Tracheal motile cilia in mice require CAMSAP3 for the formation of central microtubule pair and coordinated beating

Motile cilia of multiciliated epithelial cells undergo synchronized beating to produce fluid flow along the luminal surface of various organs. Each motile cilium consists of an axoneme and a basal body (BB), which are linked by a transition zone (TZ). The axoneme exhibits a characteristic 9+2 microtubule arrangement important for ciliary motion, but how this microtubule system is generated is not yet fully understood. Here we show that calmodulin-regulated spectrin-associated protein 3 (CAMSAP3), a protein that can stabilize the minus-end of a microtubule, concentrates at multiple sites of the cilium-BB complex, including the upper region of the TZ or the axonemal basal plate (BP) where the central pair of micro-tubules (CP) initiates. CAMSAP3 dysfunction resulted in loss of the CP and partial distortion of the BP, as well as the failure of multicilia to undergo synchronized beating. These findings suggest that CAMSAP3 plays pivotal roles in the formation or stabilization of the CP by localizing at the basal region of the axoneme and thereby supports the coordinated motion of multicilia in airway epithelial cells.

Automated summary

This study found that CAMSAP3, a protein that stabilizes the minus-end of microtubules, concentrates at various sites of the cilium-BB complex and plays a crucial role in the formation or stabilization of the central pair of microtubules (CP) for coordinated motion of multicilia in airway epithelial cells.