title: Cooperative binding of the outer arm-docking complex underlies the regular arrangement of outer arm dynein in the axoneme.
abstract: Outer arm dynein (OAD) in cilia and flagella is bound to the outer doublet microtubules every 24 nm. Periodic binding of OADs at specific sites is important for efficient cilia/flagella beating; however, the molecular mechanism that specifies OAD arrangement remains elusive. Studies using the green alga Chlamydomonas reinhardtii have shown that the OAD-docking complex (ODA-DC), a heterotrimeric complex present at the OAD base, functions as the OAD docking site on the doublet. We find that the ODA-DC has an ellipsoidal shape ∼24 nm in length. In mutant axonemes that lack OAD but retain the ODA-DC, ODA-DC molecules are aligned in an end-to-end manner along the outer doublets. When flagella of a mutant lacking ODA-DCs are supplied with ODA-DCs upon gamete fusion, ODA-DC molecules first bind to the mutant axonemes in the proximal region, and the occupied region gradually extends toward the tip, followed by binding of OADs. This and other results indicate that a cooperative association of the ODA-DC underlies its function as the OAD-docking site and is the determinant of the 24-nm periodicity.
authors: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan;
authors: Mikito
authors: M
authors: Owa
authors: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan;
authors: Akane
authors: A
authors: Furuta
authors: EcoTopia Science Institute, Nagoya University, Chikusa, Nagoya 464-8602, Japan;
authors: Jiro
authors: J
authors: Usukura
authors: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8510, Japan;
authors: Fumio
authors: F
authors: Arisaka
authors: Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030;
authors: Stephen M
authors: SM
authors: King
authors: Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655;
authors: George B
authors: GB
authors: Witman
authors: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan;Department of Life Sciences, Faculty of Science, Gakushuin University, Tokyo 171-8588, Japan; and.
authors: Ritsu
authors: R
authors: Kamiya
authors: Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan wakaba@res.titech.ac.jp.
authors: Ken-ichi
authors: K
authors: Wakabayashi
mesh_terms: D054468:Axoneme / Q000378:metabolism*; D015153:Blotting, Western; D002850:Chromatography, Gel; D004398:Dyneins / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D018274:Electroporation; D005455:Fluorescent Antibody Technique; D046911:Macromolecular Substances / Q000378:metabolism*; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D008870:Microtubules / Q000378:metabolism*; D008954:Models, Biological; D011485:Protein Binding; D012394:Rosaniline Dyes; D014461:Ultracentrifugation
chemical_list: D046911:Macromolecular Substances; D012394:Rosaniline Dyes; D004398:Dyneins; C004692:coomassie Brilliant Blue