Transition fibre protein FBF1 is required for the ciliary entry of assembled intraflagellar transport complexes.
Sensory organelle cilia have critical roles in mammalian embryonic development and tissue homeostasis. Intraflagellar transport (IFT) machinery is required for the assembly and maintenance of cilia. Yet, how this large complex passes through the size-dependent barrier at the ciliary base remains enigmatic. Here we report that FBF1, a highly conserved transition fibre protein, is required for the ciliary import of assembled IFT particles at the ciliary base. We cloned dyf-19, the Caenorhabditis elegans homologue of human FBF1, in a whole-genome screen for ciliogenesis mutants. DYF-19 localizes specifically to transition fibres and interacts directly with the IFT-B component DYF-11/IFT54. Although not a structural component of transition fibres, DYF-19 is required for the transit of assembled IFT particles through the ciliary base. Furthermore, we found that human FBF1 shares conserved localization and function with its worm counterpart. We conclude that FBF1 is a key functional transition fibre component that actively facilitates the ciliary entry of assembled IFT machinery.
Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota 55905, USA.
Qing
Q
Wei
Qingwen
Q
Xu
Yuxia
Y
Zhang
Yujie
Y
Li
Qing
Q
Zhang
Zeng
Z
Hu
Peter C
PC
Harris
Vicente E
VE
Torres
Kun
K
Ling
Jinghua
J
Hu
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000906:Antibodies; D001692:Biological Transport / Q000502:physiology; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D002923:Cilia / Q000502:physiology; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; D000906:Antibodies; D029742:Caenorhabditis elegans Proteins; C095245:FBF1 protein, human; C533180:Fbf1 protein, mouse; D016601:RNA-Binding Proteins; C109286:fem-3-binding protein, C elegans