Ciliary Length Control

Primary cilia are microtubule-based organelles that can be found on the surface of most eukaryotic cells. Primary cilia detect external cues and play an important role in subsequent signal transduction pathways. In the kidneys primary cilia act as a flow sensor. However, both abnormally short and excessively long cilia fail to correctly act as a flow sensor, which results in the formation of cysts inside the kidney and eventually kidney failure. Primary cilia are assembled and maintained by a process known as intraflagellar transport. This process involves the bidirectional transport of multimeric protein complexes along the microtubule axis by motor proteins. It is likely that lengthening and shrinkage of cilia is modulated by the intraflagellar transport machinery. This thesis contains studies aimed to gain more insight in how intraflagellar transport and cilia length are regulated. To study intraflagellar transport we use cultured mammalian cells as well as the nematode Caenorhabditis elegans.