Dynactin Increases the Processivity of the Cytoplasmic Dynein Motor

Nat Cell Biol. 2000 Jan;2(1):20-4. doi: 10.1038/71338.

Abstract

Cytoplasmic dynein supports long-range intracellular movements of cargo in vivo but does not appear to be a processive motor protein by itself. We show here that the dynein activator, dynactin, binds microtubules and increases the average length of cytoplasmic-dynein-driven movements without affecting the velocity or microtubule-stimulated ATPase kinetics of cytoplasmic dynein. Enhancement of microtubule binding and motility by dynactin are both inhibited by an antibody to dynactin's microtubule-binding domain. These results indicate that dynactin acts as a processivity factor for cytoplasmic-dynein-based motility and provide the first evidence that cytoskeletal motor processivity can be affected by extrinsic factors.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphatases / metabolism
  • Adenosine Triphosphate / metabolism
  • Adenosine Triphosphate / pharmacology
  • Animals
  • Antibodies / pharmacology
  • Binding Sites / physiology
  • Biological Transport / drug effects
  • Biological Transport / physiology
  • Chick Embryo
  • Cytoplasm / enzymology
  • Dynactin Complex
  • Dyneins / immunology
  • Dyneins / metabolism
  • Kinetics
  • Microspheres
  • Microtubule-Associated Proteins / chemistry
  • Microtubule-Associated Proteins / immunology
  • Microtubule-Associated Proteins / metabolism*
  • Microtubules / chemistry
  • Microtubules / metabolism*
  • Molecular Motor Proteins / chemistry
  • Molecular Motor Proteins / immunology
  • Molecular Motor Proteins / metabolism*

Substances

  • Antibodies
  • Dynactin Complex
  • Microtubule-Associated Proteins
  • Molecular Motor Proteins
  • Adenosine Triphosphate
  • Adenosine Triphosphatases
  • Dyneins