title: Kinesin passing permanent blockages along its protofilament track.
abstract: During movement along microtubules, kinesin usually follows a track parallel to the axis of a single protofilament. The question arises what happens when kinesin encounters blockages. The present study describes the movement of kinesin labeled by 20-nm gold beads along immobilized microtubules artificially decorated with blocking proteins. To guarantee that exactly the kinesin-binding sites were occupied and to avoid steric effects exerted by large molecules, the KIF5A motor domain was used for blocking. After binding, the blockages were irreversibly cross-linked to the microtubules to make them non-exchangeable. Under such conditions, kinesin movement became a non-continuous one. As a rule, after temporary stopping the kinesin moved on without being released from the microtubule. The results strongly suggest a bypassing mechanism based on the postulation that kinesin changes to and continues movement along a neighbouring protofilament. Bypassing is considered to ensure an efficient long-distance transport of cellular cargoes by kinesins.
authors.affiliation: Leibniz Institute for Age Research - Fritz Lipmann Institute (FLI), Beutenbergstrasse 11, 07745 Jena, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Dreblow
authors.forename: Nikolina
authors.initials: N
authors.lastname: Kalchishkova
authors.forename: Konrad J
authors.initials: KJ
authors.lastname: Böhm
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000818:Animals; D006801:Humans; D016547:Kinesins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D021381:Protein Transport; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: C470243:KIF11 protein, human; C500506:KIF5A protein, human; D011994:Recombinant Proteins; D016547:Kinesins