A hydrogen-bonded polar network in the core of the glucagon-like peptide-1 receptor is a fulcrum for biased agonism:lessons from class B crystal structuress

Wootten, Denise, Reynolds, Christopher A., Koole, Cassandra, Smith, Kevin J., Mobarec, Juan C., Simms, John, Quon, Tezz, Coudrat, Thomas, Furness, Sebastian G.B., Miller, Laurence J., Christopoulos, Arthur and Sexton, Patrick M. (2016). A hydrogen-bonded polar network in the core of the glucagon-like peptide-1 receptor is a fulcrum for biased agonism:lessons from class B crystal structuress. Molecular Pharmacology, 89 (3), pp. 335-347.

Abstract

The glucagon-like peptide 1 (GLP-1) receptor is a class B G protein-coupled receptor (GPCR) that is a key target for treatments for type II diabetes and obesity. This receptor, like other class B GPCRs, displays biased agonism, though the physiologic significance of this is yet to be elucidated. Previous work has implicated R2.60190 , N3.43240 , Q7.49394 , and H6.52363 as key residues involved in peptide-mediated biased agonism, with R2.60190 , N3.43240 , and Q7.49394 predicted to form a polar interaction network. In this study, we used novel insight gained from recent crystal structures of the transmembrane domains of the glucagon and corticotropin releasing factor 1 (CRF1) receptors to develop improved models of the GLP-1 receptor that predict additional key molecular interactions with these amino acids. We have introduced E6.53364 A, N3.43240 Q, Q7.49493N, and N3.43240 Q/Q7.49 Q/Q7.49493N mutations to probe the role of predicted H-bonding and charge-charge interactions in driving cAMP, calcium, or extracellular signal-regulated kinase (ERK) signaling. A polar interaction between E6.53364 and R2.60190 was predicted to be important for GLP-1- and exendin-4-, but not oxyntomodulin-mediated cAMP formation and also ERK1/2 phosphorylation. In contrast, Q7.49394 , but not R2.60190 /E6.53364 was critical for calcium mobilization for all three peptides. Mutation of N3.43240 and Q7.49394 had differential effects on individual peptides, providing evidence for molecular differences in activation transition. Collectively, this work expands our understanding of peptide-mediated signaling from the GLP-1 receptor and the key role that the central polar network plays in these events.

Publication DOI: https://doi.org/10.1124/mol.115.101246
Divisions: Life & Health Sciences > Biosciences
Additional Information: -This article has supplemental material available at molpharm.aspetjournals.org FUnding: National Health and Medical Research Council of Australia (NHMRC) [1061044; 1065410; and 1055134]; BBSRC [BB/M006883/1]; and MRC [G1001812].
Uncontrolled Keywords: Pharmacology,Molecular Medicine
Full Text Link: https://www.ncb ... les/PMC4767408/
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
http://molpharm ... t/89/3/335.long (Publisher URL)
Published Date: 2016-03
Authors: Wootten, Denise
Reynolds, Christopher A.
Koole, Cassandra
Smith, Kevin J.
Mobarec, Juan C.
Simms, John
Quon, Tezz
Coudrat, Thomas
Furness, Sebastian G.B.
Miller, Laurence J.
Christopoulos, Arthur
Sexton, Patrick M.

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