Ligand-induced trafficking of the sphingosine-1-phosphate receptor EDG-1

Mol Biol Cell. 1999 Apr;10(4):1179-90. doi: 10.1091/mbc.10.4.1179.

Abstract

The endothelial-derived G-protein-coupled receptor EDG-1 is a high-affinity receptor for the bioactive lipid mediator sphingosine-1-phosphate (SPP). In the present study, we constructed the EDG-1-green fluorescent protein (GFP) chimera to examine the dynamics and subcellular localization of SPP-EDG-1 interaction. SPP binds to EDG-1-GFP and transduces intracellular signals in a manner indistinguishable from that seen with the wild-type receptor. Human embryonic kidney 293 cells stably transfected with the EDG-1-GFP cDNA expressed the receptor primarily on the plasma membrane. Exogenous SPP treatment, in a dose-dependent manner, induced receptor translocation to perinuclear vesicles with a tau1/2 of approximately 15 min. The EDG-1-GFP-containing vesicles are distinct from mitochondria but colocalize in part with endocytic vesicles and lysosomes. Neither the low-affinity agonist lysophosphatidic acid nor other sphingolipids, ceramide, ceramide-1-phosphate, or sphingosylphosphorylcholine, influenced receptor trafficking. Receptor internalization was completely inhibited by truncation of the C terminus. After SPP washout, EDG-1-GFP recycles back to the plasma membrane with a tau1/2 of approximately 30 min. We conclude that the high-affinity ligand SPP specifically induces the reversible trafficking of EDG-1 via the endosomal pathway and that the C-terminal intracellular domain of the receptor is critical for this process.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Cell Line
  • Cell Membrane / physiology
  • Cell Membrane / ultrastructure
  • Green Fluorescent Proteins
  • Humans
  • Immediate-Early Proteins / chemistry
  • Immediate-Early Proteins / drug effects
  • Immediate-Early Proteins / physiology*
  • Kidney
  • Kinetics
  • Ligands
  • Luminescent Proteins / genetics
  • Lysophospholipids*
  • Molecular Sequence Data
  • Protein Structure, Secondary
  • Receptors, Cell Surface / chemistry
  • Receptors, Cell Surface / drug effects
  • Receptors, Cell Surface / physiology*
  • Receptors, G-Protein-Coupled*
  • Receptors, Lysophospholipid
  • Recombinant Fusion Proteins / metabolism
  • Sphingosine / analogs & derivatives*
  • Sphingosine / pharmacology
  • Subcellular Fractions / metabolism
  • Transfection

Substances

  • Immediate-Early Proteins
  • Ligands
  • Luminescent Proteins
  • Lysophospholipids
  • Receptors, Cell Surface
  • Receptors, G-Protein-Coupled
  • Receptors, Lysophospholipid
  • Recombinant Fusion Proteins
  • Green Fluorescent Proteins
  • sphingosine 1-phosphate
  • Sphingosine