1. Genetically Encoded Chemical Probes in Cells Reveal the Binding Path of Urocortin-I to CRF Class B GPCR
- Author
-
Coin, Irene, Katritch, Vsevolod, Sun, Tingting, Xiang, Zheng, Siu, Fai Yiu, Beyermann, Michael, Stevens, Raymond C, and Wang, Lei
- Subjects
Biochemistry and Cell Biology ,Biological Sciences ,Biotechnology ,Mental Health ,Underpinning research ,1.1 Normal biological development and functioning ,Generic health relevance ,Amino Acid Sequence ,Animals ,Click Chemistry ,Cross-Linking Reagents ,Humans ,Mice ,Models ,Molecular ,Molecular Sequence Data ,Rats ,Receptors ,Corticotropin-Releasing Hormone ,Sequence Alignment ,Urocortins ,Medical and Health Sciences ,Developmental Biology ,Biological sciences ,Biomedical and clinical sciences - Abstract
Molecular determinants regulating the activation of class B G-protein-coupled receptors (GPCRs) by native peptide agonists are largely unknown. We have investigated here the interaction between the corticotropin releasing factor receptor type 1 (CRF1R) and its native 40-mer peptide ligand Urocortin-I directly in mammalian cells. By incorporating unnatural amino acid photochemical and new click-chemical probes into the intact receptor expressed in the native membrane of live cells, 44 intermolecular spatial constraints have been derived for the ligand-receptor interaction. The data were analyzed in the context of the recently resolved crystal structure of CRF1R transmembrane domain and existing extracellular domain structures, yielding a complete conformational model for the peptide-receptor complex. Structural features of the receptor-ligand complex yield molecular insights on the mechanism of receptor activation and the basis for discrimination between agonist and antagonist function.
- Published
- 2013