Identification and characterization of surrogate peptide ligand for orphan G protein-coupled receptor mas using phage-displayed peptide library

Biochem Pharmacol. 2006 Jan 12;71(3):319-37. doi: 10.1016/j.bcp.2005.10.050. Epub 2005 Dec 5.


In the present study, a phage-displayed random peptide library was used to identify surrogate peptide ligands for orphan GPCR mas. Sequence analysis of the isolated phage clones indicated a selective enrichment of some peptide sequences. Moreover, multiple alignments of the isolated phage clones gave two conserved peptide motifs from which we synthesized peptide MBP7 for further evaluation. Characterization of the representative phage clones and the synthetic peptide MBP7 by immunocytochemistry revealed a strong punctate cell surface staining in CHO cells expressing mas-GFP fusion protein. The isolated phage clones and synthetic peptide MBP7 induced mas internalization in a stable CHO cell clone (MC0M80) over-expressing mas. In addition, MBP7-stimulated phospholipase C activity and intracellular calcium mobilization in these same cells. In summary, we have demonstrated a systematic approach to derive surrogate peptide ligands for orphan GPCRs. With this technique, we have identified two conserved peptide motifs which allow us to identify potential protein partners for mas, and have generated a peptide agonist MBP7 which will be invaluable for functional characterization of the mas oncogene.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Blotting, Northern
  • CHO Cells
  • Calcium / metabolism
  • Cloning, Molecular
  • Cricetinae
  • Cricetulus
  • Enzyme-Linked Immunosorbent Assay
  • Inositol Phosphates / metabolism
  • Ligands
  • Membrane Proteins / metabolism*
  • Microscopy, Confocal
  • Molecular Sequence Data
  • Peptide Library*
  • Protein Binding
  • Proto-Oncogene Mas
  • Proto-Oncogene Proteins / metabolism*
  • Receptors, G-Protein-Coupled / metabolism*
  • Recombinant Fusion Proteins / metabolism*
  • Transfection


  • Inositol Phosphates
  • Ligands
  • Membrane Proteins
  • Peptide Library
  • Proto-Oncogene Mas
  • Proto-Oncogene Proteins
  • Receptors, G-Protein-Coupled
  • Recombinant Fusion Proteins
  • Calcium