Protein kinase D1 regulates cofilin-mediated F-actin reorganization and cell motility through slingshot

Nat Cell Biol. 2009 May;11(5):545-56. doi: 10.1038/ncb1861. Epub 2009 Mar 29.


Dynamic actin remodelling processes at the leading edge of migrating tumour cells are concerted events controlled by a fine-tuned temporal and spatial interplay of kinases and phosphatases. Actin severing is regulated by actin depolymerizing factor (ADF)/cofilin, which regulates stimulus-induced lamellipodia protrusion and directed cell motility. Cofilin is activated by dephosphorylation through phosphatases of the slingshot (SSH) family. SSH activity is strongly increased by its binding to filamentous actin (F-actin); however, other upstream regulators remain unknown. Here we show that in response to RhoA activation, protein kinase D1 (PKD1) phosphorylates the SSH enzyme SSH1L at a serine residue located in its actin-binding motif. This generates a 14-3-3-binding motif and blocks the localization of SSH1L to F-actin-rich structures in the lamellipodium by sequestering it in the cytoplasm. Consequently, expression of constitutively active PKD1 in invasive tumour cells enhanced the phosphorylation of cofilin and effectively blocked the formation of free actin-filament barbed ends and directed cell migration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 14-3-3 Proteins / metabolism
  • Actins / metabolism*
  • Animals
  • Binding Sites / physiology
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Cell Movement / physiology*
  • Chemotaxis / drug effects
  • Chemotaxis / physiology
  • Cofilin 1 / metabolism*
  • Culture Media, Conditioned / pharmacology
  • Cytoplasm / metabolism
  • HeLa Cells
  • Humans
  • Microfilament Proteins / metabolism
  • Models, Biological
  • Phosphoprotein Phosphatases / metabolism*
  • Phosphoric Monoester Hydrolases
  • Phosphorylation
  • Protein Binding / physiology
  • Protein Kinase C / physiology*
  • Protein Kinases / physiology
  • Pseudopodia / metabolism
  • Rats
  • Signal Transduction / physiology*
  • rhoA GTP-Binding Protein / antagonists & inhibitors
  • rhoA GTP-Binding Protein / metabolism


  • 14-3-3 Proteins
  • Actins
  • Cofilin 1
  • Culture Media, Conditioned
  • Microfilament Proteins
  • Protein Kinases
  • protein kinase D
  • Protein Kinase C
  • SSH1 protein, rat
  • Phosphoprotein Phosphatases
  • SSH1 protein, human
  • Phosphoric Monoester Hydrolases
  • rhoA GTP-Binding Protein