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

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; Prasad V. Jallepalli^*

SCIENCEDIRECT

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

摘要

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

关键词

DDK Cdc7 MERIT40 PDS5B DNA replication ATR phosphoproteomics chemical genetics