Actin-dependent organelle movement in squid axoplasm

Nature. 1992 Apr 23;356(6371):722-5. doi: 10.1038/356722a0.


Studies of organelle movement in axoplasm extruded from the squid giant axon have led to the basic discoveries of microtubule-dependent organelle motility and the characterization of the microtubule-based motor proteins kinesin and cytoplasmic dynein. Rapid organelle movement in higher animal cells, especially in neurons, is considered to be microtubule-based. The role of actin filaments, which are also abundant in axonal cytoplasm, has remained unclear. The inhibition of organelle movement in axoplasm by actin-binding proteins such as DNase I, gelsolin and synapsin I has been attributed to their ability to disorganize the microtubule domains where most of the actin-filaments are located. Here we provide evidence of a new type of organelle movement in squid axoplasm which is independent of both microtubules and microtubule-based motors. This movement is ATP-dependent, unidirectional, actin-dependent, and probably generated by a myosin-like motor. These results demonstrate that an actomyosin-like mechanism can be directly involved in the generation of rapid organelle transport in nerve cells.

Publication types

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

MeSH terms

  • Actin Cytoskeleton / drug effects
  • Actin Cytoskeleton / physiology
  • Actins / drug effects
  • Actins / physiology*
  • Adenylyl Imidodiphosphate / pharmacology
  • Animals
  • Apyrase / pharmacology
  • Axons / physiology*
  • Cytochalasin B / pharmacology
  • Decapodiformes
  • Edetic Acid / pharmacology
  • Egtazic Acid / pharmacology
  • Hexokinase / pharmacology
  • Movement / drug effects
  • Movement / physiology*
  • Nocodazole / pharmacology
  • Organelles / physiology*
  • Vanadates / pharmacology


  • Actins
  • Adenylyl Imidodiphosphate
  • Cytochalasin B
  • Vanadates
  • Egtazic Acid
  • Edetic Acid
  • Hexokinase
  • Apyrase
  • Nocodazole