Centrioles are composed of a central cartwheel tethered to nine-fold symmetric microtubule (MT) blades. The centriole cartwheel and MTs are thought to grow from opposite ends of these organelles, so it is unclear how they coordinate their assembly. We previously showed that an oscillation of Polo-like kinase 4 (Plk4) initiates and times the growth of the cartwheel at the proximal end. Here, we show that CP110 and Cep97 form a complex close to the distal-end of the centriole MTs whose levels oscillate as the new centriole MTs grow. The CP110/Cep97 oscillation does not appear to time the period of centriole MT growth, but rather the oscillation is entrained by the core Cdk/Cyclin oscillator that drives the nuclear divisions in these embryos. We find that changing the levels of CP110/Cep97 alters the Plk4 oscillation and the growth of the cartwheel at the proximal end. These findings reveal an unexpected crosstalk between factors normally concentrated at opposite ends of the growing centrioles, which may help to coordinate centriole growth.
Cold Spring Harbor Laboratory