Dynactin enhances the processivity of kinesin-2

Traffic. 2007 Feb;8(2):124-9. doi: 10.1111/j.1600-0854.2006.00517.x. Epub 2006 Dec 20.

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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Binding Sites
  • Brain / embryology
  • Brain / metabolism
  • Chick Embryo
  • Dynactin Complex
  • Dyneins / metabolism*
  • Kinesins / metabolism*
  • Microtubule-Associated Proteins / metabolism*
  • Microtubules / metabolism*
  • Protein Binding
  • Protein Transport

Substances

  • Dynactin Complex
  • Microtubule-Associated Proteins
  • Dyneins
  • Kinesins