LAUSR

ABSTRACT The Cep63–Cep152 complex located at the mother centriole recruits Plk4 to initiate centriole biogenesis. How the complex is targeted to mother centrioles, however, is unclear. In this study, we show that Cep57 and its paralog, Cep57l1, colocalize with Cep63 and Cep152 at the proximal end of mother centrioles in both cycling cells and multiciliated cells undergoing centriole amplification. Both Cep57 and Cep57l1 bind to the centrosomal targeting region of Cep63. The depletion of both proteins, but not either one, blocks loading of the Cep63–Cep152 complex to mother centrioles and consequently prevents centriole duplication. We propose that Cep57 and Cep57l1 function redundantly to ensure recruitment of the Cep63–Cep152 complex to the mother centrioles for procentriole formation. Summary: Cep57 and its paralog Cep57l1 redundantly act as a molecular scaffold to recruit the Cep63–Cep152 complex to the proximal end of centrioles for centriole duplication.