title: Chemically inducible diffusion trap at cilia reveals molecular sieve-like barrier.
abstract: Primary cilia function as specialized compartments for signal transduction. The stereotyped structure and signaling function of cilia inextricably depend on the selective segregation of molecules in cilia. However, the fundamental principles governing the access of soluble proteins to primary cilia remain unresolved. We developed a methodology termed 'chemically inducible diffusion trap at cilia' to visualize the diffusion process of a series of fluorescent proteins ranging in size from 3.2 nm to 7.9 nm into primary cilia. We found that the interior of the cilium was accessible to proteins as large as 7.9 nm. The kinetics of ciliary accumulation of this panel of proteins was exponentially limited by their Stokes radii. Quantitative modeling suggests that the diffusion barrier operates as a molecular sieve at the base of cilia. Our study presents a set of powerful, generally applicable tools for the quantitative monitoring of ciliary protein diffusion under both physiological and pathological conditions.
authors.affiliation: Department of Cell Biology, Center for Cell Dynamics, School of Medicine, Johns Hopkins University.
authors.forename: Yu-Chun
authors.initials: YC
authors.lastname: Lin
authors.affiliation: Departments of Medicine and Biochemistry, School of Medicine, Stanford University.
authors.forename: Pawel
authors.initials: P
authors.lastname: Niewiadomski
authors.affiliation: Department of Cell Biology, Center for Cell Dynamics, School of Medicine, Johns Hopkins University.|Department of Biomedical Engineering, Johns Hopkins University.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Lin
authors.affiliation: Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University.
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakamura
authors.affiliation: Department of Cell Biology, Center for Cell Dynamics, School of Medicine, Johns Hopkins University.
authors.forename: Siew Cheng
authors.initials: SC
authors.lastname: Phua
authors.affiliation: Department of Cell Biology, Center for Cell Dynamics, School of Medicine, Johns Hopkins University.
authors.forename: John
authors.initials: J
authors.lastname: Jiao
authors.affiliation: Department of Biomedical Engineering, Johns Hopkins University.
authors.forename: Andre
authors.initials: A
authors.lastname: Levchenko
authors.affiliation: Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Inoue
authors.affiliation: Departments of Medicine and Biochemistry, School of Medicine, Stanford University.
authors.forename: Rajat
authors.initials: R
authors.lastname: Rohatgi
authors.affiliation: Department of Cell Biology, Center for Cell Dynamics, School of Medicine, Johns Hopkins University.|PRESTO Investigator, JST, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Takanari
authors.initials: T
authors.lastname: Inoue
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002850:Chromatography, Gel; D002923:Cilia / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D004058:Diffusion; D019281:Dimerization; D005456:Fluorescent Dyes; D049452:Green Fluorescent Proteins / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D008164:Luminescent Proteins / Q000378:metabolism; D051379:Mice; D008870:Microtubules / Q000378:metabolism; D008956:Models, Chemical; D041681:NIH 3T3 Cells; D013050:Spectrometry, Fluorescence
chemical_list: D001426:Bacterial Proteins; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins