How PLK4, STIL and SAS-6 initiate centriole duplication.
(A) Hypothetical model summarizing the first steps in centriole duplication. For further explanation, see text. (B) Detail of the above model, with focus on the release of PLK4 autoinhibition upon binding of STIL CC to both PB3 and L1 linker domains of PLK4, and the phosphorylation of the STIL STAN domain. Note that binding of STIL CC to L1 may mask the DSG motif, thereby protecting PLK4 from degradation.