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

作者：Mathew J.K. Jones^*; Camille Gelot; Stephanie Munk; Amnon Koren; Yoshitaka Kawasoe; Kelly A. George; Ruth E. Santos; Jesper V. Olsen; Steven A. McCarroll; Mark G. Frattini; Tatsuro S. Takahashi; Pra*** V. Jallepalli^*

来源：Molecular Cell, 2021, 81(3): 426-441.e8.

DOI：10.1016/j.molcel.2021.01.004

• DDK
• Cdc7
• MERIT40
• PDS5B
• DNA replication
• ATR
• phosphoproteomics
• chemical genetics

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 M

• 单位
  The University of Queensland; Harvard medical school; The university of Queensland; harvard medical school; new; Harvard Medical School; Columbia University Medical Center