The GTPase IFT27 is involved in both anterograde and retrograde intraflagellar transport.
The construction of cilia and flagella depends on intraflagellar transport (IFT), the bidirectional movement of two protein complexes (IFT-A and IFT-B) driven by specific kinesin and dynein motors. IFT-B and kinesin are associated to anterograde transport whereas IFT-A and dynein participate to retrograde transport. Surprisingly, the small GTPase IFT27, a member of the IFT-B complex, turns out to be essential for retrograde cargo transport in Trypanosoma brucei. We reveal that this is due to failure to import both the IFT-A complex and the IFT dynein into the flagellar compartment. To get further molecular insight about the role of IFT27, GDP- or GTP-locked versions were expressed in presence or absence of endogenous IFT27. The GDP-locked version is unable to enter the flagellum and to interact with other IFT-B proteins and its sole expression prevents flagellum formation. These findings demonstrate that a GTPase-competent IFT27 is required for association to the IFT complex and that IFT27 plays a role in the cargo loading of the retrograde transport machinery.DOI: http://dx.doi.org/10.7554/eLife.02419.001.
Trypanosome Cell Biology Unit, Institut Pasteur & CNRS, Paris, France Université Pierre et Marie Curie, Cellule Pasteur-UPMC, Paris, France.
Diego
D
Huet
Trypanosome Cell Biology Unit, Institut Pasteur & CNRS, Paris, France.
Thierry
T
Blisnick
Trypanosome Cell Biology Unit, Institut Pasteur & CNRS, Paris, France.
Sylvie
S
Perrot
Trypanosome Cell Biology Unit, Institut Pasteur & CNRS, Paris, France pbastin@pasteur.fr.
Philippe
P
Bastin
D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D002923:Cilia / Q000235:genetics / Q000378:metabolism; D004398:Dyneins / Q000235:genetics / Q000378:metabolism; D005407:Flagella / Q000235:genetics / Q000378:metabolism; D020558:GTP Phosphohydrolases / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D020868:Gene Silencing; D016547:Kinesins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D017354:Point Mutation; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D016415:Sequence Alignment; D014346:Trypanosoma brucei brucei / Q000235:genetics* / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism
D015800:Protozoan Proteins; D020558:GTP Phosphohydrolases; D004398:Dyneins; D016547:Kinesins; D020691:rab GTP-Binding Proteins
IFT; Trypanosoma brucei; flagellum; small GTPase