A quantitative analysis of the kinetics of the G(2) DNA damage checkpoint system

Proc Natl Acad Sci U S A. 1999 Sep 28;96(20):11352-7. doi: 10.1073/pnas.96.20.11352.


A detailed model of the G(2) DNA damage checkpoint (G2DDC) system is presented that includes complex regulatory networks of the mitotic kinase Cdc2, phosphatase Cdc25, Wee1 kinase, and damage signal transduction pathways involving Chk1 and p53. Assumptions on the kinetic equations of the G2DDC are made, and computer simulations are carried out to demonstrate how the various subsystems operate to delay or arrest cell cycle progression. The detailed model could be used to explain various experiments relevant to G2DDC reported recently, including the nuclear export of 14-3-3-bound Cdc25, the down-regulation of cyclin B1 expression by p53, the effect of Chk1 and p53 on Cdc25 levels, and Wee1 degradation. It also is shown that, under certain conditions, p53 is necessary to sustain a G(2) arrest.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Cycle Proteins / physiology
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins / physiology
  • DNA Damage*
  • G2 Phase*
  • Kinetics
  • Maturation-Promoting Factor / physiology
  • Nuclear Proteins*
  • Protein-Tyrosine Kinases / physiology
  • Signal Transduction
  • Tumor Suppressor Protein p53 / physiology
  • ras-GRF1


  • Cell Cycle Proteins
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins
  • Nuclear Proteins
  • Tumor Suppressor Protein p53
  • ras-GRF1
  • Protein-Tyrosine Kinases
  • Maturation-Promoting Factor