Identification of amino acids in the N-terminal domain of corticotropin-releasing factor receptor 1 that are important determinants of high-affinity ligand binding

J Neurochem. 1999 Jan;72(1):388-95. doi: 10.1046/j.1471-4159.1999.0720388.x.


The aim of the present study was to identify the N-terminal regions of human corticotropin-releasing factor (CRF) receptor type 1 (hCRF-R1) that are crucial for ligand binding. Mutant receptors were constructed by replacing specific residues in hCRF-R1 with amino acids from the corresponding position in the N-terminal region of the human vasoactive intestinal peptide receptor type 2 (hVIP-R2). In cyclic AMP stimulation and CRF binding assays, it was established that two regions within the N-terminal domain were crucial for the binding of CRF receptor agonists and antagonists: one region mapping to amino acids 43-50 and a second amino acid sequence extending from position 76 to 84 of hCRF-R1. Recently, it was found that the latter sequence plays a very important role in determining the high ligand selectivity of the Xenopus CRF-R1 (xCRF-R1). Replacement of amino acids 76-84 of hCRF-R1 with residues from the same segment of the hVIP-R2 N terminus markedly reduced the binding affinity of CRF ligands. Mutation of Arg76 or Asn81 but not Gly83 of hCRF-R1 to the corresponding amino acids of xCRF-R1 or hVIP-R2 resulted in 100-1,000-fold lower affinities for human/rat CRF, rat urocortin, and astressin. These data underline the importance of the N-terminal domain of CRF-R1 in high-affinity ligand binding.

MeSH terms

  • Amino Acids / analysis*
  • Animals
  • Binding Sites / physiology
  • Cells, Cultured
  • Corticotropin-Releasing Hormone / metabolism
  • Corticotropin-Releasing Hormone / pharmacology
  • Cyclic AMP / metabolism
  • DNA, Complementary
  • Humans
  • Kidney / cytology
  • Ligands
  • Molecular Sequence Data
  • Mutagenesis / physiology
  • Neuroprotective Agents / metabolism
  • Neuroprotective Agents / pharmacology
  • Peptide Fragments / metabolism
  • Peptide Fragments / pharmacology
  • Protein Structure, Tertiary
  • Rats
  • Receptors, Corticotropin-Releasing Hormone / chemistry*
  • Receptors, Corticotropin-Releasing Hormone / genetics*
  • Receptors, Corticotropin-Releasing Hormone / metabolism
  • Sequence Homology, Amino Acid
  • Transfection


  • Amino Acids
  • DNA, Complementary
  • Ligands
  • Neuroprotective Agents
  • Peptide Fragments
  • Receptors, Corticotropin-Releasing Hormone
  • astressin
  • Corticotropin-Releasing Hormone
  • Cyclic AMP