title: Getting tubulin to the tip of the cilium: one IFT train, many different tubulin cargo-binding sites?
abstract: Cilia are microtubule-based hair-like structures that project from the surfaces of eukaryotic cells. Cilium formation relies on intraflagellar transport (IFT) to move ciliary proteins such as tubulin from the site of synthesis in the cell body to the site of function in the cilium. A large protein complex (the IFT complex) is believed to mediate interactions between cargoes and the molecular motors that walk along axonemal microtubules between the ciliary base and tip. A recent study using purified IFT complexes has identified a tubulin-binding module in the two core IFT proteins IFT74 and IFT81 that likely serves to bind and transport tubulin within cilia. Here, we calculate the amount of tubulin required to support the observed cilium assembly kinetics and explore the possibility of multiple tubulin binding sites within the IFT complex.
authors.affiliation: Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Martinsried, Germany.
authors.forename: Sagar
authors.initials: S
authors.lastname: Bhogaraju
authors.forename: Kristina
authors.initials: K
authors.lastname: Weber
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Engel
authors.forename: Karl-Ferdinand
authors.initials: KF
authors.lastname: Lechtreck
authors.forename: Esben
authors.initials: E
authors.lastname: Lorentzen
mesh_terms: D000818:Animals; D001665:Binding Sites; D001692:Biological Transport; D002923:Cilia / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D006801:Humans; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism*
chemical_list: D003598:Cytoskeletal Proteins; D014404:Tubulin
keywords: cilia; ciliogenesis; flagella; intraflagellar transport (IFT); tubulin