Cilia assembly and function rely on the bidirectional transport of components between the cell body and ciliary tip via Intraflagellar Transport (IFT) trains. Anterograde and retrograde IFT trains travel along the B- and A-tubules of microtubule doublets, respectively, ensuring smooth traffic flow. However, the mechanism underlying this segregation remains unclear. Here, we test whether tubulin detyrosination (enriched on B-tubules) and tyrosination (enriched on A-tubules) have a role in IFT logistics. We report that knockout of tubulin detyrosinase VashL in Chlamydomonas reinhardtii causes frequent IFT train stoppages and impaired ciliary growth. By reconstituting IFT train motility on de-membranated axonemes and synthetic microtubules, we show that anterograde and retrograde trains preferentially associate with detyrosinated and tyrosinated microtubules, respectively. We propose that tubulin tyrosination/detyrosination is crucial for spatial segregation and collision-free IFT train motion, highlighting the significance of the tubulin code in ciliary transport.

• MeSH
• axonema * metabolismus   MeSH
• biologický transport MeSH
• Chlamydomonas reinhardtii * metabolismus   genetika   MeSH
• cilie metabolismus   MeSH
• flagella * metabolismus   MeSH
• mikrotubuly * metabolismus   MeSH
• tubulin * metabolismus   MeSH
• tyrosin * metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• tubulin * MeSH
• tyrosin * MeSH

Cilia or eukaryotic flagella are microtubule-based organelles found across the eukaryotic tree of life. Their very high aspect ratio and crowded interior are unfavorable to diffusive transport of most components required for their assembly and maintenance. Instead, a system of intraflagellar transport (IFT) trains moves cargo rapidly up and down the cilium (Figure 1A).1-3 Anterograde IFT, from the cell body to the ciliary tip, is driven by kinesin-II motors, whereas retrograde IFT is powered by cytoplasmic dynein-1b motors.4 Both motors are associated with long chains of IFT protein complexes, known as IFT trains, and their cargoes.5-8 The conversion from anterograde to retrograde motility at the ciliary tip involves (1) the dissociation of kinesin motors from trains,9 (2) a fundamental restructuring of the train from the anterograde to the retrograde architecture,8,10,11 (3) the unloading and reloading of cargo,2 and (4) the activation of the dynein motors.8,12 A prominent hypothesis is that there is dedicated calcium-dependent protein-based machinery at the ciliary tip to mediate these processes.4,13 However, the mechanisms of IFT turnaround have remained elusive. In this study, we use mechanical and chemical methods to block IFT at intermediate positions along the cilia of the green algae Chlamydomonas reinhardtii, in normal and calcium-depleted conditions. We show that IFT turnaround, kinesin dissociation, and dynein-1b activation can consistently be induced at arbitrary distances from the ciliary tip, with no stationary tip machinery being required. Instead, we demonstrate that the anterograde-to-retrograde conversion is a calcium-independent intrinsic ability of IFT.

• Klíčová slova
• TIRF microscopy, cilia and flagella, ciliary tip, intraflagellar transport, micromanipulator, total-internal reflection microscopy,
• MeSH
• biologický transport MeSH
• cilie metabolismus   MeSH
• cytoplazmatické dyneiny metabolismus   MeSH
• dyneiny * metabolismus   MeSH
• flagella fyziologie   MeSH
• kineziny * MeSH
• vápník metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cytoplazmatické dyneiny MeSH
• dyneiny * MeSH
• kineziny * MeSH
• vápník MeSH

Primary cilia play critical roles in development and disease. Their assembly and disassembly are tightly coupled to cell cycle progression. Here, we present data identifying KIF14 as a regulator of cilia formation and Hedgehog (HH) signaling. We show that RNAi depletion of KIF14 specifically leads to defects in ciliogenesis and basal body (BB) biogenesis, as its absence hampers the efficiency of primary cilium formation and the dynamics of primary cilium elongation, and disrupts the localization of the distal appendage proteins SCLT1 and FBF1 and components of the IFT-B complex. We identify deregulated Aurora A activity as a mechanism contributing to the primary cilium and BB formation defects seen after KIF14 depletion. In addition, we show that primary cilia in KIF14-depleted cells are defective in response to HH pathway activation, independently of the effects of Aurora A. In sum, our data point to KIF14 as a critical node connecting cell cycle machinery, effective ciliogenesis, and HH signaling.

• MeSH
• adaptorové proteiny signální transdukční metabolismus   MeSH
• Aurora kinasa A antagonisté a inhibitory   genetika   metabolismus   MeSH
• bazální tělíska metabolismus   MeSH
• buněčný cyklus genetika   MeSH
• chromatografie kapalinová MeSH
• cilie genetika   metabolismus   patologie   MeSH
• HEK293 buňky MeSH
• interfáze fyziologie   MeSH
• intracelulární signální peptidy a proteiny genetika   metabolismus   MeSH
• kineziny genetika   metabolismus   MeSH
• lidé MeSH
• mitóza genetika   MeSH
• onkogenní proteiny genetika   metabolismus   MeSH
• protein-serin-threoninkinasy genetika   metabolismus   MeSH
• proteiny hedgehog metabolismus   MeSH
• RNA interference MeSH
• signální transdukce genetika   MeSH
• sodíkové kanály metabolismus   MeSH
• tandemová hmotnostní spektrometrie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• AURKA protein, human MeSH Prohlížeč
• Aurora kinasa A MeSH
• citron-kinase MeSH Prohlížeč
• FBF1 protein, human MeSH Prohlížeč
• intracelulární signální peptidy a proteiny MeSH
• KIF14 protein, human MeSH Prohlížeč
• kineziny MeSH
• onkogenní proteiny MeSH
• protein-serin-threoninkinasy MeSH
• proteiny hedgehog MeSH
• SCLT1 protein, human MeSH Prohlížeč
• sodíkové kanály MeSH

Primary cilium is a solitary organelle that emanates from the surface of most postmitotic mammalian cells and serves as a sensory organelle, transmitting the mechanical and chemical cues to the cell. Primary cilia are key coordinators of various signaling pathways during development and maintenance of tissue homeostasis. The emerging evidence implicates primary cilia function in tooth development. Primary cilia are located in the dental epithelium and mesenchyme at early stages of tooth development and later during cell differentiation and production of hard tissues. The cilia are present when interactions between both the epithelium and mesenchyme are required for normal morphogenesis. As the primary cilium coordinates several signaling pathways essential for odontogenesis, ciliary defects can interrupt the latter process. Genetic or experimental alterations of cilia function lead to various developmental defects, including supernumerary or missing teeth, enamel and dentin hypoplasia, or teeth crowding. Moreover, dental phenotypes are observed in ciliopathies, including Bardet-Biedl syndrome, Ellis-van Creveld syndrome, Weyers acrofacial dysostosis, cranioectodermal dysplasia, and oral-facial-digital syndrome, altogether demonstrating that primary cilia play a critical role in regulation of both the early odontogenesis and later differentiation of hard tissue-producing cells. Here, we summarize the current evidence for the localization of primary cilia in dental tissues and the impact of disrupted cilia signaling on tooth development in ciliopathies.

• Klíčová slova
• craniofacial anomalies, growth/development, mineralized tissue/development, odontoblast(s), oral pathology, signal transduction,
• MeSH
• buněčná diferenciace fyziologie   MeSH
• cilie fyziologie   MeSH
• lidé MeSH
• maxilofaciální vývoj fyziologie   MeSH
• odontogeneze fyziologie   MeSH
• signální transdukce fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH