CDK1 Prevents Unscheduled PLK4-STIL Complex Assembly in Centriole Biogenesis

Centrioles are essential for the assembly of both centrosomes and cilia. Centriole biogenesis occurs once and only once per cell cycle and is temporally coordinated with cell-cycle progression, ensuring the formation of the right number of centrioles at the right time. The formation of new daughter centrioles is guided by a pre-existing, mother centriole. The proximity between mother and daughter centrioles was proposed to restrict new centriole formation until they separate beyond a critical distance. Paradoxically, mother and daughter centrioles overcome this distance in early mitosis, at a time when triggers for centriole biogenesis Polo-like kinase 4 (PLK4) and its substrate STIL are abundant. Here we show that in mitosis, the mitotic kinase CDK1-CyclinB binds STIL and prevents formation of the PLK4-STIL complex and STIL phosphorylation by PLK4, thus inhibiting untimely onset of centriole biogenesis. After CDK1-CyclinB inactivation upon mitotic exit, PLK4 can bind and phosphorylate STIL in G1, allowing pro-centriole assembly in the subsequent S phase. Our work shows that complementary mechanisms, such as mother-daughter centriole proximity and CDK1-CyclinB interaction with centriolar components, ensure that centriole biogenesis occurs once and only once per cell cycle, raising parallels to the cell-cycle regulation of DNA replication and centromere formation. [Display omitted] •PLK4 activity is needed in G1 for centriole biogenesis•PLK4 binds its substrate STIL upon inactivation of CDK1-CyclinB•CDK1-CyclinB binds to STIL in mitosis through the same domain to which PLK4 binds•CDK1-CyclinB prevents PLK4 from binding and phosphorylating STIL Zitouni, Francia et al. explore the mechanisms coupling the cell cycle to centrosome biogenesis, and show that in mitosis, CDK1 competes with PLK4, the trigger of centriole biogenesis, for binding to its substrate STIL. PLK4 binding and phosphorylation of STIL occurs only upon CDK1 activity drop at mitotic exit, leading to centriole biogenesis onset.