Intraflagellar transport proteins cycle between the flagellum and its base

Autor: Johanna Buisson, Thibault Lagache, Jean-Christophe Olivo-Marin, Thierry Blisnick, Philippe Bastin, Nicolas Chenouard
Přispěvatelé: Biologie Cellulaire des Trypanosomes, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Analyse d'Images Quantitative (AIQ), Work in the Trypanosome Cell Biology Unit is funded by the Institut Pasteur, the Centre National de la Recherche Scientifique (CNRS), and by two grants of the Agence Nationale de la recherche (ANR-08-MIE-027, ANR-09-GENOPAT-R09088KS). J.B. was funded by fellowships from the Ministere de l'Enseignement Supérieur et de la Recherche (ED387), the Fondation pour la Recherche Médicale and Pasteur-Weizmann. N.C. was funded by a doctoral fellowship from C'Nano Ile-de-France. T.L. is funded by a Pasteur Transversal Research Program (PTR387)., ANR-08-MIEN-0027,SENSOTRYPA,Rôles sensoriels du flagelle au cours du cycle parasitaire du trypanosome africain(2008), Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2013
Předmět:
Zdroj: Journal of Cell Science
Journal of Cell Science, 2013, 126 (1), pp.327-338. ⟨10.1242/jcs.117069⟩
Journal of Cell Science, Company of Biologists, 2013, 126 (1), pp.327-338. ⟨10.1242/jcs.117069⟩
ISSN: 1477-9137
0021-9533
DOI: 10.1242/jcs.117069
Popis: Summary Intraflagellar transport (IFT) is necessary for the construction of cilia and flagella. IFT proteins are concentrated at the base of the flagellum but little is known about the actual role of this pool of proteins. Here, IFT was investigated in Trypanosoma brucei, an attractive model for flagellum studies, using GFP fusions with IFT52 or the IFT dynein heavy chain DHC2.1. Tracking analysis by a curvelet method allowing automated separation of forward and return transport demonstrated a uniform speed for retrograde IFT (5 µm s−1) but two distinct populations for anterograde movement that are sensitive to temperature. When they reach the distal tip, anterograde trains are split into three and converted to retrograde trains. When a fast anterograde train catches up with a slow one, it is almost twice as likely to fuse with it rather than to overtake it, implying that these trains travel on a restricted set of microtubules. Using photobleaching experiments, we show for the first time that IFT proteins coming back from the flagellum are mixed with those present at the flagellum base and can reiterate a full IFT cycle in the flagellum. This recycling is dependent on flagellum length and IFT velocities. Mathematical modelling integrating all parameters actually reveals the existence of two pools of IFT proteins at the flagellum base, but only one is actively engaged in IFT.
Databáze: OpenAIRE