How the newborn centriole becomes a mother.

Abstract

The centriole is a conserved organelle in most animal cells. It is built with numerous proteins including a 9-fold symmetrical microtubule wall. Centrioles usually exist in pairs and constitute the core of the centrosome, the major microtubule-organizing center of the cell. In line with DNA replication, the centriole duplicates once every cell cycle. Beginning in G1 phase, a newly born daughter centriole assembles perpendicularly to the mother centriole, and subsequently elongates throughout S and G2. Interestingly, the daughter centriole can neither duplicate itself nor nucleate pericentriolar material (PCM), a cloud of proteins that enhances the microtubule nucleating ability of the centrosome, until the centriole has passed through mitosis.1-3 This process enabling the daughter centriole to acquire motherhood and be able to duplicate and recruit PCM has been named “centriole-to-centrosome conversion”.1 In a recent study, we demonstrated that centriole-to-centrosome conversion relies upon the building of a protein complex comprising Cep135, Ana1/Cep295 and Asl/Cep152 onto the nascent centriole in both Drosophila melanogaster and human cells.4