Recent studies have elucidated the activation mechanism of the Rad53 checkpoint kinase and the role of Rad9-like adaptor proteins in mediating signal transduction from PIKK sensor kinases that detect DNA damage to the effector kinases that play a part in mending that damage.
Pellicioli, A., & Foiani, M. (2005, September 20). Signal transduction: How Rad53 kinase is activated. Current Biology. https://doi.org/10.1016/j.cub.2005.08.057