Related Experiment Video
Updated: May 30, 2026

Visualization of DNA Repair Proteins Interaction by Immunofluorescence
Published on: June 26, 2020
Cell cycle regulation of DNA double-strand break end resection by Cdk1-dependent Dna2 phosphorylation
Xuefeng Chen1, Hengyao Niu, Woo-Hyun Chung
1Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, Texas, USA.
Abstract:
DNA recombination pathways are regulated by the cell cycle to coordinate with replication. Cyclin-dependent kinase (Cdk1) promotes efficient 5' strand resection at DNA double-strand breaks (DSBs), the initial step of homologous recombination and damage checkpoint activation. The Mre11-Rad50-Xrs2 complex with Sae2 initiates resection, whereas two nucleases, Exo1 and Dna2, and the DNA helicase-topoisomerase complex Sgs1-Top3-Rmi1 generate longer ssDNA at DSBs. Using Saccharomyces cerevisiae, we provide evidence for Cdk1-dependent phosphorylation of the resection nuclease Dna2 at Thr4, Ser17 and Ser237 that stimulates its recruitment to DSBs, resection and subsequent Mec1-dependent phosphorylation. Poorly recruited dna2T4A S17A S237A and dna2ΔN248 mutant proteins promote resection only in the presence of Exo1, suggesting cross-talk between Dna2- and Exo1-dependent resection pathways.
Related Concept Videos
DNA Damage can Stall the Cell Cycle
DNA Damage Can Stall the Cell Cycle
S-Cdk Initiates DNA Replication
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
S-Cdk Initiates DNA Replication
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
Inhibition of Cdk Activity
Inhibition of CDK Activity

