Figure 1. WEE1 and the G2-M cell-cycle checkpoint.

Schematic representation of the G2-M cell-cycle checkpoint, in which DNA damage detected by ATR triggers phosphorylation of CHK1, leading to the inhibition of the phosphatase Cdc25 and subsequent phosphorylation of WEE1 and the CDK1-CyclinB complex, resulting in mitotic arrest. Inhibition of WEE1 is sufficient to prevent cell cycle arrest, forcing the cell to undergo mitosis.