Program in Molecular Medicine and Biomedical Imaging Group; Department of Physiology
Medical Subject Headings
Animals; Carrier Proteins; Cell Cycle; Cells, Cultured; Centrosome; Cilia; Epithelial Cells; Golgi Apparatus; Humans; Mice; Protein Binding; Protein Transport; Rats; TRPP Cation Channels
Life Sciences | Medicine and Health Sciences
Eukaryotic cilia are assembled via intraflagellar transport (IFT) in which large protein particles are motored along ciliary microtubules. The IFT particles are composed of at least 17 polypeptides that are thought to contain binding sites for various cargos that need to be transported from their site of synthesis in the cell body to the site of assembly in the cilium. We show here that the IFT20 subunit of the particle is localized to the Golgi complex in addition to the basal body and cilia where all previous IFT particle proteins had been found. In living cells, fluorescently tagged IFT20 is highly dynamic and moves between the Golgi complex and the cilium as well as along ciliary microtubules. Strong knock down of IFT20 in mammalian cells blocks ciliary assembly but does not affect Golgi structure. Moderate knockdown does not block cilia assembly but reduces the amount of polycystin-2 that is localized to the cilia. This work suggests that IFT20 functions in the delivery of ciliary membrane proteins from the Golgi complex to the cilium.
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Citation: Mol Biol Cell. 2006 Sep;17(9):3781-92. Epub 2006 Jun 14. Link to article on publisher's site. Copyrighted owned by American Society for Cell Biology.
Intraflagellar Transport, Cilia, Flagella