Chk1 is a wee1 kinase in the G2 DNA damage checkpoint inhibiting cdc2 by Y15 phosphorylation

Abstract

The G2 DNA damage checkpoint ensures maintenance of cell viability by delaying progression into mitosis in cells which have suffered genomic damage. It is controlled by a number of proteins which are hypothesized to transduce signals through cell cycle regulators to delay activation of p34(cdc2). Studies in mammalian cells have correlated induction of inhibitory tyrosine 15 (Y15) phosphorylation on p34(cdc2) With the response to DNA damage. However, genetic studies in fission yeast have suggested that the major Y15 kinase, p107(wee1), is not required for the cell cycle delay in response to DNA damage, although it is required for survival after irradiation. Thus, the target of the checkpoint,..