Send to

Choose Destination
J Biol Chem. 2003 Aug 8;278(32):29940-7. Epub 2003 May 19.

Regulatory interactions between the checkpoint kinase Chk1 and the proteins of the DNA-dependent protein kinase complex.

Author information

Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0524, USA.


Checkpoints are biochemical pathways that provide cells a mechanism to detect DNA damage and respond by arresting the cell cycle to allow DNA repair. The conserved checkpoint kinase, Chk1, regulates mitotic progression in response to DNA damage by blocking the activation of Cdk1/cyclin B. In this study, we investigate the regulatory interaction between Chk1 and members of the Atm family of kinases and the functional role of the C-terminal non-catalytic domains of Chk1. Chk1 stimulates the kinase activity of DNA-PK (protein kinase) complexes, which leads to increased phosphorylation of p53 on Ser-15 and Ser-37. In addition, Chk1 stimulates DNA-PK-dependent end-joining reactions in vitro. We also show that Chk1 protein complexes bind to single-stranded DNA and DNA ends. These results indicate a connection between components that regulate the checkpoint pathways and DNA-PK complex proteins, which have a role in the repair of double strand breaks.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center