title: Distinct Interaction Modes of the Kinesin-13 Motor Domain with the Microtubule.
abstract: Kinesins-13s are members of the kinesin superfamily of motor proteins that depolymerize microtubules (MTs) and have no motile activity. Instead of generating unidirectional movement over the MT lattice, like most other kinesins, kinesins-13s undergo one-dimensional diffusion (ODD) and induce depolymerization at the MT ends. To understand the mechanism of ODD and the origin of the distinct kinesin-13 functionality, we used ensemble and single-molecule fluorescence polarization microscopy to analyze the behavior and conformation of Drosophila melanogaster kinesin-13 KLP10A protein constructs bound to the MT lattice. We found that KLP10A interacts with the MT in two coexisting modes: one in which the motor domain binds with a specific orientation to the MT lattice and another where the motor domain is very mobile and able to undergo ODD. By comparing the orientation and dynamic behavior of mutated and deletion constructs we conclude that 1) the Kinesin-13 class specific neck domain and loop-2 help orienting the motor domain relative to the MT. 2) During ODD the KLP10A motor-domain changes orientation rapidly (rocks or tumbles). 3) The motor domain alone is capable of undergoing ODD. 4) A second tubulin binding site in the KLP10A motor domain is not critical for ODD. 5) The neck domain is not the element preventing KLP10A from binding to the MT lattice like motile kinesins.
authors.affiliation: Departments of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Chandrima
authors.initials: C
authors.lastname: Chatterjee
authors.affiliation: Departments of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Matthieu P M H
authors.initials: MPMH
authors.lastname: Benoit
authors.affiliation: Departments of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Vania
authors.initials: V
authors.lastname: DePaoli
authors.affiliation: Departments of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Juan D
authors.initials: JD
authors.lastname: Diaz-Valencia
authors.affiliation: Departments of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Ana B
authors.initials: AB
authors.lastname: Asenjo
authors.affiliation: Departments of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Gerfen
authors.affiliation: Departments of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: David J
authors.initials: DJ
authors.lastname: Sharp
authors.affiliation: Departments of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York. Electronic address: hernando.sosa@einstein.yu.edu.
authors.forename: Hernando
authors.initials: H
authors.lastname: Sosa
mesh_terms: D000818:Animals; D029721:Drosophila Proteins / Q000737:chemistry / Q000378:metabolism*; D004331:Drosophila melanogaster; D016547:Kinesins / Q000737:chemistry / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008958:Models, Molecular; D011485:Protein Binding; D000072417:Protein Domains; D012399:Rotation
chemical_list: D029721:Drosophila Proteins; C481339:KLP10A protein, Drosophila; D016547:Kinesins