Cytochalasin D does not produce net depolymerization of actin filaments in HEp-2 cells

Nature. 1980 Oct 16;287(5783):637-9. doi: 10.1038/287637a0.


The altered morphology, disappearance or 'disruption' of actin filaments (microfilaments) in cells treated with cytochalasin has sometimes been attributed to depolymerization of filamentous actin (F-actin) to its globular subunit (G-actin), but attempts to confirm that mechanism have been inconclusive. Treatment of purified actin filaments with cytochalasin B (CB) decreased their viscosity, consistent with depolymerization, which was not, however, revealed by electron microscopy, although the filaments appeared abnormal. CB also increased the ATP-ase activity of F-actin, suggesting that it had been destabilized, while actin filaments in the acrosomal process were not depolymerized. CB or cytochalasin D (CD) can dissolve actin gels (reviewed in ref. 7, see also refs 8 and 9) without depolymerizing their filaments. The 'disrupted' actin structures in CD-treated cells bound heavy meromysin, indicating that at least some of the cellular actin was filamentous. Using a rapid assay for G- and F-actin in cell extracts, based on the inhibition of DNase I, we have found that neither short-nor long-term exposure of HEp-2 cells to CD produce net depolymerization of actin filaments.

Publication types

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

MeSH terms

  • Actins / metabolism*
  • Cell Line
  • Cytochalasins / pharmacology*
  • Cytoskeleton / drug effects*
  • Deoxyribonucleases / antagonists & inhibitors
  • Dimethyl Sulfoxide / pharmacology
  • Humans
  • Solubility
  • Time Factors


  • Actins
  • Cytochalasins
  • Deoxyribonucleases
  • Dimethyl Sulfoxide