title: Sequential assembly of flagellar radial spokes.
abstract: The unicellular alga Chlamydomonas can assemble two 10 μm flagella in 1 h from proteins synthesized in the cell body. Targeting and transporting these proteins to the flagella are simplified by preassembly of macromolecular complexes in the cell body. Radial spokes are flagellar complexes that are partially assembled in the cell body before entering the flagella. On the axoneme, radial spokes are "T" shaped structures with a head of five proteins and a stalk of 18 proteins that sediment together at 20S. In the cell body, radial spokes are partially assembled; about half of the radial spoke proteins (RSPs) form a 12S complex. In mutants lacking a single RSP, smaller spoke subassemblies were identified. When extracts from two such mutants were mixed in vitro the 12S complex was assembled from several smaller complexes demonstrating that portions of the stepwise assembly of radial spoke assembly can be carried out in vitro to elucidate the order of spoke assembly in the cell body.
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520, USA.
authors.forename: Dennis R
authors.initials: DR
authors.lastname: Diener
authors.forename: Pinfen
authors.initials: P
authors.lastname: Yang
authors.forename: Stefan
authors.initials: S
authors.lastname: Geimer
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Cole
authors.forename: Winfield S
authors.initials: WS
authors.lastname: Sale
authors.forename: Joel L
authors.initials: JL
authors.lastname: Rosenbaum
mesh_terms: D002696:Chlamydomonas / Q000378:metabolism* / Q000648:ultrastructure; D002923:Cilia / Q000378:metabolism / Q000648:ultrastructure; D005407:Flagella / Q000378:metabolism* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D010940:Plant Proteins; D015800:Protozoan Proteins / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D015800:Protozoan Proteins; C060324:radial spoke protein, Chlamydomonas