Alanine Scanning Mutagenesis of the Second Extracellular Loop of Type 1 Corticotropin-Releasing Factor Receptor Revealed Residues Critical for Peptide Binding

• DOI: 10.1124/mol.108.052423
• Publication Date: 2009-01-06T01:34:29Z
• Authors: Kostas Gkountelias; Theodoros Tselios; Maria Venihaki; George Deraos; Iakovos Lazaridis; Olga Rassouli; Achille Gravanis; George Liapakis
• Keywords: Alanine scanning; Alanine; Site-directed mutagenesis

Upon binding of the corticotropin-releasing factor (CRF) analog sauvagine to type 1 CRF receptor (CRF₁), amino-terminal portion peptide has been shown lie near Lys257 in receptor9s second extracellular loop (EL2). To test hypothesis that EL2 residues play a role CRF₁ we carried out an alanine-scanning mutagenesis study determine functional (Leu251 Val266). Only W259A, F260A, and W259A/F260A mutations reduced affinity potency sauvagine. In contrast, these did not seem significantly alter overall conformation, they left unchanged affinities ligands astressin antalarmin have suggested bind different regions CRF₁. The also decreased endogenous ligand, CRF, implying may common important peptides belonging family. Parallel amino acid deletions two produced with various for wild-type compared mutants, supporting interaction between 8 10 corresponding region This is first time specific implicated detailed interactions