Chk1: Lysates

The Chk1 checkpoint kinase is an integral member of the signaling cascade that controls cell cycle progression. In response to genotoxic stress, Chk1 is phosphorylated by ATM or ATM-related kinases. In turn, Chk1 phosphorylates downstream effectors, such as p53 or the Cdc25 phosphatases to halt cell cycle progression and allow time for repair of incurred damage.