The cell cycle comprises several checkpoints that ensure the fidelity of cell division. The G2/M checkpoint is crucial as it prevents the cell from entering mitosis with damaged DNA. The Wee1 kinase is a key regulator at this point. It phosphorylates and inhibits Cdc2 (also known as CDK1), a cyclin-dependent kinase, thereby preventing the activation of the cyclin B/CDK1 complex. This inhibition is vital for allowing time for DNA repair before mitosis proceeds.
