Cep295 is a conserved scaffold protein required for generation of a bona fide mother centriole.

Yuki Tsuchiya,Daiju Kitagawa,Koki Watanabe,Akshari Gupta,Satoko Yoshiba

doi:10.1038/ncomms12567

Abstract

Centrioles surrounded by pericentriolar material (PCM) serve as the core structure of the centrosome. A newly formed daughter centriole grows into a functional mother centriole. However, the underlying mechanisms remain poorly understood. Here we show that Cep295, an evolutionarily conserved protein, is required for generation of a bona fide mother centriole organizing a functional centrosome. We find that Cep295 is recruited to the proximal centriole wall in the early stages of procentriole assembly. Cep295 then acts as a scaffold for the proper assembly of the daughter centriole. We also find that Cep295 binds directly to and recruits Cep192 onto the daughter centriole wall, which presumably endows the function of the new mother centriole for PCM assembly, microtubule-organizing centre activity and the ability for centriole formation. These findings led us to propose that Cep295 acts upstream of the conserved pathway for centriole formation and promotes the daughter-to-mother centriole conversion.

Highlights

Centrioles surrounded by pericentriolar material (PCM) serve as the core structure of the centrosome
It has been recently suggested that centrosomal protein of 295 kDa (Cep295)/KIAA1731 somehow regulates the centriole-to-centrosome conversion in human cells[25], and that sequential loading of Cep[135], Cep[295] and Cep[152] onto daughter centrioles is needed for their maturation to become mother centrioles in Drosophila cells[26], the exact function of Cep[295] in centriole and centrosome biogenesis remains to be elucidated
A previous study suggested that Drosophila Ana-1, which is implicated in centriole formation[27,28,29] and human Cep[295] appear to share a short homologous sequence[30]

Summary

Introduction

Centrioles surrounded by pericentriolar material (PCM) serve as the core structure of the centrosome. We find that Cep[295] binds directly to and recruits Cep[192] onto the daughter centriole wall, which presumably endows the function of the new mother centriole for PCM assembly, microtubule-organizing centre activity and the ability for centriole formation. These findings led us to propose that Cep[295] acts upstream of the conserved pathway for centriole formation and promotes the daughter-to-mother centriole conversion. In the process of centriole formation in human cells, the presence of Cep[192] and centrosomal protein of 152 kDa (Cep152)[20,21,22] at centrioles is required for the centriolar recruitment of Plk[4]. We show that the interaction between Cep[295] and Cep[192] seems to be crucial for the integrity of centriole structure and for daughter-to-mother centriole conversion

Methods

Results

Conclusion