite this, we show here that Rad53 phosphorylates both of these substrates throughout the cell cycle at the same sites as in S-phase, suggesting roles for this pathway beyond S-phase. Indeed we show that Rad53-dependent inhibition of Sld3 and Dbf4 limits re-replication in G2/M phase, preventing inappropriate gene amplification events. In addition we show that inhibition of Sld3 and Dbf4 after DNA damage in G1 phase prevents premature replication initiation at all origins at the G1/S transition. This study redefines the scope and specificity of the ‘S-phase checkpoint’ with implications for understanding the roles of this checkpoint in the majority of cancers that lack proper cell cycle controls.
2021-01-14 | GSE159122 | GEO
Project description:In metazoans, the largest sirtuin, SIRT1, is a nuclear protein implicated in epigenetic modifications, circadian signaling, DNA recombination, replication and repair. Our previous studies have demonstrated that SIRT1 binds replication origins and inhibits replication initiation from a group of potential initiation sites (dormant origins). We studied the effects of aging and SIRT1 activity on replication origin usage and the incidence of transcription-replication collisions (creating R-loop structures) in adult human cells obtained at different time points during chronological aging and in cancer cells. In primary, untransformed cells, SIRT1 activity declined, and the prevalence of R-loops rose with chronological aging. Both the reduction of SIRT1 activity and the increased abundance of R-loops were also observed during the passage of primary cells in culture. All cells, regardless of donor age or transformation status, reacted to short-term, acute chemical inhibition of SIRT1 with the activation of excessive replication initiation events coincident with an increased prevalence of R-loops. However, only cancer cells showed genome-wide activation of dormant origins during long-term proliferation with mutated or depleted SIRT1, whereas in primary cells, aging-associated SIRT1-mediated activation of dormant origins was restricted to rDNA loci. These observations suggest that chronological aging and the associated decline in SIRT1 activity relaxes the regulatory networks that protect cells against excess replication and that the mechanisms protecting from replication-transcription collisions at the rDNA loci manifest as a differentially enhanced sensitivity to SIRT1 decline and chronological aging.
2023-11-27 | GSE247469 | GEO
Project description:ChIP-chip was used to compare DSB factor localization in wild-type and checkpoint mutant strains under S phase checkpoint inducing and uninducing conditions. We analyzed the DNA binding of factors associated with meiotic DNA replication and DSB formation by chromatin immunoprecipitation (ChIP), including; the replicative helicase Mcm2-7 and the meiotic DSB factors Mer2, Rec114 and Mre11. Immunoprecipitated and input DNA samples were differentially labeled and cohybridized to a single microarray. We have included 2-3 biological replicates of each experiment, including one dye swap experiment.
2013-09-18 | E-GEOD-46839 | biostudies-arrayexpress
Project description:Schizosaccharomyces pombe Rad3 checkpoint kinase and its human ortholog ATR are essential for maintaining genome integrity in cells treated with genotoxins that damage DNA or arrest replication forks. Rad3 and ATR also function during unperturbed growth, although the events triggering their activation and their critical functions are largely unknown. Here, we use ChIP-on-chip analysis to map genomic loci decorated by phosphorylated histone H2A (gH2A), a Rad3 substrate that establishes a chromatin-based recruitment platform for DNA repair/checkpoint proteins. Our data showed that gH2A marks a diverse array of genomic features during S-phase, including natural replication fork barriers and a fork breakage site, retrotransposons, heterochromatin in the centromeres and telomeres, and ribosomal RNA (rDNA) repeats. The enrichment of gH2A at these sites was confirmed by multiple ChiP-qPCR experiments.
2010-08-24 | GSE23758 | GEO