Composition, Structure, and Function of the Eukaryotic Flagellum Distal Tip

Cilia and flagella are long extensions commonly found on the surface of eukaryotic cells. In fact, most human cells have a flagellum, and failure to correctly form cilia leads to a spectrum of diseases gathered under the name “ciliopathies”. Since cilia are so wide spread in the body, their malfunction can affect multiple organs with symptoms such as blindness, deafness, skeletal deformations, infertility and mental retardation. The cilium distal tip is where a cilium grows and signals. Therefore, the correct structure and composition of this region should be crucial to avoid the health issues associated with the ciliopathies. Yet, out of the flagellar regions, the distal tip is probably the least intensively studied. In this review, we will summarize the current knowledge on the flagellar tip structure, the dynamicity and signalling that occurs here and the proteins localizing to this important cellular region.