Human DDK rescues stalled forks and counteracts checkpoint inhibition at unfired origins to complete DNA replication Journal Article


Authors: Jones, M. J. K.; Gelot, C.; Munk, S.; Koren, A.; Kawasoe, Y.; George, K. A.; Santos, R. E.; Olsen, J. V.; McCarroll, S. A.; Frattini, M. G.; Takahashi, T. S.; Jallepalli, P. V.
Article Title: Human DDK rescues stalled forks and counteracts checkpoint inhibition at unfired origins to complete DNA replication
Abstract: Eukaryotic genomes replicate via spatially and temporally regulated origin firing. Cyclin-dependent kinase (CDK) and Dbf4-dependent kinase (DDK) promote origin firing, whereas the S phase checkpoint limits firing to prevent nucleotide and RPA exhaustion. We used chemical genetics to interrogate human DDK with maximum precision, dissect its relationship with the S phase checkpoint, and identify DDK substrates. We show that DDK inhibition (DDKi) leads to graded suppression of origin firing and fork arrest. S phase checkpoint inhibition rescued origin firing in DDKi cells and DDK-depleted Xenopus egg extracts. DDKi also impairs RPA loading, nascent-strand protection, and fork restart. Via quantitative phosphoproteomics, we identify the BRCA1-associated (BRCA1-A) complex subunit MERIT40 and the cohesin accessory subunit PDS5B as DDK effectors in fork protection and restart. Phosphorylation neutralizes autoinhibition mediated by intrinsically disordered regions in both substrates. Our results reveal mechanisms through which DDK controls the duplication of large vertebrate genomes. © 2021 Elsevier Inc. Eukaryote genomes duplicate via spatially and temporally regulated firing of replication origins. Using chemical genetics and phosphoproteomics, Jones et al. show that human DDK promotes origin firing by counteracting the S phase checkpoint and enables the uncoupling, protection, and restart of stalled forks. © 2021 Elsevier Inc.
Keywords: dna replication; chemical genetics; atr; phosphoproteomics; cdc7; ddk; merit40; pds5b
Journal Title: Molecular Cell
Volume: 81
Issue: 3
ISSN: 1097-2765
Publisher: Cell Press  
Date Published: 2021-02-04
Start Page: 426
End Page: 441.e8
Language: English
DOI: 10.1016/j.molcel.2021.01.004
PUBMED: 33545059
PROVIDER: scopus
PMCID: PMC8211091
DOI/URL:
Notes: Article -- Export Date: 1 March 2021 -- Source: Scopus
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MSK Authors
  1. Mathew John Kimble Jones
    12 Jones
  2. Camille Marie Anne Encarna Gelot
    1 Gelot