ABSTRACT
The main structure of cilia comprises a central axoneme of tubulin polymers enriched in acetylated tubulin, the composition of which defines two types of cilia, PC (primary cilium) and MC (motile cilium). Axonemal growth is mainly maintained by the intraflagellar transport (IFT) machinery, due to the fact that the PC lacks the protein synthesis machinery. The BBSome is a transport mechanism critical for the delivery of proteins to the ciliary membrane, although it is not required for ciliary assembly itself. Entry of proteins into the cilium is a regulated process that occurs through the transition fibers and the transition zone. The ciliary pocket is a membrane domain found at the base of the cilium, which serves as a platform for cilia-related vesicular trafficking. The functions of the ciliary membrane are closely related to the general roles of primary cilia. Ciliogenesis is referred to as the assembly of primary cilia, a process in continuous dynamic regulation.
