title: Cartwheel assembly.
abstract: The cartwheel is a subcentriolar structure consisting of a central hub and nine radially arranged spokes, located at the proximal end of the centriole. It appears at the initial stage of the centriole assembly process as the first ninefold symmetrical structure. The cartwheel was first described more than 50 years ago, but it is only recently that its pivotal role in establishing the ninefold symmetry of the centriole was demonstrated. Significant progress has since been made in understanding its fine structure and assembly mechanism. Most importantly, the central part of the cartwheel, from which the ninefold symmetry originates, is shown to form by self-association of nine dimers of the protein SAS-6. This finding, together with emerging data on other components of the cartwheel, has opened new avenues in centrosome biology.
authors.affiliation: Department of Biological Sciences, University of Tokyo, Tokyo, Japan hirono@bs.s.u-tokyo.ac.jp.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Hirono
mesh_terms: D002453:Cell Cycle / Q000502:physiology*; D002502:Centrioles / Q000502:physiology* / Q000648:ultrastructure*; D020285:Cryoelectron Microscopy; D016253:Microscopy, Immunoelectron; D008870:Microtubules / Q000648:ultrastructure*; D008958:Models, Molecular; D013045:Species Specificity; D008941:Spindle Apparatus / Q000502:physiology*
keywords: Cep135/Bld10p; SAS-5/Ana2/STIL; SAS-6/Bld12p; hub; spoke