Ciliogenesis: building the cell's antenna

Abstract

The cilium is a complex organelle, the assembly of which requires the coordination of motor-driven intraflagellar transport (IFT), membrane trafficking and selective import of cilium-specific proteins through a barrier at the ciliary transition zone. Recent findings provide insights into how cilia assemble and disassemble in synchrony with the cell cycle and how the balance of ciliary assembly and disassembly determines the steady-state ciliary length, with the inherent length-dependence of IFT rendering the ciliary assembly rate a decreasing function of length. As cilia are important in sensing and processing developmental signals and directing the flow of fluids such as mucus, defects in ciliogenesis and length control are likely to underlie a range of cilium-related human diseases.

Quantitative analysis of human centrosome architecture by targeted proteomics and fluorescence imaging

“…Centrosomes are important for organelle positioning, cell shape, polarity, and motility, as well as chromosome segregation and cell division (Nigg & Stearns, 2011; Bornens, 2012). In addition to their role in nucleating centrosome assembly, fully mature centrioles also function as basal bodies for the formation of cilia and flagella (Ishikawa & Marshall, 2011; Bornens, 2012). Numerical and structural aberrations in centrioles and centrosomes have been implicated in human disease, including cancer, microcephaly, dwarfism, and ciliopathies (Nigg & Raff, 2009; Zyss & Gergely, 2009; Bettencourt‐Dias et al , 2011; Ishikawa & Marshall, 2011; Chavali et al , 2014; Jana et al , 2014; Gonczy, 2015).…”

STAR syndrome-associated CDK10/Cyclin M regulates actin network architecture and ciliogenesis

“…[6][7][8] A constant equilibrium between anterograde and retrograde intraflagellar transport regulates axonemal assembly and disassembly, to maintain primary cilium length. 9,10 Actin cytoskeleton dynamics plays a key role in ciliogenesis. 11,12 Extended cells can assemble contractile actin filaments, which repress ciliogenesis.…”

Syndrome de Bardet-Biedl : cils et obésité

“…C'est une structure dynamique présente dans les cellules en phase G0 dont la formation et la résorption sont étroitement liées au cycle cellulaire [2,5,6]. Cette dynamique et le renouvellement des éléments constitutifs du cil sont assurés par un système de transport intra-ciliaire appelé IFT pour intraflagellar transport qui transporte de manière antérograde et rétrograde des complexes cargos via des protéines motrices [7,8]. Lorsque surviennent des anomalies d'origine génétique induisant un défaut au niveau de cet organite, celles-ci causent des pathologies, souvent syndromiques, que l'on nomme les ciliopathies [9,10] Longtemps considéré comme un organite vestigial [1], le cil primaire connaît depuis une quinzaine d'années un regain d'intérêt scientifique considérable par les découvertes d'une part, de sa présence à la surface de la plupart des cellules et, d'autre part, de son rôle comme centre intégrateur impliqué dans la détection, l'interprétation et la transmission de nombreux signaux intra-et extracellulaires [2,3].…”