Inhibition of lysophosphatidate- and thrombin-induced neurite retraction and neuronal cell rounding by ADP ribosylation of the small GTP-binding protein Rho

J Cell Biol. 1994 Aug;126(3):801-10. doi: 10.1083/jcb.126.3.801.


Addition of the bioactive phospholipid lysophosphatidic acid (LPA) or a thrombin receptor-activating peptide (TRP) to serum-starved N1E-115 or NG108-15 neuronal cells causes rapid growth cone collapse, neurite retraction, and transient rounding of the cell body. These shape changes appear to be driven by receptor-mediated contraction of the cortical actomyosin system independent of classic second messengers. Treatment of the cells with Clostridium botulinum C3 exoenzyme, which ADP-ribosylates and thereby inactivates the Rho small GTP-binding protein, inhibits LPA- and TRP-induced force generation and subsequent shape changes. C3 also inhibits LPA-induced neurite retraction in PC12 cells. Biochemical analysis reveals that the ADP-ribosylated substrate is RhoA. Prolonged C3 treatment of cells maintained in 10% serum induces the phenotype of serum-starved cells, with initial cell flattening being followed by neurite outgrowth; such C3-differentiated cells fail to retract their neurites in response to agonists. We conclude that RhoA is essential for receptor-mediated force generation and ensuing neurite retraction in N1E-115 and PC12 cells, and that inactivation of RhoA by ADP-ribosylation abolishes actomyosin contractility and promotes neurite outgrowth.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADP Ribose Transferases / pharmacology
  • Actins / drug effects
  • Actins / metabolism
  • Adenosine Diphosphate / metabolism
  • Amino Acid Sequence
  • Animals
  • Botulinum Toxins*
  • Cell Line
  • Cytoskeleton / drug effects
  • GTP-Binding Proteins / metabolism
  • GTP-Binding Proteins / physiology*
  • Lysophospholipids / antagonists & inhibitors
  • Lysophospholipids / pharmacology*
  • Mice
  • Molecular Sequence Data
  • Muscle Contraction / drug effects
  • Neurites* / metabolism
  • Neurites* / ultrastructure
  • Neurons / cytology*
  • Neurons / metabolism
  • Neurons / ultrastructure
  • Proto-Oncogene Proteins p21(ras) / metabolism
  • Ribose / metabolism
  • Thrombin / antagonists & inhibitors
  • Thrombin / physiology*
  • rhoA GTP-Binding Protein


  • Actins
  • Lysophospholipids
  • Adenosine Diphosphate
  • Ribose
  • ADP Ribose Transferases
  • exoenzyme C3, Clostridium botulinum
  • Thrombin
  • Botulinum Toxins
  • GTP-Binding Proteins
  • Proto-Oncogene Proteins p21(ras)
  • rhoA GTP-Binding Protein