CRB2 controls primary ciliogenesis in association with PAR6α, HOOK2 and RAB8A

Ciliogenesis is an essential process in animal development and physiology and when affected, the origin of severe pathologies called ciliopathies. CRB2 has been recently implicated when mutated in several pathologies such as retina degeneration and a ciliopathy-like syndrome. Here, we have investigated the role of CRB2 in primary ciliogenesis and showed that CRB2 depletion blocks the formation of the ciliary vesicle after activation of the mother centriole, indicating a defect in either transport or anchoring of the ciliary vesicle. CRB2 is accumulated in intracellular vesicles in the vicinity of the centrosome and we showed here that CRB2 forms a complex made of HOOK2 and PAR6, two proteins important for primary ciliogenesis or centrosome integrity. In addition, CRB2 interacts with RAB8A which over-expression rescued CRB2 knockdown. All together, these findings indicate that CRB2 regulates a membrane transport step essential for the formation of the ciliary vesicle.