Role for the IFT-A Complex in Selective Transport to the Primary Cilium.
Intraflagellar transport sub-complex A (IFT-A) is known to regulate retrograde IFT in the cilium. To rigorously assess its other possible roles, we knocked out an IFT-A subunit, IFT121/WDR35, in mammalian cells and screened the localization of more than 50 proteins. We found that Wdr35 regulates cilium assembly by selectively regulating transport of distinct cargoes. Beyond its role in retrograde transport, we show that Wdr35 functions in fusion of Rab8 vesicles at the nascent cilium, protein exit from the cilium, and centriolar satellite organization. Furthermore, we show that Wdr35 is essential for entry of many membrane proteins into the cilium through robust interactions with cargoes and other IFT-A subunits, but the actin network functions to dampen this transport. Wdr35 is mutated in several ciliopathies, and we find that certain disease mutations impair interactions with cargo and other IFT-A subunits. Together, our data link defects in IFT-A mediated cargo transport with disease.
Department of Pathology and Perlmutter Cancer Center, NYU School of Medicine, Smilow Research Building, 522 First Avenue, New York, NY 10016, USA.
Wenxiang
W
Fu
Department of Pathology and Perlmutter Cancer Center, NYU School of Medicine, Smilow Research Building, 522 First Avenue, New York, NY 10016, USA.
Lei
L
Wang
Department of Pathology and Perlmutter Cancer Center, NYU School of Medicine, Smilow Research Building, 522 First Avenue, New York, NY 10016, USA.
Sehyun
S
Kim
Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02142, USA.
Ji
J
Li
Department of Pathology and Perlmutter Cancer Center, NYU School of Medicine, Smilow Research Building, 522 First Avenue, New York, NY 10016, USA. Electronic address: brian.dynlacht@nyumc.org.
Brian David
BD
Dynlacht
D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D002460:Cell Line; D002502:Centrioles / Q000187:drug effects / Q000378:metabolism; D018385:Centrosome / Q000187:drug effects / Q000378:metabolism; D002923:Cilia / Q000187:drug effects / Q000378:metabolism*; D015638:Cytochalasin D / Q000494:pharmacology; D003598:Cytoskeletal Proteins; D053823:Hedgehog Proteins; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008954:Models, Biological; D046912:Multiprotein Complexes / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D038081:Organogenesis / Q000187:drug effects; D021122:Protein Subunits / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D011506:Proteins / Q000378:metabolism*
D000199:Actins; D003598:Cytoskeletal Proteins; D053823:Hedgehog Proteins; D047908:Intracellular Signaling Peptides and Proteins; D046912:Multiprotein Complexes; D021122:Protein Subunits; D011506:Proteins; C558596:WDR35 protein, human; D015638:Cytochalasin D
Arl13b; IFT-A; WDR35; actin; cargo transport; centrosome; cilia; ciliary membrane; cilium