Browse
Submit Data
Databases
API
Help

Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

46 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

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

ABSTRACT: 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.

ORGANISM(S): Saccharomyces cerevisiae

SUBMITTER: Stephen Bell

PROVIDER: E-GEOD-29646 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Json Xml

Similar Datasets

Eukaryotic origin-dependent DNA replication in vitro reveals sequential action of DDK and S-CDK kinases.

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.

2011-07-22 | GSE29646 | GEO

The structural basis of Cdc7-Dbf4 kinase dependent targeting and phosphorylation of the MCM2-7 double hexamer

Project description:The controlled assembly of replication forks is critical for genome stability. The Dbf4-dependent Cdc7 kinase (DDK) initiates replisome assembly by phosphorylating the MCM2-7 replicative helicase at the N-terminal tails of Mcm2, Mcm4 and Mcm6. At present, it remains poorly understood how DDK docks onto the helicase and how the kinase targets distal Mcm subunits for phosphorylation. By cryo-electron microscopy and biochemical analysis we discovered that an interaction between the HBRCT domain of Dbf4 with Mcm2 serves as an anchoring point, which supports binding of DDK across the MCM2-7 double-hexamer interface and phosphorylation of Mcm4 on the opposite hexamer. Moreover, a rotation of DDK along its anchoring point allows phosphorylation of Mcm2 and Mcm6 on opposite hexamers. In summary, our work provides fundamental insights in the DDK structure, control and the selective activation of the MCM2-7 helicase during DNA replication, which can be exploited for development of novel DDK inhibitors.

2022-05-31 | PXD031315 | Pride

Severe congenital neutropenia with syndromic features in a patient with homozygous hypomorphic DBF4 mutation

Project description:Accurate and efficient DNA synthesis is an essential function of replicating cells. Mutations in replisome components lead to a number of syndromic diseases including immunodeficiencies. Dumbbell former 4 (DBF4) is the regulatory subunit of the DBF4-dependent kinase (DDK) which is essential for the activation of replication origins. We here studied a patient with severe congenital neutropenia (SCN) and syndromic features without a genetic diagnosis. We identified a private homozygous mutation in DBF4 (CADD 25.8 with a DBF4-specific MSC of 3.13) in a patient with SCN. The DBF4 mutant is normally expressed in stimulated PBMCs and dermal fibroblasts, but has a decreased CDC7-binding capacity in overexpression assays. DDK-specific phosphorylation of MCM2 was decreased in stimulated PBMCs with accumulation of CDK inhibitor p21, a G0 cell cycle arrest and impaired proliferation. Serum-starved fibroblasts showed a similar cell cycle phenotype but no p21 accumulation and normal MCM2 phosphorylation. In vitro differentiation of primary CD34+ cells recapitulated the SCN phenotype observed in vivo and was associated with a 4-fold increase in p21 gene expression. Single cell RNA sequencing of whole bone marrow revealed upregulation of p53 targets and activation of the PERK pathway of the unfolded protein response. Autosomal recessive functional DBF4 deficiency causes SCN with syndromic features.

2022-06-10 | GSE160517 | GEO

DBF4, not DRF1, is the crucial regulator of CDC7 kinase at replication forks.

Project description:In eukaryotes, CDC7 kinase is crucial for DNA replication initiation and has been involved in fork processing and replication stress response. Human CDC7 requires the binding of either one of two regulatory subunits, DBF4 and DRF1, for its activity. However, it is unclear whether the two regulatory subunits target CDC7 to a specific set of substrates, thus having different biological functions, or if they act redundantly. Using genome editing technology, we generated an isogenic set of cell lines deficient in either one of the two CDC7-activating subunits: these cells are viable but present signs of genomic instability, indicating that both DBF4 and DRF1 can independently support CDC7 for bulk DNA replication. Nonetheless, DBF4-deficient cells show altered replication efficiency, including partial deficiency in MCM helicase phosphorylation and alterations in the replication timing of discrete genomic regions. Notably, we find that CDC7 function at replication forks is entirely dependent on DBF4 and not DRF1. Thus, DBF4 is the primary regulator of CDC7 activity, likely mediating most of its functions in unperturbed DNA replication and during replication fork processing upon replication interference.

2024-03-28 | GSE248981 | GEO

Dbf4-dependent kinase (DDK) and the Rtt107 scaffold promote Mus81-Mms4 resolvase activation during mitosis

Project description:DNA repair by homologous recombination is under stringent cell cycle control. This includes the last step of the reaction, disentanglement of DNA joint molecules (JMs). Previous work has established that JMs resolving nucleases are activated specifically at the onset of mitosis. In case of budding yeast Mus81-Mms4, this cell cycle stage-specific activation is known to depend on phosphorylation by CDK and Cdc5 kinases. Here, we show that a third cell cycle kinase, Cdc7-Dbf4 (DDK), targets Mus81-Mms4 in conjunction with Cdc5 - both kinases bind to as well as phosphorylate Mus81-Mms4 in an interdependent manner. Moreover, DDK-mediated phosphorylation of Mms4 is strictly required for Mus81 activation in mitosis, establishing DDK as a novel regulator of homologous recombination. The scaffold protein Rtt107, which is part of the Mus81-Mms4 complex, interacts with Cdc7 and thereby targets DDK and Cdc5 to the complex enabling full Mus81 activation. Therefore, Mus81 activation in mitosis involves at least three cell cycle kinases, Cdk1, Cdc5 and DDK. Furthermore, tethering of the kinases in a stable complex with Mus81 is critical for efficient JM resolution

2017-01-21 | PXD005356 | Pride

Replication profile from total DNA

Project description:DNA duplication is intimately connected to setting up post-replicative chromosome structures and events, but molecular details of this coordination are not well understood. A striking example occurs during yeast meiosis, where replication locally influences timing of the DNA double-strand breaks (DSBs) that initiate recombination. We show here that replication-DSB coordination is eliminated by overexpressing Dbf4-dependent Cdc7 kinase (DDK) or removing Tof1 or Csm3, components of the replication fork protection complex (FPC). DDK physically associates with Tof1, and Tof1 is dispensable for replication-DSB coordination if DDK is artificially tethered to replisomes. Furthermore, DDK phosphorylation of the DSB-promoting factor Mer2 is locally coordinated with replication, dependent on Tof1. These findings indicate that DDK recruited by FPC to replisomes phosphorylates chromatin-bound Mer2 in the wake of the replication fork, thus synchronizing replication with an early prerequisite for DSB formation. This may be a general mechanism to ensure spatial and temporal coordination of replication with other chromosomal processes. Forty-eight samples total: 8 time points from WT ARS+, WT arsM-bM-^HM-^F, DDK OP ARS+, DDK OP arsM-bM-^HM-^F,tof1M-bM-^HM-^F ARS+,tof1M-bM-^HM-^F arsM-bM-^HM-^F strains

2014-07-21 | E-GEOD-52987 | biostudies-arrayexpress

Dbf4 Zn-finger motif is specifically required for stimulation of Ctf19-activated origins in S. cerevisiae

Project description:Eukaryotic genomes are replicated in spatiotemporal patterns that are stereotypical for individual genomes and developmental profiles. In the model system S. cerevisiae, two primary mechanisms determine the preferential activation of replication origins during early S phase, thereby largely defining the consequent replication profiles of these cells. Both mechanisms are thought to act through specific recruitment of a rate-limiting initiation factor, Dbf4-dependent kinase (DDK), to a subset of licensed replication origins. Fkh1/2 is responsible for stimulation of most early-firing origins, except for centromere (CEN)-proximal origins that recruit DDK via the kinetochore protein Ctf19, which is required for their early-firing. The C-terminus of Dbf4 has been implicated in its recruitment to origins via both the Fkh1/2 and Ctf19 mechanisms. Here, we show that the Zn-finger motif within the C-terminus is specifically required for Dbf4 recruitment to CENs to stimulate CEN-proximal/Ctf19-dependent origins, whereas stimulation of origins via the Fkh1/2 pathway remains largely intact. These findings re-open the question of exactly how Fkh1/2 and DDK act together to stimulate replication origin initiation.

2022-11-10 | GSE215190 | GEO

Phosphoproteomic dataset comparing wild type, bob1-1 and bob1-1dbf4∆ cells in M-phase arrested S.cerevisiae.

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). We uncovered a novel role for the Dbf4-dependent kinase Cdc7 (DDK) in regulating HR and DNA end resection. We therefore analyzed phosphorylation substrates of DDK by phosphoproteomics, where we compared wild type, bob1-1 and bob1-1dbf4∆ cells in M-phase arrested S.cerevisiae.

2024-02-15 | PXD042607 | Pride

Replication profile from total DNA

2014-07-21 | GSE52987 | GEO

Rec114 ChIP-seq

2014-07-21 | GSE52970 | GEO