Myosin-Va is required for preciliary vesicle transportation to the mother centriole during ciliogenesis.

Primary cilia play essential roles in signal transduction and development. The docking of preciliary vesicles at the distal appendages of a mother centriole is an initial/critical step of ciliogenesis, but the mechanisms are unclear. Here, we demonstrate that myosin-Va mediates the transportation of preciliary vesicles to the mother centriole and reveal the underlying mechanism. We also show that the myosin-Va-mediated transportation of preciliary vesicles is the earliest event that defines the onset of ciliogenesis. Depletion of myosin-Va significantly inhibits the attachment of preciliary vesicles to the distal appendages of the mother centriole and decreases cilia assembly. Myosin-Va functions upstream of EHD1- and Rab11-mediated ciliary vesicle formation. Importantly, dynein mediates myosin-Va-associated preciliary vesicle transportation to the pericentrosomal region along microtubules, while myosin-Va mediates preciliary vesicle transportation from the pericentrosomal region to the distal appendages of the mother centriole via the Arp2/3-associated branched actin network.