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Cytoskeletal alterations in Dictyostelium induced by expression of human cdc42

E Lee1, D A Knecht

  • 1Department of Molecular and Cell Biology, University of Connecticut, Storrs 06260, USA.

European Journal of Cell Biology
|August 4, 2001
PubMed

Insights

Human cdc42 expression in Dictyostelium cells induced dynamic actin cytoskeleton changes, including wrinkles and filopods. This suggests a conserved role for small GTPases in regulating cellular structure.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Rho family small G proteins regulate actin filament dynamics.
  • Understanding functional overlap between human and Dictyostelium proteins is crucial.

Purpose of the Study:

  • To evaluate the functional overlap between human and Dictyostelium G proteins.
  • To investigate the effects of constitutively active human cdc42 (V12-cdc42) on Dictyostelium cells.

Main Methods:

  • Conditional expression of V12-cdc42 in Dictyostelium.
  • Morphological analysis of cells.
  • Phalloidin staining to visualize actin structures.
  • Biochemical assays to quantify F-actin and associated proteins.

Main Results:

  • Cells expressing V12-cdc42 adopted a unique flattened morphology with dynamic wrinkles.
  • Wrinkles contained dense actin structures, and filopods projected vertically.
  • Increased F-actin association with the cytoskeleton was observed.
  • Increased association of actin-binding proteins (34-kDa bundler, ABP-120, alpha-actinin) with the cytoskeleton.

Conclusions:

  • Human cdc42 influences the Dictyostelium actin cytoskeleton.
  • Results are consistent with a conserved role for small GTPases in cytoskeleton regulation.
  • Functional overlap exists between human and Dictyostelium G proteins in controlling actin dynamics.

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