Protein kinase C induces actin reorganization via a Src- and Rho-dependent pathway

J Biol Chem. 2002 Jun 7;277(23):20903-10. doi: 10.1074/jbc.M200946200. Epub 2002 Mar 29.


We have investigated the mechanism of PKC-induced actin reorganization in A7r5 vascular smooth muscle cells. PKC activation by 12-O-tetradecanoylphorbol-13-acetate induces the disassembly of actin stress fibers concomitant with the appearance of membrane ruffles. PKC also induces rapid tyrosine phosphorylation in these cells. As we could show, utilizing the Src-specific inhibitor PP2 and a kinase-deficient c-Src mutant, actin reorganization is dependent on PKC-induced Src activation. Subsequently, the activity of the small G-protein RhoA is decreased, whereas Rac and Cdc42 activities remain unchanged. Disassembly of actin stress fibers could also be observed using the Rho kinase-specific inhibitor Y-27632, indicating that the decrease in RhoA activity on its own is responsible for actin reorganization. In addition, we show that tyrosine phosphorylation of p190RhoGAP is increased upon 12-O-tetradecanoylphorbol-13-acetate stimulation, directly linking Src activation to a decrease in RhoA activity. Our data provide substantial evidence for a model elucidating the molecular mechanisms of PKC-induced actin rearrangements.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism*
  • Cell Line
  • Enzyme Activation
  • Phosphorylation
  • Protein Kinase C / metabolism*
  • Proto-Oncogene Proteins pp60(c-src) / metabolism*
  • Tetradecanoylphorbol Acetate / pharmacology
  • Tyrosine / metabolism
  • rho GTP-Binding Proteins / antagonists & inhibitors
  • rho GTP-Binding Proteins / metabolism*


  • Actins
  • Tyrosine
  • Proto-Oncogene Proteins pp60(c-src)
  • Protein Kinase C
  • rho GTP-Binding Proteins
  • Tetradecanoylphorbol Acetate