Capturing Polo Kinase

Abstract
The interactions of kinases in signaling cascades and cell cycle pathways are so complex that it can be difficult to identify the protein binding domains that mediate these interactions. In a Perspective, Silljé and Nigg discuss a new proteomic screen (Elia et al.) that identifies the Polo-box binding domain of the mitotic kinase Plk1 as the domain that binds to phosphorylated sites in docking proteins such as Cdc25.