Different microtubule motors move early and late endocytic compartments

Traffic. 2008 Apr;9(4):492-509. doi: 10.1111/j.1600-0854.2008.00704.x. Epub 2008 Jan 10.

Abstract

Important progress has been made during the past decade in the identification of molecular motors required in the distribution of early and late endosomes and the proper trafficking along the endocytic pathway. There is little direct evidence, however, that these motors drive movement of the endosomes. To evaluate the contributions of kinesin-1, dynein and kinesin-2 to the movement of early and late endosomes along microtubules, we made use of a cytosol-free motility assay using magnetically isolated early and late endosomes as well as biochemical analyses and live-cell imaging. By making use of specific antibodies, we confirmed that kinesin-1 and dynein move early endosomes and we found that kinesin-2 moves both early and late endosomes in the cell-free assay. Unexpectedly, dynein did not move late endosomes in the cell-free assay. We provide evidence from disruption of dynein function and latrunculin A treatment, suggesting that dynein regulates late endosome movement indirectly, possibly through a mechanism involving the actin cytoskeleton. These data provide new insights into the complex regulation of endosomes' motility and suggest that dynein is not the major motor required to move late endosomes toward the minus end of microtubules.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dyneins / metabolism
  • Endocytosis / physiology*
  • Endosomes / metabolism*
  • Endosomes / ultrastructure
  • Golgi Apparatus / genetics
  • Golgi Apparatus / metabolism
  • HeLa Cells
  • Humans
  • Kinesin / metabolism
  • Lysosome-Associated Membrane Glycoproteins / genetics
  • Lysosome-Associated Membrane Glycoproteins / metabolism
  • Lysosomes / metabolism
  • Magnetics
  • Microtubule Proteins / genetics
  • Microtubule Proteins / metabolism*
  • Microtubules / metabolism*
  • Molecular Motor Proteins / genetics
  • Molecular Motor Proteins / metabolism*
  • Nanoparticles
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / metabolism
  • rab GTP-Binding Proteins / genetics
  • rab GTP-Binding Proteins / metabolism
  • rab5 GTP-Binding Proteins / genetics
  • rab5 GTP-Binding Proteins / metabolism

Substances

  • LAMP1 protein, human
  • Lysosome-Associated Membrane Glycoproteins
  • Microtubule Proteins
  • Molecular Motor Proteins
  • Protein Isoforms
  • RNA, Small Interfering
  • Vesicular Transport Proteins
  • early endosome antigen 1
  • rab7 protein
  • Dyneins
  • Kinesin
  • rab GTP-Binding Proteins
  • rab5 GTP-Binding Proteins