Akt-mediated phosphorylation of the G protein-coupled receptor EDG-1 is required for endothelial cell chemotaxis

Mol Cell. 2001 Sep;8(3):693-704. doi: 10.1016/s1097-2765(01)00324-0.

Abstract

The role of the protein kinase Akt in cell migration is incompletely understood. Here we show that sphingosine-1-phosphate (S1P)-induced endothelial cell migration requires the Akt-mediated phosphorylation of the G protein-coupled receptor (GPCR) EDG-1. Activated Akt binds to EDG-1 and phosphorylates the third intracellular loop at the T(236) residue. Transactivation of EDG-1 by Akt is not required for G(i)-dependent signaling but is indispensable for Rac activation, cortical actin assembly, and chemotaxis. Indeed, T236AEDG-1 mutant sequestered Akt and acted as a dominant-negative GPCR to inhibit S1P-induced Rac activation, chemotaxis, and angiogenesis. Transactivation of GPCRs by Akt may constitute a specificity switch to integrate rapid G protein-dependent signals into long-term cellular phenomena such as cell migration.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actins / metabolism
  • Animals
  • Cell Line
  • Chemotaxis / physiology*
  • Endothelium, Vascular / cytology*
  • Endothelium, Vascular / drug effects
  • Enzyme Activation / physiology
  • Humans
  • Immediate-Early Proteins / metabolism*
  • Lysophospholipids*
  • Models, Biological
  • Neovascularization, Physiologic / physiology
  • Phosphorylation
  • Protein Binding
  • Protein Structure, Tertiary
  • Protein-Serine-Threonine Kinases*
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-akt
  • Receptors, Cell Surface
  • Receptors, G-Protein-Coupled*
  • Receptors, Lysophospholipid
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Signal Transduction / physiology*
  • Sphingosine / analogs & derivatives
  • Sphingosine / pharmacology
  • rac GTP-Binding Proteins / genetics
  • rac GTP-Binding Proteins / metabolism

Substances

  • Actins
  • Immediate-Early Proteins
  • Lysophospholipids
  • Proto-Oncogene Proteins
  • Receptors, Cell Surface
  • Receptors, G-Protein-Coupled
  • Receptors, Lysophospholipid
  • Recombinant Fusion Proteins
  • sphingosine 1-phosphate
  • AKT1 protein, human
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • rac GTP-Binding Proteins
  • Sphingosine