title: Dynein and kinesin share an overlapping microtubule-binding site.
abstract: Dyneins and kinesins move in opposite directions on microtubules. The question of how the same-track microtubules are able to support movement in two directions remains unanswered due to the absence of details on dynein-microtubule interactions. To address this issue, we studied dynein-microtubule interactions using the tip of the microtubule-binding stalk, the dynein stalk head (DSH), which directly interacts with microtubules upon receiving conformational change from the ATPase domain. Biochemical and cryo-electron microscopic studies revealed that DSH bound to tubulin dimers with a periodicity of 80 A, corresponding to the step size of dyneins. The DSH molecule was observed as a globular corn grain-like shape that bound the same region as kinesin. Biochemical crosslinking experiments and image analyses of the DSH-kinesin head-microtubule complex revealed competition between DSH and the kinesin head for microtubule binding. Our results demonstrate that dynein and kinesin share an overlapping microtubule-binding site, and imply that binding at this site has an essential role for these motor proteins.
authors.affiliation: Department of Cell Biology, Southwestern Medical Center, University of Texas, Dallas, TX 75390-9039, USA.
authors.forename: Naoko
authors.initials: N
authors.lastname: Mizuno
authors.forename: Shiori
authors.initials: S
authors.lastname: Toba
authors.forename: Masaki
authors.initials: M
authors.lastname: Edamatsu
authors.forename: Junko
authors.initials: J
authors.lastname: Watai-Nishii
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Hirokawa
authors.forename: Yoko Y
authors.initials: YY
authors.lastname: Toyoshima
authors.forename: Masahide
authors.initials: M
authors.lastname: Kikkawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D002417:Cattle; D003432:Cross-Linking Reagents / Q000494:pharmacology; D020285:Cryoelectron Microscopy; D019281:Dimerization; D004330:Drosophila; D029721:Drosophila Proteins / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D004398:Dyneins / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D004591:Electrophoresis, Polyacrylamide Gel; D021621:Imaging, Three-Dimensional; D016547:Kinesins / Q000378:metabolism* / Q000648:ultrastructure; D007700:Kinetics; D008870:Microtubules / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D008958:Models, Molecular; D008961:Models, Structural; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013552:Swine; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D003432:Cross-Linking Reagents; D029721:Drosophila Proteins; D011994:Recombinant Proteins; D014404:Tubulin; D004398:Dyneins; D016547:Kinesins