Identification of Chlamydomonas centriolar central core proteins reveals a role for human WDR90 in ciliogenesis

ABSTRACT: Centrioles are evolutionary conserved macromolecular structures that are fundamental for templating the formation of cilia and flagella, as well as for assembling centrosomes. Centrioles are nine-fold symmetrical microtubule-based cylindrical structures, which have three regions that can be clearly distinguished in the Chlamydomonas reinhardtii organelle: a ~100nm-long proximal region harboring a cartwheel, a ~250nm-long central core region containing the Y-shaped linker and a ~150nm-long distal region ending at the transitional plate. Despite the discovery of a growing number of centriolar components in many systems, no protein has been attributed to the central core region of the centriole thus far. Here, combining relative quantitative mass spectrometry and super-resolution microscopy on purified Chlamydomonas centrioles, we identified POB15 and POC16 as two proteins of the central core region. We also uncovered that POB15 and POC16 distribution correlates with that of centriolar microtubule glutamylation. Moreover, we developed an assay to uncover temporal relationships between centriolar proteins during organelle assembly, and thus established that POB15 is recruited after the cartwheel protein CrSAS-6, but before microtubule glutamylation takes place. Furthermore, we uncovered that WDR90, the human homolog of POC16, localizes to the distal lumen of human centrioles and is required for proper ciliogenesis. Overall, our work provides the first insights into the molecular identity and the function of components of the central core region of centrioles.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Chlamydomonas Reinhardtii

SUBMITTER: Romain Hamelin  

LAB HEAD: Pierre Gönczy

PROVIDER: PXD005818 | Pride | 2018-06-12

REPOSITORIES: Pride