Cytoplasmic dynein-associated structures move bidirectionally in vivo

Shuo Ma*, Rex L. Chisholm

*Corresponding author for this work

Research output: Contribution to journalArticle

86 Scopus citations

Abstract

Intracellular organelle transport is driven by motors that act upon microtubules or microfilaments. The microtubule-based motors, cytoplasmic dynein and kinesin, are believed to be responsible for retrograde and anterograde transport of intracellular cargo along microtubules. Many vesicles display bidirectional movement; however, the mechanism regulating directionality is unresolved. Directional movement might be accomplished by alternative binding of different motility factors to the cargo. Alternatively, different motors could associate with the same cargo and have their motor activity regulated. Although several studies have focused on the behavior of specific types of cargoes, little is known about the traffic of the motors themselves and how it correlates with cargo movement. To address this question, we studied cytoplasmic dynein dynamics in living Dictyostelium cells expressing dynein intermediate chain-green fluorescent protein (IC-GFP) fusion in an IC-null background. Dynein-associated structures display fast linear movement along microtubules in both minus-end and plus-end directions, with velocities similar to that of dynein and kinesin-like motors. In addition, dynein puncta often rapidly reverse their direction. Dynein stably associates with cargo moving in both directions as well as with those that rapidly reverse their direction of movement, suggesting that directional movement is not regulated by altering motor-cargo association but rather by switching activity of motors associated with the cargo. These observations suggest that both plus- and minus-end-directed motors associate with a given cargo and that coordinated regulation of motor activities controls vesicle directionality.

Original languageEnglish (US)
Pages (from-to)1453-1460
Number of pages8
JournalJournal of cell science
Volume115
Issue number7
StatePublished - Apr 1 2002

Keywords

  • Cytoplasmic dynein
  • Green fluorescent protein
  • Live cell imaging
  • Molecular motor regulation
  • Organelle
  • Transport

ASJC Scopus subject areas

  • Cell Biology

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