title: Dynactin enhances the processivity of kinesin-2.
abstract: Kinesin-2 is a major microtubule-based motor in most cell types. Its in vitro motile properties have been analyzed extensively and been found to differ considerably from kinesin-1. Although recombinant kinesin-2 heterodimers exhibit processive movement, the processivity of the native kinesin-2 holoenzyme has never been evaluated. Kinesin-2 can interact with dynactin, a 'processivity factor' for cytoplasmic dynein, which may alter its motile properties. In this study, we analyze the in vitro motility of single native kinesin-2 molecules and determine the effects of dynactin on motor processivity. We find that individual native kinesin-2 molecules travel processively. Dynactin has no effect on velocity but significantly increases the run length of kinesin-2 movements. These results show that the interaction with dynactin has important functional consequences on the activity of the kinesin-2 motor.
authors.affiliation: Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Berezuk
authors.forename: Trina A
authors.initials: TA
authors.lastname: Schroer
mesh_terms: D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000196:embryology / Q000378:metabolism; D002642:Chick Embryo; D000072159:Dynactin Complex; D004398:Dyneins / Q000378:metabolism*; D016547:Kinesins / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D011485:Protein Binding; D021381:Protein Transport
chemical_list: D000072159:Dynactin Complex; D008869:Microtubule-Associated Proteins; D004398:Dyneins; D016547:Kinesins