Five amino acids of the Xenopus laevis CRF (corticotropin-releasing factor) type 2 receptor mediate differential binding of CRF ligands in comparison with its human counterpart.

The ligand selectivity of human (hCRF(2A)) and Xenopus laevis (xCRF(2)) forms of the corticotropin-releasing factor type 2 (CRF(2)) receptor differs. The purpose of this study was to identify amino acids in these two CRF(2) receptors conferring these differences. An amino acid triplet in the third extracellular domain (Asp(262)Leu(263)Val(264) in hCRF(2A) or Lys(264)Tyr(265)Ile(266) in xCRF(2)) was found to diverge between both receptors.