6NIY

A high-resolution cryo-electron microscopy structure of a calcitonin receptor-heterotrimeric Gs protein complex

Summary for 6NIY

• Entry DOI: 10.2210/pdb6niy/pdb
• EMDB information: 8623 9382
• Descriptor: Guanine nucleotide-binding protein G(s) subunit alpha isoforms short, Nanobody35, Calcitonin receptor, ... (6 entities in total)
• Functional Keywords: gpcr, transmembrane, receptor, calcitonin, membrane protein
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 6
• Total formula weight: 164970.54

Authors

dal Maso, E.,Glukhova, A.,Zhu, Y.,Garcia-Nafria, J.,Tate, C.G.,Atanasio, S.,Reynolds, C.A.,Ramirez-Aportela, E.,Carazo, J.-M.,Hick, C.A.,Furness, S.G.B.,Hay, D.L.,Liang, Y.-L.,Miller, L.J.,Christopoulos, A.,Wang, M.-W.,Wootten, D.,Sexton, P.M. (deposition date: 2019-01-02, release date: 2019-01-23, Last modification date: 2024-10-09)

Primary citation

Dal Maso, E.,Glukhova, A.,Zhu, Y.,Garcia-Nafria, J.,Tate, C.G.,Atanasio, S.,Reynolds, C.A.,Ramirez-Aportela, E.,Carazo, J.M.,Hick, C.A.,Furness, S.G.B.,Hay, D.L.,Liang, Y.L.,Miller, L.J.,Christopoulos, A.,Wang, M.W.,Wootten, D.,Sexton, P.M.
The Molecular Control of Calcitonin Receptor Signaling.
Acs Pharmacol Transl Sci, 2:31-51, 2019

PubMed Abstract: The calcitonin receptor (CTR) is a class B G protein-coupled receptor (GPCR) that responds to the peptide hormone calcitonin (CT). CTs are clinically approved for the treatment of bone diseases. We previously reported a 4.1 Å structure of the activated CTR bound to salmon CT (sCT) and heterotrimeric Gs protein by cryo-electron microscopy (Liang, Y.-L., . Phase-plate cryo- EM structure of a class B GPCR-G protein complex. , , 118-123). In the current study, we have reprocessed the electron micrographs to yield a 3.3 Å map of the complex. This has allowed us to model extracellular loops (ECLs) 2 and 3, and the peptide N-terminus that previously could not be resolved. We have also performed alanine scanning mutagenesis of ECL1 and the upper segment of transmembrane helix 1 (TM1) and its extension into the receptor extracellular domain (TM1 stalk), with effects on peptide binding and function assessed by cAMP accumulation and ERK1/2 phosphorylation. These data were combined with previously published alanine scanning mutagenesis of ECL2 and ECL3 and the new structural information to provide a comprehensive 3D map of the molecular surface of the CTR that controls binding and signaling of distinct CT and related peptides. The work highlights distinctions in how different, related, class B receptors may be activated. The new mutational data on the TM1 stalk and ECL1 have also provided critical insights into the divergent control of cAMP versus pERK signaling and, collectively with previous mutagenesis data, offer evidence that the conformations linked to these different signaling pathways are, in many ways, mutually exclusive. This study furthers our understanding of the complex nature of signaling elicited by GPCRs and, in particular, that of the therapeutically important class B subfamily.

PubMed: 32219215
DOI: 10.1021/acsptsci.8b00056

Experimental method

ELECTRON MICROSCOPY (3.34 Å)