title: The ciliary rootlet maintains long-term stability of sensory cilia.
abstract: The striated ciliary rootlet is a prominent cytoskeleton originating from basal bodies of ciliated cells. Although a familiar structure in cell biology, its function has remained unresolved. In this study, we carried out targeted disruption in mice of the gene for rootletin, a component of the rootlet. In the mutant, ciliated cells are devoid of rootlets. Phototransduction and ciliary beating in sensory and motile cilia initially exhibit no apparent functional deficits. However, photoreceptors degenerate over time, and mutant lungs appear prone to pathological changes consistent with insufficient mucociliary clearance. Further analyses revealed a striking fragility at the ciliary base in photoreceptors lacking rootlets. In vitro assays suggest that the rootlet is among the least dynamic of all cytoskeletons and interacts with actin filaments. Thus, a primary function of the rootlet is to provide structural support for the cilium. Inasmuch as photoreceptors elaborate an exceptionally enlarged sensory cilium, they are especially dependent on the rootlet for structural integrity and long-term survival.
authors.affiliation: The Berman-Gund Laboratory for the Study of Retinal Degenerations, Howe Laboratory, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Jiangang
authors.initials: J
authors.lastname: Gao
authors.forename: Michael
authors.initials: M
authors.lastname: Adamian
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Wen
authors.forename: Basil
authors.initials: B
authors.lastname: Pawlyk
authors.forename: Luo
authors.initials: L
authors.lastname: Zhang
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Sanderson
authors.forename: Jian
authors.initials: J
authors.lastname: Zuo
authors.forename: Clint L
authors.initials: CL
authors.lastname: Makino
authors.forename: Tiansen
authors.initials: T
authors.lastname: Li
mesh_terms: D000818:Animals; D002502:Centrioles / Q000502:physiology; D002923:Cilia / Q000502:physiology*; D003598:Cytoskeletal Proteins / Q000172:deficiency / Q000235:genetics; D003599:Cytoskeleton / Q000502:physiology*; D007700:Kinetics; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology; D051379:Mice; D009154:Mutation / Q000235:genetics; D015388:Organelles / Q000502:physiology; D020419:Photoreceptor Cells, Vertebrate / Q000166:cytology / Q000502:physiology; D012162:Retinal Degeneration; D013997:Time Factors
chemical_list: C469436:Crocc protein, mouse; D003598:Cytoskeletal Proteins