Polo-like kinase 4 shapes up.

Polo-like kinase 4 (Plk4) is a master regulator of centriole duplication and targets to centrioles through the association of its cryptic polo box domain with centriole receptors. In this issue of Structure, Shimanovskaya and colleagues unveil a new dimeric architecture of Plk4's cryptic polo box that reveals a conserved mechanism for centriole targeting of the kinase.