Two checkpoint complexes are independently recruited to sites of DNA damage in vivo.

@article{Melo2001TwoCC,
  title={Two checkpoint complexes are independently recruited to sites of DNA damage in vivo.},
  author={Justine A Melo and Jeffrey C. Cohen and David Paul Toczyski},
  journal={Genes & development},
  year={2001},
  volume={15 21},
  pages={2809-21}
}
The Ddc1/Rad17/Mec3 complex and Rad24 are DNA damage checkpoint components with limited homology to replication factors PCNA and RF-C, respectively, suggesting that these factors promote checkpoint activation by "sensing" DNA damage directly. Mec1 kinase, however, phosphorylates the checkpoint protein Ddc2 in response to damage in the absence of all other… CONTINUE READING