Identification by site-directed mutagenesis of amino acids contributing to ligand-binding specificity or signal transduction properties of the human FP prostanoid receptor

Biochem J. 2003 Apr 15;371(Pt 2):443-9. doi: 10.1042/BJ20021429.


Prostanoid receptors belong to the class of heptahelical plasma membrane receptors. For the five prostanoids, eight receptor subtypes have been identified. They display an overall sequence similarity of roughly 30%. Based on sequence comparison, single amino acids in different subtypes of different species have previously been identified by site-directed mutagenesis or in hybrid receptors that appear to be essential for ligand binding or G-protein coupling. Based on this information, a series of mutants of the human FP receptor was generated and characterized in ligand-binding and second-messenger-formation studies. It was found that mutation of His-81 to Ala in transmembrane domain 2 and of Arg-291 to Leu in transmembrane domain 7, which are putative interaction partners for the prostanoid's carboxyl group, abolished ligand binding. Mutants in which Ser-263 in transmembrane domain 6 or Asp-300 in transmembrane domain 7 had been replaced by Ala or Gln, respectively, no longer discriminated between prostaglandins PGF(2alpha) and PGD(2). Thus distortion of the topology of transmembrane domains 6 and 7 appears to interfere with the cyclopentane ring selectivity of the receptor. PGF(2alpha)-induced inositol formation was strongly reduced in the mutant Asp-300Gln, inferring a role for this residue in agonist-induced G-protein activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution
  • Base Sequence
  • Binding Sites
  • DNA Primers
  • Dinoprost / metabolism
  • Female
  • Humans
  • Kinetics
  • Ligands
  • Mutagenesis, Site-Directed
  • Placenta / metabolism
  • Pregnancy
  • Receptors, Prostaglandin / chemistry
  • Receptors, Prostaglandin / genetics
  • Receptors, Prostaglandin / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Signal Transduction


  • DNA Primers
  • Ligands
  • Receptors, Prostaglandin
  • Recombinant Proteins
  • prostaglandin F2alpha receptor
  • Dinoprost