Involvement of Ras and Ral in chemotactic migration of skeletal myoblasts

Mol Cell Biol. 2000 Jul;20(13):4658-65. doi: 10.1128/MCB.20.13.4658-4665.2000.

Abstract

In skeletal myoblasts, Ras has been considered to be a strong inhibitor of myogenesis. Here, we demonstrate that Ras is involved also in the chemotactic response of skeletal myoblasts. Expression of a dominant-negative mutant of Ras inhibited chemotaxis of C2C12 myoblasts in response to basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), and insulin-like growth factor 1 (IGF-1), key regulators of limb muscle development and skeletal muscle regeneration. A dominant-negative Ral also decreased chemotactic migration by these growth factors, while inhibitors for phosphatidylinositol 3-kinase and mitogen-activated protein kinase kinase (MEK) showed no effect. Activation of the Ras-Ral pathway by expression of an activated mutant of either Ras, the guanine-nucleotide dissociation stimulator for Ral, or Ral resulted in increased motility of myoblasts. The ability of Ral to stimulate motility was reduced by introduction of a mutation which prevents binding to Ral-binding protein 1 or phospholipase D. These results suggest that the Ras-Ral pathway is essential for the migration of myoblasts. Furthermore, we found that Ras and Ral are activated in C2C12 cells by bFGF, HGF and IGF-1 and that the Ral activation is regulated by the Ras- and the intracellular Ca(2+)-mediated pathways. Taken together, our data indicate that Ras and Ral regulate the chemotactic migration of skeletal muscle progenitors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Butadienes / pharmacology
  • Calcimycin / pharmacology
  • Calcium / metabolism
  • Cell Line
  • Cell Movement / drug effects
  • Cell Movement / genetics
  • Chemotaxis / drug effects
  • Chemotaxis / physiology*
  • Chromones / pharmacology
  • Egtazic Acid / analogs & derivatives
  • Egtazic Acid / pharmacology
  • Enzyme Inhibitors / pharmacology
  • Extracellular Matrix Proteins / chemistry
  • Extracellular Matrix Proteins / metabolism
  • Genes, ras
  • Growth Substances / pharmacology
  • Insulin-Like Growth Factor I / metabolism
  • Insulin-Like Growth Factor I / pharmacology
  • Isopropyl Thiogalactoside / pharmacology
  • MAP Kinase Kinase Kinase 1*
  • Mice
  • Morpholines / pharmacology
  • Muscle, Skeletal / cytology*
  • Muscle, Skeletal / metabolism*
  • Nitriles / pharmacology
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Serine-Threonine Kinases / antagonists & inhibitors
  • Protein Serine-Threonine Kinases / metabolism
  • Signal Transduction
  • ral GTP-Binding Proteins / genetics
  • ral GTP-Binding Proteins / metabolism*
  • ras Proteins / genetics
  • ras Proteins / metabolism*

Substances

  • Butadienes
  • Chromones
  • Enzyme Inhibitors
  • Extracellular Matrix Proteins
  • Growth Substances
  • Morpholines
  • Nitriles
  • Phosphoinositide-3 Kinase Inhibitors
  • U 0126
  • 1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester
  • 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one
  • Isopropyl Thiogalactoside
  • Calcimycin
  • Egtazic Acid
  • Insulin-Like Growth Factor I
  • Protein Serine-Threonine Kinases
  • MAP Kinase Kinase Kinase 1
  • Map3k1 protein, mouse
  • ral GTP-Binding Proteins
  • ras Proteins
  • Calcium