Regulators of cyclin-dependent kinases are crucial for maintaining genome integrity in S phase.
Maintenance of genome integrity is of critical importance to cells. To identify key regulators of genomic integrity, we screened a human cell line with a kinome small interfering RNA library. WEE1, a major regulator of mitotic entry, and CHK1 were among the genes identified. Both kinases are important negative regulators of CDK1 and -2. Strikingly, WEE1 depletion rapidly induced DNA damage in S phase in newly replicated DNA, which was accompanied by a marked increase in single-stranded DNA. This DNA damage is dependent on CDK1 and -2 as well as the replication proteins MCM2 and CDT1 but not CDC25A. Conversely, DNA damage after CHK1 inhibition is highly dependent on CDC25A. Furthermore, the inferior proliferation of CHK1-depleted cells is improved substantially by codepletion of CDC25A. We conclude that the mitotic kinase WEE1 and CHK1 jointly maintain balanced cellular control of Cdk activity during normal DNA replication, which is crucial to prevent the generation of harmful DNA lesions during replication.
Beck
Halfdan
H
Biotech Research and Innovation Centre, University of Copenhagen, 2200 Copenhagen N, Denmark.
Nähse
Viola
V
Larsen
Marie Sofie Yoo
MS
Groth
Petra
P
Clancy
Trevor
T
Lees
Michael
M
Jørgensen
Mette
M
Helleday
Thomas
T
Syljuåsen
Randi G
RG
Sørensen
Claus Storgaard
CS
D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D000071877:Checkpoint Kinase 1; D018844:Cyclin-Dependent Kinases / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage; D004261:DNA Replication; D005434:Flow Cytometry; D015894:Genome, Human; D042822:Genomic Instability; D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D016196:S Phase / Q000502:physiology*; D020687:cdc25 Phosphatases / Q000235:genetics / Q000378:metabolism
D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; C499349:WEE1 protein, human; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; D018844:Cyclin-Dependent Kinases; C517004:CDC25A protein, human; D020687:cdc25 Phosphatases