Comparison of intrinsic activities of the putative sphingosine 1-phosphate receptor subtypes to regulate several signaling pathways in their cDNA-transfected Chinese hamster ovary cells

J Biol Chem. 1999 Aug 20;274(34):23940-7. doi: 10.1074/jbc.274.34.23940.

Abstract

We examined the actions of sphingosine 1-phosphate (S1P) on signaling pathways in Chinese hamster ovary cells transfected with putative S1P receptor subtypes, i.e. Edg-1, AGR16/H218 (Edg-5), and Edg-3. Among these receptor-transfected cells, there was no significant difference in the expressing numbers of the S1P receptors and their affinities to S1P, which were estimated by [(3)H]S1P binding to the cells. In vector-transfected cells, S1P slightly increased cytosolic Ca(2+) concentration ([Ca(2+)](i)) in association with inositol phosphate production, reflecting phospholipase C activation; the S1P-induced actions were markedly enhanced in the Edg-3-transfected cells and moderately so in the AGR16-transfected cells. In comparison with vector-transfected cells, the S1P-induced [Ca(2+)](i) increase was also slightly enhanced in the Edg-1-transfected cells. In all cases, the inositol phosphate and Ca(2+) responses to S1P were partially inhibited by pertussis toxin (PTX). S1P also significantly increased cAMP content in a PTX-insensitive manner in all the transfected cells; the rank order of their intrinsic activity of S1P receptor subtypes was AGR16 > Edg-3 > Edg-1. In the presence of forskolin, however, S1P significantly inhibited cAMP accumulation at a lower concentration (1-100 nM) of S1P in a manner sensitive to PTX in the Edg-1-transfected cells but not in either the Edg-3 or AGR16-transfected cells. As for cell migration activity evaluated by cell number across the filter of blind Boyden chamber, Edg-1 and Edg-3 were equally potent, but AGR16 was ineffective. Thus, S1P receptors may couple to both PTX-sensitive and -insensitive G-proteins, resulting in the selective regulation of the phospholipase C-Ca(2+) system, adenylyl cyclase-cAMP system, and cell migration activity, according to the receptor subtype.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenylate Cyclase Toxin
  • Adenylyl Cyclases / metabolism
  • Animals
  • CHO Cells
  • Calcium / metabolism
  • Cell Movement
  • Cricetinae
  • Cyclic AMP / biosynthesis
  • DNA-Binding Proteins / physiology
  • I-kappa B Proteins*
  • NF-KappaB Inhibitor alpha
  • Pertussis Toxin
  • Receptors, Cell Surface / classification
  • Receptors, Cell Surface / physiology*
  • Receptors, G-Protein-Coupled*
  • Receptors, Lysophospholipid
  • Transfection
  • Type C Phospholipases / metabolism
  • Virulence Factors, Bordetella / pharmacology

Substances

  • Adenylate Cyclase Toxin
  • DNA-Binding Proteins
  • I-kappa B Proteins
  • Receptors, Cell Surface
  • Receptors, G-Protein-Coupled
  • Receptors, Lysophospholipid
  • Virulence Factors, Bordetella
  • NF-KappaB Inhibitor alpha
  • Cyclic AMP
  • Pertussis Toxin
  • Type C Phospholipases
  • Adenylyl Cyclases
  • Calcium