Stimulation of actin stress fibre formation mediated by activation of phospholipase D

Curr Biol. 1996 May 1;6(5):588-97. doi: 10.1016/s0960-9822(02)00545-6.


Background: Agonist-stimulated phospholipase D (PLD) catalyzes the hydrolysis of phosphatidylcholine, generating the putative messenger phosphatidate (PA). Proposed functions for PA, and hence for PLD, include kinase activation, the regulation of small molecular weight GTP-binding proteins, actin polymerization and secretion. It has not been possible to define a physiological function for PLD activation as it is generally stimulated together with other signalling pathways, such as those involving phospholipases A2 and C, phosphatidylinositide (PI) 3-kinase and the p21(ras)/mitogen-activated protein (MAP) kinase cascade.

Results: We report that, in porcine aortic endothelial (PAE) cells, lysophosphatidic acid (LPA) stimulated PLD activity and rapidly generated PA in the absence of other phospholipase, PI 3-kinase or MAP kinase activities. PLD activation was controlled by a tyrosine kinase-regulated pathway. LPA also stimulated actin stress fibre formation, but was inhibited by butan-1-ol; the alcohol also reduced the accumulation of PA. The addition of PA to cells did not stimulate PLD activity, but did cause stress fibre formation in a manner that was insensitive to butan-1-ol. Stimulation of stress fibre formation by LPA and PA was sensitive to genistein, and was inhibited by micro-injection of the Rho-inhibiting C3 exotoxin into PAE cells.

Conclusions: This study provides the first clear demonstration of a physiological role for PLD activity. In PAE cells, the stimulation of actin stress fibre formation was a consequence of PA generation and, therefore, PLD activation. The results suggest that PA generation is upstream of Rho activation, and imply a role for PLD in the regulation of Rho-mediated pathways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism*
  • Animals
  • Cells, Cultured
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / enzymology
  • Enzyme Activation
  • GTP-Binding Proteins / metabolism
  • Lysophospholipids / pharmacology
  • Phospholipase D / metabolism*
  • Signal Transduction
  • Swine


  • Actins
  • Lysophospholipids
  • Phospholipase D
  • GTP-Binding Proteins