Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Helicase subunit Cdc45 targets the checkpoint kinase Rad53 to both replication initiation and elongation complexes after fork stalling

ABSTRACT: Across eukaryotes, inhibition of the progression of the DNA replication machinery causes an S-phase checkpoint response. This response regulates multiple processes, including inhibition of replication initiation and fork stabilisation. How these events are coordinated remains poorly understood. Here we show that the replicative helicase component Cdc45 targets the checkpoint kinase Rad53 to distinct replication complexes in the budding yeast Saccharomyces cerevisiae. Rad53 binds to FHA-interaction motifs in an unstructured loop region of Cdc45, which is phosphorylated by Rad53 itself, and this interaction is necessary for the inhibition of origin firing through Sld3. In addition to regulating replication initiation, Cdc45 also recruits Rad53 to stalled replication forks, which we demonstrate is important for the response to replication stress. Finally we show that a Cdc45 mutation that is orthologous to an allele found in patients with Meier-Gorlin Syndrome disrupts the functional interaction with Rad53. Together we present a single mechanism by which Rad53 targets replication initiation and elongation complexes, which may be relevant to human disease.

ORGANISM(S): Saccharomyces cerevisiae

PROVIDER: GSE122110 | GEO | 2019/02/26

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Checkpoint inhibition of origin firing prevents inappropriate replication in G2/M phase.

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

Checkpoint inhibition of origin firing prevents inappropriate replication outside of S-phase

2021-01-14 | GSE159122 | GEO

Helicase subunit Cdc45 targets the checkpoint kinase Rad53 to both replication initiation and elongation complexes after fork stalling

Project description:Helicase subunit Cdc45 targets the checkpoint kinase Rad53 to both replication initiation and elongation complexes after fork stalling

| PRJNA503611 | ENA

Rad53 checkpoint kinase couples leading and lagging strand DNA synthesis

Project description:In response to DNA replication stress, DNA replication checkpoint is activated to maintain fork stability, a process critical for maintenance of genome stability. However, how DNA replication checkpoint regulates replication forks remain elusive. Here we show that Rad53, a highly conserved replication checkpoint kinase, functions to couple leading and lagging strand DNA synthesis. In wild type cells under HU induced replication stress, synthesis of lagging strand, which contains ssDNA gaps, is comparable to leading strand DNA. In contrast, synthesis of lagging strand is much more than leading strand, and consequently, leading template ssDNA coated with ssDNA binding protein RPA was detected in rad53-1 mutant cells, suggesting that synthesis of leading strand and lagging strand DNA is uncoupled. Mechanistically, we show that replicative helicase MCM and leading strand DNA polymerase Pole move beyond actual DNA synthesis and that an increase in dNTP pools largely suppresses the uncoupled leading and lagging strand DNA synthesis. Our studies reveal an unexpected mechanism whereby Rad53 regulates replication fork stability.

2018-02-11 | GSE89721 | GEO

H2B mono-ubiquitylation facilitates fork stalling and recovery during replication stress by coordinating Rad53 activation and chromatin assembly

Project description:The influence of mono-ubiquitylation of histone H2B (H2Bub) on transcription via nucleosome reassembly has been widely documented. Recently, it has also been shown that H2Bub promotes recovery from replication stress; however, the underling molecular mechanism remains unclear. Here, we show that H2B ubiquitylation coordinates activation of the intra-S replication checkpoint and chromatin re-assembly, in order to limit fork progression and DNA damage in the presence of replication stress. In particular, we show that the absence of H2Bub affects replication dynamics (enhanced fork progression and reduced origin firing), leading to γH2A accumulation and increased hydroxyurea sensitivity. Further genetic analysis indicates a role for H2Bub in transducing Rad53 phosphorylation. Concomitantly, we found that a change in replication dynamics is not due to a change in dNTP level, but is mediated by reduced Rad53 activation and destabilization of the RecQ helicase Sgs1 at the fork. Furthermore, we demonstrate that H2Bub facilitates the dissociation of the histone chaperone Asf1 from Rad53, and nucleosome reassembly behind the fork is compromised in cells lacking H2Bub. Taken together, these results indicate that the regulation of H2B ubiquitylation is a key event in the maintenance of genome stability, through coordination of intra-S checkpoint activation, chromatin assembly and replication fork progression. S.cerevisiae oligonucleotide microarrays were provided by Affymetrix (S.cerevisiae Tiling 1.0R, P/N 900645). BrdU and proteins ChIP-chip analyses were carried out as described (Fachinetti et al., M Cell, 2010).

2014-09-12 | E-GEOD-61030 | biostudies-arrayexpress

Origin-Dependent DNA Replication in vitro: Insights into DDK and S-CDK function and Replisome Assembly

Project description:Initiation of eukaryotic DNA replication requires temporal separation of helicase loading from helicase activation and replisome assembly. Using an in vitro assay for eukaryotic origin-dependent replication initiation, we investigated the control of these events. After helicase loading, we found that the Dbf4-dependent Cdc7 kinase (DDK) initially drives origin recruitment of Sld3 and the Cdc45 helicase-activating protein. Corresponding in vivo studies found that DDK was required for Cdc45 binding at early origins during G1. Upon activation of S-phase cyclin-dependent kinases (S-CDK), a second helicase-activating protein (GINS) and the remainder of the replisome are recruited to the origin. Investigation of DNA polymerase recruitment showed that Mcm10 and DNA unwinding both were critical for recruitment of the lagging but not leading strand DNA polymerases. Our studies identify distinct roles for DDK and S-CDK during helicase activation and support a model in which the leading strand DNA polymerase is recruited prior to DNA unwinding and initial RNA primer synthesis. We performed chromatin immunoprecipitation (ChIP) against Cdc45 in CDC7 and cdc7-4 cells arrested in G1 phase to assess the requirement of the Dbf4-dependent kinase on the recruitment of Cdc45 to origin DNA during G1.

2011-07-21 | E-GEOD-29646 | biostudies-arrayexpress

Quantitative, genome-wide analysis of eukaryotic replication initiation and termination

Project description:Via the deep-sequencing of Okazaki fragments from Saccharomyces cerevisiae, we report the first comprehensive documentation of genome-wide replication directionality in any eukaryote; this permits the systematic analysis of both replication initiation and termination. We conduct a genome-wide analysis of origin competence and efficiency, and conclude that the majority of origins are competent to fire in each cell cycle and generally do so with high efficiency. Additionally, the spatial resolution of our data allow us to determine that leading-strand initiation generally occurs within the nucleosome-free region at origins. Using a strain in which late origins can be induced to fire early, we show that replication termination is a largely passive phenomenon that does not rely on cis-acting sequences or replication fork pausing and that the replication profile is determined largely by the kinetics of origin firing, allowing us to reconstruct chromosome-wide timing profiles from an asynchronous culture. 5 samples are included. Two are replicate, paired-end, wild-type samples sequenced via Illumina methodology. The raw data for these two are also deposited in the GEO repository under accession numbers GSM835650 and GSM835651. Two replicate, single-end, Sld2, Sld3, Dbf4, Dpb11, Cdc45 and Sld7 (SSDDCS) overexpression via galactose induction experiments are reported sequenced via Ion Torrent methodology. One single-end, Sld2, Sld3, Dbf4, Dpb11, Cdc45 and Sld7 (SSDDCS) normal expression control via glucose media experiment is reported sequenced via Ion Torrent methodology.

2013-02-28 | E-GEOD-40696 | biostudies-arrayexpress

H2B mono-ubiquitylation facilitates fork stalling and recovery during replication stress by coordinating Rad53 activation and chromatin assembly

2014-09-12 | GSE61030 | GEO

Rad53-mediated regulation of Rrm3 and Pif1 DNA helicases contributes to prevention of aberrant fork transitions under replication stress.

Project description:Replication stress activates the Mec1ATR and Rad53 kinases. Rad53 phosphorylates nuclear pores to counteract gene gating, thus preventing aberrant transitions at forks approaching transcribed genes. Here, we show that Rrm3 and Pif1, DNA helicases assisting fork progression across pausing sites, are detrimental in rad53 mutants experiencing replication stress. Rrm3 and Pif1 ablations rescue cell lethality, chromosome fragmentation, replisome-fork dissociation, fork reversal, and processing in rad53 cells. Through phosphorylation, Rad53 regulates Rrm3 and Pif1; phospho-mimicking rrm3 mutants ameliorate rad53 phenotypes following replication stress without affecting replication across pausing elements under normal conditions. Hence, the Mec1-Rad53 axis protects fork stability by regulating nuclear pores and DNA helicases. We propose that following replication stress, forks stall in an asymmetric conformation by inhibiting Rrm3 and Pif1, thus impeding lagging strand extension and preventing fork reversal; conversely, under unperturbed conditions, the peculiar conformation of forks encountering pausing sites would depend on active Rrm3 and Pif1.

2015-09-24 | GSE68214 | GEO

Rad53-mediated regulation of Rrm3 and Pif1 DNA helicases contributes to prevention of aberrant fork transitions under replication stress.

2015-09-24 | E-GEOD-68214 | biostudies-arrayexpress