title: The intraflagellar transport dynein complex of trypanosomes is made of a heterodimer of dynein heavy chains and of light and intermediate chains of distinct functions.
abstract: Cilia and flagella are assembled by intraflagellar transport (IFT) of protein complexes that bring tubulin and other precursors to the incorporation site at their distal tip. Anterograde transport is driven by kinesin, whereas retrograde transport is ensured by a specific dynein. In the protist Trypanosoma brucei, two distinct genes encode fairly different dynein heavy chains (DHCs; ∼40% identity) termed DHC2.1 and DHC2.2, which form a heterodimer and are both essential for retrograde IFT. The stability of each heavy chain relies on the presence of a dynein light intermediate chain (DLI1; also known as XBX-1/D1bLIC). The presence of both heavy chains and of DLI1 at the base of the flagellum depends on the intermediate dynein chain DIC5 (FAP133/WDR34). In the IFT140(RNAi) mutant, an IFT-A protein essential for retrograde transport, the IFT dynein components are found at high concentration at the flagellar base but fail to penetrate the flagellar compartment. We propose a model by which the IFT dynein particle is assembled in the cytoplasm, reaches the base of the flagellum, and associates with the IFT machinery in a manner dependent on the IFT-A complex.
authors.affiliation: Trypanosome Cell Biology Unit, Institut Pasteur, and Centre National de la Recherche Scientifique URA 2581, 75015 Paris, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Blisnick
authors.affiliation: Trypanosome Cell Biology Unit, Institut Pasteur, and Centre National de la Recherche Scientifique URA 2581, 75015 Paris, France.
authors.forename: Johanna
authors.initials: J
authors.lastname: Buisson
authors.affiliation: Trypanosome Cell Biology Unit, Institut Pasteur, and Centre National de la Recherche Scientifique URA 2581, 75015 Paris, France.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Absalon
authors.affiliation: Trypanosome Cell Biology Unit, Institut Pasteur, and Centre National de la Recherche Scientifique URA 2581, 75015 Paris, France.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Marie
authors.affiliation: Imagopole Platform, Institut Pasteur, 75015 Paris, France.
authors.forename: Nadège
authors.initials: N
authors.lastname: Cayet
authors.affiliation: Trypanosome Cell Biology Unit, Institut Pasteur, and Centre National de la Recherche Scientifique URA 2581, 75015 Paris, France pbastin@pasteur.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Bastin
mesh_terms: D054468:Axoneme; D001692:Biological Transport; D002923:Cilia / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D019281:Dimerization; D004398:Dyneins / Q000378:metabolism*; D005407:Flagella / Q000378:metabolism; D008954:Models, Biological; D014346:Trypanosoma brucei brucei / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D004398:Dyneins